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JEPM July 2013—Abstracts
ABSTRACTS
JEPM JULY 2013—ABSTRACTS ___________ Sato J, Sasaki S, Yamada N, et al: Hereditary cerebellar degenerative disease (cerebellar cortical abiotrophy) in rabbits. Vet Path 49 (4):621-628, 2012
reaches adulthood. The same parent rabbits mated again and produced a litter of 6 rabbits (3 males and 3 females), 1 female of which developed similar clinical signs. Pressanti C, Delverdier M, Iriart X, et al: A case of Trichophyton mentagrophytes infection in a fennec fox (Vulpes zerda). Vet Derm 23:456-e87, 2012
Six white rabbit littermates (3 males and 3 females) were examined after 5 of the animals developed ataxia and became emaciated between postnatal days 25 and 31. Beginning on day 10, the affected rabbits progressively lost the ability to stand, and from day 20 onward, they were recumbent, frequently lifted their heads, or thrashed all 4 limbs. Other clinical signs included infrequent opisthotonus and hypertonia, seizures, tension in the hind limbs, and, rarely, nystagmus. A sex predilection was not evident. Between postnatal days 25 and 31, the 5 diseased rabbits and a clinically normal control were euthanized and submitted for necropsy. No gross abnormalities were seen in the cerebrum, cerebellum, medulla oblongata, or spinal cord of any of the affected rabbits. Histopathologically, the width of the molecular layer in the cerebellar vermis was thinner in affected rabbits than in the control. Other lesions included a reduced density of Purkinje cell dendrites and an irregular thickness in their branchlets, a reduced density of granular cells, and scattered apoptotic cells in the granular layer. Electron microscopy confirmed the thinning of the molecular layer and demonstrated a reduced number of both granular cell axons and synaptic junctions between Purkinje and granular cells. The Purkinje cells contained irregular nuclei and cytoplasm with a high electron density, indicating a clumping of organelles. The medulla contained numerous degenerated axon and myelin sheaths. No viral particles were observed when the tissues were evaluated using electron microscopy. The postmortem findings were consistent with cerebellar cortical abiotrophy, a hereditary condition causing nerve function impairment and leading to early-onset, progressive degeneration of the cerebellar cortex. In this condition, no abnormalities are noted at birth (because the cerebellum is not hypoplastic), but degeneration occurs either soon after birth or when the animal
A 2-year-old male fennec fox (Vulpes zerda) presented with a 4-month history of nonpruritic, crusty skin lesions on the forehead, pinnae, and tail tip. Treatment with systemic griseofulvin and topical enilconazole 4 months earlier had resulted in no clinical improvement of the disease condition. On presentation, examination revealed alopecia and moderate erythema of the pinnae and ear margins as well as yellow crusts and large scales overlying exudative skin at the same sites. Similar lesions were seen on the bridge of the nose, around the eyes, and on the tail tip. Results of hematology, biochemical analysis, multiple skin scrapings, a trichoscopic examination, a Wood’s lamp examination, and fungal cultures were negative. Cephalexin was administered orally for 3 weeks with no improvement. The fennec fox was anesthetized, and punch biopsy samples were obtained from the pinnal skin. Histopathologic analysis revealed an interface dermatitis pattern, with lymphocyte infiltration in the basal layer, a significant lymphocytic exocytosis, and occasional apoptotic basal epidermal keratinocytes. A periodic acid Schiff stain did not reveal any fungal elements. One month later, skin biopsies were again collected; this time, the histopathologic evaluation showed a pustular neutrophilic dermatitis with numerous crusts containing arthrospores and fungal hyphae. Results of periodic acid Schiff staining confirmed the presence of fungal elements. A fungal culture of scales and crusts showed a growth after 1 week of Trichophyton mentagrophytes. The diagnosis was confirmed by polymerase chain reaction testing. Based on the recommendation for dogs, a combination systemic and topical treatment protocol was instituted. The fennec fox was treated with itraconazole (5 mg/kg PO q24h) for 6 weeks, and a miconazole and chlorhexidine shampoo was applied on affected
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Journal of Exotic Pet Medicine 22 (2013), pp 310–314
areas once weekly, followed by an enilconazole dip. Clinical improvement was steady, and a fungal culture performed 6 weeks after treatment was negative. Antifungal treatment was discontinued at that time. The fennec fox became icteric and anorexic several days later, and liver failure was confirmed by elevated levels of alanine aminotransferase, alkaline phosphatase, and total bilirubin. Despite supportive care, the fennec fox died. The body was unavailable for necropsy. This is the first report of a Trichophyton infection in a fennec fox, and the authors suspect acute liver failure was associated with itraconazole use. Banzato T, Russo E, Finotti L, et al: Development of a technique for contrast radiographic examination of the gastrointestinal tract in ball pythons (Python regius). Am J Vet Res 73(7):9961001, 2012 The purpose of this study was to develop a technique for contrast radiographic evaluation of the cranial gastrointestinal tract in ball pythons (Python regius). Particular goals were to determine the optimal concentration of contrast medium and the post-contrast times at which radiographic images could be used to describe anatomic features in this snake species. In the first part of the study, 10 cadavers of ball pythons that had died of natural causes were dissected in order to characterize the anatomy and individual variations