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A diagnostic approach to feather picking
A Diagnostic Approach to Feather Picking Nadine Lambershi, DVM
Feather picking is a common clinical presentation. The disorder can be frustrating to the client as well as the veterinarian both in terms of diagnosis and treatment. This article discusses a diagnostic approach to feather picking that begins by obtaining a detailed environmental, behavioral, and nutritional history. Suggestions are made for obtaining a minimum data base. Additional laboratory testing is often required to rule in or out a disease process. Diagnosing a behavioral or psychological feather picker can be achieved by ruling out organic disease.
Copyright 9 1995 by W.B. Saunders Company Key words: Avian, diagnosis, feather picking.
e t e r m i n i n g the cause o f f e a t h e r picking in
D avian patients is frustrating for the veterinarian as well as the client. Feather picking is not a disease but r a t h e r a clinical sign o f an u n d e r l y i n g p r o b l e m or disease process. Feather picking is often described as a behavioral or psychological p r o b l e m in birds, but it is very i m p o r t a n t to rule out a medical condition that may not be immediately obvious. Client education must begin early. T h e client must be willing to invest time and m o n e y and must be willing to accept that the u n d e r l y i n g cause may n e v e r be d e t e r m i n e d . It should be stressed to the o w n e r that the most likely cases to be resolved are the acute onset or recent feather picker and that it may be m o r e difficuh to definitively d e t e r m i n e the i n c i t i n g cause o f feather picking in a bird that has been overp r e e n i n g for years. As with o t h e r species, the avian i n t e g u m e n t reflects the overall health and nutritional plane o f the patient. Generalized p o o r feather quality should be differentiated f r o m feathers that are d a m a g e d as a result o f o v e r p r e e n i n g . However, this is often difficult to do as both conditions can occur simultaneously. Birds will pick feathers because o f a primary feather or skin From the Riverbanks ZoologicalPark and Botanical Garden, Columbia, SC. Address reprint requests to Nadine Lamberski, DVM, Riverbanks Zoological Park and Botanical Garden, PO Box 1060, Columbia, SC 29202-1060. Copyright 9 1995 by W.B. Saunders Company 1055-937X/95/0404-000755.00/0
disease or may pick feathers secondary to ano t h e r problem. Additionally, feathers can app e a r unthrifty secondary to p o o r health or nutrition. T h e diagnosis o f f e a t h e r picking in birds is o f t e n by the process of elimination. Diseases are ruled in or ruled out by p e r f o r m i n g a series of tests. T h e o r d e r in which the clinician p e r f o r m s these tests may vary d e p e n d i n g on the p r i m a r y rule outs a n d on the financial c o m m i t t m e n t o f the owner. Tests that are inexpensive and easy to p e r f o r m are often perf o r m e d initially to save the m o r e involved and expensive tests if m o r e i n f o r m a t i o n is n e e d e d to make a diagnosis. By ruling out an overt o r covert disease process, one can back into a diagnosis o f behavioral or psychological f e a t h e r picking. It is very i m p o r t a n t to d e t e r m i n e the cause o f the f e a t h e r picking in o r d e r to treat the disease process and not just the clinical sign. However, for the owner, f e a t h e r picking is a serious problem and d e t e r m i n i n g the cause is just the first step. T r e a t m e n t o f this d i s o r d e r is d e p e n d e n t on the inciting cause and has been discussed elsewhere. 1-6 Clients should be r e m i n d e d that d e t e r m i n i n g the diagnosis does not g u a r a n t e e that the bird will be successfully treated. It is i m p o r t a n t to discuss all o f this in advance so the o w n e r will not have unrealistic expectations. T h e initial visit is an e x t r e m e l y i m p o r t a n t one. T h e client must be m a d e aware of the diagnostic and t r e a t m e n t challenge that lies ahead. A significant a m o u n t of time should be devoted to acquiring a detailed and accurate history for the p r i m a r y caregiver o f the bird. T h e information g a t h e r e d will help in determining the diagnostic tests necessary to determine the etiology o f the disorder. Instructing the client to fill out a patient history f o r m (Table 1) ensures that the a p p r o p r i a t e questions are asked, but only reviewing this f o r m with the owner ensures that all questions are a p p r o priately answered. Clients can be mailed the forms in advance or can be allowed to complete the forms before meeting with the veterinarian. In o r d e r to obtain the necessary infor-
Seminars in Avian and Exotic Pet Medicine, Vol 4, No 4 (October), 1995: pp 161-168
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Table 1. Patient History Form 1. 2. 3. 4.
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.
34.
Where and when did you get your bird? How old is your bird now? How was the bird housed before you acquired it? How is the bird housed now? Isolated? In a group? In a breeding situation? Household? Aviary? Describe the bird's cage/enclosure How often do you handle your bird? What do you feed your bird? Any treats or table scraps offered? Any vitamins or minerals offered? How often do you provide fresh water for your bird? How often do you clean and disinfect the cage? Food/water dishes? What products do you use? Have you owned or kept birds before? Do you have any other birds now? Do you have any other pets? What room in the house do you keep your bird? Has the bird been kept in the same area or moved around? Does your bird have exposure to the outdoors? Has the bird been exposed to any other birds? Wild birds? Neighbor's birds? Birds at shows? W h e n did your bird last molt? What is the sex of your bird and how was it determined (if known)? Has your bird ever exhibited breeding behavior? Does your bird fly around the house or in a flight cage? Has your bird ever been in a breeding situation? What was the result? When does your bird vocalize the most? W h e n did you first notice your bird picking its feathers? What part of the body was first affected? How often does the bird pick? Do you ever see the bird pick its feathers? Has the pattern of picking changed over time? Has the severity of picking changed over time? Has your bird been seen by another veterinarian for this problem? W h e n does the bird pick the most? T h e least? Have any changes occurred in your life resulting in a change in your bird's routine? Have you recently moved? Have the number of people in the household changed? Have your work hours changed? Have you changed the amount o f time you spend with your bird? Do you or any household members smoke?
