Dermatologic diseases in psittacine birds: An investigational approach

Dermatologic Diseases in Psittacine Birds: An Investigational Approach Ma,ilyn A. Koski, D VM

Dermatologic conditions are common and potentially frustrating clinical problems in psittacine birds. There may be several possible causes for a particular clinical presentation. Differential diagnoses, the diagnostic approach, and the therapeutic approach are discussed for the following clinical presentations: abnormal feather structure or development, changes in feather color, feather loss without picking, feather picking, cutaneous masses, lesions of the head or beak, lesions of the feet or legs, and lesions involving the uropygial gland. Copyright 2002, Elsevier Science (USA). All

rights reserved. Key words: psittacine, dermatology, skin diseases, avian.

D

ermatologic problems are a m o n g the most c o m m o n conditions veterinarians are called u p o n to treat in psittacine birds. Pet owners, owing to the ease of visual inspection, often readily detect avian skin a n d feather diseases. T h o u g h these conditions are highly visible, avian dermatologic diseases represent a c o m p l e x and often frustrating p r o b l e m for veterinarians to diagnose and treat. T h e health of a bird's skin and feathers reflects all aspects of its clinical and environmental condition. Because of the multifactorial nature of m a n y avian skin diseases, finding an etiologic diagnosis is often a difficult endeavor. It is i m p o r t a n t to educate clients a b o u t the complexity of avian dermatologic diseases, since resolution of m a n y conditions may take long periods of time, if correctable at all. Encouraging the client's participation and support will ensure a better working relationship and potentially a better outcome for your patient. T h e s u b j e c t of avian dermatology still presents m a n y unanswered questions, a n d offers the veterinary practitioner few diagnostic and treatm e n t certaiiaties. Much of the research in this field is based on studies in poultry, and extrapolation to psittacine species should be r e g a r d e d with caution. More information is b e c o m i n g available regarding psittacine dermatologic disease as n u m e r o u s literature references and educational opportunities continue to be provided.

T h e r e are several excellent reviews of avian dermatology in which the disease conditions are g r o u p e d by etiology. These include reviews by Hillyer et al, 1 Perry et al, 2 B u r g m a n n , 3 and Gill. 4 This review takes a m o r e investigational app r o a c h by grouping the various conditions according to their p r i m a r y clinical manifestation (s).

Abnormal Appearance of the Feathers T h e various conditions a n d factors that can affect feather structure, growth, condition, or color are listed in Table 1. Below are discussions of the m o r e c o m m o n or clinically i m p o r t a n t conditions. Investigation of feather abnormalities should begin with a t h o r o u g h history, with particular attention to the diet, housing, and m a n a g e m e n t . 1,<5 A c o m p l e t e physical examination should t h e n be carried out, even if the cause of the p r o b l e m is a p p a r e n t f r o m the history and the bird's appearance. 5 Appropriate laboratory tests can t h e n be considered that are based on initial findings and clinical suspicions. A m i n i m u m database should include a complete b l o o d c o u n t (CBC), a s e r u m biochemistry panel (glucose, calcium, uric acid, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, total serum proteins, a n d bile acid), fecal parasite examination, a n d choanal and cloacal G r a m stains. Additional tests may include feather pulp cytology a n d culture (bacterial and fungal), and feather follicle biopsy and histologic examination. T h e therapeutic plan will deFrom the Companion Avian and Exotic Pet Medicine Service, VeterinaU Medical Teaching" Hospital, School of Veterinary Medicine, Universily of Cali[brnia at Davis, Davis, CA. Address reprint requests to Ma,rilyn A. Koski, DVM, Companion Avian and Exotic Pet Medicine Seroice, University of Califor'rda, Veterinary Medical Teaching Hospital, 1 Shields Avenue, Davis, CA 95616-8747. Copyr~gt~t2002, Elsevier Science (USA). All rights reserved. 1055 937X/02/1103 0002535.00/0 doi: 10.1053/saep. 2002.123981

Seminars in A v i a n and Exotic Pet Medicine, Vol 11, No 3 (July), 2002: lop 105-124

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Table 1. Causes of Abnormal Feather Appearance

P o o r Feather C o n d i t i o n

9 Stress bars--illness, stress, malnutrition 9 Broken or damaged feathers--injury, mineral deficiencies (weakened feathers) 9 Poor feather condition--inability to preen, feather mites, lice, internal parasites, low humidity, inappropriate photoperiod, household aerosols, cigarette smoke, mycotoxins, systemic illness, malnutrition 9 Feather dystrophy--psittacine circovirus disease (PBFD), chronic polyomavirus infection, polyfolliculitis, feather-duster disease (budgerigars) 9 Color change--malnutrition, liver disease, hypothyroidism, thyroxine therapy, early PBFD, genetic mutation, inflammation of the feather follicle (color change in individual feather)

Anything that prevents a bird f r o m p r e e n i n g normally can result in e n t r a p m e n t of new feathers within their sheaths, giving the p l u m a g e a ragged, u n k e m p t appearance. Examples include use of an Elizabethan collar or neck brace, beak malformations, obesity, arthritis, pathologic fractures (a result of osteoporosis), and o t h e r painful conditions that restrict the bird's m o v e m e n t . 4 Feather condition may also be adversely affected by feather or quill mites, 3,s low humidity, irregular or inappropriate p h o t o p e r i o d , exposure to household aerosols or cigarette smoke, 4 ingestion of feed c o n t a m i n a t e d with the mycotoxin trichothecene, 9 systemic illness, and malnutrition. Quill mites live and r e p r o d u c e inside the quills and feed on available secretions and quill materials, s Quill mites of the family Ascouracaridae can be f o u n d on psittacines and cause damage by destroying the m e d u l l a f r o m the quill to the rachis, s Quill wall mites (Laminosioptidae a n d Fainocoptinae) may also .parasitize developing feathers on psittacines, causing hyperkeratosis of the feather sheath. Feather mites have b e e n identified in 26 species of Psittaciformes a n d have highly specific microhabitats. 3 These mites inhabit specific feather regions and feed on feather fragments a n d lipids, scaly skin debris, fungal spores and algae. 3 They are generally n o n p a t h o g e n i c , but in high n u m b e r s or on n o n - h o s t - a d a p t e d species, they can cause clinical problems. Two species that can infect Budgerigars include Protolichus lunula and Dubininia melopsittaci, s They a p p e a r as tiny dark spots or grains of sand to the naked eye. Most mites can be treated with ivermectin alone (0.2 m g / k g orally or intramuscularly for a m i n i m u m of 2 treatments, 14 days apart), or in c o m b i n a t i o n with topical acaricides. 3 Malnutrition. Severe or chronic malnutrition can delay or interrupt the n o r m a l molting process. As a result, chronically m a l n o u r i s h e d birds often exhibit dull, ragged feathers and thickened, scaly skin, especially on the face, feet, and a r o u n d the vent. 1 Generalized malnutrition, whether caused by p o o r diet, parasitism, or systemic disease, m a y also manifest as a b n o r m a l feather structure if the feathers were actively growing at the time of the deficiency or ill-

p e n d on the final or presumptive diagnosis. In all cases it is i m p o r t a n t to correct any dietary imbalances and make necessary i m p r o v e m e n t s in housing, environment, and m a n a g e m e n t . Stress Bars Stress bars or stress lines are translucent, linear breaks in the n o r m a l structure a n d color of the feather vane. They are generally oriented p e r p e n d i c u l a r to the feather shaft and r e p r e s e n t segmental dysplasia of the developing b a r b and barbules during a brief period of dysfunction in the e p i d e r m a l collar. 4 Factors that can induce stress bars include restraint, transient illness, environmental stressors, and malnutrition (food deprivation or nutritional deficiencies, especially in neonatal birds).3.4,6 B r o k e n or D a m a g e d Feathers Broken or a b r a d e d flight and tail feathers are relatively c o m m o n i n caged birds housed in small or overcrowded cages a n d as. the result of crash landings following aggressive wing trims. 4 D a m a g e to the protective keratin sheath o f a developing pin or blood feather or dislodging a feather f r o m the follicle can cause excessive bleeding f r o m the vascular pulp. 6 H e m o r r h a g e can be severe a n d a d a m a g e d pin feather should be removed. Injury to the feather follicles may result in p e r m a n e n t feather dystrophy at that site. 7 Bleeding f r o m d a m a g e d blood feathers is best controlled by pulling out the feather f r o m its base in the direction of feather growth. 5,6

Dermatologic Diseases in Psittacine Birds

hess. 2,s~ Obesity has been suggested as the most c o m m o n malnutrition-related problem in comp a n i o n avian medicine. 11 This condition is generally due to simple overconsumption of high-oil seeds (sunflower, safflower, hemp, rape, niger), high-fat h u m a n table foods, and lack of exercise.l,11.12 The nutrients that are particularly important for normal feather growth are protein, essential fatty acids, copper, zinc, and vitamins A, B, and E. l Poor feathering may result from imbalances of amino acids, 5,12,1s vitamin B12,14 pantothenic acid, a5 or vitamin A. a,asa2 O t h e r signs of vitamin A deficiency include rough scaly skin, dry eyes, thickened third eyelids, and lesions on the feet and legs. a,11 Brittle, frayed feathers may result from deficiencies of calcium, zinc, selenium, manganese, and magnesium, la Changes in molting and feather structure have also been attributed to iodine deficiency. 1~

