Methods of contraception are necessary for management of zoo felids; however, the most commonly used contraceptive (melengestrol acetate implant) is associated with serious adverse reactions with long-term use. Porcine zona pellucida (pZP) vaccines are promising as contraceptives, but their safety in zoo felids has not been tested. pZP vaccine was administered to 27 female felids representing 10 species, including African lion (Panthera leo), Asian leopard (P. pardus), jaguar (P. onca), tiger (P. tigris), snow leopard (P. uncia), cougar (Felis concolor), Siberian lynx (F. lynx), Canada lynx (F. canadensis), serval (F. serval), and bobcat (F. rufus), in 15 facilities. Over 6 wk, each animal received three i.m. injections of 65 μg pZP with Freund's complete adjuvant (FCA), Freund's incomplete adjuvant, or carbopol as the adjuvant. Behavioral signs of estrus were seen in 14 of the vaccinated felids. An unacceptably high incidence of adverse reactions was seen including injection site swelling, lameness, limb swelling, or abscessation (or all) in five felids after injection with FCA as the initial adjuvant. Adverse behavioral signs, including increased irritability and aggression, were seen in four felids. Six of the felids were assayed for antibodies against pZP during the 12 mo after vaccination; all showed antibody production. Antibody levels appeared to peak 1–4 mo after vaccination began, although elevated antibody levels persisted in two animals for >12 mo after the first injection. All vaccinated felids were ovariohysterectomized 3–13 mo after vaccination. Folliculogenesis was present in all treated animals, and there was no histopathologic evidence of inflammatory damage to ovaries. Contraceptive efficacy was not specifically evaluated in this study; however, two of the three felids housed with an intact male became pregnant during the study, one of which gave birth to healthy cubs.

Pancreatic islet fibrosis with varying degrees of islet cell hyperplasia or islet effacement was diagnosed histologically in 19 rock hyraxes (Procavia capensis) from seven zoological parks. Some, but not all, affected hyraxes were from a common lineage. The condition was associated with apparent hyperglycemia in seven and diabetes mellitus in two. Immunohistochemistry revealed hyperplasia of beta, alpha, and delta cells proportional to the degree of the fibrosis. Electron microscopy revealed collagen deposition and fibroplasia within and around the islets. Special stains and electron microscopy were negative for the presence of amyloid. Beta cell depletion was never identified. The condition has morphologic features that resemble islet fibrosis of human infants born to diabetic mothers.

Six of 15 (40%) inactive medical records of adult black howler monkeys (Alouatta caraya) at one zoological institution included either a pre- or postmortem diagnosis of renal disease. In these six cases, significantly abnormal hematologic and serum chemistry values were reported at onset of azotemia, onset of clinical signs, and at euthanasia. Average age of onset of azotemia was 14.8 ± 2.9 yr, with clinical signs of disease noted at 17 ± 4.7 yr. In four of the cases (66.6%), azotemia was documented earlier than the onset of clinical signs of renal disease. Average duration of clinical disease was 2.83 ± 1.6 yr, with an average age at euthanasia of 18 ± 4.7 yr. Chronic tubulointerstitial nephritis with secondary glomerular sclerosis was present in all cases. Thirteen of an additional 20 institutions in the United States that have held Alouatta caraya responded to a survey for prevalence of renal disease. These institutions showed a lower prevalence (15.1%) of renal disease in complete, inactive records, a higher prevalence of glomerulonephritis, and similar significant clinicopathologic values.

Conventional inhalation anesthesia of wildlife species within natural habitats presents significant practical problems. Heavy cylinders of medical grade oxygen are often unavailable in field situations. Equipment has been modified to permit the delivery of isoflurane in ambient air as the carrier and to be fitted with circuitry adaptable for different species and anesthetic situations. Preliminary empirical studies at low altitude in a range of small mammalian and avian species demonstrate the suitability of this combination and these techniques for inducing and maintaining anesthesia in clinically normal patients undergoing relatively minor procedures. The equipment has also been used to deepen and prolong anesthesia in several larger species, including great apes and large cats, after induction with injectable agents. These techniques, in combination with pulse oximetry to detect hypoxemia, provide a cheap, robust, and portable inhalation anesthetic system for field situations that is not dependent on compressed gasses.