m a t i o n , a n e x t e n d e d office visit m a y be required. D e t e r m i n i n g the i n t e n d e d use o f the b i r d m a y alter the a m o u n t o f e f f o r t d e v o t e d to det e r m i n i n g the cause o f the o v e r p r e e n i n g a n d t h e a t t e m p t s at alleviating the b e h a v i o r . Clients t h a t k e e p b i r d s in a b r e e d i n g situation m a y o n l y be i n t e r e s t e d in r u l i n g o u t an infectious o r
metabolic disease process, w h e r e a s t h e client k e e p i n g a b i r d as a c o m p a n i o n a n i m a l m a y be m o r e i n t e r e s t e d in the physical a p p e a r a n c e o f the bird. T h e i n f o r m a t i o n g a t h e r e d d u r i n g t h e initial examination period should include a detailed e n v i r o n m e n t a l history. O w i n g to the a m o u n t o f time a n d responsibility i n v o l v e d in k e e p i n g
A Diagnostic Approach to Feather Picking
a bird as a companion animal coupled with the longevity of some species, m a n y birds will go t h r o u g h several owners d u r i n g their lifetime. T h e feather picking may be a problem comm o n to previous housing situations or may be related to a novel situation. For example, a bird previously kept in an aviary may not adapt well to a single-bird household. Additionally, a bird once provided with e n o u g h r o o m to fly may have difficulty adapting to a small cage. Question the owner as to any changes in the bird's routine that coincide with the onset of feather picking. Perhaps a new job, roommate, or addition to the family have altered the a m o u n t of attention devoted to the bird. Perhaps the bird has been moved to a new location in the house altering the a m o u n t of interaction with family members. A detailed dietary history may show obvious nutritional deficiencies such as the proteinand vitamin-deficient all-seed diet. But it is not only important to ask what the bird is being fed but also to ask what the bird usually consumes. Some birds will toss aside fresh greens to get at the seeds in the bottom of the bowl. Birds may also pick up and crush pellets without necessarily ingesting them. Many clients will feed an a b u n d a n c e o f fresh fruits overlooking the value of feeding a variety of dark green and yellow vegetables. Adequate nutrition is p a r a m o u n t to maintaining feather health and condition. Because molting increases metabolic rate and protein d e m a n d , malnutrition can result in an incomplete or irregular molt. T h e feathers will look worn and dull and may even take on a gray color. Retained feather sheaths may irritate the bird, resulting in overpreening behavior. Questioning the owner in regards to the bird's molt cycle may show valuable information. Molting is cyclic in adult birds but varies with species. Some birds molt t h r o u g h o u t the year, others molt once a year, and still others may only molt once in a 2-year period. Birds can either go t h r o u g h a progressive molt, losing only e n o u g h feathers so that they can still fly, whereas others replace all of the flight and tail feathers at one time. 7 T h e inexperienced bird owner may associate this normal physiological process with a pathological condition. Discussing cleaning and disinfecting practices may demonstrate an unnecessary exposure of the bird to potential pathogens. Food
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and water bowls must be cleaned and disinfected on a regular basis in order to prevent the accumulation of h a r m f u l bacteria. Additionally, birds that are fed nectar should have the solutions replaced twice daily. Uneaten fresh foods should be removed the same day they are offered. Perches and substrates should also be cleaned, disinfected, or replaced on a regular basis. Birds are extremely intelligent, and m a n y species need to be provided with toys or objects to prevent boredom. However, careful questioning of the owner may show cases of overcrowding by excessive enclosure f u r n i t u r e . T h e bird may be traumatizing its wings or tail as it maneuvers about the cage (Fig 1). It may be more effective to rotate the toys presented to the bird in o r d e r to capture the bird's attention. Offering browse on a regular basis is an inexpensive form of behavioral enrichment. Many clients do not know the age or sex of their birds and may be surprised when their pet of several years begins to exhibit breeding
Figure 1. Mild trauma to the feather on the left resulted in a frayed appearance to its distal end. Normal feathers are on the right for comparison. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, so.)
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behavior. The onset of sexual maturity varies with species and may result in a personality change. Many veterinarians consider frustrated mating instincts a common cause o f psychological feather picking in birds. 8 The information just listed should provide the veterinarian with a mental picture of the bird, its environment, and its daily routine. A change in the routine of any species can often result in maladaptation behavior. Specific infbrmation on the feather picking should then be gathered. The onset, progression, and distribution of the feather picking may provide some valuable clues as to the cause. Feather picking involving the breast, abdomen, and legs has been associated with reproductive frustration during the breeding season (Fig 2). 9 Abnormal-appearing feathers on the top of the bird's head suggests a primary feather disease or feather picking by a cagemate. Another important but difficult dis-
Figure 2. Feather loss as a result of behavioral feather picking on the breast, abdomen, and legs of this scarlet macaw. Note the normal appearing feathers on the head and the presence of pin feathers in the inguinal region. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