Feather Dystrophy Dystrophic feathers can occur as a result of direct or indirect damage to the follicular collar or the developing feathers. The most c o m m o n causes are presented. Psittacine beak and feather disease/psittacine circovirus disease. Psittacine beak and feather disease (PBFD), also called psittacine circovirus disease, is a potentially devastating condition that predominantly affects immature birds. 1,2,4,7 It is caused by a n o n e n v e l o p e d virus of the family Circoviridae and is characterized by both an acute and a chronic f o r m . s,6,7,16-18 Acute PBFD is most often seen in nestlings and can cause severe feather abnormalities. The major clinical signs in these birds are intrapulp h e m o r r h a g e and feather necrosisl Birds with acute PBFD often 'become systemically ill and may die before developing obvious feather abnormalities. Insidious onset and a gradual'progression of feather dystrophy in older birds characterize chronic PBFD. Affected birds can exhibit bilaterally symmetrical, progressive dystrophy of the feathers, including retained feather sheaths, blood within the feather shaft or pulp cavity, stunted or clubbed feathers, stress lines across the vanes, pinching or narrowing of the feather shafts as they leave the feather follicle, and curling of the feathers. 1,2,4,6,7 Both c o n t o u r and

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down feathers are affected. As the virus affects growing feathers, the initial pattern o f feather dystrophy relates to the stage o f molt at the time of infection. 1,7 The clinical course of chronic PBFD may run from m o n t h s to years, with signs fluctuating in severity? In addition, affected birds appear to be m o r e susceptible to other infections, so they may have other dermatologic conditions concurrently. 1,2,7,16 All age groups and psittacine species are considered susceptible to the disease; 7 however, there appears to be considerable variation in susceptibility and manifestations. Cockatoos are most c o m m o n l y affected; the disease is seen less often in Amazon parrots and macaws. 6 Some birds and species show only subtle signs, either because of age or immunity. Adult Eclectus Parrots 4 and Neophema species are such birds, for which the only clinical manifestation may be feather loss (apparently normal feathers fall out or are easily plucked out).7 Replacement of the normally green feathers with yellow feathers (or blue feathers with white), along with varying degrees of feather loss can be seen. 4 Lorikeets lose their primary flight and tail feathers, whereas their c o n t o u r feathers remain relatively unaffected. 4 In Sulphur-Crested Cockatoos, the first feathers to be affected are often those on the crest. 2 In African Lovebirds and Galahs, feather abnormalities in the early stages may be limited to the area of the tibiotarsus and thigh. 2 Early manifestations of PBFD in African Grey Parrots can include replacement of gray plumage with red feathers (although red feathers can develop in birds that do not have PBFD).17 In lovebirds, PBFD may manifest as multiple skin nodules (granulomatous dermatitis) .19 Beak lesions caused by circovirus infection include palatine necrosis, ulceration, elongation, and increased friability. 4,6,7,9~ In some psittacines with PBFD (primarily cockatoos), 21 beak dystrophy is more p r o m i n e n t than feather dystrophy, whereas in others the beak is minimally affected. 1,6 One other c o m m o n manifestation of PBFD, most obvious in cockatoos, is a shiny appearance of the beak and feet owing to a loss of powdery down feathers. 1,2,4,6,7 This loss of powder also causes white birds to appear dull and dirty. 2,4 Severe psittacine circovirus disease can be presumptively diagnosed on the bird's appear-

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ance4,7; however, diagnosis should be c o n f i r m e d by the polymerase chain reaction (PCR) on blood, fresh feather pulp, or tissue samples. 3,4,7,16 PCR may be the most sensitive m e t h o d for detecting latent or early infection, although a diagnosis should n o t be d e t e r m i n e d by a single test. PCR should not be used as the sole m e t h o d of diagnosis. 7 Histologic examination of feather follicles (plucked feathers or follicle biopsy) is can be used to confirm clinical disease, but such histologic tests are unsuitable for diagnosing subclinical infections. 4,7 O t h e r diagnostic options include a hemagglutination assay (HA) on feather samples and a hemagglutination inhibition (HI) test o n b l o o d , g,4,7,16 T h e r e is no t r e a t m e n t for psittacine circovirus disease. P r e v e n t i o n a n d c o n t r o l m e a sures for circovirus infection are discussed elsewhere.7,16,22 Polyomavirus. Polyomavirus can infect all psittacines, but it m o s t frequently affects budgerigars, macaws, conures, Eclectus Parrots, Ringneck Parrots and lovebirds. Polyomavirus infection is m o r e severe in nestlings, causing an acute, frequently fatal disease characterized by subcutaneous h e m o r r h a g e s and edema. A chronic f o r m is r e p o r t e d in older birds, especially budgerigars, in which affected birds develop feather dystrophy similar to that seen with PBFD. Many of these birds c a n n o t fly and are c a l l e d " r u n n e r s . ''1-4,7,16A8

Presumptive diagnosis of polyomavirus infection may be based on history, clinical findings, and gross and histopathologic features. Definitive diagnosis requires serology or PCR. Many veterinarians prefer to collect cloacal swabs for PCR sampling, because they are minimally invasive; however, if single sampling is used for PCR detection of viral DNA, both b l o o d / a n d cloacal swabs a r e r e c o m m e n d e d . 7,16,23 T h e r e is presently no t r e a t m e n t for polyomavirus infection. T h e r e is a commercially available polyomavirus vaccine (Avian Polyomavirus Vaccine, killed virus, Biomune Co, Lenexa, KS, USA). Prevention and control measures for polyomavirus infection are discussed elsewhere. 7,16,24 French molt. French molt is a descriptive t e r m sometimes used by breeders to describe feather dystrophy and severely a b n o r m a l molt in y o u n g psittacine birds, primarily budgerigarsY 5 T h e n a m e stems f r o m an o u t b r e a k of disease that

affected large budgerigar farms in France in the 1920s. 4 The t e r m has since b e e n used to describe the outcome of PBFD and chronic polyomavirus infection. Polyfolliculitis. This u n c o m m o n condition, rep o r t e d in budgerigars a n d lovebirds, is characterized by pruritus and feather dystrophyY 6 The etiology is unknown, although a viral agent is suspected. An acute f o r m occurs most comm o n l y in y o u n g budgerigars a n d is often referred to as budgerigar short-tail disease. Typical feather abnormalities include deformity of the rectrices (twisting, shortening, and so forth), accumulations of keratin a n d dried blood on the underside of the rachis a n d ramus of affected feathers, and persistence o f parts of the feather sheath. T h e chronic f o r m is seen in mature birds. Although the tail may be normal, there are bilaterally symmetrical areas with shortened, def o r m e d quills. T h e most c o m m o n l y affected sites are the rump, flanks, and neck. Dystrophic quills are short, stout, and may be tightly curled; realalignment of feathers a n d curling of u n e r u p t e d feathers b e n e a t h the skin are also seen. Probably the most characteristic feather abnormality is division of affected feathers along keratin clefts, which gives the a p p e a r a n c e of m o r e than one quill growing f r o m the follicle. The condition apparently c a u s e s pruritus, because affected birds p r e e n with intensity a n d may cause tissue damage.a26 Polyfolliculitis is largely a diagnosis of exclusion and histologic examination of feather follicle biopsy samples. Although a viral etiology is presumed, no inclusion bodies have yet b e e n identified in biopsy samples of feather follicles. 26 T h e r e is no specific t r e a t m e n t for polyfolliculitis. O n e r e p o r t e d r e g i m e n comprises a combination of m e d r o x y p r o g e s t e r o n e acetate a n d / o r methylprednisolone acetate by injection and a topical application of a mixture of dimethyl sulfoxide, trimethoprim-sulfonamide (injectable formulation), and d e x a m e t h a s o n e (injectable solution) applied to the lesions twice daily. 26 T h e use of glucocorticoid drugs and synthetic progestins in avian species is highly controversial and potentially dangerous. T h e author presents the a f o r e m e n t i o n e d t r e a t m e n t r e g i m e n solely as a p o i n t of d o c u m e n t a t i o n of a published report: T h e clinician is advised to carefully consider i m p l e m e n t a t i o n of such a treatment.

Dermatologic Diseases in Psittacine Birds

Feather duster disease. With this unmistakable congenital condition, the contour, tail, and flight feathers of affected budgerigars grow continuously, giving the bird the appearance of a feather duster. A n o t h e r name for this condition is c h r y s a n t h e m u m disease. These birds are often described as less mentally alert than their nestmates and are unable to fly. It is t h o u g h t to be an inherited defect and is seen infrequently in avian veterinary practice, because breeders usually euthanize affected birds. 2,4

Abnormal Color The most c o m m o n cause of a generalized change in feather color is malnutrition. ~ Specific dietary deficiencies that can affect feather coloration include carotenoids (muted feather color) ,1.11 amino acids (dull plumage),3.1~,12 choline and riboflavin (achromatosis of primary feathers in cockatiels),15 and tyrosine or c o p p e r (lightening of dark feathers).n O t h e r causes of changes in feather color include liver disease (yellow feathers in cockatiels), ls,25,27 chronic lead toxicosis (graying of cockatoo feathers), 2s hypothyroidism, 29 thyroxine therapy, 29 early circovirus i n f e c t i o n , 4,7,17 pituitary t u m o r a~ and genetic mutation. 4 Color change involving single feathers is most likely caused by a n inflammatory process that affects the feather follicle during the growth of that feather. ~

Feather Loss Without Picking In most psittacine birds with feather loss presented to veterinarians for examination and treatment, the feather loss is a result of feather picking by the bird or by a n o t h e r bird. Feather picking is discussed in the next section. Causes of feather loss unassociated with fe/tther picking are listed in Table 2, g r o u p e d a c c o r d i n g to whether the skin in the featherless area appears normal or abnormal. Some of the listed causes are self-explanatory. Circovirus and polyomavirus infections~ and French molt are discussed in the previou s section. Knemidokoptic mite infestation, candidiasis, and dermatophytosis are discussed in a later section describing lesions o f the head and beak. Focal feather loss is c o m m o n over subcutaneous abscesses, tumors, and xanthomas. 2 These and other cutaneous masses are discussed in a later section.