of the animals’ gastrointestinal tracts. During the second part of the study, 18 healthy client-owned ball pythons, with a mean bodyweight of 1.3 ⫾ 0.4 kg, were fasted for 7 to 10 days prior to radiographic examination. The snakes were assigned to 1 of 3 groups to be given a particular concentration (wt/vol) of barium sulfate contrast medium: 25% (group A), 35% (group B), and 45% (group C). In each group, barium sulfate was dosed at 25 mg/kg bodyweight and delivered through a feeding tube placed in the mouth and down the esophagus. Each unsedated snake was placed in a 6.3-cm diameter radiolucent tube for radiographic examination. A computed radiographic device (Kodak point-of-care CR-360 system, Carestream Health Inc., Rochester, NY USA) was used to obtain dorsoventral radiographs by use of the following settings: 52 to 58 kV (depending on the size of the snake), 300 mA, and 0.02 seconds. No grid was used. Radiographs were taken at 5 minutes and then 1, 2, 3, 6, 9, 12, 24, 48, and 72 hours after the contrast medium was administered. Imaging was discontinued after all contrast medium reached the large intestine. Parameters evaluated were esophageal transit time,
onset of gastric filling, gastric emptying time, onset of small intestine transit (OSIT), small intestine transit time, and onset of large intestine transit. The parameters used to evaluate radiographs for the concentration of contrast medium that provided the best imaging quality included the general distribution of contrast medium (flocculation and segmentation in the small intestine) as well as the visibility of esophageal folds, gastric folds, intestinal villi, the pylorus, and superimposed loops of small intestine. Among the cadavers, gross anatomic features of the esophagus and stomach were consistent, while the gross appearance and topography of the small intestine differed. Radiographically, the esophagus and stomach had a consistent distribution pattern of contrast medium, whereas the radiographic patterns in the small intestine fell into 3 distribution groups, regardless of the concentration of the contrast medium. In distribution pattern 1, the OSIT started at the 5-minute time point, intestinal loops and villi were evident during the entire transit through the small intestine, and there was a clear distinction between the large and small intestine. Distribution pattern 2 also had an OSIT at 5 minutes; however, the outline of intestinal loops from the contrast medium was less evident. Villi could be seen until 24 hours after contrast medium had been administered, and the distinction between the small and large intestine was obvious. With distribution pattern 3, the OSIT started 3 to 6 hours after administration of the contrast medium, intestinal loops or villi were not outlined, and the distinction between the large and small intestine was not obvious. The contrast medium was also completely segmented, and diffuse flocculation was evident. The authors speculated that the 3 different distribution patterns observed in the small intestine could have been a result of intraspecific anatomic differences or the expression of various gastrointestinal digestive phases or morphological changes attributable to each snake’s conditions of captivity. Since there are anatomic and physiologic differences between snake species, the results of this study may only apply to ball pythons. Cook AJ, McCobb EM: Quantifying the shelter rabbit population: an analysis of Massachusetts and Rhode Island animal shelters. J Applied Anim Welfare Sci 15(4):297-312, 2012 The current estimated population of pet rabbits in the United States is 6.2 million, and according to the Human Society of the United States, the American Humane Association, and the House Rabbit Society, rabbits are believed to be the third
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
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most surrendered pet to animal shelters. However, data on the intake, euthanasia, and adoption rates of shelter rabbits have not been previously reported. In this study, the records from 4 companion animal shelters in Massachusetts and Rhode Island were analyzed in order to describe the population dynamics of domestic rabbits in shelters. All shelters were members of their respective state’s federation or coalition of humane societies. Site 1 served Newport County, RI, which has an estimated population of 85,000 people, while site 2 was a smaller shelter located in Providence, RI, a city with an estimated population of 178,000 people. Sites 3 and 4 were large facilities, with 3 and 4 branch shelters, respectively, located in Boston and several Massachusetts suburbs. The records on rabbits surrendered from a 6-year period (January 1, 2005, through December 31, 2010) were examined. A majority (77.26%) of rabbits were surrendered by their caregivers, and 71.11% of the surrendered rabbits were adults (1 to 6 years of age). The most common reasons given for surrender were inability of the caretaker to care for the rabbit or a disinterest in doing so. Both motives may suggest that pet caregivers do not understand and/or are not prepared for the amount of work involved with caring for a pet rabbit. Dissimilar to a major cause of dog and cat surrender to a shelter, behavioral issues were not a common cause for relinquishment of rabbits. At the time of intake, 81.47% of rabbits were unaltered; in contrast, only 54.7% of dogs and 46.8% of cats surrendered to shelters are intact. Why rabbit caregivers fail to have their pets altered is unknown, but could be that they are unaware of the health and behavioral benefits of doing so, want to breed their rabbits, are unable to afford the cost of the procedure, or do not bring their rabbits to a veterinarian. However, the high percentage of sexually intact rabbits may also be due to a lack of veterinarians who feel comfortable spaying or neutering rabbits. A majority (ranging from 78.15% to 91.94%) of rabbits at the 4 sites were there for 3 months or less, which is longer than the median length of stay for cats (15 to 23 days) and dogs (9 to 18 days). More than half (59.32%) the total rabbit population of the 4 shelters was adopted. In some of the cases, use of a foster care system was associated with a decreased euthanasia rate. Rabbit adoption fees ranged from $45.00 (sites 1 and 2) to $60 (site 3) and $55.00 to $75.00 at site 4 (depending on the branch). All fees included spay/ neuter surgery, which was required before adoption at all 4 sites. The authors emphasized that the results of this study could not be generalized to 3 1 2