tinction to make is whether the feathers were abnormal initially or whether they became abnormal in appearance as a result of the selftrauma. Once a complete dietary and environmental history is obtained and the characteristics of the feather picking have been ascertained, the physical examination can be initiated. T h e goal now is to uncover more clues that may be helpful in determining the cause of the problem. Observe the bird before restraining it, paying close attention to its attitude, posture, and behavior. Describe any feather picking observed. Record all findings in the patient's medical record. This will facilitate case evaluation and retrospective analysis of diagnostic and therapeutic techniques. Isoflurane anesthesia can be used to facilitate examination of the bird and the collection of laboratory samples. However, clients should be made aware of the inherent risks involved with general anesthesia. A complete physical examination should include an evaluation of the eyes, ears, nares, and throat. Included in the oral examination is an examination of the choanal opening and choanal papillae. The choanal slit should be free from excessive mucus or other discharges. The choanal papillae should be sharp. Blunting of the choanal papillae is suggestive of hypovitaminosis A. Inspect the oral cavity for the presence of plaques. Assess body condition as well as the quality of the plumage. Remove a few feathers for closer inspection at another time. Examine the skin. Extend both wings and palpate the patagium. Note the distribution of any missing or broken feathers. Evaluate the involvement of the developing feathers by noting the presence of new feathers as well as their quality and quantity. Extend both legs and closely examine the digits and plantar surface of the feet. Inspect the cloaca everting the cloacal rim examining it for papillomas. Evaluate the uropygial gland if present. Auscult, palpate, and weigh the bird. The feathers can be examined by using a magnifying glass, dissecting microscope, or light microscope. The goal is to determine whether the feathers themselves are abnormal or if the bird is picking at a normal appearing feather. Malformed, dystrophic, or discolored feathers are abnormal as are retained feather sheaths, clubbed feathers, curled feathers, and
A Diagnostic Approach to Feather Picking
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broken feathers. Hemorrhage within the pulp cavity also is abnormal. Feathers that easily fall out, although common in a restrained turaco, may be considered abnormal in some species and can result from dermatitis caused by Mycobacterium species, a~ Feathers that are frayed or broken at the distal ends may have been traumatized (Fig 3). Stress lines are translucent lines across the vane of the feather. These marks can occur as a result of inadequate nutrition, e n v i r o n m e n t a l extremes, or poor health (Fig 4).9 Although uncommon in psittacine birds, feathers should also be examined for evidence of ectoparasitism (Fig 5).11,12 The information obtained during the physical examination plus the information gathered from the minimum database is used to identify the body system or systems affected. In more cases than not, the information will indicate that the integumentary system is involved primarily or secondarily and will rule out the involvement of other body systems.
Figure 4. Translucent mark characteristic of a stress line in a macaw feather. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
Figure 3. Severely damaged distal feathers in a seriema as a result of a heat lamp burn. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
The minimum database should include intially a complete blood count (CBC), chemistry panel, fecal flotation and direct smear, and choanal and cloacal gram stains. Additional information can be gathered from choanal and cloacal cultures, choanal and cloacal cytology (Wright's stain), and fecal acid fast stains. This should provide the' clinician with information on the overall health of the bird. If the patient is anesthetized, whole body radiographs can be obtained (this can be performed without anesthesia in some species) and feather and skin biopsy samples can be taken as well. Be sure to include affected developing or pin feathers in the samples collected. Gram's and Wright's stain of the feather pulp and feather pulp cultures may provide useful information (Fig 6). 9 Depending on the clinical presentation and
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Figure 5. Normal barn owl feather on the left and two abnormal feathers on the right. The rachis of the middle feather is mildly damaged from ectoparasites. The rachis of the feather on the right is severely affected and there is hemorrhage within the pulp cavity. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.) the species involved, tests for o t h e r diseases should be considered. This includes but is not limited to Psittacine Beak and Feather Disease (PBFD) p o l y m e r a s e c h a i n r e a c t i o n (PCR), polyomavirus D N A probe, thyroid function evaluation, Giardia Indirect Fluorescent Antibody (IFA) test, bile acids, and a chlamydia titer. T h e thyroid gland as well as the gonads regulate the metabolic processes that result in f e a t h e r formation, la M e a s u r e m e n t o f plasma T S H and t h y r o x i n e concentrations plus perf o r m i n g T R H and T S H stimulation tests are u s e d to d i a g n o s e t h y r o i d d i s o r d e r s . 14"15 I f m o r e i n f o r m a t i o n is necessary to d e t e r m i n e the cause o f the feather condition, endoscopy can be used to c o n f i r m sex and stage o f r e p r o duction as well as evaluate the air sacs and o t h e r internal organs (Table 2). T h e CBC is a useful indicator o f inflammation and may suggest infection as well. An inf l a m m a t o r y l e u k o g r a m is not u n e x p e c t e d in a feather-picking bird, especially if the e x t e n t o f the picking is severe. In the author's experience, eosinophila is not c o m m o n l y observed with external or internal parasites in psittacine birds but can be observed frequently with hemoparasites in raptors. T h e hematocrit and total protein values provide i n f o r m a t i o n o n the overall health a n d hydration status o f the bird. A n e m i a can result f r o m chronic disease. T h e chemistry panel is used to evaluate for liver and kidney disease. It is i m p o r t a n t to note that
m a n y species o f birds have A S T a n d L D H present in liver as well as skeletal muscle. Many feather-picking birds will have a mild elevation in these enzymes secondary to muscle trauma. T h e r e f o r e , it is i m p o r t a n t to measure C P K as well to help differentiate between liver and muscle disease. It is also i m p o r t a n t to r e m e m ber that AST and L D H do not reflect hepatic function. Bile acids should be c o n s i d e r e d if impaired liver function is suspected a f t e r the m i n i m u m database is obtained. Calcium, phosp h o r u s , c a l c i u m - t o - p h o s p h o r u s ratio, total protein, and albumin are evaluated as a reflection of nutritional status. Elevated calcium and alkaline phosphatase can be associated with ovulation and s u b s e q u e n t oviposition. Uric acid can be elevated secondary to renal as well as n o n r e n a l factors. Cloacal and choanal gram stains a n d cultures are used to evaluate the overall health o f the bird. Results must be i n t e r p r e t e d with caution and with knowledge o f n o r m a l flora. Findings should be used to s u p p o r t a diagnosis not make a diagnosis irrespective o f the clinical presentation o f the patient. Similarly, biopsy results should be carefully interpreted. 16 Mild inflammation may occur a r o u n d the f e a t h e r follicle as a r e s u l t o f the s e l f - t r a u m a a n d should not be misinterpreted as the inciting cause. In o r d e r to save the client time a n d money, multiple laboratory samples can be collected