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Table 2. Causes of Feather Loss Without Picking Normal Skin: 9 Normal apteria or normal molt (inexperienced bird owner) 9 Excessive or irregular molt pattern induced by irregular photoperiod or malnutrition 9 Previous damage to feather follicles 9 Manifestation of PBFD or polyomavirus infection 9 Genetic condition (eg, baldness in lutino cockatiels) 9 Obesity (budgerigars) 9 Systemic infection (septicemic alopecia) Abnormal Skin: 9 Ectoparasites (eg, Knemidokoptes pilae) 9 Polyomavirus infection 9 Candidiasis in lovebirds 9 Dermatophytosis 9 Abscesses, tumors, xanthomas 9 Fungal/yeast dermatitis 9 Bacterial dermatitis (Cl0stridium, Aeromonas,

KlebsieUa) 9 Liver or kidney disease 9 Hypothyroidism Abbreviation: PBFD, psittacine beak and feather disease.

Feather loss over the breast is relatively comm o n in obese budgerigars. 2 Septicemic alopecia is another condition that can cause nonpruritic feather loss concentrated over the breast; it has been reported in birds with systemic bacterial or fungal infections. 5 Hepatic disease can cause feather loss on the a b d o m e n , with pruritus and dermatitis; renal disease can also cause feather loss, retarded feather growth, and dermatitis. 18 Abnormal molting and feather loss can have a variety of other causes, including parasitic infections, malnutrition, and genetic and environmental influences; it may also be idiopathic. 1,5,13,sl Investigation of feather loss without picking should begin with a t h o r o u g h history and a complete physical examination. I m p o r t a n t aspects of the history include diet, housing, management, and details of the presenting complaint, such as duration, initial appearance, progression, previous treatments and responses, and the presence of pruritus or self-trauma. 1 A clinical examination and the minimal database described in previous sections are important in identifying birds with systemic illness. The therapeutic p l a n will d e p e n d on the final or presumptive diagnosis. Diet, housing, environment, and m a n a g e m e n t should be improved as needed.

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Bacterial Dermatitis Primary bacterial dermatitis is u n c o m m o n in birds, possibly due to the presence of bacteriostatic and mycostatic agents in the e p i d e r m a l lipids. ~as Staphylococcus spp (especially S aureus) are the m o s t c o m m o n avian dermal isolates a n d are considered part of the n o r m a l flora. ~s,32 Most Staphylococcus infections originate f r o m end o g e n o u s flora and develop as the result of damaged skin or a c o m p r o m i s e d i m m u n e system. 3~ P r i m m y bacterial folliculitis and dermatitis have also b e e n attributed to Serratia, Nocardia, Mycobacterium, and Pseudomonas species. ~,3~ ColoniZation of d a m a g e d skin by Clostridium spp or Aeromonas hydrophila can lead to gangrenous dermatitis, characterized by dark discoloration of the skin and sudden regional feather loss. Subcutaneous e m p h y s e m a may also be found. 3 Dermatitis and feather loss with little feather picking have also b e e n r e p o r t e d with KlebsieUa spp infection. 17 Diagnosis of bacterial dermatitis is based on bacterial culture of the skin lesions. Biopsy is r e c o m m e n d e d for definitive diagnosis of Staphylococcus dermatitis because culture of even normal skin typically yields staphylococci. 32 T r e a t m e n t of bacterial dermatitis should be guided by culture and sensitivity results. Treatm e n t options for staphylococcal dermatitis include oxacillin (100 m g / k g orally three times p e r day, for 4 to 6 weeks), 32 cephalexin oral suspension, 32 and amoxycillin-clavulanate potassium (up to 100 m g / k g orally twice p e r day). is Reasonable empirical antibiotic choices based on Gram-stained cytologic specimens include trim e t h o p r i m - s u l f o n a m i d e combinations, first-generation cephalosporins, a n d penicillins for gram-positive infections, and aminoglycosides, quinolones, third-generation cephalosporins, and potentiated penicillins for gram-negative or m i x e d infections. ~3

Fungal Dermatitis Dermatologic fungal and yeast infections are not c o m m o n in psittacine birds. 3,3~ Infections are generally chronic and confined to the thinskinned areas of the h e a d and u p p e r neck. 3 These conditions will be discussed in the section devoted to lesions of the face and head. A cutan e o u s Cryptococcus infection in a Goffin's Cockatoo, affecting large expanses of skin along the

ventral and dorsal a b d o m e n and axillary and inguinal regions, was c o n f i r m e d on r e p e a t e d culture and r e s p o n d e d well to long-term itraconazole therapy. 34,35 A suspected Malassezia dermatitis was described in a cockatiel, an eclectus, and a mynah. T h e diagnosis was m a d e by histopathology of the skin and feathers. No cultures were made. All birds had a leukocytosis. 36 Malassezia has also b e e n described as a pruritic condition in Galahs. 4 Definitive diagnosis of cutaneous fungal and yeast infections should involve r e p e a t e d isolation of the fungal or yeast agent, and histopathologic examination of the lesions. 3~ T r e a t m e n t should be based on culture and sensitivity results. R e c o m m e n d e d treatments for dermatomycosis include improved sanitation a n d biweekly topical application of c o p p e r sulf a t e (1:2000 dilution) or STA (3 g salicylic acid, 3 g tannic acid, and ethyl alcohol to 100 mL).1,37 Oral ketoconazole 36 or miconazole washes 4 reportedly are effective against Malassezia spp infections. Cutaneous candidiasis may be treated with fluconazole (5-15 m g / k g orally, twice per day), ketoconazole (10-15 m g / k g orally, twice p e r day), flucytosine (250 m g / k g orally, twice p e r day).33 Dermatologic infections with Cuptococcus neoformans or Aspergillus spp can be treated with itraconazole (5-10 m g / k g orally, twice per day) or fluconazole (5-15 m g / k g orally, twice p e r day).3s

Hypothyroidism Hypothyroidism is often m e n t i o n e d as a cause of dermatologic conditions in birds, but to date there is only o n e well-documented, c o n f i r m e d case of hypothyroidism in a psittacine bird (an adult Scarlet Macaw). In that bird, dermatologic signs comprised folds o f excessive skin (hyperkeratosis) and thickening of the subcutaneous tissue (fat deposits) over the legs and ventral a b d o m e n , and diffuse loss of c o n t o u r feathers over the h e a d and body. R e m a i n i n g feathers were structurally n o r m a l but had signs of wear (tattering, intermittent bronzing, and so forth) because the bird had not m o l t e d in the past year. Within 2 m o n t h s o f b e g i n n i n g L-thyroxine therapy, the bird u n d e r w e n t a molt; feathering was n o r m a l 5 m o n t h s after therapy began. 29

Dermatologic Diseases in Psittacine Birds

P o o r f e a t h e r i n g was n o t an obvious sign o f acute h y p o t h y r o i d i s m in r a d i o t h y r o i d e c t o m i z e d cockatiels, a l t h o u g h a few birds that h a d b e e n m o l t i n g at the time o f thyroid ablation s t o p p e d molting. 39 Hillyer et al I c o m m e n t e d that the few cases o f h y p o t h y r o i d i s m with which they were familiar all involved o l d e r A m a z o n parrots that were obese a n d p r e s e n t e d with m o l t i n g p r o b lems a n d mild anemia. T h o s e birds did n o t exp e r i e n c e d r a m a t i c f e a t h e r loss. 1 Diagnosis o f h y p o t h y r o i d i s m s h o u l d be based o n an a b n o r m a l response to a thyroid-stimulating h o r m o n e stimulation test; however, limited i n f o r m a t i o n r e g a r d i n g n o r m a l thyroxine levels in psittacines makes diagnosis difficult at present.i, 3 H y p o t h y r o i d i s m in the Scarlet Macaw was successfully treated with 0.02 m g L-thyroxine (15.4 / , g / k g orally, twice p e r day).29 Hillyer et al reco m m e n d c r u s h i n g 0.1 m g tablets o f L-thyroxine a n d m i x i n g it in the d r i n k i n g water. For birds that n o r m a l l y c o n s u m e large a m o u n t s o f water, o n e adds 3 tablets to 4 oz o f water. For birds with low water n e e d s (eg, budgerigars), a d o s a g e o f two 0.1 m g tablets p e r 4 oz o f water is r e c o m m e n d e d . 1 A d m i n i s t r a t i o n o f t h y r o x i n e will accelerate the m o l t i n g process, a n d thus i m p r o v e f e a t h e r i n g in s o m e species. However, c o r r e c t i n g the bird's diet a n d p h o t o p e r i o d (ie, p r o v i d i n g e x p o s u r e to sufficient natural daylight) can have the same effect with less risk. 3

Feather Picking F e a t h e r picking is o n e o f the m o s t c o m m o n a n d u n d o u b t e d l y the m o s t frustrating o f the d e r m a t o l o g i c conditions seen in psittacine birds. In m a n y cases f e a t h e r picking is muitifactorial in etiology, which can pose a diagnogtic a n d therapeutic challenge. N u m e r o u s papers have b e e n p u b l i s h e d o n this topic, a n d the r e a d e r is ref e r r e d to t h e m for detailed p r e s e n t a t i o n s o f this condition.36,40-4a Table 3 summarizes the various causes o f f e a t h e r picking a n d self-trauma in psittacine birds. W h a t follows is a s h o r t discussion o f the diagnostic a n d therapeutic a p p r o a c h to f e a t h e r picking. Because space is limited, this discussion does n o t include f e a t h e r picking by a n o t h e r bird, such as a c a g e m a t e or parent.

Table 3.