rabbit shelter population dynamics on a national level. The characteristics analyzed in this study may be quite different at other animal shelters located in other regions of the United States. Diab SS, Uzal FA, Giannitti F, et al: Cerebrospinal nematodiasis outbreak in an urban outdoor aviary of cockatiels (Nymphicus hollandicus) in southern California. J Vet Diagn Invest 24 (5):994-999, 2012 While cerebrospinal nematodiasis (CSN) has been reported in humans as well as several mammalian and more than 90 avian species, reports of CSN in psittacines are rare. This report describes an outbreak of CSN due to Baylisascaris sp. in an outdoor urban aviary in southern California. The aviary had open-top wooden feeders hanging from the side walls approximately 1 m off the ground. Insects, mice, and small rats could enter the aviary through small cracks, although large animals did not have known access to the facility. Over a period of 5 months, 34 of the aviary’s 35 cockatiels (Nymphicus hollandicus) exhibited neurologic signs including ataxia, lateral recumbency, opisthotonus, and torticollis. Thirteen cockatiels of different ages and sexes were submitted for necropsy and diagnostic workup. Significant histopathological lesions were limited to the brain and spinal cord and were predominately degenerative, characterized by multifocal white matter vacuolation, gliosis, axonal swelling, gitter cell infiltration, and mild hemorrhage. In contrast to previous descriptions of CSN in many other avian species, lesions in the cockatiels were only rarely accompanied by mild granulomatous inflammation and mild lymphocytic perivascular cuffing. In 5 of the 13 birds, cross or tangential sections of nematode larvae, morphologically compatible with Baylisascaris sp., were identified, but they were found away from lesion sites and only after examining up to 30 brain sections. Based on the morphological characteristics of the parasite larvae visualized on tissue sections and the epidemiological characteristics of the outbreak, the species considered most likely to be involved was Baylisascaris procyonis. After the initial diagnosis of CSN was made, the aviary’s owner noticed fecal accumulation, suspected to be from raccoons, on the aviary roof. Raccoons were also frequently observed in the neighborhood. Baylisascaris eggs are highly resistant to environmental degradation and can remain viable and potentially infective in soil for many years. In addition, the eggs are sticky and can adhere to animal fur and other objects,
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
including human fingers, which has implications for zoonotic disease. In this case, it was speculated that the soil, feed, or open-top food bowls may have been contaminated with Baylisascaris spp. Alternatively, eggs could have been carried into the aviary by small rodents or insects, or the soil may have been contaminated with Baylisascaris eggs before the aviary was built. In cases where nematode larvae are not visualized in brain tissue, the presence of malacia and Wallerian degeneration in the white matter of the brainstem and cerebellum of birds with a history of neurologic signs as well as the presence of raccoons in the area are highly suggestive of CSN. In these cases, a recently described polymerase chain reaction assay for the detection of B. procyonis eggs and larvae from fecal, environmental, and tissue samples would help confirm a diagnosis. Petritz OA, Antinoff N, Chen S, et al: Evaluation of portable blood glucose meters for measurement of blood glucose concentration in ferrets (Mustela putorius furo). J Am Vet Med Assoc 242(3):350-354, 2013 The purpose of this study was to evaluate the agreement of 3 commercially available models of portable blood glucose meters (PBGM) with a laboratory analyzer reference standard for the measurement of blood glucose (BG) concentrations in ferrets (Mustela putorius furo). One PBGM was designed for veterinary use (AlphaTrak, Abbott Laboratories, Abbott Park, IL USA) and had separate settings for canine or feline samples; 2 PBGMs of the same model were tested for the study’s duration— one programmed to a canine setting (ATC) and the other programmed to a feline setting (ATF). The 2 PBGMs designed for use with human samples were the One Touch Ultra 2 (OTU) (Life Scan Inc., Milpitas, CA USA), and the AccuChek Aviva (ACA) (Roche Diagnostics, Indianapolis, IN USA). The OTU and Alpha Trak used a colorimetric methodology while the ACA used an amperometric methodology to measure BG concentrations; the laboratory analyzer used a hexokinase reaction. Fifty-two client-owned ferrets were used in this prospective study performed between June 21, 2010 and March 8, 2011. Blood was collected from each ferret by accessing the jugular, lateral saphenous, or cephalic vein. One drop of whole blood from each sample was immediately placed on the test strip of each PBGM, while the remainder of the blood sample was centrifuged and the plasma harvested for BG measurement with the laboratory analyzer. Plasma glucose concentrations measured with the laboratory analyzer ranged from 41 to 160 mg/dL.