A Diagnostic App~)ach to Feather Picking
d u r i n g the initial visit but submission for laboratory testing can be staggered. This allows the clinical to tailor the diagnostic work-up to each patient. For instance, choanal and cloacal swabs can be obtained and several slides m a d e but left unstained. T h e clinician can later go back and stain the slides as d e e m e d appropriate based on o t h e r information. Swabs can be obtained for culture and held for 24 hours in t r a n s p o r t media until gram stains are evaluated. In larger birds, extra b l o o d can be collected and stored. T h e sample can later be used for additional testing (bile acids, PBFDPCR, chlamydia titer) once the m i n i m u m database has been evaluated. Feces can be saved in saline or formalin for Giardia IFA if the fecal flotation and direct smear are negative, but Giardia remains on the rule out list. Feces can also be collected and later submitted for polyomavirus-specific DNA probes if this disease is on the rule-out list. I f the bird is being anesthetized for the physical examination or sample collection, f e a t h e r and skin biopsies samples can be obtained. Slides o f f e a t h e r pulp can be obtained for later staining if necessary, and swabs o f feather pulp can be held for 24 hours in t r a n s p o r t media before culture. Tissue samples can be placed in formalin and submission p e n d i n g evaluation o f other findings. For example, if PBFD is suspected, blood can be s u b m i t t e d f o r D N A p r o b e testing. T h e Table 2. Diagnostic Approach to the Feather Picker Minimum database: Complete blood count (CBC) Chemistry panel Choanal and cloacal gram stains Fecal flotation and direct smear Additional diagnostic information: Choanal and cloacal cytology Choanal and cloacal culture Whole body radiographs Feather and skin biopsy Feather pulp gram stain, cytology, and culture Giardia 1FA Miscellaneous diagnostic infbrmation Fecal acid fast stain PBFD-PCR Polyomavirus DNA probe Thyroid function evaluation Bile acids Chlamydia titer Endoscopy
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Figure 6. Microphotograph of histological crosssection through an avian feather %llicle. The numerous normal melanin granules can easily be mistaken for bacterial rods when gram stains of feather follicle squash preparations are performed. (Reprinted with permission from Alan M. Fudge, DVM.) PBFD-PCR is a m o r e sensitive test than f e a t h e r biopsies in d i a g n o s i n g the virus. H o w e v e r , false-negatives can occur, iv I f the results are negative and the virus is still suspected, biopsy specimens can later be submitted. In s u m m a r y , the diagnostic a p p r o a c h to feather picking begins by obtaining a complete environmental, nutritional, and behavioral history. T h e overall health o f the bird must then be evaluated. Physical examination o f the int e g u m e n t a r y system as well as the entire bird is p a r a m o u n t to making a diagnosis. Diseases are ruled in or out by p e r f o r m i n g a series of diagnostic tests. B e h a v i o r a l o r psychological feather picking is often diagnosed by a process o f elimination. T h e collection and retrospective evaluation of clinical information may increase proficiency in making a diagnosis. Client education is i m p o r t a n t to client satisfaction. T h e d i f f e r e n t i a l diagnosis o f f e a t h e r picking has been discussed several times in the literature. T h e avian clinician is e n c o u r a g e d to keep abreast of new trends in diagnosis and treatment. 18-21
References 1. Johnson-Delaney C: Feather picking: Diagnosis and treatment. J Assoc Avian Vet 6:82-88, 1992 2. Lennox AM, VanDerHeyden N: Haloperidol for use
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in treatment of psittacine self-nmtilation and feather plucking. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 119 Worrell AB, Farber WL: The use of acupuncture in the treatment of feather picking in psittacine birds. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 121 Krinsley M: Use of DermCaps Liquid and hydroxyzine hydrochloride for the treatment of feather picking. J Assoc Avian Vet 7:221, 1993 Ramsay EC, Grindlinger H: Use of clomipramine in the treatment of obsessive behavior in psittacine birds. J Assoc Avian Vet 8:9-15, 1994 Turner R: Trexan (naltrexone hydrochloride) use in feather picking in avian species. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 116 Cooper JE, Harrison GJ: Dermatology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 620 Harrison GJ: Perspective on parrot behavior, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 107 Cooper JE, Harrison GJ: Dermatology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application: Lake Worth, FL, Wingers, 1994, p 633 Drew ML, Ramsay EC: Dermatitis associated with Mycobacterium spp. in a blue-fronted amazon parrot. Proceedings of the Association of Avian Veterinarians. Chicago, IL, 1991, pp 252-254
11. Shoshana R: Knemidokoptes mites on feathers of the red-fronted parakeet. J Assoc Avian Vet 7;202, 1993 12. Phillips JR: Avian mites. Comp Cont Ed Pract Vet 15:671, 1993 13. Lumeij JT: Endocrinology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 601 14. Lumeij JT: Endocrinology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, pp 594-596 15. Oglesbee BL: Hypothyroidism in a scarlet macaw. J Am Vet Med Assoc 201:1599-1601, 1992 16. Schmidt RE: Use of biopsies in the differential diagnosis of feather picking and avian skin disease. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 113 17. Ritchie BW: Personal communication 18. Harris D: Basic avian medicine: Overview of considerations in diagnosing feather problems. J Assoc Avian Vet 1:199, 1987 19. Rosenthal K: Differential diagnosis of feather picking in pet birds. Proceedings of the Association of Avian Veterinarians, Chicago, IL, 1991, p 108 20. Oppenheimer J: Feather picking: Systemic approach. Proceedings of the Association of Avian Veterinarians. Chicago, IL, 1991, pp 314-315 21. Reavill DR, Schmidt RE, Fudge AM: Avian skin and feather disorders: A retrospective study. Proceedings of the Association of Avian Veterinarians, Phoneix, AZ, 1990, p 248-255
Feather picking is a common clinical presentation. The disorder can be frustrating to the client as well as the veterinarian both in terms of diagnosis and treatment. This article discusses a diagnostic approach to feather picking that begins by obtaining a detailed environmental, behavioral, and nutritional history. Suggestions are made for obtaining a minimum data base. Additional laboratory testing is often required to rule in or out a disease process. Diagnosing a behavioral or psychological feather picker can be achieved by ruling out organic disease.