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Causes of Feather Picking

Skin Disease 9 Pox virus infection (esp. in lovebirds) 9 Cutaneous neoplasms (self-trauma over affected area) 9 Bacterial dermatitis/folliculitis (esp. Staphylococcus) 9 Fungal dermatitis/folliculitis 9 Poor feather condition (see Table 1) 9 Inadequate bathing 9 Polyfolliculitis (budgerigars, lovebirds) 9 Injury or skin irritation 9 Allergies (food, environmental toxins) 9 Mites 9 Lice 9 Circovirus/PBFD Intestinal or Systemic Disease 9 Malnutrition (deficiency of vitamin A, niacin, riboflavin, pantothenic acid, biotin, zinc, salt, sulfur-containing amino acids, arginine, folic acid, vitamin E, or selenium) 9 Giardiasis (esp. cockatiels) 9 Internal parasites (nematodes, cestodes) 9 Intestinal candidiasis 9 Chlamydophila infection 9 Liver or kidney disease 9 Bacterial or fungal disease 9 Any internal disease, especially if it causes pain Other 9 Normal preening or nesting behavior (obsewations by an inexperienced owner) 9 Over-preening (eg, young birds raised in isolation from adult birds) 9 Inappropriate preening (eg, young parrots raised with other psittacine species) 9 Sexual (hormonal) 9 Psychological-boredom, frustration, anxiety or fear, environmental change, attention-seeking, jealousy, incompatible company, social isolation or change, separation anxiety, overcrowding, sexual frustration, and so on 9 Habitual, despite resolution of the inciting physical cause Abbreviation: PBFD, psittacine beak and feather disease.

Diagnostic Approach T h e general a p p r o a c h to f e a t h e r picking is to d e t e r m i n e w h e t h e r t h e r e are any physical causes for f e a t h e r mutilation. Investigation begins with a t h o r o u g h history a n d physical examination. A n i m p o r t a n t first step is to establish that the f e a t h e r loss is i n d e e d c a u s e d by the bird picking or pulling its feathers. W h e r e a s f e a t h e r loss unassociated with f e a t h e r picking can o c c u r o n any p a r t o f the body, i n c l u d i n g the head, the hallm a r k o f f e a t h e r picking by the bird is n o r m a l

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feathering on the h e a d (ie, the one area inaccessible to the bird's own beak). 1,4,4~ L u n g and R o m a g n a n o describe a practical, cost-effective, three-visit a p p r o a c h to investigating feather picking: 33 1. First visit. Conduct an in-depth discussion with owner, a t h o r o u g h physical examination, a feather examination (gross and microscopic), skin scraping (ectoparasites, cytologic examination), a feather squash p r e p a r a t i o n (pluck new feather f r o m affected area, cut shaft longitudinally, and smear contents on a slide for cytologic examination), a cloacal swab (Gram stain, cytology, bacterial a n d fungal culture, sensitivity), and a fecal sample examination (gross exam, flotation for parasite ova, direct and trichromestained microscopic examination for Giarclia). If a medical cause is highly suspected, also consider carrying out a complete blood cell c o u n t (CBC), a serum biochemistry panel, and perhaps Chlamydophila or viral screens at this visit. Make therapeutic r e c o m m e n d a t i o n s based on the results. 2. Second visit. If diagnosis was not possible at the first visit or if the t r e a t m e n t plan did not result in clinical i m p r o v e m e n t , review the history, evaluate owner compliance with the initial r e c o m m e n d a t i o n s , repeat the physical examination, and consider any or all of the following: CBC, s e r u m biochemistry panel, heavy metal testing (especially lead and zinc), radiography, skin/follicle biopsy (histopathology and bacterial a n d fungal culture), Chlamydophila assay (serology or antigen capture tests), culture and sensitivity of cloaca or skin lesions, DNA p r o b e tests for PBFD and polyomavirus. A m e n d therapeutic r e c o m m e n d a t i o n s according!y. 3. T h i r d visit. If findings of the s e c o n d visit suggest a systemic problem, p r o c e d u r e s that may be a p p r o p r i a t e at this time include excision of cutaneous masses (submit for histopathology), laparoscopy, and a thyroid-stimulating h o r m o n e stimulation test. If after this visit' there is still no evidence exists of a medical problem, a high probability exists that the p r o b l e m is psychological/behavioral. T h e author offers two points of clarification regarding the diagnostic a p p r o a c h recomm e n d e d by Lung and R o m a g n a n o . First, the use of feather pulp cytology is controversial a m o n g veterinary pathologists and e x p e r i e n c e d avian microscopists. N o r m a l p i g m e n t granules are of-

ten incorrectly identified as bacterial rods. Bacterial and fungal culture of the feather pulp will provide a m o r e accurate m e t h o d of identification of potential micrroorganisms than pulp cytology alone. Although pulp cytology may offer evidence of bacterial or fungal infection, or inflammation, it should n o t be used as a substitute for feather follicle biopsy a n d histopathology. Second, the stated association of heavy metal toxicosis (specifically lead and zinc) a n d feather picking has never b e e n clinically proven. To the author's knowledge, no published reports or clinical d o c u m e n t a t i o n exist proving either lead or zinc toxicosis to be a cause of feather picking in avian species. N u m e r o u s testimonials have b e e n presented in the literature suggesting a link between zinc toxicosis a n d feather picking, but actual clinical study is warrranted to support or disprove this clinical impression.

Therapeutic Approach T h e therapeutic a p p r o a c h will d e p e n d on what is f o u n d during the initial visit a n d on the results of diagnostic tests. T h e initial therapeutic plan will often include dietary changes a n d modifications to the bird's housing, environment, and m a n a g e m e n t to address any environmental and psychological factors that may be involved. A discussion of some o f the specific causes of feather picking follows. Giardiasis. Most c o m m o n l y seen in cockatiels, giardiasis has b e e n linked to feather picking. Skin in the affected area often appears norreal, but some birds are severely pruritic and will self-mutilate, especially in the axillary region. Malabsorption of fat-soluble vitamins has b e e n p r o p o s e d as the m e c h a n i s m of disease. Giardia spp trophozoites can often be d e m o n strated in a wet m o u n t of fresh feces (<1 hour, and preferably < 1 0 minutes old). Identification may be e n h a n c e d by staining the smear using iodine solutions (eg, Lugol's or D'Antoni's). Fecal flotation using a saturated zinc sulfate solution can be used to concentrate the cysts. 44,45 As trophozoites are shed intermittently, a positive result in a bird with giardiasis is m o r e likely to be obtained by collecting a n d testing the first m o r n ing droppings for 3 consecutive days. 46 Air-dried smearS or feces preserved in alcohol or formalin can be submitted to the laboratory for detection of Giardia spp if the initial fecal

Dermatolog@ Diseases in Psittacine Birds

examination is negative but giardiasis is suspected. 42,44 A fecal enzyme-linked i m m u n o s o r b e n t assay (ELISA) developed for use in h u m a n s may be employed, but as false-negative results are possible it should not be relied u p o n as the sole m e a n s of diagnosis. 44 T h e most c o m m o n l y used drug for giardiasis is metronidazole. R e p o r t e d dosages vary widely. Oral dosages range f r o m 5 m g / k g orally, twice p e r day S~ to 50-60 m g / k g orally, once p e r day. 47 Metronidazole is unpalatable and poorly soluble in water, so it should not be administered via the drinking water. 44,47 The drug can be given intramuscularly; r e p o r t e d dosages range f r o m 10-20 m g / k g once or twice per day for 2 days 47 to a one-time dose of 15-50 m g / k g . 44 Resistance to metronidazole is c o m m o n , as are relapse and reinfection. 45 W h e r e available, other imidazoles (eg, ronidazole, dimetridazole, ipronidazole, tinidazole) may be m o r e effectiveY A p p r o p r i a t e measures should be taken to prevent reinfection, such as limiting access to cont a m i n a t e d feces, treating c o n t a m i n a t e d surfaces with quaternary a m m o n i u m c o m p o u n d s , a n d maintaining i m m u n o c o m p e t e n c e t h r o u g h good nutrition and an a p p r o p r i a t e density o f the bird stock. 45 Parasites. Many species of ectoparasites can infest psittacine birds, but as Gill sagaciously states, infestation is not as c o m m o n (or as problematic) in psittacines as the array of mite a n d lice sprays sold in pet stores would suggest. 4 T h e biting lice known to affect psittacines include Neopsittaconirmus, Psittacornimus, Eomenopon, a n d Pacifimenopon. These lice can cause mild to moderate pruritus a n d hyperkeratosis, which can lead to picking behavior. Care should be exercised when treating psittacines infested with lice. Pyrethrin sprays and powders are the least toxic and.yet effective topical products, but they have little residual effect. Carbaril may be used as a dusting or spraying t r e a t m e n t in caged birds to provide residual protection, s T r e a t m e n t s should be rep e a t e d after 2 weeks to kill newly h a t c h e d lice. Because lice c a n n o t survive long away f r o m the host, t r e a t m e n t of the e n v i r o n m e n t is not essential. 8 Mites may inhabit feathers, quills, skin, and the subcutaneous tissue of birds, and m a n y are considered apathogenic to their host species. 3 Feather mites Protolichus lunula and Dubininia

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melopsittaci infecting budgerigars will move to skin surfaces when infestations are heavy and cause irritation a n d feather pulling. Pruritus and feather picking can also arise when mites infest an aberrant host. As with lice, ivermectin will effectively treat most mite infections. B u r g m a n n presents an excellent review of avian parasites, including arthropods. ~ Allergies. I n t r a d e r m a l skin testing for a range of environmental and f o o d allergens has b e e n r e p o r t e d in psittacine birds. 4s-5~ Preliminary studies have shown a significant difference between n o r m a l and self-mutilating psittacine birds in their reactions to various allergens. 48 However, testing protocols are still in the research stage and interpretation of the test requires experience. 5~ In addition to dietary a n d environmental modifications to decrease or eliminate exposure to the allergen(s), some investigators have suggested the use of antihistamines a n d / o r corticosteroids for suspected allergic skin conditions. 4-~ T h e use of corticosteroids in birds is highly controversial because of the potential for p r o f o u n d immunosuppression. W h e t h e r or not feather picking is caused by hypersensitivity, hydroxyzine hydrochloride (2 m g / k g orally, three times p e r day, or 4 m g per 4 oz drinking water) may be useful in relieving pruritus, and it has the additional benefit of causing a mild drowsiness. T M A c o m b i n a t i o n of hydroxyzine hydrochloride a n d Dermcaps (an eicosapentaenoic acid s u p p l e m e n t ) was rep o r t e d in one article to be effective in controlling feather picking, 51 Recent studies of intradermal skin testing in birds may provide a future diagnostic tool for the identification of offending allergens in avian allergic dermatitis. 49,5~ Bacterial infections/fungal infections. T h e selection of antibacterial agents for t r e a t m e n t of cutaneous or systemic bacterial and fungal infections should be based on culture and sensitivity results. A discussion regarding diagnosis and t r e a t m e n t is presented in the previous section, since these agents can cause cutaneous infections with or without feather picking. Sexual feather picking. Seasonal feather picking associated with excessive nesting behavior in single pet birds may be m a n a g e d by providing a suitable mate a n d nesting a c c o m m o d a t i o n . 4 O t h e r options include t r e a t m e n t with a d e p o t gonadotropin-releasing h o r m o n e (GnRH) aria-