BG concentrations measured with the ATC agreed most closely with the laboratory analyzer values (mean bias, 1.9 mg/dL), while those from the ACA had the least agreement (mean bias, 34.0). Results from the ATF and OTU were also significantly different from those obtained by the laboratory analyzer. The ACA, OTU, and ATF significantly underestimated BG concentrations, while the ATC significantly overestimated the levels. In human medicine, the current standard is that BG measurements obtained from a PBGM should not vary by more than 15% from the laboratory reference value. Results for the ATF, OTU, and ACA often differed from the laboratory analyzer values by more than 15%. Although the ATC and ATF had the least amount of bias, these were the only meters to misclassify samples deemed to be hypoglycemic (on the basis of results, ranging from 66 to 69 mg/dL from the laboratory analyzer) as being euglycemic. If sample evaluation had not been repeated using the laboratory analyzer, treatment for these patients may have been delayed based on PBGM test results. There was no significant difference between results for the peripheral and central blood samples for any of the PBGMs or laboratory analyzer. The results indicated that BG concentrations should be confirmed by using a validated laboratory analyzer prior to making treatment recommendations for ferrets. Hawkins MG, Malka S, Pascoe PJ, et al: Evaluation of the effects of dorsal versus lateral recumbency on the cardiopulmonary system during anesthesia with isoflurane in red-tailed hawks (Buteo jamaicensis). Am J Vet Res 74 (1):136-143, 2013 It has been hypothesized that the internal organs of birds anesthetized in dorsal recumbency could compress the lungs and air sacs, resulting in hypoventilation and hypoxemia that might worsen with increasing duration of anesthesia. The purpose of this study was to evaluate the effects of dorsal vs lateral recumbency on the cardiopulmonary system during isoflurane anesthesia in red-tailed hawks (Buteo jamaicensis). Six healthy adult red-tailed hawks, weighing 1.1 to 1.6 kg, were used in the study. The effects of isoflurane anesthesia with the bird in right lateral recumbency and in dorsal recumbency were compared by subjecting all birds to both forms of treatment in a randomized, crossover study design. Throughout a 75-minute anesthesia period, measurements of the following parameters were recorded: respiratory rate, tidal volume, minute ventilation, heart rate, mean arterial and indirect blood pressures, end tidal PCO2 (measured every 5
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
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minutes); and PaCO2, PaO2, and arterial pH (measured every 15 minutes). The respiratory and heart rates were higher, the tidal volume was lower, and the minute ventilation did not differ in birds in lateral vs dorsal recumbency. Positioning did not affect the mean arterial or indirect blood pressure. While the birds hypoventilated in both lateral and dorsal recumbency, the PCO2 in birds in dorsal recumbency steadily increased by 8 Torr, while it remained relatively constant in birds in lateral recumbency. The end tidal PCO2 for birds in dorsal recumbency was lower for the first 10 minutes then steadily increased over the study period, while the end tidal PCO2 of birds in lateral recumbency started higher and stayed relatively steady. The PaO2 was 32 Torr greater in birds in dorsal vs lateral recumbency. Birds had respiratory acidosis in both positions, but there was no significant difference in arterial pH between positions or over time. The study’s results refuted the hypothesis that dorsal recumbency compromises ventilation and oxygen transport more than lateral recumbency in red-tailed hawks. Hess LR, Ravich ML, Reavill DR: Diagnosis and treatment of an insulinoma in a guinea pig (Cavia porcellus). J Am Vet Med Assoc 242(4): 522-526, 2013 A 5-year-old male guinea pig (Cavia porcellus) was examined because of lethargy, weight loss, and recurrent episodes of paddling in lateral recumbency. The animal had previously been diagnosed with hypoglycemia at an emergency clinic and treated with dextrose-supplemented intravenous fluids. Other treatments had included an unknown dosage of sulfadimethoxazole and the owner feeding corn syrup when the animal seemed lethargic. During the initial examination, the guinea pig was responsive and eating well but was lethargic with a depressed mentation. The animal had a thin body condition and exhibited mild torticollis and circling behavior. Radiography revealed moderate thickening and sclerosis of both tympanic bullae, consistent with chronic otitis media and interna. Results of serum biochemical analysis showed hypoglycemia (45 mg/dL; reference range 89 to 287 mg/dL), and additional blood was collected to measure the insulin concentration. The guinea pig was given 1 mL of a 50% dextrose solution orally, and the owner was instructed to feed a hand-feeding formula meant for herbivores. The blood insulin
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level was markedly elevated (41440 mpol/L [4201 μU/L]; no reported values for guinea pigs) with concurrent hypoglycemia (0.6 mmol/L [11 mg/dL]), resulting in an elevated insulin-toglucose ratio (42400 pmol/mmol; no reported values for guinea pigs). The presumptive diagnosis was insulinoma. Abdominal ultrasonography revealed mild hepatomegaly with no parenchymal changes, a normal-sized pancreas, and no obvious hepatic or pancreatic nodules. Treatment with diazoxide was started (5 mg/kg orally, twice a day), and a blood glucose curve was measured 7 days later. Blood glucose concentrations evaluated with a portable blood glucose meter (AlphaTrak, Abbott Laboratories, North Chicago, IL USA) showed persistent hypoglycemia (33 to 46 mg/dL) in spite of increased dosages of diazoxide (up to 15 mg/kg orally, twice a day). The diazoxide dose was subsequently increased to 25 mg/kg orally, twice a day. A blood glucose curve measured 12 days later demonstrated blood glucose levels consistently within the reference range (85 to 152 mg/dL). The animal did very well for 3 weeks on the higher dose of diazoxide until presenting for abdominal distension and gastrointestinal