Copyright 9 1995 by W.B. Saunders Company Key words: Avian, diagnosis, feather picking.
e t e r m i n i n g the cause o f f e a t h e r picking in
D avian patients is frustrating for the veterinarian as well as the client. Feather picking is not a disease but r a t h e r a clinical sign o f an u n d e r l y i n g p r o b l e m or disease process. Feather picking is often described as a behavioral or psychological p r o b l e m in birds, but it is very i m p o r t a n t to rule out a medical condition that may not be immediately obvious. Client education must begin early. T h e client must be willing to invest time and m o n e y and must be willing to accept that the u n d e r l y i n g cause may n e v e r be d e t e r m i n e d . It should be stressed to the o w n e r that the most likely cases to be resolved are the acute onset or recent feather picker and that it may be m o r e difficuh to definitively d e t e r m i n e the i n c i t i n g cause o f feather picking in a bird that has been overp r e e n i n g for years. As with o t h e r species, the avian i n t e g u m e n t reflects the overall health and nutritional plane o f the patient. Generalized p o o r feather quality should be differentiated f r o m feathers that are d a m a g e d as a result o f o v e r p r e e n i n g . However, this is often difficult to do as both conditions can occur simultaneously. Birds will pick feathers because o f a primary feather or skin From the Riverbanks ZoologicalPark and Botanical Garden, Columbia, SC. Address reprint requests to Nadine Lamberski, DVM, Riverbanks Zoological Park and Botanical Garden, PO Box 1060, Columbia, SC 29202-1060. Copyright 9 1995 by W.B. Saunders Company 1055-937X/95/0404-000755.00/0
disease or may pick feathers secondary to ano t h e r problem. Additionally, feathers can app e a r unthrifty secondary to p o o r health or nutrition. T h e diagnosis o f f e a t h e r picking in birds is o f t e n by the process of elimination. Diseases are ruled in or ruled out by p e r f o r m i n g a series of tests. T h e o r d e r in which the clinician p e r f o r m s these tests may vary d e p e n d i n g on the p r i m a r y rule outs a n d on the financial c o m m i t t m e n t o f the owner. Tests that are inexpensive and easy to p e r f o r m are often perf o r m e d initially to save the m o r e involved and expensive tests if m o r e i n f o r m a t i o n is n e e d e d to make a diagnosis. By ruling out an overt o r covert disease process, one can back into a diagnosis o f behavioral or psychological f e a t h e r picking. It is very i m p o r t a n t to d e t e r m i n e the cause o f the f e a t h e r picking in o r d e r to treat the disease process and not just the clinical sign. However, for the owner, f e a t h e r picking is a serious problem and d e t e r m i n i n g the cause is just the first step. T r e a t m e n t o f this d i s o r d e r is d e p e n d e n t on the inciting cause and has been discussed elsewhere. 1-6 Clients should be r e m i n d e d that d e t e r m i n i n g the diagnosis does not g u a r a n t e e that the bird will be successfully treated. It is i m p o r t a n t to discuss all o f this in advance so the o w n e r will not have unrealistic expectations. T h e initial visit is an e x t r e m e l y i m p o r t a n t one. T h e client must be m a d e aware of the diagnostic and t r e a t m e n t challenge that lies ahead. A significant a m o u n t of time should be devoted to acquiring a detailed and accurate history for the p r i m a r y caregiver o f the bird. T h e information g a t h e r e d will help in determining the diagnostic tests necessary to determine the etiology o f the disorder. Instructing the client to fill out a patient history f o r m (Table 1) ensures that the a p p r o p r i a t e questions are asked, but only reviewing this f o r m with the owner ensures that all questions are a p p r o priately answered. Clients can be mailed the forms in advance or can be allowed to complete the forms before meeting with the veterinarian. In o r d e r to obtain the necessary infor-
Seminars in Avian and Exotic Pet Medicine, Vol 4, No 4 (October), 1995: pp 161-168
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Table 1. Patient History Form 1. 2. 3. 4.
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.
20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33.
34.
Where and when did you get your bird? How old is your bird now? How was the bird housed before you acquired it? How is the bird housed now? Isolated? In a group? In a breeding situation? Household? Aviary? Describe the bird's cage/enclosure How often do you handle your bird? What do you feed your bird? Any treats or table scraps offered? Any vitamins or minerals offered? How often do you provide fresh water for your bird? How often do you clean and disinfect the cage? Food/water dishes? What products do you use? Have you owned or kept birds before? Do you have any other birds now? Do you have any other pets? What room in the house do you keep your bird? Has the bird been kept in the same area or moved around? Does your bird have exposure to the outdoors? Has the bird been exposed to any other birds? Wild birds? Neighbor's birds? Birds at shows? W h e n did your bird last molt? What is the sex of your bird and how was it determined (if known)? Has your bird ever exhibited breeding behavior? Does your bird fly around the house or in a flight cage? Has your bird ever been in a breeding situation? What was the result? When does your bird vocalize the most? W h e n did you first notice your bird picking its feathers? What part of the body was first affected? How often does the bird pick? Do you ever see the bird pick its feathers? Has the pattern of picking changed over time? Has the severity of picking changed over time? Has your bird been seen by another veterinarian for this problem? W h e n does the bird pick the most? T h e least? Have any changes occurred in your life resulting in a change in your bird's routine? Have you recently moved? Have the number of people in the household changed? Have your work hours changed? Have you changed the amount o f time you spend with your bird? Do you or any household members smoke?