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log or leuprolide acetate (a single intramuscular injection at a daily dosage of 0.1 m g / k g for the desired n u m b e r of days. 4 M e d r o x y p r o g e s t e r o n e acetate and megestrol acetate have b e e n used to control sexual frustration a n d feather picking. 33,4~ Medroxyprogesterone acetate (5-50 m g / k g subcutaneously or intramuscularly) has a nonspecific calming effect; however, potential adverse effects include anorexia, polydipsia/polyuria, obesity, lipid hepatopathy, diabetes mellitus, a n d sudden death.a,a.s~, 52 Ketoconazole inhibits gonadal and adrenal steroidogenesis and may be useful in some cases where feather picking is associated with b r e e d i n g behavior. 1 Behavior-modifying drugs. W h e n a psychological p r o b l e m is felt to be the primary cause o f the feather picking, and when changes in the bird's diet, housing, environment, and routine have not h a d a significant impact on the feather picking a n d self-trauma, behavior-modifying drugs may be tried. Options include diazepam (0.5-0.6 m g / k g intramuscularly or intravenously, o n c e to three times p e r day), 4,52 haloperidol (0.1-0.4 m g / k g orally, twice p e r day), 4,53 amitriptyline (1-5 m g / k g orally, twice per day), 52 d o x e p i n hydrochloride (0.5-1 m g / k g orally, twice per day), 52 fluoxetine (0.4 m g / k g orally, once p e r day), 52 and naltrexone hydrochloride (1.5 m g / k g orally, twice per day).52,54 C l o m i p r a m i n e hydrochloride (0.5-1 m g / k g once or twice a day) has h a d mixed results. 4 Collars and neck braces. Elizabethan collars and neck braces can be useful in the short t e r m to stop the bird f r o m self-mutilating; they may even help prevent or b r e a k the cycle of habitual feather picking. 1,4~ However, some birds do not r e s p o n d well to application of a collar, a n d unless o t h e r measures are instituted concurrently, collaring the bird is only a short-term solution. 4 It is a worthwhile precaution to hospitalize the bird for 1-2 days when first applying a collar. 4,4~ Judicious use of diazepam (0.5 m g / k g intramuscularly) may also be helpful in preventing the bird f r o m injuring itself. 4 Collars and neck braces prevent n o r m a l p r e e n i n g behavior, so longer term use of the collar should include instructing the owner on the removal of keratin sheaths as new feathers emerge. 1 Other. If the bird has d a m a g e d the skin, topical antibiotic therapy (eg, silver sulfadiazine)

may be indicated to p r e v e n t infection and soothe the d a m a g e d skin. 4,4~ Aloe vera and amm o n i u m solution may also be useful in relieving pruritus and limiting f u r t h e r self-mutilation. 4 A c u p u n c t u r e has b e e n used with some success in feather-picking birds. 55 Radical beak grinding has b e e n suggested as a possible solution in unresponsive cases. 1,4~ For a practical, n o n m e d ical a p p r o a c h to behavioral feather picking, see the article by Wilson. 4S

Cutaneous Masses T h e types of lesions that can cause cutaneous or subcutaneous masses in psittacine birds are listed in Table 4 and are g r o u p e d by etiologic agent. With some masses a presumptive diagnosis can be m a d e on clinical a p p e a r a n c e alone. However, needle aspiration cytology or histopathologic examination of a biopsy specimen is n e e d e d to confirm a diagnosis. Some cutaneous masses, such as mycobacterial granulomas a n d lymphosarcomas, may be manifestations of systemic disease, so a systemic workup (eg, CBC, s e r u m biochemistry panel, radiography, laparoscopy, PCR, acid-fast stains) should be carried out when these conditions are suspected. Diagnosis a n d t r e a t m e n t of specific conditions are discussed below. Lipomas

Lipomas are benign, fatty, subcutaneous masses that are c o m m o n in obese caged birds, particularly budgerigars, Galahs, cockatiels, and Amazon parrots. >4 This hyperplastic adipose tis-

Table 4. Types of Cutaneous Masses 9 Bacterial--bacterial abscess, mycobacterial

granuloma 9 Viral--avian pox virus lesions, cutaneous papillomatosis, circovirus, polyomavirus (subcutaneous hemorrhages/edema in nestlings) 9 Parasitic--mosquitoes, biting flies, ants, ticks, mites, lice 9 Neoplastic--squamous-cell carcinoma, fibrosarcoma, hemangioma/hemangiosarcoma, lymphosarcoma, lymphohistiocytoma, liposarcoma, basal cell tumors 9 Other--lipoma, xanthoma, epidermal or follicular cysts, subcutaneous emphysema (trauma or hyperinflation of cervicocephalic air sacs), cutaneous pseudolymphoma

Dermatologic Diseases in Psittacine Birds

sue can occur anywhere on the body, but is most often f o u n d over the keel and ventral a b d o m e n and along the inner thighs; lipomas may be single or multiple. 1,2,4 Grossly, lipomas a p p e a r as soft, s m o o t h or lobulated, raised masses in the subcutaneous tissue, with a yellow color that is visible through the skin.L3 Lipomas may b e c o m e very large and exhibit variable growth rates, with some growing so rapidly that overlying skin becomes ulcerated. 4 Cytologic examination will not readily distinguish a benign lipoma f r o m a liposarcoma or a myelolipoma, thus cautious surgical biopsy is r e c o m m e n d e d for diagnosis. 3~ T r e a t m e n t centers on dietary m a n a g e m e n t . Even if surgical removal of the lipoma(s) is considered, the bird should be placed on a diet before surgery.l.2,4,5 In m a n y cases the lipomas slowly resolve once the obesity is addressed, avoiding the n e e d for surgery. ~,~ Some investigators have r e p o r t e d shrinkage of lipomatous growths in budgerigars and Galahs in response to therapy with L-thyroxine (a half or whole 0.1 m g tablet in 4 oz drinking water).5<57 Hillyer et aP have r e c o m m e n d e d s u p p l e m e n t a l iodine for obese birds, especially budgerigars, because hypothyroidism may predispose to the d e v e l o p m e n t o f lipomas. 1

Xanthomas X a n t h o m a s are not considered neoplasms, but are dermal masses of lipid-laden macrophages and cholesterol. ~,4,3~ T h e lesions a p p e a r as featherless areas of thickened, dimpled, yellow-orange skin, single or multiple, diffuse (xanthomatosis) or discrete, with variable vascularity and friabilityA -3 Although x a n t h o m a s may be f o u n d anywhere on the body, the dorsum, wings, thighs, and ventral a b d o m e n are c o m m o n sitesJ -4 X a n t h o m a s are p a r t i c u l a r l y : c o m m o n in female budgerigars and cockatiels, but they also occur in other species) ,4,a~ Presumptive diagnosis may b e m a d e on app e a r a n c e alone, with surgical biopsy to confirm diagnosis. Because x a n t h o m a s may be f o u n d overlying a n o t h e r lesion, such as a lipoma, hernia, or areas of chronic inflammation, f u r t h e r evaluation is a wise precaution in x a n t h o m a s that present as a discrete mass? -3 Surgical removal can be difficult because incisions t h r o u g h x a n t h o m a t o u s skin heal slowly, and affected skin is friable and will not hold

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sutures u n d e r tension. X a n t h o m a s often are best left untreated. 2,4 Surgical excision is recomm e n d e d for large x a n t h o m a s or in birds that self-traumatize the x a n t h o m a and cause bleedingY, 5s H y p e r t h e r m i a a n d irradiation with lowenergy x-rays have b e e n suggested as possible treatments for x a n t h o m a s that are not a m e n a b l e to surgical excision. 59 Rosskopf and Woerpel have noted that some x a n t h o m a s are responsive to L-thyroxine therapy, as described above for lipomas. 5~

Basal Cell Tumors/Feather Folliculomas/ Basal Cell Carcinomas Basal cell tumors or f e a t h e r folliculomas are benign neoplasms often associated with feather cysts. 3~ In gross aspect, these lesions are firm, yellow nodules that distort the skin. Folliculomas occur most c o m m o n l y in budgerigars; the nodules may be single or multiple and usually involve the flight feathers. 9,~ T r e a t m e n t may be unwarranted for small, isolated lesions. Multiple lesions or those causing irritation or discomfort should be surgically removed. 4 Basal cell carcinomas are of low-grade malignancy and are rare in birds. 59,6~ The typical appearance is that of a b r o a d based mass anywhere in the skinY ~ Recurrence has b e e n r e p o r t e d after surgical excision. 6~

Squamous Cell Carcinomas Squamous cell carcinomas (SCCs) are comm o n malignant neoplasms in budgerigars and o t h e r psittacine species. 6~ C o m m o n dermal sites include the wing, beak, and uropygial gland. 1 Areas of chronic irritation and inflammation may p r o m o t e SCCs, such as sites of chronic feather picking. 61 Grossly, cutaneous SCCs are poorly defined (irregular), raised, proliferative, and sometimes ulcerated masses. These lesions can resemble keratomas (keratoacanthoma), which are benign follicular t u m o r s 2 ~ Definitive diagnosis requires cytologic or histopathologic examination. 1 SCCs tend to be locally invasive and rarely metastasize. Standard therapy involves surgical excision a n d / o r radiation. Intralesional therapy has also b e e n explored with carboplatin a n d cisplafin and has yield varying results. 61 Cryosurgery has b e e n r e c o m m e n d e d for SCCs a r o u n d the oral cavity and nares. 4

