Biomedical evaluation of black lemurs (Eulemur macaco macaco) in Lokobe Reserve, Madagascar.

Complete medical evaluations were performed on 25 wild black lemurs (Eulemur macaco macaco) in Lokobe Reserve, northwestern Madagascar. Each animal received a complete physical examination. Weight, body temperature, heart rate, and respiratory rate were recorded. Blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fat-soluble vitamin analysis, trace mineral analysis, and Toxoplasma gondii and viral serology. Fecal samples were collected for bacterial culture and endoparasite examination. Ectoparasites were collected and identified. Values were compared to established ranges from captive black lemurs in North American zoos. Significant differences exist between captive and wild animals for total white blood cell count, segmented neutrophil count, band neutrophil count, eosinophil count, monocyte count, and basophil count, and for serum biochemistry values of aspartate aminotransferase, alanine aminotransferase, total bilirubin, serum alkaline phosphatase, total protein, creatinine, phosphorus, calcium, sodium, potassium, and creatine phosphokinase. One animal had a positive Toxoplasma titer. Detected endoparasites were identified as Lemuricola and Callistroura. Two ectoparasite mites were identified, one within the Psoroptes genus and one within the Laelapidae family. Enteric bacterial flora included Enterococcus sp., Staphylococcus sp., Escherichia coli, Streptococcus sp., Klebsiella ozaenae and Bacillus cereus.     

Preventing dental calculus formation in lemurs (Lemur catta, Eulemur fulvus collaris) and baboons (Papio cynocephalus).

The prevention of calculus accumulation in exotic animals is a relatively unexplored topic. A 6-mo study in ring-tailed lemurs (Lemur catta) and collared lemurs (Eulemur fulvus collaris) and two studies in baboons (Papio cynocephalus) (7.5 wks and 6.5 mo) tested the benefits of a primate diet coated with 0.6% sodium hexametaphosphate (HMP) in controlling calculus in these species using a sequential crossover design. The control regimen was an identical, but non-HMP-coated, dry primate chow. At study initiation, the primates were given a thorough dental prophylaxis and provided with the control diet or experimental diet. At the conclusion of the test period, the animals were anesthetized and examined for clinical calculus independently by two examiners. The animals were then given another dental prophylaxis, provided the alternate ration, and the foregoing procedures were repeated. When the animals were provided the HMP-coated diet, significant reductions in calculus formation of 48-62% were observed in the lemurs and the baboons. No clinically significant changes were observed in body weights or in blood chemistry values as a result of ingestion of the HMP-coated regimen.     

Chemical and surgical interventions to alleviate intraspecific aggression in male collared lemurs (Eulemur collaris)

To reduce male-male aggression in collared lemurs (Eulemur collaris) at Disney's Animal Kingdom, a clinical trial of leuprolide acetate (Depo-Lupron) injections through one breeding season (24 wk), followed by surgical castration after the breeding season was implemented. Daily behavioral observations to record occurrences of aggression were conducted before and during the injection period, as well as after castration. Fecal sample collection began 2 wk before the first injection and continued throughout the clinical trial to determine testosterone metabolite concentration. Samples were collected 3 times per week. Fecal collection and behavioral observation continued for 5 mo after castration. Fecal samples from 3 intact males from other institutions were obtained to compare testosterone values. While the lemurs were treated with Depo-Lupron, testosterone concentrations spiked immediately after injection, and then returned to pretreatment, nonbreeding-season levels after varying lengths of time. Analysis of the behavioral data indicated that aggression was not significantly reduced with Depo-Lupron treatment. However, after castration, contact aggression and wounding decreased to zero. Although the sample is small, this study presents the first documented data on the effects that chemical treatment with Depo-Lupron and surgical castration have upon hormone levels and aggressive behavior in eulemurs.     

Enzyme-linked immunosorbent assay to quantitate serum ferritin in black and white ruffed lemurs (Varecia variegata variegata).

Lemurs in captivity progressively accumulate iron deposits in a variety of organs (hemosiderosis) including duodenum, liver, and spleen throughout their lives. When excessive, the toxic effects of intracellular iron on parenchymal cells, particularly the liver, can result in clinical disease and death. The pathogenesis of excessive iron storage in these species has been attributed to dietary factors related to diets commonly fed in captivity. Tissue iron stores can be directly estimated by tissue biopsy and histologic examination, or quantitated by chemical analysis of biopsy tissue, However, expense and risk associated with anesthesia and surgery prevent routine use of tissue biopsy to assess iron status. A noninvasive means of assessing total body iron stores is needed to monitor iron stores in lemurs to determine whether dietary modification is preventing excessive iron deposition, and to monitor potential therapies such as phlebotomy or chelation. Serum ferritin concentration correlates with tissue iron stores in humans, horses, calves, dogs, cats, and pigs. Serum ferritin is considered the best serum analyte to predict total body iron stores in these species and is more reliable than serum iron or total iron binding capacity, both of which may be affected by disorders unrelated to iron adequacy or excess including hypoproteinemia, chronic infection, hemolytic anemia, hypothyroidism, renal disease, and drug administration. We have developed an enzyme-linked immunosorbent assay to measure serum ferritin in lemurs. The assay uses polyclonal rabbit anti-human ferritin antibodies in a sandwich arrangement. Ferritin isolated from liver and spleen of a black and white ruffed lemur (Varecia variegata variegata) was used as a standard. Ferritin standards were linear from 0 to 50 microg/L. Recovery of purified ferritin from lemur serum varied from 95% to 110%. The within-assay variability was 4.5%, and the assay-to-assay variability for three different samples ranged from 10% to 17%. The assay also measures serum ferritin in several other lemur species.     