m a t i o n , a n e x t e n d e d office visit m a y be required. D e t e r m i n i n g the i n t e n d e d use o f the b i r d m a y alter the a m o u n t o f e f f o r t d e v o t e d to det e r m i n i n g the cause o f the o v e r p r e e n i n g a n d t h e a t t e m p t s at alleviating the b e h a v i o r . Clients t h a t k e e p b i r d s in a b r e e d i n g situation m a y o n l y be i n t e r e s t e d in r u l i n g o u t an infectious o r
metabolic disease process, w h e r e a s t h e client k e e p i n g a b i r d as a c o m p a n i o n a n i m a l m a y be m o r e i n t e r e s t e d in the physical a p p e a r a n c e o f the bird. T h e i n f o r m a t i o n g a t h e r e d d u r i n g t h e initial examination period should include a detailed e n v i r o n m e n t a l history. O w i n g to the a m o u n t o f time a n d responsibility i n v o l v e d in k e e p i n g
A Diagnostic Approach to Feather Picking
a bird as a companion animal coupled with the longevity of some species, m a n y birds will go t h r o u g h several owners d u r i n g their lifetime. T h e feather picking may be a problem comm o n to previous housing situations or may be related to a novel situation. For example, a bird previously kept in an aviary may not adapt well to a single-bird household. Additionally, a bird once provided with e n o u g h r o o m to fly may have difficulty adapting to a small cage. Question the owner as to any changes in the bird's routine that coincide with the onset of feather picking. Perhaps a new job, roommate, or addition to the family have altered the a m o u n t of attention devoted to the bird. Perhaps the bird has been moved to a new location in the house altering the a m o u n t of interaction with family members. A detailed dietary history may show obvious nutritional deficiencies such as the proteinand vitamin-deficient all-seed diet. But it is not only important to ask what the bird is being fed but also to ask what the bird usually consumes. Some birds will toss aside fresh greens to get at the seeds in the bottom of the bowl. Birds may also pick up and crush pellets without necessarily ingesting them. Many clients will feed an a b u n d a n c e o f fresh fruits overlooking the value of feeding a variety of dark green and yellow vegetables. Adequate nutrition is p a r a m o u n t to maintaining feather health and condition. Because molting increases metabolic rate and protein d e m a n d , malnutrition can result in an incomplete or irregular molt. T h e feathers will look worn and dull and may even take on a gray color. Retained feather sheaths may irritate the bird, resulting in overpreening behavior. Questioning the owner in regards to the bird's molt cycle may show valuable information. Molting is cyclic in adult birds but varies with species. Some birds molt t h r o u g h o u t the year, others molt once a year, and still others may only molt once in a 2-year period. Birds can either go t h r o u g h a progressive molt, losing only e n o u g h feathers so that they can still fly, whereas others replace all of the flight and tail feathers at one time. 7 T h e inexperienced bird owner may associate this normal physiological process with a pathological condition. Discussing cleaning and disinfecting practices may demonstrate an unnecessary exposure of the bird to potential pathogens. Food
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and water bowls must be cleaned and disinfected on a regular basis in order to prevent the accumulation of h a r m f u l bacteria. Additionally, birds that are fed nectar should have the solutions replaced twice daily. Uneaten fresh foods should be removed the same day they are offered. Perches and substrates should also be cleaned, disinfected, or replaced on a regular basis. Birds are extremely intelligent, and m a n y species need to be provided with toys or objects to prevent boredom. However, careful questioning of the owner may show cases of overcrowding by excessive enclosure f u r n i t u r e . T h e bird may be traumatizing its wings or tail as it maneuvers about the cage (Fig 1). It may be more effective to rotate the toys presented to the bird in o r d e r to capture the bird's attention. Offering browse on a regular basis is an inexpensive form of behavioral enrichment. Many clients do not know the age or sex of their birds and may be surprised when their pet of several years begins to exhibit breeding
Figure 1. Mild trauma to the feather on the left resulted in a frayed appearance to its distal end. Normal feathers are on the right for comparison. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, so.)
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behavior. The onset of sexual maturity varies with species and may result in a personality change. Many veterinarians consider frustrated mating instincts a common cause o f psychological feather picking in birds. 8 The information just listed should provide the veterinarian with a mental picture of the bird, its environment, and its daily routine. A change in the routine of any species can often result in maladaptation behavior. Specific infbrmation on the feather picking should then be gathered. The onset, progression, and distribution of the feather picking may provide some valuable clues as to the cause. Feather picking involving the breast, abdomen, and legs has been associated with reproductive frustration during the breeding season (Fig 2). 9 Abnormal-appearing feathers on the top of the bird's head suggests a primary feather disease or feather picking by a cagemate. Another important but difficult dis-
Figure 2. Feather loss as a result of behavioral feather picking on the breast, abdomen, and legs of this scarlet macaw. Note the normal appearing feathers on the head and the presence of pin feathers in the inguinal region. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
tinction to make is whether the feathers were abnormal initially or whether they became abnormal in appearance as a result of the selftrauma. Once a complete dietary and environmental history is obtained and the characteristics of the feather picking have been ascertained, the physical examination can be initiated. T h e goal now is to uncover more clues that may be helpful in determining the cause of the problem. Observe the bird before restraining it, paying close attention to its attitude, posture, and behavior. Describe any feather picking observed. Record all findings in the patient's medical record. This will facilitate case evaluation and retrospective analysis of diagnostic and therapeutic techniques. Isoflurane anesthesia can be used to facilitate examination of the bird and the collection of laboratory samples. However, clients should be made aware of the inherent risks involved with general anesthesia. A complete physical examination should include an evaluation of the eyes, ears, nares, and throat. Included in the oral examination is an examination of the choanal opening and choanal papillae. The choanal slit should be free from excessive mucus or other discharges. The choanal papillae should be sharp. Blunting of the choanal papillae is suggestive of hypovitaminosis A. Inspect the oral cavity for the presence of plaques. Assess body condition as well as the quality of the plumage. Remove a few feathers for closer inspection at another time. Examine the skin. Extend both wings and palpate the patagium. Note the distribution of any missing or broken feathers. Evaluate the involvement of the developing feathers by noting the presence of new feathers as well as their quality and quantity. Extend both legs and closely examine the digits and plantar surface of the feet. Inspect the cloaca everting the cloacal rim examining it for papillomas. Evaluate the uropygial gland if present. Auscult, palpate, and weigh the bird. The feathers can be examined by using a magnifying glass, dissecting microscope, or light microscope. The goal is to determine whether the feathers themselves are abnormal or if the bird is picking at a normal appearing feather. Malformed, dystrophic, or discolored feathers are abnormal as are retained feather sheaths, clubbed feathers, curled feathers, and
A Diagnostic Approach to Feather Picking
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broken feathers. Hemorrhage within the pulp cavity also is abnormal. Feathers that easily fall out, although common in a restrained turaco, may be considered abnormal in some species and can result from dermatitis caused by Mycobacterium species, a~ Feathers that are frayed or broken at the distal ends may have been traumatized (Fig 3). Stress lines are translucent lines across the vane of the feather. These marks can occur as a result of inadequate nutrition, e n v i r o n m e n t a l extremes, or poor health (Fig 4).9 Although uncommon in psittacine birds, feathers should also be examined for evidence of ectoparasitism (Fig 5).11,12 The information obtained during the physical examination plus the information gathered from the minimum database is used to identify the body system or systems affected. In more cases than not, the information will indicate that the integumentary system is involved primarily or secondarily and will rule out the involvement of other body systems.
