Through the Red Wolf Species Survival Plan, the captive red wolf (Canis rufus) population was developed with the intent of reestablishing wild populations. One part of the plan was a survey for diseases that might occur as a result of population homogeneity or that might impede breeding success and reintroduction. For this survey, complete necropsies and histopathologic analyses were performed on 62 red wolves from 1992 to 1996. Major causes of 22 neonatal deaths were parental trauma, parasitic pneumonia, and septicemia. Common neonatal lesions included pododermatitis and systemic ascariasis. Cardiovascular anomalies and systemic parasitism were found in two juveniles. Causes of death in the 38 adults included conspecific trauma, neoplasia, or gastrointestinal diseases such as necrotizing enteritis, intestinal perforation, and gastric volvulus. Lymphosarcoma represented 50% of the fatal neoplasms. Three adults died from cardiovascular failure or hyperthermia during handling, and several adults were euthanized for suspected genetic diseases. Overall, the captive population had few significant health problems, but population fitness might be improved by continued removal of potentially deleterious genes from the breeding population and by modifying the husbandry of neonates and adults.

Twenty-six anesthetic procedures involving 24 free-living mountain gorillas (Gorilla gorilla beringei) from Rwanda or the Democratic Republic of Congo were performed between February 1987 and October 1997. Sixteen procedures were performed to remove snares or to treat snare-related wounds, and four of the animals died without recovering consciousness because of their severe medical conditions. Ketamine was used for induction 19 times, tiletamine/zolazepam was used five times, and the agent was not recorded for two procedures. The mean (± SD) ketamine dosage for four animals of known weight was 7.1 ± 0.9 mg/kg. All induction agents were delivered i.m. by remote injection, and mean induction times for ketamine and tiletamine/zolazepam were 5.5 ± 2.6 min (n = 12) and 5.4 ± 3.7 min (n = 5), respectively. Mean recovery times were significantly shorter with ketamine compared with tiletamine/zolazepam (42.0 ± 24.9 min, n = 9 vs. 75.25 ± 22.1 min, n = 4). Low hemoglobin oxygen saturation (mean = 86.7%) was recorded in three cases under ketamine anesthesia, and oxygen insufflation is therefore recommended to prevent hypoxemia. Gorillas induced with tiletamine/zolazepam had significantly higher respiratory rates compared with animals given ketamine. Successful anesthesia and recovery, in particular, depended on the assistance of local personnel.

Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10–19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

Fifteen snakes representing seven species with segmental, proliferative osteoarthritis and osteoarthrosis of the spine were presented for examination. All the snakes were captive, privately owned, and fed domestic rodents. Physical examination, radiography, blood culture, bone culture, necropsy, and histopathology were performed on each snake. All the snakes had similar physical examination, radiologic, and necropsy findings. There were three histologic types of lesions: active bacterial osteoarthritis, predominantly noninflammatory osteoarthrosis with multifocal inflammation suggestive of chronic bacterial osteoarthritis, and noninflammatory lesions consistent with osteoarthrosis without evidence of inflammation or bacteria. These findings suggest that all these snakes represent a single disease process, bacterial infection of the vertebrae. The different histologic lesions observed in these snakes may be a continuum of lesions, from acute to chronic. Gram-negative bacteria were isolated from the blood or bone lesions of 8 of the 15 snakes. In six of these eight snakes, Salmonella species were isolated. Gram-positive bacteria (Streptococcus sp.) were isolated from two other snakes. Blood and bone culture results were well correlated, so blood culture may be effective for detecting active bacterial osteoarthritis.

Ten desert tortoises (Gopherus agassizii) were given i.m. injections of 150 µg/kg of medetomidine. Sedation was achieved in all tortoises by 20 min postinjection and was accompanied by a significant decrease in mean heart and respiratory rates, systolic, diastolic, and mean ventricular pressures, and mean ventricular partial pressure of oxygen (Po₂). There was no change in mean blood pH, HCO₃⁻, Na , K , ionized calcium values, and mean ventricular partial pressure of carbon dioxide (Pco₂). There were statistically significant but clinically insignificant changes in mean base excess and pH-corrected ionized calcium values. Atipamezole given to five of the tortoises at 0.75 mg/kg i.m. significantly reversed the sedative effects of the medetomidine, with all tortoises returning to a normal state by 30 min after administration of the reversal agent. In comparison, the other five tortoises given an equal volume of physiologic saline in place of atipamezole (control group) remained significantly sedated for the duration of the study. In addition, the heart rate and ventricular Po₂ returned to baseline, but the respiratory rate and ventricular blood pressures were not significantly altered by the atipamezole as compared with those of the control group. These cardiopulmonary and physiologic effects are similar to those seen in some domestic mammals. Medetomidine can be used to safely induce sedation in desert tortoises. For procedures lasting greater than 120 min, supplemental oxygen should be provided. Atipamezole will reverse the sedation but not all of the cardiopulmonary effects, thus necessitating continued monitoring after reversal. Future studies should address the anesthetic and cardiopulmonary effects of medetomidine in combination with other agents such as ketamine and/or butorphanol.