Twelve adult rhebok (Pelea capreolus) were immobilized using a combination of 0.4 mg/kg xylazine and either 0.01 mg/kg of carfentanil (n = 6) or 0.01 mg/kg etorphine (n = 6), delivered i.m. using a remote injection system. Induction and recovery times, heart rate, respiratory rate, rectal temperature, oxygen saturation, end-tidal CO₂ (ETCO₂), anesthetic depth, indirect blood pressure, and arterial blood gases were recorded. Rhebok were not intubated but nasal oxygen was administered. Forty minutes after induction, anesthesia was antagonized with naltrexone and yohimbine. Mean initial heart rate was significantly higher in the carfentanil group than in the etorphine group. Mean initial oxygen saturation was consistent with hypoxia in both the carfentanil group and the etorphine group. In both groups, arterial pH decreased and partial pressure of carbon dioxide increased during the first 15 min of anesthesia, and values were similar in both groups. These findings were consistent with respiratory acidosis and decreased ventilation. Values for respiratory rate, temperature, oxygen saturation, ETCO₂, and blood pressure were similar for both groups at all time periods. During the first 5 min of anesthesia, rhebok in the carfentanil group were more responsive to stimuli than rhebok in the etorphine group. After administration of antagonists, time to first arousal was significantly shorter in the etorphine group than in the carfentanil group. Although cardiopulmonary values were similar for the two groups, rhebok in the carfentanil group were at a comparatively lighter plane of anesthesia, and some individuals in this group required additional manual and chemical restraint for medical procedures to be performed. In conclusion, for captive adult rhebok, 0.01 mg/kg of etorphine and 0.4 mg/kg of xylazine are recommended over 0.01 mg/kg carfentanil and 0.4 mg/kg xylazine because of qualitatively better anesthetic episodes and shorter recovery times.

Two α₂-adrenoceptor agents, xylazine and medetomidine, in combination with midazolam and ketamine safely and effectively immobilized Siberian tigers (Panthera tigris altaica). The medetomidine protocol used smaller drug volumes, and induction and recovery times were shorter. Although cardiopulmonary abnormalities were noted, none were likely to be life threatening.

We compared the effects of dipotassium ethylenediaminetetraacetic acid (EDTA) and lithium heparin on hematologic values of green iguanas (Iguana iguana). Thirty-two privately owned sibling iguanas had blood drawn, and the sample was divided into three components: an EDTA tube, a heparin tube, and a nonanticoagulated blood smear. A full reptilian complete blood count was performed on each anticoagulated sample, and white blood cell (WBC) and leukocyte differential counts were performed on the whole-blood smears. Heparin and EDTA samples differed significantly in absolute values of thrombocytes, WBC, heterophils, and monocytes. The EDTA had no significant effect on the packed cell volume or plasma protein values, and the white blood count and differential counts produced with EDTA were more similar to those of the nonanticoagulated blood smear than were the counts produced with heparin.

