Results of wellness examinations of 28 African hunting dog (Lycaon pictus) puppies at the Denver Zoological Foundation.

Since 2002 the Denver Zoological Foundation has produced 28 African hunting dog (Lycaon pictus) puppies in 3 litters (7, 14 and 7 pups) from the same dam and sire. Wellness examinations were performed on each puppy. The wellness examinations spanned the range of 6-14 weeks of age. During the wellness examinations, in addition to physical examinations and vaccinations, blood samples for complete blood counts and sera biochemistry were obtained. Weights, morphometric measurements, rectal cultures for enteric pathogens and dental eruption patterns were recorded. Blood samples from each age group were compared with adult values from the Denver Zoo. It was noted that animals from the 14-pup litter were 63.6% of the mean weight of the two 7-pup litters, but size differences (in, for example, total body length) were less apparent. Two organisms were recovered from rectal cultures, namely Yersinia enterocolitica (n = 2) and Plesiomonas shigelloides (n = 3). The following deciduous eruption patterns were also noted; at 6 weeks, 11-3, i1-3, C1, c1, P1-2 and p1-2 (n = 7) were present, at 9-10 weeks, P3 and p3 (n = 21), and finally at 12-14 weeks, P4 (n = 28).

A case of anaemia in a neonatal warthog (Phacochoerus aethiopicus) and evaluation of serum-soluble iron in warthogs.

A 38-day-old male warthog (Phacochoerus aethiopicus) with marked anaemia (haematocrit = 14 %) presented to the Denver Zoological Gardens hospital with ataxia, tachypnoea, suspected stunted growth and cardiomegaly. The piglet demonstrated some features consistent with both iron deficiency anaemia and autoimmune haemolytic anaemia. Serum-soluble iron was below the level of detection (< 8.96 micromol/l). Iron deficiency anaemia is a well recognised entity in domestic swine reared on concrete and denied access to soil. Fifteen captive warthogs were subsequently evaluated for serum soluble iron content (mean = 21.62 +/- 4.36 micromol/l as well as 5 neonatal warthog piglets that required hand-rearing. Only 1 of 5 neonatal warthog piglets had measurable serum soluble iron (9.50 micromol/l). These data suggest that warthogs are similar to domestic swine and are born with low iron stores. Some form of iron supplementation should be considered for captive neonatal warthog piglets, especially if they are reared on concrete.

Role of excessive maternal iron in the pathogenesis of congenital leukoencephalomalacia in captive black rhinoceroses (Diceros bicornis).

OBJECTIVE: To investigate the possibility that excessive maternal iron (overload) may contribute to development of congenital leukoencephalomalacia in captive black rhinoceroses. SAMPLE POPULATION: Tissue specimens and serum samples from 18 rhinoceroses in 2 kindreds harboring 4 (possibly 5) affected female calves. PROCEDURE: Fresh and archival sera and necropsy tissue specimens were evaluated to determine the nature and extent of iron overload in captive and wild black rhinoceroses as well as other rhinoceros species. RESULTS: Quantitative serum and tissue assays of iron and iron analytes, corroborated by histopathologic findings, indicated that these kindreds carried the greatest body burdens of iron yet found among captive black rhinoceroses. Fourteen of 18 rhinoceroses had the highest serum ferritin concentrations measured among 64 black rhinoceroses in captivity in the United States. Dams of affected calves had serum ferritin concentrations 2 orders of magnitude higher than clinically normal humans, equids, or free-ranging rhinoceroses. A neonatal serum sample from 1 affected female calf had a high ferritin concentration (approx 100-fold increase), but a male sibling of another affected female did not, suggesting a possible sex disparity in fetal response to maternal iron overload. Morphologic hallmarks of hemochromatosis were prominent in dams and grandams of affected calves. CONCLUSIONS AND CLINICAL RELEVANCE: Excessive maternal iron may affect female fetuses more than males, possibly inducing leukoencephalomalacia by catalyzing production of highly toxic hydroxyl free radicals during crucial periods of in utero development. Reduction of maternal iron overload may decrease the probability of developing leukoencephalomalacia and some other disorders commonly affecting rhinoceroses in captivity.

Exposure of hooded capuchin monkeys (Cebus apella cay) to a rabid bat at a zoological park.

On 27 May 1999, a big brown bat (Eptesicus fuscus) was discovered on an island exhibit at the Denver Zoo that contained a troop of 15 hooded capuchin monkeys (Cebus apella cay). The monkeys were attacking the bat when it was discovered. The bat was collected and humanely euthanatized without direct handling and submitted to the Colorado Department of Public Health and Environment Virology Laboratory for rabies evaluation. The monkeys had not been vaccinated against rabies virus. The next day, the laboratory confirmed that the bat was positive for rabies. The recommendations from the Colorado Department of Public Health and Environment and the Centers for Disease Control and Prevention were to euthanatize the monkeys or quarantine them and comply with the human nonvaccinated postexposure protocol. A 1-ml dose of a killed rabies vaccine was administered i.m. in the hip on each of days 2, 7, 12, 19, and 33 postexposure, and a single dose of human rabies immune globulin was administered i.m. 5 days postexposure. Blood was collected under anesthesia in order to evaluate the immune response after rabies vaccination from six monkeys 5 days postexposure, six monkeys 19 days postexposure (five of the six monkeys were the same monkeys bled 5 days postexposure), 15 monkeys 67 days postexposure, and 13 monkeys approximately 1 yr postexposure. All of the monkeys developed and maintained levels of rabies virus neutralizing antibody above 0.05 IU/ml by 67 days postexposure. Although a serologic titer of 0.05 IU/ml indicates an adequate human response after rabies vaccination, no similar information is available for nonhuman primates. To date, none of the monkeys has succumbed to rabies.