stasis. Despite supportive care, the animal was found dead the following day. Necropsy revealed gas distension of the stomach, cecum, and colon. Intestinal loops were adhered to each other and adjacent to a 1- 1cm mass in the pancreas. Histologic evaluation identified a pancreatic islet cell tumor (insulinoma) and vacuolar hepatopathy, the latter being consistent with abnormalities of glucose metabolism. A definitive cause of death remained unknown. To the authors’ knowledge, this is the first report of premortem diagnosis and treatment of an insulinoma in a guinea pig. Although the authors recommended that diazoxide treatment be studied further in this species, this case showed that administration of diazoxide in addition to frequent feeding of meals containing complex carbohydrates can improve the quality of life in guinea pigs with hypoglycemia resulting from insulinoma. CONNIE ORCUTT, DVM, Dip. ABVP (Avian and Exotic Companion Mammals), Associate Editor Putnam Veterinary Clinic, 70 Centre Street, Brookline, MA 02446, USA r 2013 Published by Elsevier Inc. 1557-5063/13/2101-$30.00 http://dx.doi.org/10.1053/j.jepm.2013.08.005
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
JEPM JULY 2013—ABSTRACTS ___________ Sato J, Sasaki S, Yamada N, et al: Hereditary cerebellar degenerative disease (cerebellar cortical abiotrophy) in rabbits. Vet Path 49 (4):621-628, 2012
reaches adulthood. The same parent rabbits mated again and produced a litter of 6 rabbits (3 males and 3 females), 1 female of which developed similar clinical signs. Pressanti C, Delverdier M, Iriart X, et al: A case of Trichophyton mentagrophytes infection in a fennec fox (Vulpes zerda). Vet Derm 23:456-e87, 2012
Six white rabbit littermates (3 males and 3 females) were examined after 5 of the animals developed ataxia and became emaciated between postnatal days 25 and 31. Beginning on day 10, the affected rabbits progressively lost the ability to stand, and from day 20 onward, they were recumbent, frequently lifted their heads, or thrashed all 4 limbs. Other clinical signs included infrequent opisthotonus and hypertonia, seizures, tension in the hind limbs, and, rarely, nystagmus. A sex predilection was not evident. Between postnatal days 25 and 31, the 5 diseased rabbits and a clinically normal control were euthanized and submitted for necropsy. No gross abnormalities were seen in the cerebrum, cerebellum, medulla oblongata, or spinal cord of any of the affected rabbits. Histopathologically, the width of the molecular layer in the cerebellar vermis was thinner in affected rabbits than in the control. Other lesions included a reduced density of Purkinje cell dendrites and an irregular thickness in their branchlets, a reduced density of granular cells, and scattered apoptotic cells in the granular layer. Electron microscopy confirmed the thinning of the molecular layer and demonstrated a reduced number of both granular cell axons and synaptic junctions between Purkinje and granular cells. The Purkinje cells contained irregular nuclei and cytoplasm with a high electron density, indicating a clumping of organelles. The medulla contained numerous degenerated axon and myelin sheaths. No viral particles were observed when the tissues were evaluated using electron microscopy. The postmortem findings were consistent with cerebellar cortical abiotrophy, a hereditary condition causing nerve function impairment and leading to early-onset, progressive degeneration of the cerebellar cortex. In this condition, no abnormalities are noted at birth (because the cerebellum is not hypoplastic), but degeneration occurs either soon after birth or when the animal
A 2-year-old male fennec fox (Vulpes zerda) presented with a 4-month history of nonpruritic, crusty skin lesions on the forehead, pinnae, and tail tip. Treatment with systemic griseofulvin and topical enilconazole 4 months earlier had resulted in no clinical improvement of the disease condition. On presentation, examination revealed alopecia and moderate erythema of the pinnae and ear margins as well as yellow crusts and large scales overlying exudative skin at the same sites. Similar lesions were seen on the bridge of the nose, around the eyes, and on the tail tip. Results of hematology, biochemical analysis, multiple skin scrapings, a trichoscopic examination, a Wood’s lamp examination, and fungal cultures were negative. Cephalexin was administered orally for 3 weeks with no improvement. The fennec fox was anesthetized, and punch biopsy samples were obtained from the pinnal skin. Histopathologic analysis revealed an interface dermatitis pattern, with lymphocyte infiltration in the basal layer, a significant lymphocytic exocytosis, and occasional apoptotic basal epidermal keratinocytes. A periodic acid Schiff stain did not reveal any fungal elements. One month later, skin biopsies were again collected; this time, the histopathologic evaluation showed a pustular neutrophilic dermatitis with numerous crusts containing arthrospores and fungal hyphae. Results of periodic acid Schiff staining confirmed the presence of fungal elements. A fungal culture of scales and crusts showed a growth after 1 week of Trichophyton mentagrophytes. The diagnosis was confirmed by polymerase chain reaction testing. Based on the recommendation for dogs, a combination systemic and topical treatment protocol was instituted. The fennec fox was treated with itraconazole (5 mg/kg PO q24h) for 6 weeks, and a miconazole and chlorhexidine shampoo was applied on affected
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Journal of Exotic Pet Medicine 22 (2013), pp 310–314