The pharmacokinetics of enrofloxacin administered orally and i.v. to American alligators (Alligator mississippiensis) at 5 mg/kg was determined. Plasma levels of enrofloxacin and its metabolite ciprofloxacin were measured using high-performance liquid chromatography and the resulting concentration versus time curve analyzed using compartmental modeling techniques for the i.v. data and noncompartmental modeling techniques for the oral data. A two-compartment model best represented the i.v. data. Intravenous administration of enrofloxacin resulted in an extrapolated mean plasma concentration of 4.19 ± 4.23 μg/ml at time zero, with average plasma drug levels remaining above 1.0 μg/ml for an average of 36 hr. Plasma volume of distribution for i.v. enrofloxacin was 1.88 ± 0.96 L/kg, with a harmonic mean elimination half-life of 21.05 hr and mean total body clearance rate of 0.047 ± 0.021 L/hr/kg. Plasma levels of p.o. enrofloxacin remained below 1.0 μg/ml in all test animals, and average concentrations ranged from 0.08 to 0.50 μg/ml throughout the sampling period. Oral administration of enrofloxacin achieved a mean maximum plasma concentration of 0.50 ± 0.27 μg/ml at 55 ± 29 hr after administration, with a harmonic mean terminal elimination half-life of 77.73 hr. Minimal levels of ciprofloxacin were detected after both oral and i.v. enrofloxacin administration, with concentrations below minimum inhibitory concentrations for most susceptible organisms. On the basis of the results of this study, enrofloxacin administered to American alligators at 5 mg/kg i.v. q 36 hr is expected to maintain plasma concentrations that approximate the minimum inhibitory concentration for susceptible organisms (0.5 μg/ml). Enrofloxacin administered to American alligators at 5 mg/kg p.o. is not expected to achieve minimum inhibitory values for susceptible organisms.

The pharmacokinetics of a long-acting oxytetracycline preparation administered i.v. and i.m. to American alligators (Alligator mississippiensis) at 10 mg/kg was determined. Plasma levels of oxytetracycline were measured using high-performance liquid chromatography, and the resulting concentration versus time curve was analyzed using compartmental modeling and noncompartmental modeling techniques for i.v. and i.m. samples, respectively. A two-compartment model best represented the i.v. data. Intravenous administration of oxytetracycline resulted in an extrapolated mean plasma concentration at time zero of 60.63 ± 28.26 μg/ml, with average plasma drug levels of 2.82 ± 0.71 μg/ml at the end of the 192-hr sampling period. Plasma volume of distribution for i.v. oxytetracycline was 0.20 ± 0.09 L/kg, with a harmonic mean elimination half-life of 15.15 hr and mean total body clearance rate of 0.007 ± 0.002 L/hr/kg. Intramuscular administration of oxytetracycline achieved a mean peak plasma concentration of 6.85 ± 1.96 μg/ml at 1 hr after administration, with average plasma drug levels of 4.96 ± 1.97 μg/ml at the end of the 192-hr sampling period. The harmonic mean terminal elimination half-life for i.m. oxytetracycline was 131.23 hr. Based on the results of this study, long-acting preparations of oxytetracycline administered parenterally to American alligators at 10 mg/kg q 5 days is expected to maintain plasma concentrations above the minimum inhibitory concentration of 4.0 μg/ml for susceptible organisms.

Iodine in the form of iodide is required for synthesis of tri-iodothyronine and thyroxine in fish. Iodine chemical speciation in aliquots of raw artificial seawater mix was measured before, during, and after exposure for fixed time periods to air only and to concentrations of ozone required to achieve oxidation–reduction potentials typical of a protein skimmer (400 mV) and an ozone contact chamber (800 mV). Chemical species of iodine were also measured in tank water from a large, recirculating, ozonated aquarium system that has a low-grade incidence of thyroid lesions (e.g., thyroiditis, hyperplasia, adenoma, and adenocarcinoma) in its fish. With increasing exposure to ozone, concentrations of iodide and dissolved organic iodine (DOI) decreased, whereas iodate levels increased. As a result of exposure to 400 mV, iodide concentration dropped to less than half the amount found in raw artificial seawater mix. After exposure to 800 mV, initial iodide levels decreased by 67%, and DOI became undetectable, whereas iodate concentration increased by 155%, with no remarkable change in total iodine concentration. These results indicate ozone-induced conversions from iodide to iodate, and DOI to iodide or iodate (or both). Iodide and DOI were not detectable in the aquarium system's water samples. Ozonation of artificial seawater may alter the relative concentrations of iodine species in a closed tank system, so that iodide supplementation of the diet or tank water of captive teleosts and elasmobranchs living in ozonated seawater is advisable.