Apparent digestibility of macronutrients in captive babirusa (Babyrousa babyrussa).

The apparent digestibilities of macronutrients by babirusa (Babyrousa babyrussa) were measured. Three group-housed captive babirusa were fed a diet of pelleted feed, boiled potatoes, grains, vegetables, and fruits. To determine reproducibility of the results, two digestibility trials were conducted 5 wk apart. The apparent digestibilities for crude protein, crude fat, and nonstructural carbohydrates (nitrogen-free extract) were 71, 76, and 78% of intake, respectively. Average apparent digestibilities of neutral detergent fiber and acid detergent fiber were 62 and 19% of intake, respectively. Hemicellulose (neutral detergent fiber minus acid detergent fiber) digestibility was 75%. Cellulose digestibility on average was 19% of intake, i.e., identical to acid detergent fiber digestibility because the diet did not contain a detectable amount of acid detergent lignin.     

Fiber digestibility by the orangutan (Pongo abelii): in vitro and in vivo.

Limited nutritional information exists on diets of free-ranging orangutans, Pongo abelii and P. pygmaeus. Although they are classified as frugivores, the chemical composition of their diet and their gastrointestinal anatomy suggest that they rely on fiber fermentation for a substantial portion of energy. However, the extent to which they can ferment fiber is not known. Continuous culture systems, inoculated with orangutan fecal bacteria, were established to determine the fiber-digesting capacity of orangutan hindgut microflora. The cultures received one of four treatments: soybean hulls, ground corncobs, corn starch, or no food. Neither dry matter nor neutral detergent fiber digestibilities differed significantly among treatments. However, neutral detergent fiber digestibilities were high for both the soybean hull (88.4%) and ground corncob (86.1%) treatments, indicating that the microflora had a strong fibrolytic capability. To determine whether the same fiber-degrading capacity occurred in vivo, two adult orangutans and one juvenile were fed four gel-matrix diets containing soybean hulls, ground corncobs, or ground primate biscuits. Neutral detergent fiber concentrations (dry matter basis) of the gel matrices were 52.9% with soybean hulls, 46.8% and 63.7% with ground corncobs, and 31.3% with ground primate biscuits. A fifth diet consisted of primate biscuits with 27.3% neutral detergent fiber (dry matter basis) and was considered the baseline diet. Neutral detergent fiber digestibility (74.5%) was greatest (P < 0.05) for the soybean hull gel diet and least (57.5% and 45.0%, respectively; P < 0.05) for the 63.7% neutral detergent fiber (dry matter basis) corncob gel diet and the baseline primate biscuit diet. Total volatile fatty acid concentrations in orangutan feces were not significantly different among diets; however, molar proportions of acetic, propionic, and butyric acid differed (P < 0.05) among diets. The results from both studies indicated that orangutans are capable of extensive fiber fermentation.     

Gongylonema pulchrum infection and esophageal squamous cell carcinoma in a vari (Lemur macaco variegata; Kehr 1792).

This report describes the morphologic and histologic features of a case of esophageal Gongylonema pulchrum infection and esophageal squamous cell carcinoma in a 17-yr-old, female vari (Lemur macaco variegates). The lemur had lived in a German zoo and had a clinical history of dyspnea, vomiting, and anorexia. At necropsy, a whitish, soft, nodular, centrally necrotic mass was found in the caudal third of the esophagus. In addition, numerous intraepithelial nematodes (G. pulchrum) were observed in the entire esophagus. Results suggest a relation between infection with G. pulchrum and development of an esophageal squamous cell carcinoma.     

Comparison of the efficacy and cardiorespiratory effects of medetomidine-based anesthetic protocols in ring-tailed lemurs (Lemur catta).