areas once weekly, followed by an enilconazole dip. Clinical improvement was steady, and a fungal culture performed 6 weeks after treatment was negative. Antifungal treatment was discontinued at that time. The fennec fox became icteric and anorexic several days later, and liver failure was confirmed by elevated levels of alanine aminotransferase, alkaline phosphatase, and total bilirubin. Despite supportive care, the fennec fox died. The body was unavailable for necropsy. This is the first report of a Trichophyton infection in a fennec fox, and the authors suspect acute liver failure was associated with itraconazole use. Banzato T, Russo E, Finotti L, et al: Development of a technique for contrast radiographic examination of the gastrointestinal tract in ball pythons (Python regius). Am J Vet Res 73(7):9961001, 2012 The purpose of this study was to develop a technique for contrast radiographic evaluation of the cranial gastrointestinal tract in ball pythons (Python regius). Particular goals were to determine the optimal concentration of contrast medium and the post-contrast times at which radiographic images could be used to describe anatomic features in this snake species. In the first part of the study, 10 cadavers of ball pythons that had died of natural causes were dissected in order to characterize the anatomy and individual variations of the animals’ gastrointestinal tracts. During the second part of the study, 18 healthy client-owned ball pythons, with a mean bodyweight of 1.3 ⫾ 0.4 kg, were fasted for 7 to 10 days prior to radiographic examination. The snakes were assigned to 1 of 3 groups to be given a particular concentration (wt/vol) of barium sulfate contrast medium: 25% (group A), 35% (group B), and 45% (group C). In each group, barium sulfate was dosed at 25 mg/kg bodyweight and delivered through a feeding tube placed in the mouth and down the esophagus. Each unsedated snake was placed in a 6.3-cm diameter radiolucent tube for radiographic examination. A computed radiographic device (Kodak point-of-care CR-360 system, Carestream Health Inc., Rochester, NY USA) was used to obtain dorsoventral radiographs by use of the following settings: 52 to 58 kV (depending on the size of the snake), 300 mA, and 0.02 seconds. No grid was used. Radiographs were taken at 5 minutes and then 1, 2, 3, 6, 9, 12, 24, 48, and 72 hours after the contrast medium was administered. Imaging was discontinued after all contrast medium reached the large intestine. Parameters evaluated were esophageal transit time,
onset of gastric filling, gastric emptying time, onset of small intestine transit (OSIT), small intestine transit time, and onset of large intestine transit. The parameters used to evaluate radiographs for the concentration of contrast medium that provided the best imaging quality included the general distribution of contrast medium (flocculation and segmentation in the small intestine) as well as the visibility of esophageal folds, gastric folds, intestinal villi, the pylorus, and superimposed loops of small intestine. Among the cadavers, gross anatomic features of the esophagus and stomach were consistent, while the gross appearance and topography of the small intestine differed. Radiographically, the esophagus and stomach had a consistent distribution pattern of contrast medium, whereas the radiographic patterns in the small intestine fell into 3 distribution groups, regardless of the concentration of the contrast medium. In distribution pattern 1, the OSIT started at the 5-minute time point, intestinal loops and villi were evident during the entire transit through the small intestine, and there was a clear distinction between the large and small intestine. Distribution pattern 2 also had an OSIT at 5 minutes; however, the outline of intestinal loops from the contrast medium was less evident. Villi could be seen until 24 hours after contrast medium had been administered, and the distinction between the small and large intestine was obvious. With distribution pattern 3, the OSIT started 3 to 6 hours after administration of the contrast medium, intestinal loops or villi were not outlined, and the distinction between the large and small intestine was not obvious. The contrast medium was also completely segmented, and diffuse flocculation was evident. The authors speculated that the 3 different distribution patterns observed in the small intestine could have been a result of intraspecific anatomic differences or the expression of various gastrointestinal digestive phases or morphological changes attributable to each snake’s conditions of captivity. Since there are anatomic and physiologic differences between snake species, the results of this study may only apply to ball pythons. Cook AJ, McCobb EM: Quantifying the shelter rabbit population: an analysis of Massachusetts and Rhode Island animal shelters. J Applied Anim Welfare Sci 15(4):297-312, 2012 The current estimated population of pet rabbits in the United States is 6.2 million, and according to the Human Society of the United States, the American Humane Association, and the House Rabbit Society, rabbits are believed to be the third
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
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most surrendered pet to animal shelters. However, data on the intake, euthanasia, and adoption rates of shelter rabbits have not been previously reported. In this study, the records from 4 companion animal shelters in Massachusetts and Rhode Island were analyzed in order to describe the population dynamics of domestic rabbits in shelters. All shelters were members of their respective state’s federation or coalition of humane societies. Site 1 served Newport County, RI, which has an estimated population of 85,000 people, while site 2 was a smaller shelter located in Providence, RI, a city with an estimated population of 178,000 people. Sites 3 and 4 were large facilities, with 3 and 4 branch shelters, respectively, located in Boston and several Massachusetts suburbs. The records on rabbits surrendered from a 6-year period (January 1, 2005, through December 31, 2010) were examined. A majority (77.26%) of rabbits were surrendered by their caregivers, and 71.11% of the surrendered rabbits were adults (1 to 6 years of age). The most common reasons given for surrender were inability of the caretaker to care for the rabbit or a disinterest in doing so. Both motives may suggest that pet caregivers do not understand and/or are not prepared for the amount of work involved with caring for a pet rabbit. Dissimilar to a major cause of dog and cat surrender to a shelter, behavioral issues were not a common cause for relinquishment of rabbits. At the time of intake, 81.47% of rabbits were unaltered; in contrast, only 54.7% of dogs and 46.8% of cats surrendered to shelters are intact. Why rabbit