Ultrasonography is currently used in veterinary medicine to examine the anatomy and physiology of internal organs and to establish normal standards for exotic animal species. Specifically, the kidneys may be evaluated and measured in length, width, and height. The kidneys in 33 oncilla (Leopardus tigrinus), including 20 males and 13 females, were opportunistically located, characterized, and measured by ultrasound using a 7.5-MHz linear transducer at two different zoologic facilities in São Paulo, Brazil. Renal volume was calculated from these linear measurements. The mean linear measurements and volume of the right and left kidneys were not significantly different.

Two adult female rock hyraxes (Procavia capensis) at the Dallas Zoo were confirmed with spontaneous diabetes mellitus from 1997–2000, whereas a third animal with a similar clinical presentation never became hyperglycemic. The pancreas in all three animals showed pancreatic islet fibrosis (PIF). Retrospective examination of medical records for rock hyraxes acquired by this collection or born into it from 1991–2002 identified eight more animals affected with PIF. All affected animals, including three males and eight females, were 1–7 yr of age and presented either with vague clinical signs of soft feces and rough hair coat or were acutely moribund or dead. Clinical pathology data was available for seven of the animals before onset of overt clinical signs and revealed inappropriate hyperglycemia in six, as well as elevated serum concentrations of creatine phosphokinase, amylase, and lipase in all seven animals. Pedigree evaluation did not support a familial pattern for PIF. Review of the histopathology findings from nine other zoologic collections with rock hyrax deaths during the study period identified six institutions with 12 additional cases genetically unrelated to the incident collection. Histopathology and viral serology did not support an infectious cause. Analysis of serum anti-islet and anti-insulin antibodies did not suggest autoimmune disease, and none of the animals had known exposure to toxic substances. Limited nutritional analyses did not support a nutritional basis for the condition, and the cause for PIF remains unknown.

Transitional cell carcinomas (TCC) of the urinary bladder were diagnosed in four related fishing cats (Prionailurus viverrinus). The major clinical sign in each case was persistent hematuria unresponsive to medical therapy. Cystotomy and biopsy provided an antemortem diagnosis in three of the fishing cats before euthanasia because of progression of clinical signs. The diagnosis was made in the fourth cat after euthanasia because of renal failure. Hematuria improved temporarily in one of the cats diagnosed antemortem and treated with piroxicam and carboplatin. Attempts to isolate a herpesvirus in two of the cats failed. Histopathologic appearance of the TCC was similar to that described for other species. TCC metastasis to the lungs was noted at necropsy in one cat; metastatic disease was not noted in the other fishing cats on gross or histopathologic examination. TCC of the urinary bladder appears to be more prevalent in fishing cats than in other species of domestic or nondomestic felids.

Renal myxosporidiasis and associated lesions were seen in Asian horned frogs, Megaphrys nasuta, at the Detroit Zoological Institute and the Toledo Zoo. The organism was identified as Chloromyxum sp. on the basis of histopathology, cytology, and electron microscopy. Histologic changes in the kidneys included varying degrees of renal tubular dilation and necrosis, and mild to severe nonsuppurative tubulointerstitial nephritis associated with vegetative stages of the myxosporidian. This is the second known identification of Chloromyxum sp. in amphibian kidneys, and the first report of death attributed primarily to the parasite.

An outbreak of herpesvirus caused the death of four of five common marmosets (Callithrix jacchus) in a private colony. Gross lesions included acute ulcerative gingivitis, glossitis, and enlarged mandibular lymph nodes. Histologically, all fatal cases showed meningoencephalitis and eosinophilia with intranuclear inclusion bodies in neurons and glial cells. A herpes simplex–like virus was cultured from the brain and was identified as herpes simplex type 1 virus or a closely related virus by immunofluorescence. Serologic testing (complement fixation test) indicated that the surviving adult female was serologically positive for more than 4 yr and that the offspring she produced was seronegative. The most likely source of the outbreak was the owner who mouth fed hand-raised offspring.