Figure 4. Translucent mark characteristic of a stress line in a macaw feather. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
Figure 3. Severely damaged distal feathers in a seriema as a result of a heat lamp burn. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.)
The minimum database should include intially a complete blood count (CBC), chemistry panel, fecal flotation and direct smear, and choanal and cloacal gram stains. Additional information can be gathered from choanal and cloacal cultures, choanal and cloacal cytology (Wright's stain), and fecal acid fast stains. This should provide the' clinician with information on the overall health of the bird. If the patient is anesthetized, whole body radiographs can be obtained (this can be performed without anesthesia in some species) and feather and skin biopsy samples can be taken as well. Be sure to include affected developing or pin feathers in the samples collected. Gram's and Wright's stain of the feather pulp and feather pulp cultures may provide useful information (Fig 6). 9 Depending on the clinical presentation and
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Figure 5. Normal barn owl feather on the left and two abnormal feathers on the right. The rachis of the middle feather is mildly damaged from ectoparasites. The rachis of the feather on the right is severely affected and there is hemorrhage within the pulp cavity. (Courtesy of Emily Short and Riverbanks Zoo, Columbia, SC.) the species involved, tests for o t h e r diseases should be considered. This includes but is not limited to Psittacine Beak and Feather Disease (PBFD) p o l y m e r a s e c h a i n r e a c t i o n (PCR), polyomavirus D N A probe, thyroid function evaluation, Giardia Indirect Fluorescent Antibody (IFA) test, bile acids, and a chlamydia titer. T h e thyroid gland as well as the gonads regulate the metabolic processes that result in f e a t h e r formation, la M e a s u r e m e n t o f plasma T S H and t h y r o x i n e concentrations plus perf o r m i n g T R H and T S H stimulation tests are u s e d to d i a g n o s e t h y r o i d d i s o r d e r s . 14"15 I f m o r e i n f o r m a t i o n is necessary to d e t e r m i n e the cause o f the feather condition, endoscopy can be used to c o n f i r m sex and stage o f r e p r o duction as well as evaluate the air sacs and o t h e r internal organs (Table 2). T h e CBC is a useful indicator o f inflammation and may suggest infection as well. An inf l a m m a t o r y l e u k o g r a m is not u n e x p e c t e d in a feather-picking bird, especially if the e x t e n t o f the picking is severe. In the author's experience, eosinophila is not c o m m o n l y observed with external or internal parasites in psittacine birds but can be observed frequently with hemoparasites in raptors. T h e hematocrit and total protein values provide i n f o r m a t i o n o n the overall health a n d hydration status o f the bird. A n e m i a can result f r o m chronic disease. T h e chemistry panel is used to evaluate for liver and kidney disease. It is i m p o r t a n t to note that
m a n y species o f birds have A S T a n d L D H present in liver as well as skeletal muscle. Many feather-picking birds will have a mild elevation in these enzymes secondary to muscle trauma. T h e r e f o r e , it is i m p o r t a n t to measure C P K as well to help differentiate between liver and muscle disease. It is also i m p o r t a n t to r e m e m ber that AST and L D H do not reflect hepatic function. Bile acids should be c o n s i d e r e d if impaired liver function is suspected a f t e r the m i n i m u m database is obtained. Calcium, phosp h o r u s , c a l c i u m - t o - p h o s p h o r u s ratio, total protein, and albumin are evaluated as a reflection of nutritional status. Elevated calcium and alkaline phosphatase can be associated with ovulation and s u b s e q u e n t oviposition. Uric acid can be elevated secondary to renal as well as n o n r e n a l factors. Cloacal and choanal gram stains a n d cultures are used to evaluate the overall health o f the bird. Results must be i n t e r p r e t e d with caution and with knowledge o f n o r m a l flora. Findings should be used to s u p p o r t a diagnosis not make a diagnosis irrespective o f the clinical presentation o f the patient. Similarly, biopsy results should be carefully interpreted. 16 Mild inflammation may occur a r o u n d the f e a t h e r follicle as a r e s u l t o f the s e l f - t r a u m a a n d should not be misinterpreted as the inciting cause. In o r d e r to save the client time a n d money, multiple laboratory samples can be collected
A Diagnostic App~)ach to Feather Picking
d u r i n g the initial visit but submission for laboratory testing can be staggered. This allows the clinical to tailor the diagnostic work-up to each patient. For instance, choanal and cloacal swabs can be obtained and several slides m a d e but left unstained. T h e clinician can later go back and stain the slides as d e e m e d appropriate based on o t h e r information. Swabs can be obtained for culture and held for 24 hours in t r a n s p o r t media until gram stains are evaluated. In larger birds, extra b l o o d can be collected and stored. T h e sample can later be used for additional testing (bile acids, PBFDPCR, chlamydia titer) once the m i n i m u m database has been evaluated. Feces can be saved in saline or formalin for Giardia IFA if the fecal flotation and direct smear are negative, but Giardia remains on