Hematologic, serum biochemistry, and serum cortisol reference ranges were established and tonsil/rectal bacterial and fecal parasite examinations were performed on 21 wild arctic fox (Alopex lagopus) cubs during July 1996. Several of the hematologic and serum biochemistry values fell within normal ranges for other wild canids or domestic dogs of the same age class. Serum alanine transaminase and creatine phosphokinase values were significantly higher in the youngest cubs. Proteus vulgaris and Escherichia coli were isolated from both tonsilar and rectal swabs of several cubs in all dens. The most common gastrointestinal parasite ova were Toxascaris leonina (59%), Isospora spp. (52%), Uncinaria stenocephala (33%), and Capillaria spp. (26%). Prevalence of T. leonina differed significantly between dens and between age groups. Hematologic and serum biochemistry values and degree of parasitism may be indicators of health, stress, and nutritional status of arctic foxes.

Serum oxytetracycline pharmacokinetics were studied in 18 African elephant (Loxodonta africana) calves. Each elephant received separate injections of oxytetracycline at approximately 18 mg/kg i.m. and 8 mg/kg i.v. in a cross-over study. Blood samples were drawn at 0, 24, 48, 72, and 96 hr postinjection. An additional sample was drawn 110 hr before the animals were reinjected in the cross-over study and a final blood sample was drawn 48 hr after the second dose. No lameness or stiffness was observed following i.m. injections. Serum oxytetracycline concentrations >0.5 µg/ml were present 48 hr after initial dosing for all elephants (i.m., i.v., high or low dosage). Only elephants given the high i.m. dosage (18 mg/kg) maintained levels >0.5 µg/ml 72 hr postinjection. No significant difference in serum oxytetracycline concentration with time was observed between the groups given different i.v. dosages. These studies demonstrated that quantifiable serum oxytetracycline concentrations can be maintained in young African elephants with a low-dosage multidose i.m. regimen.

This study characterized and compared the pharmacokinetics of piperacillin after single 100 mg/kg i.m. injections in nine red-tailed hawks (Buteo jamaicensis) and five great horned owls (Bubo virginianus) over 48 hr by a modified agar well diffusion microbial inhibition assay. The mean maximum plasma piperacillin concentrations were 204 µg/ml and 221 µg/ml for the hawks and owls, respectively, and times of maximum concentrations were 15 min and 30 min, respectively. The calculated mean terminal elimination half-lives were 77 min in the hawks and 118 min in the owls. Area-under-the-curve values were 218 ± 52 µg·hr/ml in the hawks and 444 ± 104 µg·hr/ml in the owls. On the basis of the most common minimal inhibitory concentration (90%) for various bacterial isolates from clinical samples of 8 µg/ml, analysis of the data suggests that the maximum dosing interval for piperacillin at 100 mg/kg in medium sized raptors should be 4–6 hr.

The suitabilities of two subcutaneous and two intraabdominal surgical approaches were evaluated for implantation of telemetry transmitters in the European badger (Meles meles). Two transmitters, one for heart rate and the other for body temperature, were needed in each badger. Five wild badgers were trapped, housed in an outdoor pen, anesthetized, and surgically implanted with one or two transmitters per procedure. A total of 16 transmitters were implanted, 10 subcutaneously and six intraabdominally, and each badger had up to three procedures performed. Six subcutaneous transmitters were placed over the chest wall and four on the dorsal aspect of the neck. Three intraabdominal transmitters were placed free in the abdomen and three were fixed to the abdominal wall. Eight of the subcutaneous transmitters were later damaged or dislodged, probably by mechanical friction, injuries from fighting, or wound licking. The intraabdominal implantation procedures were easier and faster to perform compared with subcutaneous procedures. Two of the free intraabdominal transmitters became thinly encapsulated, with some omental adhesions. The fixed intraabdominal approach for transmitter implantation is preferable in badgers.

Fecal samples from 33 lions (Panthera leo) in Serengeti National Park and Ngorongoro Crater Conservation Area in northern Tanzania contained 19 different parasites, 12 of which, including Aelurostrongylus sp., a species of Acanthocephala, a species of Anoplocephalidae, Capillaria sp., Demodex sp., Eimeria sp., Habronema sp., Isospora felis, Isospora rivolta, one species of Isospora that was previously undescribed from lions, one species of Trematoda that was previously undescribed from lions, and Trichuris sp., were new reports for lions. Seven other species had been previously reported from lions.