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Fibrosarcomas Fibrosarcomas are relatively c o m m o n , malignant, dermal tumors in birds, particularly budgerigars. 1,3,4 These neoplasms can occur anywhere on the body but typically are f o u n d on the limbs and head. They are firm, broad-based, i m m o b i l e masses with irregular margins and, in some cases, an ulcerated surface. 3,~ Fibrosarcomas are locally invasive, but metastasis is u n c o m m o n a ,<3~ Diagnosis requires aspiration cytology or histopathology. 1 Recurrence is c o m m o n following excision. 3 Owing to their invasive nature, the r e c o m m e n d e d t r e a t m e n t for fibrosarcomas on the limbs is amputation.La4 One published case of a facial fibrosarcoma in an adult Blue a n d Gold Macaw described c o m b i n a t i o n treatm e n t involving partial surgical excision, intratum o r a l cisplatin, and 44 Gy total radiation. T h e t u m o r r e c u r r e d at 29 months post-treatment. 62

Other Neoplasms T h e following cutaneous neoplasms are unc o m m o n in psittacine birds. Malignant melanomas a p p e a r as firm, dark masses. They are most often r e p o r t e d on the h e a d or face but can occur in other locations, such as the wing. 3,6a64 T h e prognosis is grave, owing to their highly metastatic nature. 6~,64 H e m a n g i o m a s and hemangiosarcomas are single or multiple, circumscribed, soft, red to black swellings in the skin a n d subcutis.a30 In gross aspect they can look like melanomas; an i m p o r t a n t distinction is that h e m a n g i o m a s and h e m a n g i o s a r c o m a s contain b l o o d and may bleed profusely. Surgical removal is r e c o m m e n d e d . 4 Cutaneous lymphosarcomas typ!cally are f o u n d a r o u n d the h e a d and neck, Where they are seen as diffuse, gray-yellow swelfings. Biopsy is n e e d e d to differentiate lymphosarComas f r o m x a n t h o m a s or inflammatory lesions.4. ~~ Lymphohistiocytic tumors are cutaneous manifestations of lymphoid neoplasia. They are c o m m o n l y f o u n d in the periorbital area. Aspiration cytology a n d a full systemic workup are recomm e n d e d for diagnosis. 1 Liposarcoma is a malignant tumor that has been reported in budgerigars, cockatiels, a Quaker Parrot, and a Green-Cheeked Conure. 61,65 Whereas these tumors tend to occur in areas similar to those described for lipomas, liposarcomas are firmer, m o r e vascular, and poorly encapsulated. !.3 Diagno-

sis is based on histopathologic examination of a biopsy specimen. These tumors tend to be locally invasive and may metastasize, so they can be difficult to completely excise. 1 Myelolipomas are benign tumors c o m p o s e d of well-differentiated adipose cells and hematopoietic tissue. These tumors are f o u n d most often in the subcutis of the wing tip and thigh. Careful attention to hemostasis during surgery is imperative as these lesions are highly vascular. 6c~6s

Myeobacterial Granulomas Dermatologic manifestations of mycobacterial infection include g r a n u l o m a t o u s masses, wartlike or dry flaky swellings, thickening of the skin, and raised ulcers, often with feather loss over the lesion. 1,~,<69-71 O f the avian species affected by mycobacterial infections, psittacines exhibit m o r e dermatologic changes, with the m o s t c o m m o n sites being tile face and head. 3,69 In some cases the skin lesions a c c o m p a n y disseminated mycobacterial infection. 7~ Because the culture o f mycobacteria can be difficult, diagnosis requires either cytology or histopathology with acid-fast staining or PER. ~,69,7~In tile event of positive identification, it is i m p o r t a n t to c o m m u n i c a t e the zoonotic potential of mycobacteria to the bird's owner. ~ Euthanasia, rather than t r e a t m e n t is recomm e n d e d because of the zoonotic potential. If t r e a t m e n t is to be attempted, a n u m b e r of antimycobacterial drug protocols exist for use in birds, including macrolides, rifamycins, quinolones, aminoglycosides, clofazimine, and ethambutol hydrochloride. 69, 72-75

Avian Pox Viruses Virtually every avian family has its own pox virus, and 3 distinct psittacine p o x viruses have so far b e e n identified. 3~ Agapornis (lovebird) p o x yields pruritic, dark, and discolored skin in the areas of oral and nasal cavities, palpebrae, axilla, shoulder, and a b d o m e n . 1,1<:4~Budgerigar pox is apathogenic and was an incidental finding while studying other viruses. A m a z o n a (neotropical) pox has a wide host range of South American psittacines, and may present in 2 possible forms, either as a wet (diphtheric) f o r m or as a dry (cutaneous) form. 3~ T h e cutaneous f o r m of avian p o x generally is characterized by skin lesions in n o n f e a t h e r e d areas, m o s t notably in the

Dermatologic Diseases in Psittacine Birds

periorbital area, beak margins, nares, cere, lower legs, and feet. 2,3,5,7,16,76 In chronic severe infections lesions may also involve feather tracts. 2 D e p e n d i n g on the stage of infection, the lesions may present as vesicles, papules, pustules, erosions, or crusty scabs. 7,~6 Typically, crusts f o r m within 2 to 4 days of papule a p p e a r a n c e ; adjacent lesions may coalesce to f o r m large crusts. 2,3 Secondary bacterial or fungal infection is c o m m o n and can complicate b o t h diagnosis and resolution of the lesions. 1,7,16,3~ Avian p o x should be considered when the history indicates a w o u n d that is slow to heal2 ~ Definitive diagnosis requires histopathologic examination of biopsy specimens, electron microscopy, or virus isolationT,ls; feather quills may be the best specimens for virus isolation. 77 Treatm e n t is supportive. Most cases o f cutaneous avian pox are relatively mild and self-limiting, and u n c o m p l i c a t e d lesions usually heal within 4 weeks. 7,16 Because secondary bacterial or fungal infection is c o m m o n , antimicrobial therapy is an i m p o r t a n t c o m p o n e n t of supportive care. 5,1s,v6 Prevention and control of avian p o x are discussed elsewhere. 16,7s

Miscellaneous Conditions Bacterial abscesses may be f o u n d anywhere on the bird. 4 They may be a c o n s e q u e n c e of wounds, d a m a g e d feather follicles, blocked uropygial glands, foreign bodies (eg, tick m o u t h parts), or r e p e a t e d skin trauma2, s Surgical deb r i d e m e n t and a p p r o p r i a t e antibiotic therapy based on culture sensitivity is warranted. Virally caused papillomatous c u t a n e o u s growths have b e e n identified in a cockatoo, 79 chaffinches, s~ bramlings, sl canaries, s3 a n d an African Grey Parrots. s
1 17

or multiple. T h e primary histologic finding is epidermal hyperplasia and dysplasiaY 3 A confirmed diagnosis of papillomavirus requires imm u n o h i s t o c h e m i c a l techniques, electron microscopy, a n d / o r gene sequencing. 83-85,s7,ss O n e investigator r e c o m m e n d e d surgical removal, 1 whereas in the case of the African Grey described b y J a c o b s o n et al, s4 the lesions regressed without treatment. Mosquitoes, biting flies, ants, ticks, mites, and o t h e r external parasites can cause cutaneous masses in birds. Suggested t r e a t m e n t for severe reactions has included antihistamines a n d / o r corticosteroids, s Ivermectin (0.2 m g / k g orally or intramuscularly in 2 treatments, 2 weeks apart) is an effective acaricide for t r e a t m e n t of mite infestation in birds, s Follicular cysts typically a p p e a r as swellings on the wing or back; they may be congenital or acquired (eg, trauma-induced). Obstruction of the follicular orifice results in accumulation of keratinaceous debris and, in some cases, a tightly curled feather in the feather follicleJ ,~ Surgical treatment, whether curettage, cauterization, or excision, is r e c o m m e n d e d if the bird is self-traumatizing the area.
Lesions of the Head or Beak Conditions that can cause skin lesions or feather loss on the f a c e / h e a d , or specifically

118

Marikyn A. Koski

Table 5. Causes of Lesions of the Head or Beak Skin 9 Mites (esp. Knemidohoptespilae infestation) 9 Fungal infections (Candida, dermatophytes,

CUptococcus) 9 Avian pox virus 9 Cutaneous papillomas 9 Neoplasms 9 Trauma 9 Arthropods 9 Bacterial infection (Pasteurella, Pseudomonas) Cere 9 Knemidohoptespilae infestation 9 Brown cere hypertrophy (older female budgies) Beak 9 K:nemidohoptespilae infestation 9 Nutritional or metabolic disorders 9 Liver disease 9 Trauma (eg, crash landing, poor feeding techniques in neonates) 9 Circovirus/PBFD 9 Neoplasms 9 Oral Candidiasis 9 Avian pox virus 9 Cutaneous papillomas 9 Trichomoniasis 9 Congenital or genetic defects Abbreviation: PBFD, psittacine beak and feather disease.

