Diagnosis and management of atypical hypoadrenocorticism in a variable flying fox (Pteropus hypomelanus).

A 19-yr-old intact female variable flying fox (Pteropus hypomelanus) presented with lethargy, behavior changes, and substantial weight loss. Initial clinical pathology revealed hypoglycemia and reduced ionized serum calcium, and imaging, including computed tomography, did not lead to a diagnosis. An adrenocorticotropic hormone (ACTH) stimulation test revealed baseline and post-ACTH cortisol concentrations that were lower than reported normal baseline cortisol concentrations in this species. Treatment with prednisolone resolved the clinical signs and laboratory abnormalities. Repeated attempts to decrease the prednisolone dose caused recurrence of clinical signs and weight loss. Based on diagnostic test results and response to therapy, a diagnosis of atypical hypoadrenocorticism was made.

Comparison of osmolality and refractometric readings of Hispaniolan Amazon parrot (Amazona ventralis) urine.

To evaluate the relationship between osmolality and specific gravity of urine samples from clinically normal adult parrots and to determine a formula to convert urine specific gravity (USG) measured on a reference scale to a more accurate USG value for an avian species, urine samples were collected opportunistically from a colony of Hispaniolan Amazon parrots (Amazona ventralis). Samples were analyzed by using a veterinary refractometer, and specific gravity was measured on both canine and feline scales. Osmolality was measured by vapor pressure osmometry. Specific gravity and osmolality measurements were highly correlated (r = 0.96). The linear relationship between refractivity measurements on a reference scale and osmolality was determined. An equation was calculated to allow specific gravity results from a medical refractometer to be converted to specific gravity values of Hispaniolan Amazon parrots: USGHAp = 0.201 +0.798(USGref). Use of the reference-canine scale to approximate the osmolality of parrot urine leads to an overestimation of the true osmolality of the sample. In addition, this error increases as the concentration of urine increases. Compared with the human-canine scale, the feline scale provides a closer approximation to urine osmolality of Hispaniolan Amazon parrots but still results in overestimation of osmolality.

Estimates of the pharmacokinetics of famciclovir and its active metabolite penciclovir in young Asian elephants (Elephas maximus).

OBJECTIVE: To determine plasma pharmacokinetics of penciclovir following oral and rectal administration of famciclovir to young Asian elephants (Elephas maximus). ANIMALS: 6 healthy Asian elephants (5 females and 1 male), 4.5 to 9 years old and weighing 1,646 to 2,438 kg. PROCEDURES: Famciclovir was administered orally or rectally in accordance with an incomplete crossover design. Three treatment groups, each comprising 4 elephants, received single doses of famciclovir (5 mg/kg, PO, or 5 or 15 mg/kg, rectally); there was a minimum 12-week washout period between subsequent famciclovir administrations. Serial blood samples were collected after each administration. Samples were analyzed for famciclovir and penciclovir with a validated liquid chromatography-mass spectroscopy assay. RESULTS: Famciclovir was tolerated well for both routes of administration and underwent complete biotransformation to the active metabolite, penciclovir. Mean maximum plasma concentration of penciclovir was 1.3 µg/mL at 1.1 hours after oral administration of 5 mg/kg. Similar results were detected after rectal administration of 5 mg/kg. Mean maximum plasma concentration was 3.6 µg/mL at 0.66 hours after rectal administration of 15 mg/kg; this concentration was similar to results reported for humans receiving 7 mg/kg orally. CONCLUSIONS AND CLINICAL RELEVANCE: Juvenile Asian elephants are susceptible to elephant endotheliotropic herpesvirus. Although most infections are fatal, case reports indicate administration of famciclovir has been associated with survival of 3 elephants. In Asian elephants, a dose of 8 to 15 mg of famciclovir/kg given orally or rectally at least every 8 hours may result in penciclovir concentrations that are considered therapeutic in humans.