Idiopathic hemorrhagic vasculopathy syndrome in seven black rhinoceros.

Idiopathic hemorrhagic vasculopathy syndrome (IHVS) was diagnosed in 7 black rhinoceros; this newly described syndrome is characterized by severe body swelling in conjunction with a rapid and profound decrease in Hct. The disorder may be acute or chronic, may recur, and is potentially fatal. Five of the rhinoceros survived an initial episode of IHVS, and 2 of these 5 survived a recurrent episode of IHVS. Two rhinoceros died during treatment of IHVS. Treatment protocols varied, but all 7 rhinoceros received broad-spectrum antibiotics, because an infectious cause was suspected. All rhinoceros also received nonsteroidal antiinflammatory drugs and supportive care. Idiopathic hemorrhagic vasculopathy syndrome has many similarities to other vasculopathies of domestic animals, such as equine purpura hemorrhagica, but it also appears to have unique identifying features. It has been hypothesized that IHVS may be an immune response to an as yet unidentified infectious agent. Thorough and extensive testing has not identified the potential causative agent, nor the factors that predispose some black rhinoceros to developing IHVS. Further research into the rhinoceros immune system is ongoing and should help elucidate the mechanisms through which IHVS develops.

Presumptive dirofilariasis in a pale-headed saki monkey (Pithecia pithecia).

A 6-yr-old male pale-headed saki monkey (Pithecia pithecia), born at the Dallas Zoo, reentered the collection in 1994 after it was housed for 4 yr in Rhode Island and 2 yr in Florida. The monkey tested negative for both Dirofilaria immitis microfilariae and D. immitis adult antigens (via commercially available tests) upon return. However, it tested positive for adult antigens 1 yr later, and additional testing, including ultrasonography, suggested a diagnosis of aberrant dirofilariasis. Relevant evidence of previous microfilaremia in pale-headed saki monkeys at the Dallas Zoo is reviewed. Dirofilaria immitis infection should be included in the differential diagnosis list for any nonhuman primate with cardiopulmonary disease wherever the parasite is enzootic.

Pharmacokinetics of a single intravenous enrofloxacin dose in scimitar-horned oryx (Oryx dammah).

Based on a 1.3 mg/kg mean dosage determined by metabolic energy scaling, enrofloxacin pharmacokinetics of a single i.v. dose of enrofloxacin in five adult scimitar-horned oryx (Oryx dammah) were determined. Drug concentration versus time curves were best fit by residual analysis to a one-compartment open model with a maximum (mean +/- SD) serum concentration after distribution of 1.887 +/- 0.632 micrograms/ml and an elimination half-life of 41.2 +/- 27.5 min. Model-independent parameters were area under the curve (173.63 +/- 147.5 micrograms.min/ml), mean volume of distribution (steady state) (0.80 +/- 0.30 L/kg), clearance (12.07 +/- 7.12 ml/min/kg), and residence time (77.22 +/- 72.8 min). Mean serum enrofloxacin concentrations reached the recommended minimum inhibitory concentration (1.0 micrograms/ml). Drug concentrations remained above the minimum inhibitory concentration of most sensitive bacteria (0.5 micrograms/ml) consistently for 90 min. Based on this study, enrofloxacin would have to be administered parenterally to scimitar-horned oryx at 1.6 mg/kg every 6-8 hr (minimally) to maintain appropriate serum concentrations against susceptible bacteria. The metabolic energy scaled dosed regiment from this study appeared to be too low for the oryx.

Itraconazole plasma and tissue concentrations in the spiny lizard (Sceloporus sp.) following once-daily dosing.

Mycotic infections in reptiles present as primary diseases and as secondary problems in healing wounds and immunocompromised animals. A triazole antimycotic drug, itraconazole is orally active and well distributed and is effective against many common fungal pathogens in humans. To assess plasma and tissues concentrations after oral dosing in reptiles, a 23.5-mg/kg (mean) itraconazole dose was administered orally with a standard food bolus once daily for 3 days to 10 groups of three or four spiny lizards (Sceloporus sp.). On days 0, 1, 2, 3, 4, 6, 9, 12, and 18, group samples of blood, liver, and muscle were collected. Microbiologic assay of itraconazole concentrations was performed on these pooled samples. Values from an elimination graph of the concentrations of area under the curve (377.21 micrograms.hr/ml) and terminal elimination half-life (48.3 hr) were obtained for itraconazole in spiny lizard plasma. Peak itraconazole concentration of 2.48 micrograms/ml was obtained in two half-lives and would be expected to achieve steady state at approximately 3.1 micrograms/ml plasma concentration in 10 days. Peak liver concentration of 4.27 micrograms/ml was attained in 89.95 hr. Muscle concentration did not exceed 0.63 micrograms/ml and declined by 97.3 hr. With this dosing regimen, itraconazole plasma and liver concentrations would persist within reported minimum inhibitory concentrations for many fungal pathogens for 6 days beyond the peak concentration.