caregivers fail to have their pets altered is unknown, but could be that they are unaware of the health and behavioral benefits of doing so, want to breed their rabbits, are unable to afford the cost of the procedure, or do not bring their rabbits to a veterinarian. However, the high percentage of sexually intact rabbits may also be due to a lack of veterinarians who feel comfortable spaying or neutering rabbits. A majority (ranging from 78.15% to 91.94%) of rabbits at the 4 sites were there for 3 months or less, which is longer than the median length of stay for cats (15 to 23 days) and dogs (9 to 18 days). More than half (59.32%) the total rabbit population of the 4 shelters was adopted. In some of the cases, use of a foster care system was associated with a decreased euthanasia rate. Rabbit adoption fees ranged from $45.00 (sites 1 and 2) to $60 (site 3) and $55.00 to $75.00 at site 4 (depending on the branch). All fees included spay/ neuter surgery, which was required before adoption at all 4 sites. The authors emphasized that the results of this study could not be generalized to 3 1 2
rabbit shelter population dynamics on a national level. The characteristics analyzed in this study may be quite different at other animal shelters located in other regions of the United States. Diab SS, Uzal FA, Giannitti F, et al: Cerebrospinal nematodiasis outbreak in an urban outdoor aviary of cockatiels (Nymphicus hollandicus) in southern California. J Vet Diagn Invest 24 (5):994-999, 2012 While cerebrospinal nematodiasis (CSN) has been reported in humans as well as several mammalian and more than 90 avian species, reports of CSN in psittacines are rare. This report describes an outbreak of CSN due to Baylisascaris sp. in an outdoor urban aviary in southern California. The aviary had open-top wooden feeders hanging from the side walls approximately 1 m off the ground. Insects, mice, and small rats could enter the aviary through small cracks, although large animals did not have known access to the facility. Over a period of 5 months, 34 of the aviary’s 35 cockatiels (Nymphicus hollandicus) exhibited neurologic signs including ataxia, lateral recumbency, opisthotonus, and torticollis. Thirteen cockatiels of different ages and sexes were submitted for necropsy and diagnostic workup. Significant histopathological lesions were limited to the brain and spinal cord and were predominately degenerative, characterized by multifocal white matter vacuolation, gliosis, axonal swelling, gitter cell infiltration, and mild hemorrhage. In contrast to previous descriptions of CSN in many other avian species, lesions in the cockatiels were only rarely accompanied by mild granulomatous inflammation and mild lymphocytic perivascular cuffing. In 5 of the 13 birds, cross or tangential sections of nematode larvae, morphologically compatible with Baylisascaris sp., were identified, but they were found away from lesion sites and only after examining up to 30 brain sections. Based on the morphological characteristics of the parasite larvae visualized on tissue sections and the epidemiological characteristics of the outbreak, the species considered most likely to be involved was Baylisascaris procyonis. After the initial diagnosis of CSN was made, the aviary’s owner noticed fecal accumulation, suspected to be from raccoons, on the aviary roof. Raccoons were also frequently observed in the neighborhood. Baylisascaris eggs are highly resistant to environmental degradation and can remain viable and potentially infective in soil for many years. In addition, the eggs are sticky and can adhere to animal fur and other objects,
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
including human fingers, which has implications for zoonotic disease. In this case, it was speculated that the soil, feed, or open-top food bowls may have been contaminated with Baylisascaris spp. Alternatively, eggs could have been carried into the aviary by small rodents or insects, or the soil may have been contaminated with Baylisascaris eggs before the aviary was built. In cases where nematode larvae are not visualized in brain tissue, the presence of malacia and Wallerian degeneration in the white matter of the brainstem and cerebellum of birds with a history of neurologic signs as well as the presence of raccoons in the area are highly suggestive of CSN. In these cases, a recently described polymerase chain reaction assay for the detection of B. procyonis eggs and larvae from fecal, environmental, and tissue samples would help confirm a diagnosis. Petritz OA, Antinoff N, Chen S, et al: Evaluation of portable blood glucose meters for measurement of blood glucose concentration in ferrets (Mustela putorius furo). J Am Vet Med Assoc 242(3):350-354, 2013 The purpose of this study was to evaluate the agreement of 3 commercially available models of portable blood glucose meters (PBGM) with a laboratory analyzer reference standard for the measurement of blood glucose (BG) concentrations in ferrets (Mustela putorius furo). One PBGM was designed for veterinary use (AlphaTrak, Abbott Laboratories, Abbott Park, IL USA) and had separate settings for canine or feline samples; 2 PBGMs of the same model were tested for the study’s duration— one programmed to a canine setting (ATC) and the other programmed to a feline setting (ATF). The 2 PBGMs designed for use with human samples were the One Touch Ultra 2 (OTU) (Life Scan Inc., Milpitas, CA USA), and the AccuChek Aviva (ACA) (Roche Diagnostics, Indianapolis, IN USA). The OTU and Alpha Trak used a colorimetric methodology while the ACA used an amperometric methodology to measure BG concentrations; the laboratory analyzer used a hexokinase reaction. Fifty-two client-owned ferrets were used in this prospective study performed between June 21, 2010 and March 8, 2011. Blood was collected from each ferret by accessing the jugular, lateral saphenous, or cephalic vein. One drop of whole blood from each sample was immediately placed on the test strip of each PBGM, while the remainder of the blood sample was centrifuged and the plasma harvested for BG measurement with the laboratory analyzer. Plasma glucose concentrations measured with the laboratory analyzer ranged from 41 to 160 mg/dL.