The relative efficacies and cardiorespiratory effects of three injectable anesthetic combinations containing medetomidine were evaluated in ring-tailed lemurs (Lemur catta). In addition, the direct effects of medetomidine on heart rate and blood pressure were evaluated in lemurs anesthetized with isoflurane. For injectable anesthesia, captive adult ring-tailed lemurs were anesthetized with medetomidine and ketamine (0.04-0.06 mg/kg, i.m. and 3 mg/kg, i.m., respectively), medetomidine, butorphanol, and ketamine (0.04 mg/kg, i.m., 0.4 mg/kg, i.m., and 3 mg/kg, i.m., respectively), or medetomidine, butorphanol, and midazolam (0.04 mg/kg, i.m., 0.4 mg/kg, i.m., and 0.3 mg/kg, i.m., respectively). For inhalation anesthesia, lemurs were mask-induced and maintained with isoflurane for 30 min before receiving medetomidine (0.04 mg/kg, i.m.). Sedation produced by medetomidine-ketamine was unpredictable and of short duration. Both medetomidine-butorphanol-ketamine (MBK) and medetomidine-butorphanol-midazolam (MBMz) provided adequate anesthesia for routine physical exams; however, the effects of MBMz lasted longer than those of MBK. Heart rates and respiratory rates were within clinically normal ranges for all groups, and lemurs remained normotensive throughout the study. Common side effects such as hypertension and bradycardia associated with the use of alpha2-adrenergic receptor agonist combinations in other species were not observed. Likewise, medetomidine administration had no effect on HR in lemurs receiving isoflurane. Lemurs in all groups were well ventilated and remained well oxygenated throughout the procedures, though arterial partial pressure of O2 was lowest in the MBMz group. All three injectable medetomidine combinations were effective in ring-tailed lemurs but only MBK and MBMz provided adequate depth and duration of anesthesia for use as sole regimes. For many clinical procedures in lemurs, MBMz offers advantages over MBK because of its longer duration of action and its rapid and more complete reversibility with specific antagonists.     

Leptospira infection in two black rhinoceroses (Diceros bicornis michaeli).

Two black rhinoceroses (Diceros bicornis michaeli) developed clinical leptospirosis without hemolytic crises. The first rhinoceros presented with peracute depression, anorexia, rear leg trembling, dysuria, glucosuria, gastrointestinal discomfort, and decreased fecal output and died within 12 hr. Necropsy and histopathology revealed lesions within multiple organs. Leptospirosis was diagnosed postmortem based on positive fluorescent antibody staining of liver. The second rhinoceros presented 2 mo later with similar signs. It survived with treatment and was diagnosed with leptospirosis based on serology using microscopic agglutination testing and detection of urinary antigen using a fluorescent antibody technique. Leptospira kirschneri serovar grippotyphosa was postulated as the etiologic agent, with transmission probably occurring through wallow contamination by wild raccoons (Procyon lotor).     

Trypanosoma evansi infections in Himalayan black bears (Selenarctos thibetanus).

The Asiatic or Himalayan black bear (Selenarctos thibetanus) is an endangered species. In South Asian countries, captive tamed Himalayan bears are commonly used by roving bear-charmers to entertain the people in rural and urban areas. In captivity, this species confronts several psychophysical traumas and communicable diseases, which are prevalent in other domestic species. The present report describes four cases of Trypanosoma evansi infection in live Himalayan charming bears, which originated from the Faisalabad and Jhang districts of Pakistan. The condition was characterized by pyrexia, accelerated pulse, tachypnea, depression, anemic mucous membranes, and ataxia (n = 3). Microscopic examination of peripheral blood films revealed moderate (n = 2) or high (n = 2) numbers of T. evansi. All four bears were treated twice at 3-day intervals with suramin sodium by using almost twice the dosage recommended for common domestic animals (10 mg/kg). The treated bears were found aparasitemic on repeat blood testing on days 5, 7, and 10 post-treatment. No adverse effects were noted and all four cases recovered in 3-7 days after completion of the second round of treatment. One bear died 8 days after the second treatment (day 11). This is the first report of T. evansi in bears.     

Survey and clinical application of serum iron, total iron binding capacity, transferrin saturation, and serum ferritin in captive black and white ruffed lemurs (Varecia variegata variegata).

Serum samples from 63 clinically normal captive black and white ruffed lemurs (Varecia variegata variegata) were analyzed to survey serum iron, total iron binding capacity, transferrin saturation, and serum ferritin levels. Data analysis showed no differences in these analytes attributable to sex, but significantly higher levels of serum iron, transferrin saturation, and serum ferritin in older animals. The survey data were examined in light of two black and white ruffed lemurs that were treated for iron overload with serial phlebotomies. Prior to therapy, both phlebotomized lemurs had excess hepatic iron deposition, but had serum iron, transferrin saturation, and serum ferritin below the upper limits observed in the survey animals, suggesting that some clinically normal animals included in the survey may have accumulated excess systemic iron. Serial phlebotomy therapy reduced serum iron, transferrin saturation, and serum ferritin in both animals. Three years after the conclusion of therapy in the one remaining case, serum iron and transferrin saturation have risen substantially, whereas serum ferritin has risen slightly. Serum iron, transferrin saturation, and serum ferritin may be useful predictors of systemic iron stores in this species, though the correlation between these parameters and systemic iron stores needs to be determined.     