the rule out list. Feces can also be collected and later submitted for polyomavirus-specific DNA probes if this disease is on the rule-out list. I f the bird is being anesthetized for the physical examination or sample collection, f e a t h e r and skin biopsies samples can be obtained. Slides o f f e a t h e r pulp can be obtained for later staining if necessary, and swabs o f feather pulp can be held for 24 hours in t r a n s p o r t media before culture. Tissue samples can be placed in formalin and submission p e n d i n g evaluation o f other findings. For example, if PBFD is suspected, blood can be s u b m i t t e d f o r D N A p r o b e testing. T h e Table 2. Diagnostic Approach to the Feather Picker Minimum database: Complete blood count (CBC) Chemistry panel Choanal and cloacal gram stains Fecal flotation and direct smear Additional diagnostic information: Choanal and cloacal cytology Choanal and cloacal culture Whole body radiographs Feather and skin biopsy Feather pulp gram stain, cytology, and culture Giardia 1FA Miscellaneous diagnostic infbrmation Fecal acid fast stain PBFD-PCR Polyomavirus DNA probe Thyroid function evaluation Bile acids Chlamydia titer Endoscopy
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Figure 6. Microphotograph of histological crosssection through an avian feather %llicle. The numerous normal melanin granules can easily be mistaken for bacterial rods when gram stains of feather follicle squash preparations are performed. (Reprinted with permission from Alan M. Fudge, DVM.) PBFD-PCR is a m o r e sensitive test than f e a t h e r biopsies in d i a g n o s i n g the virus. H o w e v e r , false-negatives can occur, iv I f the results are negative and the virus is still suspected, biopsy specimens can later be submitted. In s u m m a r y , the diagnostic a p p r o a c h to feather picking begins by obtaining a complete environmental, nutritional, and behavioral history. T h e overall health o f the bird must then be evaluated. Physical examination o f the int e g u m e n t a r y system as well as the entire bird is p a r a m o u n t to making a diagnosis. Diseases are ruled in or out by p e r f o r m i n g a series of diagnostic tests. B e h a v i o r a l o r psychological feather picking is often diagnosed by a process o f elimination. T h e collection and retrospective evaluation of clinical information may increase proficiency in making a diagnosis. Client education is i m p o r t a n t to client satisfaction. T h e d i f f e r e n t i a l diagnosis o f f e a t h e r picking has been discussed several times in the literature. T h e avian clinician is e n c o u r a g e d to keep abreast of new trends in diagnosis and treatment. 18-21
References 1. Johnson-Delaney C: Feather picking: Diagnosis and treatment. J Assoc Avian Vet 6:82-88, 1992 2. Lennox AM, VanDerHeyden N: Haloperidol for use
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7.
8.
9.
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in treatment of psittacine self-nmtilation and feather plucking. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 119 Worrell AB, Farber WL: The use of acupuncture in the treatment of feather picking in psittacine birds. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 121 Krinsley M: Use of DermCaps Liquid and hydroxyzine hydrochloride for the treatment of feather picking. J Assoc Avian Vet 7:221, 1993 Ramsay EC, Grindlinger H: Use of clomipramine in the treatment of obsessive behavior in psittacine birds. J Assoc Avian Vet 8:9-15, 1994 Turner R: Trexan (naltrexone hydrochloride) use in feather picking in avian species. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 116 Cooper JE, Harrison GJ: Dermatology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 620 Harrison GJ: Perspective on parrot behavior, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 107 Cooper JE, Harrison GJ: Dermatology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application: Lake Worth, FL, Wingers, 1994, p 633 Drew ML, Ramsay EC: Dermatitis associated with Mycobacterium spp. in a blue-fronted amazon parrot. Proceedings of the Association of Avian Veterinarians. Chicago, IL, 1991, pp 252-254
11. Shoshana R: Knemidokoptes mites on feathers of the red-fronted parakeet. J Assoc Avian Vet 7;202, 1993 12. Phillips JR: Avian mites. Comp Cont Ed Pract Vet 15:671, 1993 13. Lumeij JT: Endocrinology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, p 601 14. Lumeij JT: Endocrinology, in Ritchie BW, Harrison GJ, Harrison LR (eds): Avian Medicine: Principles and Application. Lake Worth, FL, Wingers, 1994, pp 594-596 15. Oglesbee BL: Hypothyroidism in a scarlet macaw. J Am Vet Med Assoc 201:1599-1601, 1992 16. Schmidt RE: Use of biopsies in the differential diagnosis of feather picking and avian skin disease. Proceedings of the Association of Avian Veterinarians. Nashville, TN, 1993, p 113 17. Ritchie BW: Personal communication 18. Harris D: Basic avian medicine: Overview of considerations in diagnosing feather problems. J Assoc Avian Vet 1:199, 1987 19. Rosenthal K: Differential diagnosis of feather picking in pet birds. Proceedings of the Association of Avian Veterinarians, Chicago, IL, 1991, p 108 20. Oppenheimer J: Feather picking: Systemic approach. Proceedings of the Association of Avian Veterinarians. Chicago, IL, 1991, pp 314-315 21. Reavill DR, Schmidt RE, Fudge AM: Avian skin and feather disorders: A retrospective study. Proceedings of the Association of Avian Veterinarians, Phoneix, AZ, 1990, p 248-255