lesions o n t h e c e r e o r b e a k , a r e listed in T a b l e 5. M a n y o f these c o n d i t i o n s a r e d i s c u s s e d in t h e p r e v i o u s s e c t i o n d e s c r i b i n g c u t a n e o u s masses, a n d t h e r e a d e r is d i r e c t e d t h e r e f o r m o r e det a i l e d discussion. D i a g n o s i s a n d t r e a t m e n t o f s o m e specific c o n d i t i o n s a r e d i s c u s s e d below. Skin of the Face or Head A v i a n p o x virus lesions, c u t a n e o u s p a p i l l o m a tosis, a n d t u m o r s a r e d i s c u s s e d in t h e e a r l i e r s e c t i o n o n c u t a n e o u s masses. Skin lesions o n t h e face o r h e a d c a n b e c a u s e d by t r a u m a , a n d art h r o p o d s such as m o s q u i t o e s , b i t i n g flies, ticks, s t i c k t i g h t fleas (Echidnophaga gallinacea), e p i d e r m o p h y t i d m i t e s (Psittaphagoides spp, Myialges spp, a n d so o n ) , t h e Procnemidoptes m i t e , a n d lice.l,3.1s,gs Upper

r e s p i r a t o r y / s i n u s i t i s i n f e c t i o n s with

Pasteurella s p p Or Chlamyophila psittaci m a y c a u s e m a t t i n g o f t h e f e a t h e r s a r o u n d t h e eyes a n d b e a k . Scaly o r crusty lesions o n t h e u n f e a t h e r e d p a r t s o f t h e h e a d m a y b e s e e n with c h r o n i c p a s t e u r e l l o s i s . ~ I n n e o n a t e s , Pseudomonas s p p c a n c a u s e cellulitis involving t h e h e a d . 3 Mycob a c t e r i a isolates have b e e n r e c o v e r e d f r o m eye-

lid n o d u l e s o n a G r e e n - W i n g e d Macaw, a n d a n a u r a l mass o n a B l u e - H e a d e d ( p i o n u s ) P a r r o t . 69 Knemidohoptic mites. O n e o f t h e m o s t c o m m o n causes o f skin lesions o n t h e face in p s i t t a c i n e b i r d s is i n f e s t a t i o n by Knemidokoptes pilae, o f t e n c a l l e d the scaly face a n d l e g mite. It is a p a r t i c u l a r l y c o m m o n p r o b l e m in b u d g e r i gars. I n f e s t a t i o n typically causes h o n e y c o m b - l i k e e n c r u s t a t i o n s o n t h e f e a t h e r l e s s skin o f t h e face, eyelids, cere, a n d b e a k , a n d less c o m m o n l y o n t h e legs, feet, a n d a r o u n d t h e cloaca. 1-4,45,76 Def o r m e d o r excessive g r o w t h o f t h e b e a k a n d nails m a y o c c u r in c h r o n i c i n f e c t i o n s . 1,2,6.76 A s e p a r a t e s p e c i e s o f Knemidokoptes r e p o r t e d l y causes p r o m i n e n t f e a t h e r loss o n t h e h e a d a n d n e c k , with h y p e r e m i a o f t h e f e a t h e r l e s s skin. 3 Affected individuals generally are young birds. 1 C a g e m a t e s m a y b e u n a f f e c t e d o r asympt o m a t i c , w h i c h suggests t h a t t h e clinical disease m a y have a n i m m u n o l o g i c c o m p o n e n t . A g e n e r a l i z e d f o r m o f Knemidokoptes i n f e s t a t i o n s i m i l a r to g e n e r a l i z e d d e m o d e c t i c m a n g e in d o g s has b e e n r e p o r t e d . I n t h e s e cases f e a t h e r follicles o n t h e b o d y , wings, a n d tail a r e also affected. 2,4 I n p a r r o t s , i n f e s t a t i o n m a y b e a s s o c i a t e d with PBFD. 4 Gross a p p e a r a n c e o f t h e facial lesions g e n erally is d i a g n o s t i c , p a r t i c u l a r l y in s m a l l e r psitr a c i n e species. D i a g n o s i s is r e a d i l y c o n f i r m e d by m i c r o s c o p i c e x a m i n a t i o n o f a skin s c r a p i n g c l e a r e d with 10% p o t a s s i u m h y d r o x i d e , w h i c h reveals the p l u m p , r o u n d mites. 1,1s T r e a t m e n t with i v e r m e c t i n (0.2 m g / k g , e i t h e r orally, s u b c u t a n e o u s l y , i n t r a m u s c u l a r l y , o r topically at 2- to 4-week intervals) g e n e r a l l y is effective. 2,4,6 G o o d results m a y also b e a c h i e v e d with moxidectin. 4 Intramuscular administration of i v e r m e c t i n is n o t r e c o m m e n d e d f o r b i r d s weighi n g < 5 0 0 g. O n e r e c o m m e n d a t i o n f o r small b i r d s s m a l l e r t h a n 100 g is to d i l u t e t h e i v e r m e c tin to 1 m g / m L a n d a p p l y 1 d r o p o f t h e m i x t u r e to a f e a t h e r l e s s a r e a o f skin o n t h e b i r d ' s n e c k . 45 I n b i r d s with severe b e a k lesions, a p p l y i n g a t h i n layer o f m i n e r a l oil to t h e lesions a n d rem o d e l i n g t h e b e a k at w e e k l y intervals is r e c o m m e n d e d to e n h a n c e t h e r a t e o f r e c o v e r y a n d improve the appearance of the beak. ~ Because clinical Knemidokoptes i n f e s t a t i o n in m a t u r e b i r d s is o f t e n a s s o c i a t e d with p e r i o d s o f stress o r m a p n n t r i t i o n , s,s a p p r o p r i a t e d i e t a r y a n d m a n a g e m e n t c h a n g e s s h o u l d also b e m a d e .

Dermatologic Diseases in Psittacine Birds

Fungal infections. Various fungal infections can cause skin lesions on the face. Cytology, histopathology, and fungal culture may b e required for diagnosis. Even though t r e a t m e n t focuses on antifungal preparations, it is also imp o r t a n t to identify and address any underlying conditions, such as vitamin A deficiency or concurrent infections that affect i m m u n e function. is Candida spp may cause lesions at the commissures of the m o u t h and a r o u n d the nares. Less often, feather follicles on the head, back, and v e n t r u m are involved. Lesions consist o f powdery white accumulations of crusty material. 2 Candidiasis has also b e e n associated with scaling and feather loss a r o u n d the eye, neck, and thorax in lovebirds. 92 Candidiasis is discussed further in the later section on beak lesions. Although u n c o m m o n , Microsporum spp and T'yichophyton spp can cause scaly encrustations and patchy feather loss on the face, head, neck, a n d chest. 1,2,4 T r e a t m e n t options include oral itraconazole for several months, 93 griseofulvin (125 m g / k g orally), a m p h o t e r i c i n B (1 m g / k g orally), topical application of nystatin c r e a m (twice p e r day for 1 week),2 and topical STA. 18 Cryptococcus neoformans occasionally causes granulomatous lesions on the face, beak, and sinuses. T h e species most often affected are Eclectus Parrots, African Greys, and macaws. 94 Diagnosis requires histopathologic e x a m i n a t i o n and culture of a biopsy specimen. Recomm e n d e d t r e a t m e n t includes surgical excision (where possible) and systemic antifungal therapy. 4 Cere T h e cere is one of the c o m m o n sites for Knemidokoptes pilae infestationA ,4 A n o t h e r c o m m o n condition is brown h y p e r t r o p h y o f the cere, which is seen in older female budgerigars. It is characterized by symmetrical hyperplasia o f the cornified layer' of the cere, which creates a rhinoceros hornlike a p p e a r a n c e ) ,4,6 If the hypertrophic tissue threatens to occlude the nostrils, it should be softened with a small a m o u n t of mineral oil or ophthalmic o i n t m e n t and then gently s c r a p e d away, 3,6,76 Brown h y p e r t r o p h y of the cere has also b e e n r e p o r t e d in male budgerigars with gonadal tumors.6, 95

1 19

Beak Abnormalities of the b e a k can arise f r o m a surprising variety of conditions (see Table 5). Beak abnormalities or overgrowth are c o m m o n with Knemidokoptes mite infestation in parrots. `i,Ta This condition is discussed above. Overgrowth of the beak can also occur if the bird is not provided with a suitable abrasive surface with which to maintain its beak. 5 Malnutrition may cause the beak to b e c o m e soft, flaky, and m o r e susceptible to injury. 2,6,11 In growing cockatiels, malnutrition may also cause narrowing of the beak. 1-~ Nutritional or metabolic problems that can affect the quality of the b e a k or its supporting tissues include inappropriate diet (either i n c o m p l e t e or stale/spoiled), alimentary tract or renal disease, osteodystrophy, m e t h i o n i n e deficiency, and p o o r lighting for p r o l o n g e d periods. 2,76,96 Liver disease can result in overgrowth o f the beak, especially in budgerigars a n d cockatiels) ,6 Avian p o x virus infection and papillomatosis are discussed in the earlier section on cutaneous masses. Trichomoniasis can cause skin necrosis in the beak a r e a ) Beak abnormalities in nestlings may be the result of congenital or genetic defects, but acquired conditions (injury, infection, feeding practices, nutritional imbalances) should also be considered. 2,4,96

Psittacine beak and feather disease/psittacine circovirus disease. Beak dystrophy associated with psittacine circovirus infection is most c o m m o n in cockatoos. 2,4,7 In affected birds the b e a k becomes soft and friable; o t h e r abnormalities include a color change (eg, f r o m gray to black), overgrowth, irregular growth, necrosis, and transverse or longitudinal splitting (fracture or delamination) of the beak. 1,6,7,13,16 Bacterial or fungal invasion of clefts in the beak can lead to serious infection and possible necrosis. 2,13 Diagnosis of PBFD is discussed in the earlier section on feather abnormalities. Neoplasms. Neoplastic conditions involving the beak include carcinomas, sarcomas, and osteosarcomas, as stated in the earlier section discussing cutaneous masses. Although u n c o m m o n in any psittacine species, they are most often seen in budgerigars. Manifestations include overgrowth, irregular peeling, cracking, necrosis, or distortion of the beak. Differentiating this condition f r o m bacterial or fungal granulomas

Marilyn A. Koski

120

a n d f r o m b e a k injuries that cause intralaminal h e m o r r h a g e is i m p o r t a n t . Most beak t u m o r s are inoperable, b u t s o m e m a y be treated with electrocautery or cryosurgery. 2 Fungal/yeast. Oral candidiasis m a y cause raised, crusty lesions at the commissures o f the m o u t h that bleed freely if disturbed. T h e s e lesions are m o s t o f t e n seen in lorikeets a n d m a y be associated with vitamin A deficiency. Diagnosis is b a s e d o n a p p e a r a n c e o f the lesions a n d e i t h e r cytology or culture, v7 Affected birds r e s p o n d well to therapy with topical nystatin or o n e o f the antifungal azoles (ketoconazole, fluconazole, itraconazole, miconazole), parenteral vitamin A, and diet correction. 4,97 Vitamin A supplementation is discussed in the earlier section o n feather abnormalities. A r e c o m m e n d e d dosage for ketoconazole in birds is 10-30 m g / k g orally, twice per day for 10-20 days. 98 Candidiasis is an opportunistic infection, so predisposing factors such as p o o r hygiene and environment, subclinical malnutrition, stress, viral infection, a n d antibiotic use should also be addressed. 97,9s Penicillium cyclopium isolated f r o m the b e a k o f a m a c a w p r e s e n t e d as a whitish, s q u a m o u s prot u b e r a n c e . Diagnosis was c o n f i r m e d o n cytology by the p r e s e n c e o f septate h y p h a e a n d conidia. ~9 T h e sample was collected via d e e p scrape o f the affected area with a scalpel blade.