BG concentrations measured with the ATC agreed most closely with the laboratory analyzer values (mean bias, 1.9 mg/dL), while those from the ACA had the least agreement (mean bias, 34.0). Results from the ATF and OTU were also significantly different from those obtained by the laboratory analyzer. The ACA, OTU, and ATF significantly underestimated BG concentrations, while the ATC significantly overestimated the levels. In human medicine, the current standard is that BG measurements obtained from a PBGM should not vary by more than 15% from the laboratory reference value. Results for the ATF, OTU, and ACA often differed from the laboratory analyzer values by more than 15%. Although the ATC and ATF had the least amount of bias, these were the only meters to misclassify samples deemed to be hypoglycemic (on the basis of results, ranging from 66 to 69 mg/dL from the laboratory analyzer) as being euglycemic. If sample evaluation had not been repeated using the laboratory analyzer, treatment for these patients may have been delayed based on PBGM test results. There was no significant difference between results for the peripheral and central blood samples for any of the PBGMs or laboratory analyzer. The results indicated that BG concentrations should be confirmed by using a validated laboratory analyzer prior to making treatment recommendations for ferrets. Hawkins MG, Malka S, Pascoe PJ, et al: Evaluation of the effects of dorsal versus lateral recumbency on the cardiopulmonary system during anesthesia with isoflurane in red-tailed hawks (Buteo jamaicensis). Am J Vet Res 74 (1):136-143, 2013 It has been hypothesized that the internal organs of birds anesthetized in dorsal recumbency could compress the lungs and air sacs, resulting in hypoventilation and hypoxemia that might worsen with increasing duration of anesthesia. The purpose of this study was to evaluate the effects of dorsal vs lateral recumbency on the cardiopulmonary system during isoflurane anesthesia in red-tailed hawks (Buteo jamaicensis). Six healthy adult red-tailed hawks, weighing 1.1 to 1.6 kg, were used in the study. The effects of isoflurane anesthesia with the bird in right lateral recumbency and in dorsal recumbency were compared by subjecting all birds to both forms of treatment in a randomized, crossover study design. Throughout a 75-minute anesthesia period, measurements of the following parameters were recorded: respiratory rate, tidal volume, minute ventilation, heart rate, mean arterial and indirect blood pressures, end tidal PCO2 (measured every 5
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314
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minutes); and PaCO2, PaO2, and arterial pH (measured every 15 minutes). The respiratory and heart rates were higher, the tidal volume was lower, and the minute ventilation did not differ in birds in lateral vs dorsal recumbency. Positioning did not affect the mean arterial or indirect blood pressure. While the birds hypoventilated in both lateral and dorsal recumbency, the PCO2 in birds in dorsal recumbency steadily increased by 8 Torr, while it remained relatively constant in birds in lateral recumbency. The end tidal PCO2 for birds in dorsal recumbency was lower for the first 10 minutes then steadily increased over the study period, while the end tidal PCO2 of birds in lateral recumbency started higher and stayed relatively steady. The PaO2 was 32 Torr greater in birds in dorsal vs lateral recumbency. Birds had respiratory acidosis in both positions, but there was no significant difference in arterial pH between positions or over time. The study’s results refuted the hypothesis that dorsal recumbency compromises ventilation and oxygen transport more than lateral recumbency in red-tailed hawks. Hess LR, Ravich ML, Reavill DR: Diagnosis and treatment of an insulinoma in a guinea pig (Cavia porcellus). J Am Vet Med Assoc 242(4): 522-526, 2013 A 5-year-old male guinea pig (Cavia porcellus) was examined because of lethargy, weight loss, and recurrent episodes of paddling in lateral recumbency. The animal had previously been diagnosed with hypoglycemia at an emergency clinic and treated with dextrose-supplemented intravenous fluids. Other treatments had included an unknown dosage of sulfadimethoxazole and the owner feeding corn syrup when the animal seemed lethargic. During the initial examination, the guinea pig was responsive and eating well but was lethargic with a depressed mentation. The animal had a thin body condition and exhibited mild torticollis and circling behavior. Radiography revealed moderate thickening and sclerosis of both tympanic bullae, consistent with chronic otitis media and interna. Results of serum biochemical analysis showed hypoglycemia (45 mg/dL; reference range 89 to 287 mg/dL), and additional blood was collected to measure the insulin concentration. The guinea pig was given 1 mL of a 50% dextrose solution orally, and the owner was instructed to feed a hand-feeding formula meant for herbivores. The blood insulin
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level was markedly elevated (41440 mpol/L [4201 μU/L]; no reported values for guinea pigs) with concurrent hypoglycemia (0.6 mmol/L [11 mg/dL]), resulting in an elevated insulin-toglucose ratio (42400 pmol/mmol; no reported values for guinea pigs). The presumptive diagnosis was insulinoma. Abdominal ultrasonography revealed mild hepatomegaly with no parenchymal changes, a normal-sized pancreas, and no obvious hepatic or pancreatic nodules. Treatment with diazoxide was started (5 mg/kg orally, twice a day), and a blood glucose curve was measured 7 days later. Blood glucose concentrations evaluated with a portable blood glucose meter (AlphaTrak, Abbott Laboratories, North Chicago, IL USA) showed persistent hypoglycemia (33 to 46 mg/dL) in spite of increased dosages of diazoxide (up to 15 mg/kg orally, twice a day). The diazoxide dose was subsequently increased to 25 mg/kg orally, twice a day. A blood glucose curve measured 12 days later demonstrated blood glucose levels consistently within the reference range (85 to 152 mg/dL). The animal did very well for 3 weeks on the higher dose of diazoxide until presenting for abdominal distension and gastrointestinal stasis. Despite supportive care, the animal was found dead the following day. Necropsy revealed gas distension of the stomach, cecum, and colon. Intestinal loops were adhered to each other and adjacent to a 1- 1cm mass in the pancreas. Histologic evaluation identified a pancreatic islet cell tumor (insulinoma) and vacuolar hepatopathy, the latter being consistent with abnormalities of glucose metabolism. A definitive cause of death remained unknown. To the authors’ knowledge, this is the first report of premortem diagnosis and treatment of an insulinoma in a guinea pig. Although the authors recommended that diazoxide treatment be studied further in this species, this case showed that administration of diazoxide in addition to frequent feeding of meals containing complex carbohydrates can improve the quality of life in guinea pigs with hypoglycemia resulting from insulinoma. CONNIE ORCUTT, DVM, Dip. ABVP (Avian and Exotic Companion Mammals), Associate Editor Putnam Veterinary Clinic, 70 Centre Street, Brookline, MA 02446, USA r 2013 Published by Elsevier Inc. 1557-5063/13/2101-$30.00 http://dx.doi.org/10.1053/j.jepm.2013.08.005
Abstracts/Journal of Exotic Pet Medicine 22 (2013), pp 310–314