Eleven adult fallow deer (Cervus dama) were anesthetized using a mixture of xylazine/tiletamine/zolazepam, and 10 were anesthetized with a mixture of medetomidine/tiletamine/zolazepam. Anesthesia was adequate for capture in all instances, and minor surgical procedures were possible in seven of the animals treated with xylazine/tiletamine/zolazepam and in all of the animals treated with medetomidine/tiletamine/zolazepam. Blood gas, hematologic, serum biochemical, and cardiorespiratory parameters were measured during all immobilizations. The deer immobilized with xylazine/tiletamine/zolazepam had significantly higher lactate and cortisol values than the deer immobilized with the medetomidine combination. Although both methods were adequate for fallow deer, the medetomidine/tiletamine/zolazepam combination produced superior results.

A white-handed gibbon (Hylobates lar) lost the use of its right hand. Complete blood count, serum chemistry profile, electrocardiographic findings, blood pressure, and radiographic work-up were normal, but the gibbon died 2 days later. The gibbon was serologically positive for herpes simplex I and Epstein-Barr virus. Necropsy and histopathology showed acute infarction of the right cerebrum and multifocal to coalescing severe myocardial fibrosis.

A 21-mo-old female southern black rhinoceros (Diceros bicornis minor) developed acute upper respiratory dyspnea in association with lymphadenopathy and marked immature lymphocytosis. A diagnosis of acute lymphoblastic leukemia was reached on the basis of the morphologic and cytochemical characteristics of peripheral lymphoblasts. Antineoplastic chemotherapy included administration of cytarabine, cyclophosphamide, vincristine, and doxorubicin, with clinical remission achieved 19 days after initiation of treatment. The rhinoceros died, however, of congestive heart failure, presumably secondary to doxorubicin cardiotoxicity and a particular sensitivity of rhinoceros myocardial tissue to free hydroxyl radicals. The pharmacologic effects of any therapeutic agent need to be carefully considered before use in the black rhinoceros, especially within the context of the unique physiology of this species.

A 6-yr-old female Grevy's zebra (Equus grevyi) with a disseminated rhabditiform nematode infection is described. Antemortem clinical signs were limited to blindness and abnormal behavior believed to be caused by a recurrent nematode-induced uveitis. Histologic examination of the kidneys, heart, eyes, uterus, and lymph nodes revealed granulomas containing multiple sections of rhabditiform nematodes. Most of the recovered nematodes were larval stages with only a few adult females noted. The adults measured 243–297 µm × 11–16 µm (x̄ = 269 × 14 µm). The distinctive rhabditiform esophagi had corpus:isthmus:bulb proportions of 19:11:5. On the basis of adult morphology, the nematode was identified as Halicephalobus gingivalis. This is the first report of this parasite in a zebra and indicates that this parasitic granulomatous disease should be considered in zebras with neurologic disease.

An 8-yr-old intact male Grant's zebra (Equus burchelli bohmi) was referred to the Veterinary Medical Teaching Hospital of the University of California–Davis after being found in the owner's pasture obtunded and in lateral recumbency. The animal was hypothermic, weak, and unwilling to rise. There was no evidence of trauma, and the zebra had seemed normal the preceding evening. There was no extensor rigidity, and cranial nerve reflexes were normal. Flexor and extensor reflexes were weak upon initial examination. A complete blood count and serum biochemistry analysis revealed a mild leukocytosis, hyperfibrinogenemia, hypoglycemia, hyponatremia, hypochloremia, hypocalcemia, and hypoalbuminemia. Urinalysis was normal, and a urine toxicology screen for alkaloids was negative. No toxic substance was found in the hay or pasture grasses although the owner reported the presence of yellow star thistle and mushrooms in the pasture. The cerebrospinal fluid cytologic and biochemical analyses were normal, but antibodies to Sarcocystis neurona were detected. The zebra died despite aggressive supportive therapy over a 4-day period. The necropsy demonstrated severe gastrointestinal nematodiasis that could account for hypoalbuminemia and electrolyte abnormalities. Histopathologic examination of the nervous system revealed focal areas of perivascular cuffing in the brainstem that were comprised mainly of lymphocytes, monocytes, and plasma cells. Immunohistochemical staining identified the presence of S. neurona merozoites associated with the lesions. This zebra probably died from severe endoparasitism that resulted in malabsorption, weakness, and recumbency rather than from encephalitis associated with S. neurona merozoites. Equine protozoal myeloencephalitis has not been reported previously in nondomestic equids.