L e s i o n s o n t h e Feet or Legs Causes o f skin lesions o n the feet or legs are listed in Table 6. T h e feet a n d legs are c o m -

Table 6. Causes of Skin Lesions on tile Feet or Legs 9 9 9 9 9 9 9 9 9 9 9 9 9

Mites (eg, Knemidokoptespilae infestatiOn) Cutaneous papillomas Avian pox virus Avian herpes virus Trauma (broken toes or nails, strangulation by synthetic or cotton fiber, improperly applied leg bands, and so on) Pododermatitis (bumblefoot) Amazon foot necrosis Psittacine mutilation syndrome Constricted toe syndrome Vitamin A deficiency Circovirus/PBFD Articular gout Filariid nematodes

Abbreviation: PBFD, psittacine beak and feather disease.

m o n l y involved in Knemidokoptes mite infestation a n d m a y be sites w h e r e papillomas a n d p o x lesions can be f o u n d . T h e s e conditions are discussed in earlier sections. Herpesvirus-like lesions have b e e n r e p o r t e d on the feet o f psittacines, specifically cockatoos and macaws. 77,l~176 B u m b l e f o o t is a t e r m u s e d to describe p o d o d e r m a t i t i s lesions o n the p l a n t a r surface o f the p h a l a n g e s or o n the tarsometatarsus. P o d o d e r m a t i t i s a n d focal hyperkeratosis (plantar corns) are possible d e r m a t o l o g i c manifestations o f vitamin A deficiency. 1/,96 This c o n d i t i o n has b e e n w e l l described a n d the r e a d e r is ref e r r e d to Gill, 4 B u r g m a n n , 3 a n d Bauck. 1~ Psittacine circovirus infection, or PBFD can also cause hyperkeratosis o n the extremities a n d dystrophy o f the nails, a n d e x p o s u r e to sunlight m a y cause this skin to b e c o m e darkly pigmented. 7 Articular g o u t can cause firm, white swellings (tophi) over the joints o f limbs, primarily the feet. It is regularly seen in b u d g e r i g a r s a n d o t h e r parrots. Articular g o u t is n o t always associated with h i g h uric acid levels or with visceral gout. T h e therapeutic a p p r o a c h s h o u l d i n c l u d e adj u s t i n g the p e r c h e s as n e e d e d to m a k e the bird m o r e c o m f o r t a b l e a n d i m p r o v i n g the bird's diet (ie, the c o r r e c t vitamin A levels a n d avoiding excess calcium a n d protein).~ Filariid n e m a t o d e s (eg, Pelecitus) can cause s u b c u t a n e o u s n o d u l e s that are m o s t c o m m o n l y f o u n d o n the feet a n d legs. l v e r m e c t i n is effective against the microfilaria, b u t surgical excision o f the masses is necessary to r e m o v e the adult n e m a t o d e s . 45

Amazon Foot Necrosis This s y n d r o m e affecting A m a z o n parrots comprises irregular patches o f erythema, skin necrosis, a n d self-mutilation o f the legs a n d feet. 1,4,1~ Yellow-Naped a n d D o u b l e YellowH e a d e d A m a z o n Parrots a p p e a r to be particularly p r o n e to the disease, a,z,l~ I n these birds the wing webs m a y also be involved. 6,1~ T h e condition can o c c u r in birds o f all ages. T h e etiology is u n k n o w n , b u t o n e possibility is hypersensitivity to staphylococcal antigens, s T r e a t m e n t r e c o m m e n d a t i o n s include longt e r m k e t o c o n a z o l e therapy, strict sanitation, collaring a n d use o f topical creams, p a r e n t e r a l a n d topical corticosteroids a l o n g with topical disin-

Dermatologic Diseases in Psittacine Birds

f e c t a n t s a n d c a g e s a n i t a t i o n , h y d r o x y z i n e with an oral antibiotic (trimethoprim-sulfonamide),l oral steroids, S a n t i p s y c h o t i c drugs, 6 a n d L-thyr o x i n e A 0s B u r g m a n n also r e c o m m e n d s p r e v e n t i n g e x p o s u r e to e n v i r o n m e n t a l i r r i t a n t s (eg, n i c o t i n e , h a i r spray) a n d e n s u r i n g a d e q u a t e nut r i t i o n a n d e x p o s u r e to daylight. 3 A f f e c t e d b i r d s m a y have r e c u r r i n g episodes.L4

Constricted Toe Syndrome This c o n d i t i o n o c c u r s m o s t c o m m o n l y in y o u n g birds a n d m i m i c s t h e l e s i o n c a u s e d by a f o r e i g n m a t e r i a l (eg, a s y n t h e t i c o r c o t t o n fiber) w r a p p e d tightly a r o u n d t h e digit. A f i b r o u s b a n d o f n e c r o t i c tissue e n c i r c l e s t h e d i g i t a n d i n d u c e s swelling a n d avascular n e c r o s i s distal to t h e site. T h e e t i o l o g y is u n k n o w n , b u t p o s s i b l e factors i n c l u d e low h u m i d i t y , e g g - r e l a t e d strictures, a n d e r g o t l i k e i n t o x i c a t i o n . 4,6 T h i s s y n d r o m e has b e e n r e p o r t e d in a variety o f p s i t t a c i n e birds, p a r t i c u l a r l y t h e l a r g e r species. 3,4 I n m i l d cases, a p p l i c a t i o n o f a n o p h t h a l m i c a n t i b i o t i c o i n t m e n t to t h e f i b r o u s b a n d c a n r e l i e v e t h e c o n s t r i c t i o n . I n m o r e s e v e r e cases surgical correction involving making several s m a l l s t a b i n c i s i o n s a c r o s s t h e f i b r o u s b a n d is n e c e s s a r y to r e l i e v e t h e s t r i c t u r e . 4,6 Gill caut i o n s t h a t a t t e m p t i n g to r e m o v e t h e s c a b c a n l e a d to e x c e s s i v e b l e e d i n g . 4 A m p u t a t i o n is reco m m e n d e d i f t h e d i g i t d i s t a l to t h e c o n s t r i c t i o n is n e c r o t i c . 6

Uropygial Gland Lesions Diseases o f t h e u r o p y g i a l g l a n d i n c l u d e tumors, abscessation or impaction of the gland, a n d f u n g a l g r a n u l o m a s . 14,17 B a c t e r i a l i n f e c t i o n o f t h e u r o p y g i a l g l a n d is relatively c o m m o n in b u d g e r i g a r s . Signs i n c l u d e a c h a n g e in c o n t o u r over t h e tail base, p i c k i n g at t h e area, a n d rep e a t e d tail f l i c k i n g 2 I m p a c t i o n s m a y b e r e l i e v e d by g e n t l y e x p r e s s i n g t h e g l a n d ; abscesses a r e b e s t t r e a t e d by surgical d r a i n a g e . 2 Uropygial gland tumors include adenocarcin o m a s (the m o s t c o m m o n ) , s q u a m o u s cell carc i n o m a s , a d e n o m a s , a n d f i b r o s a r c o m a s . TM Alt h o u g h exfoliative c y t o l o g y m a y b e u s e f u l f o r d i a g n o s i s , h i s t o p a t h o l o g i c e x a m i n a t i o n o f a biopsy s p e c i m e n is o f t e n r e q u i r e d . ~ R a d i o g r a p h y is r e c o m m e n d e d p r i o r to s u r g e r y as l o c a l i n v a s i o n c a n e x t e n d to pelvic b o n e s , w h i c h r e n d e r s t h e

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t u m o r i n o p e r a b l e , o r c a n involve t h e pygostyle, w h i c h r e q u i r e s a m p u t a t i o n . 1,4

Miscellaneous Conditions S k i n Wounds W o u n d s m a y b e self-inflicted o r c a u s e d by a n o t h e r b i r d o r a n i m a l (eg, a cat). L a c e r a t i o n s in f e a t h e r e d a r e a s u s u a l l y h e a l well with a p p r o p r i a t e w o u n d care. H o w e v e r , l a c e r a t i o n s in n o n f e a t h e r e d a r e a s o f t e n r e q u i r e s u t u r i n g f o r optim a l h e a l i n g . 5 Bite w o u n d s s h o u l d b e t r e a t e d p r o m p t l y a n d aggressively with t h o r o u g h w o u n d c l e a n i n g , s u p p o r t i v e c a r e (eg, fluids a n d nutrit i o n ) , a n d t h e use o f b r o a d - s p e c t r u m a n t i b i o t i c s with a n a e r o b i c c o v e r a g e .

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