Salmonella spp. survey of captive rhinoceroses in U.S. zoological institutions and private ranches.

A survey was mailed to 72 institutions in the USA requesting information on Salmonella spp. cultures in black rhinoceroses (Diceros bicornis), white rhinoceroses (Ceratotherium simum), and Indian rhinoceroses (Rhinoceros unicornis). Sixty-one institutions responded (85% return rate), with seven reporting positive cultures (11% prevalence rate; 10% if survey nonresponders had negative cultures). There were 17 positive cultures from 16 different animals, with nine different serotypes of Salmonella and 2 additional cultures identified to the group level.

Rickets in two hand-reared polar bear (Ursus maritimus) cubs.

Two polar bear (Ursus maritimus) cubs born at the Denver Zoological Gardens were abandoned by a primiparous mother. Lethargic and extremely chilled, the cubs were transported to the zoo hospital for intensive care and hand rearing. Both cubs developed rickets. Dietary changes were instituted, and both cubs completely recovered with the exception of a bowed right femur (genu varum) in the female cub.

Salmonellosis in captive black rhinoceroses (Diceros bicornis).

Salmonellosis caused by Salmonella enterica subspecies arizonae (formerly known as Salmonella arizonae) was diagnosed in three of five captive black rhinoceroses (Diceros bicornis) at the Denver Zoological Gardens. Two of the three animals died despite supportive treatment. The other two rhinoceroses remained asymptomatic and were negative for Salmonella spp. after serial fecal cultures. The source for the salmonellosis was never identified.

Hypertrophic osteoarthropathy in a blesbok (Damaliscus dorcas phillipsi).

A 4.5-yr-old female blesbok (Damaliscus dorcas phillipsi) was radiographed following the appearance of lameness and swelling of the right front fetlock. Radiographic interpretation at that time was osteoarthritis caused by periosteal proliferation of the right metacarpus with periarticular osteophytes surrounding the fetlock. No treatment was initiated. Gradual abdominal enlargement over several months was interpreted as evidence of pregnancy. Six months after the initial lameness complaint, the blesbok suddenly collapsed and was unable to stand. Physical examination revealed a large firm mass occupying most of the abdomen that was found to be inoperable. Following exploratory laporotomy, the blesbok was euthanized. At necropsy, the mass weighed 17 kg. It had probably caused the animal's collapse. Histologically, the bony lesions of the right metacarpus, seen radiographically at the previous examination, were consistent with hypertrophic osteoarthropathy and may have been a sequela of the intra-abdominal mass.

Cardiopulmonary effects of three prolonged periods of isoflurane anesthesia in an adult elephant.

An adult 3,500-kg female African elephant was anesthetized 3 times for treatment of subcutaneous fistulas over the lateral aspect of each cubitus (anesthesia 1 and 2) and for repair of a fractured tusk (anesthesia 3). Lateral recumbency and anesthesia were achieved with etorphine (anesthesia 1 and 2) or etorphine and azaperone (anesthesia 3). The elephant's trachea was intubated and anesthesia was maintained by use of isoflurane and oxygen delivered via 2 standard large animal anesthesia machines joined in parallel. The range of total recumbency time was 2.4 to 3.3 hours. Breathing and heart rates, systemic arterial pressure, rectal temperature, PaO2, pH, and end-tidal gases were monitored. After administration of etorphine, measurements were made while the air-breathing elephant was recumbent, then every 5 minutes (cardiovascular) or 15 minutes (blood gases) after commencement of administration of isoflurane and oxygen. Tachycardia and hypertension were detected after administration of etorphine, but heart rate and systemic arterial pressure decreased to within normal ranges after administration of isoflurane and oxygen. The elephant remained well oxygenated while anesthetized and breathing a high oxygen mixture. The elephant had an uneventful recovery from each anesthesia.

Use of naltrexone for treatment of psychogenically induced dermatoses in five zoo animals.

Naltrexone was used successfully in controlling self-mutilation behavior in 3 zoo animals from 2 families (Felidae and Sciuridae). It had no effect on 2 other zoo animals from 2 families (Canidae and Ursidae). Long-term administration of glucocorticoids was not satisfactory in controlling the behaviors, and concerns were raised about potential long-term adverse effects, especially with regard to fertility. Detrimental effects were not noticed in any of the zoo animals treated with naltrexone. Two males successfully sired healthy offspring.

Freemartinism in a captive herd of Rocky Mountain bighorn sheep (Ovis canadensis).

Freemartinism in two animals from a captive herd of Rocky Mountain bighorn sheep (Ovis canadensis) at the Denver Zoological Gardens (Denver, Colorado, USA) is described. A young ewe had female external genitalia, a masculine appearance, and demonstrated male behavior as she matured. Another ewe with female external genitalia died as a yearling. Necropsy revealed a non-patent vagina and internal male genitalia. Both females were chimeric with karyotypes containing XX and XY sex chromosomes.