An 11-yr-old female Eurasian otter (Lutra lutra) presented with multiple cutaneous nodules identified histologically as malignant melanomas of spindle cell and epithelioid cell type. Metastases were detected in lymph nodes and liver, and the tumor, which was derived from melanocytes, showed aggressive biological behavior. Only occasional reports exist of neoplastic disease in otters.

Two wild-caught Bosc's monitor lizards (Varanus exanthematicus) developed clinical signs of pentasomiasis approximately 3 yr after arrival in the United Kingdom. One died of chronic parasitic pneumonia associated with adult pentastomids of an undescribed Sambonia species. Eggs and immature pentastomids were also seen in histologic sections of the lungs and liver. The other animal was treated for pneumonia and for nodular inflammation of the larynx that restricted the diameter of the glottis. Fragments of pentastomid larvae were seen in a laryngeal biopsy, and the animal recovered after treatment with ivermectin and supportive therapy.

An adult female lesser flamingo (Phoeniconaias minor), caught in the African Rift Valley in 1991 and subsequently housed at the Baltimore Zoo, died of severe visceral gout in 1996. Necropsy revealed a white, moderately firm, nodular lesion, 1 cm in diameter, in the serosal wall of the small intestine. Although it was initially thought to be a tumor or focal granuloma, histologic examination revealed multiple cestodes deeply embedded at the base of the crypts between the intestinal villi, with their massive scolices (up to 3.4 mm in diameter) distending these spaces into multiple diverticulae. The mucosal epithelium surrounding the scolices was severely attenuated. Around the diverticulae, in the submucosa and muscularis, was a mild to moderate lymphocytic reaction and mild fibrosis. The proximity of multiple scolices and extensive invasion of host tissue suggested that the infection occupied a preexisting lesion. The cestodes were cyclophyllids but were distinct from any species previously reported from flamingos. Helminths should be included in differential diagnoses for gastrointestinal nodules in flamingos.

A 12-yr-old male koala (Phascolarctos cinereus) in a zoo collection developed bilateral, noninflammatory, periocular alopecia. Deep periocular skin scrapings yielded multiple adult, nymphal, and larval mites of a previously undescribed Demodex species. Skin biopsies from affected areas revealed multiple mites in superficial keratin and within hair follicles, associated with a mild intramural lymphocytic folliculitis. Treatment with daily oral ivermectin was safe and effective. Although Demodex sp. are previously reported from skin scrapings in another koala with periocular alopecia, this is the first confirmed case of koala demodicosis.

A castrated adult male 1.0-kg domestic ferret (Mustela putorius furo) was referred for evaluation of a mass of >5 mo duration that was associated with the thoracic spine. The ferret had motor dysfunction and no conscious proprioception or pain perception in either hind limb. Segmental reflexes were present. Survey radiography, myelography, and magnetic resonance imaging showed a mass involving the ninth and 10 thoracic vertebrae and compressing the spinal cord. Decompressive surgery was performed, but clinical signs persisted. A diagnosis of chordoma was made using histopathology and immunohistochemistry. This is the first reported case of a chordoma involving the thoracic vertebrae in a domestic ferret.

Acute unilateral keratomalacia, probably secondary to trauma, occurred in a greater one-horned rhinoceros (Rhinoceros unicornis) transferred between zoologic facilities. Following 2 days of medical treatment, a 360° conjunctival surgical graft was performed. Staphylococcus and yeast were isolated from a perioperative culture of the affected eye and were treated with antimicrobials. There was rapid healing and minimal midcorneal scar formation with peripheral corneal clarity.

An Asian elephant (Elephas maximus) required general anesthesia for orthopedic foot surgery. The elephant was unable to lie down, so it was placed in a custom-made sling, administered i.m. etorphine hydrochloride in the standing position, and lowered to lateral recumbency. General anesthesia was maintained with isoflurane administered through an endotracheal tube. After surgery, the isoflurane anesthesia was terminated, with immobilization maintained with additional i.v. etorphine. The elephant was lifted to the vertical position, and the immobilizing effects of etorphine were reversed with naltrexone. The suspension system and hoist for the sling were designed specifically for the elephant house.

A group of four red kangaroos (Megaleia rufa), a Bennett's wallaby (Macropus rufogriseus fruticus), and a Gunther's dik dik (Maloqua guentheri smithi) were presented over a 2-mo period with draining lesions over the thorax or on the lateral aspect of a hind leg. Only one animal exhibited more than one lesion. Physical examinations revealed infections with fly larvae. The parasites were manually removed and identified as Cuterebra spp. All of the affected animals survived, with no apparent side effects.