A mature male Risso's dolphin (Grampus griseus) stranded along the coasts of Friuli Venezia Giulia, northeast Italy, in May 2001. Parasitic infection with Crassicauda grampicola is often found in the tympanic bullae and pterygoid sinuses in many of the Risso's dolphins examined from the same area. For this reason, it was decided to perform computed tomography of the head to assess this imaging technique for the diagnosis of crassicaudosis in dolphins. A full postmortem examination confirmed the pathologic findings of the computed tomography scan. This technique can be considered a useful adjunct in the diagnosis of cranial crassicaudosis in live dolphins.

Plasma levels of the parasiticide ivermectin were studied by high-performance liquid chromatography in five llamas (Lama glama) after single 200 μg/kg s.c. injections. Ivermectin levels were undetectable in plasma samples drawn up to 4 wk after injection, suggesting that the dosage used was insufficient to reach therapeutic concentrations in this species.

A 37-yr-old female Asian elephant (Elephas maximus) presented with anorexia, restlessness, and dark-colored urine. Urinalyses showed hematuria, leukocyturia, isosthenuria, proteinuria, granular casts, and no calcium oxalate crystals. Bloodwork revealed azotemia. Urine culture revealed a pure growth of Streptococcus zooepidemicus resistant to sulfamethoxazole–trimethoprim but susceptible to cephalosporins. A presumptive diagnosis of pyelonephritis was made based on bloodwork, urinalysis, and urine culture. The animal was treated with intravenous ceftiofur, and intravenous and per rectum fluids were given for hydration. The elephant's attitude and appetite returned to normal, the abnormal blood parameters resolved, and urinary calcium oxalate crystals reappeared after treatment, supporting presumptive diagnosis. Follow-up ultrasonography revealed an abnormal outline of both kidneys with parenchymal hyperechogenicity and multiple uterine leiomyomas.

A male Swainson's hawk (Buteo swainsoni) at a rehabilitation facility in Colorado was presented with severe crusting of the skin on the medial thighs and caudal ventral body. Male and female Knemidokoptes mites were found on a cellophane tape preparation of the affected area. The hawk's clinical signs resolved with treatment with ivermectin administered at 200 μg/kg, i.m., every 10 days for three treatments.

Intra-alveolar infraction and malformation of the apical part of the permanent left maxillary canine in an adult male wild boar (Sus scrofa L.) is documented. The infraction and its sequelae produced an irregular mass of reparative tissue that led to the formation of two growing ends of the tooth

A 4-yr-old striped skunk (Mephitis mephitis) developed an 11- × 7- × 7-cm retroperitoneal mass caudal to the left kidney. The mass was surgically excised and, on the basis of histology and immunohistochemistry, diagnosed as a benign teratoma. Six months later, a second histologically similar neoplasm was excised from the same location and was considered to represent local tumor recurrence. The skunk died 16 mo later without recurrence. Complete excision of the tumor appeared curative in this case and supported the benign diagnosis. An extragonadal teratoma should be considered as a differential diagnosis for an abdominal mass in a skunk.

A 14.6-yr-old, female, multiparous polar bear (Ursus maritimus) acutely developed an apparent hind limb weakness. Physical examination and diagnostic tests including a hemogram, serum biochemistry, electrolytes, radiographs, and myelogram did not provide a definitive diagnosis. No improvement in condition was noted during 4 days of supportive care, and the bear was euthanized. An ovoid mass was present in the anterior mediastinum, and a thymoma was confirmed histologically. Compared with control polar bears, elevated serum acetylcholine receptor (AChR) antibodies (0.13 ± 0.06 nmol/L vs. 0.86 nmol/L) were detected by immunoprecipitation radioimmunoassay, which is consistent with myasthenia gravis (MG) in other species. Although the AChR antibody test has not been validated in the polar bear, we are confident in the postmortem diagnosis of MG, which is commonly associated with thymoma in other species.