Nocardia nova causing pulmonary nocardiosis of black crakes (Limnocorax flavirostra).

Natural nocardial infection has been reported in many different species including mammals and fish, but reports in birds remain uncommon. Eight juvenile Black Crakes (Limnocoraxflavirostra) died unexpectedly at the Basle Zoo. Necropsy revealed disseminated white, firm nodules, 1-3 mm in diameter, throughout the lung parenchyma. Histologically, the lungs contained multiple, often confluent granulomas with central necrosis. Delicate, gram-positive, 0.5- to 1.0-microm-wide, branching, occasionally beaded, filamentous organisms were visible in necrotic centers. These organisms were acid fast when stained with Fite-Faraco. No histologic lesions were seen in other organs. Nocardia nova was isolated from liver, spleen, kidney, and lung. Granulomatous and necrotizing nocardial pneumonia with agonal septicemia was diagnosed, suggesting an aerogenous infection. To our knowledge, this is the first reported epizootic outbreak of nocardiosis in birds, which is additionally unusual because it was caused by N. nova.     

Gastrointestinal Morphology of the Crowned Lemur (Eulemur coronatus)

I provide measurements of the gastrointestinal tract of a captive female Eulemur coronatus, obtained at necropsy, and describe its morphology. The small intestine, caecum and colon were short when compared with those of other lemur species. The ratio of intestine length to body length was low. Distinct sacculations were present in the caecum, but not in the colon. The results suggest that E. coronatus is able to digest a certain amount of structural polysaccharides as contained in plant cell wall. The main fermentation chamber seems to be the caecum. Its digestive morphology implies that E. coronatus relies on a diet higher in energy‐rich cell contents than those of other lemur species of similar body size.     

Visceral mast cell tumor in a captive black jaguar (Panthera onca).

Little is known about neoplasia in the jaguar (Panthera onca), the largest American feline. A captive black jaguar was diagnosed at necropsy with a mastocytic form of visceral mast cell tumor similar to that which occurs in domestic cats. This animal had no previous clinical disease and died during anesthesia for a routine dental treatment.     

Spotted black snake (Pseudechis guttatus) envenomation in a maned wolf (Chrysocyon brachyurus).

Envenomation by a spotted black snake (Pseudechis guttatus), following multiple bites on the buccal mucosa of a captive maned wolf (Chrysocyon brachyurus), caused the animal's collapse, hemolysis, rhabdomyolysis, local tissue necrosis, hepatic and renal failure, and subsequent death. The wolf died despite intensive supportive care including antivenom administration, fluid support, and a blood transfusion. Gross necropsy findings included myocardial and intestinal hemorrhage, pulmonary congestion, hepatomegaly, and splenomegaly. Microscopic examination of formalin-fixed tissues demonstrated pulmonary and abdominal visceral hemorrhage, acute nephrosis with casts, multifocal hepatic necrosis, and splenic congestion.     

Acute lymphoblastic leukemia in a juvenile southern black rhinoceros (Diceros bicornis minor).

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.     

Idiopathic distal esophageal dilation in a southern black rhinoceros (Diceros bicornis minor).

An adult female southern black rhinoceros (Diceros bicornis minor) experienced intermittent periods of regurgitation while eating, suggesting an esophageal disorder. Endoscopy for evaluation of the trachea, esophagus, and stomach revealed a 30-mm nasopharyngeal orifice with associated recess located in the caudodorsal pharynx and a 10-cm dilated segment of the distal esophagus that was presumably the cause of regurgitation. Dietary management of esophageal dilation through short-term utilization of a "soft feed" program successfully eliminated the regurgitation. This is the first report of esophageal dysfunction in a rhinoceros.     

Laryngeal squamous cell carcinoma in a North American black bear (Ursus americanus).

A 10-yr-old female black bear (Ursus americanus) at the North Carolina Zoological Park presented with a 2-wk history of intermittent coughing and stertor. The animal was anesthetized for examination, and at intubation, a large mass associated with the tonsils and larynx was observed obstructing the airway. Cardiopulmonary collapse occurred during the procedure, and efforts at resuscitation were ineffective. At necropsy, an 8 cm times 6 cm times 5 cm mass was present in the larynx, infiltrating the epiglottis and obstructing the airway. Regional lymph nodes were mildly enlarged and contained tan inspissated substance. Histologically, the neoplasm was composed of nests of keratinizing squamous epithelial cells with evidence of lymphatic invasion and metastases to regional lymph nodes.     

Retrospective evaluation of renal disease in captive black howler monkeys (Alouatta caraya).

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.