Patrick J. Morris

OSTEOMYELITIS ASSOCIATED WITH SALMONELLA ENTERICA SS ARIZONAE IN A COLONY OF RIDGENOSE RATTLESNAKES (CROTALUS WILLARDI)

Abstract The identification of three Arizona ridgenose rattlesnakes (Crotalus willardi) with Salmonella arizonae–associated osteomyelitis led to a 5-yr prospective study of radiographic signs and Salmonella intestinal carriage rates in a 19-member colony of this rattlesnake species. Ventrodorsal radiographs were performed and cloacal swabs were cultured for Salmonella spp. annually. Ten snakes survived the 5-yr period, with six of them remaining free of bony lesions. Three snakes that had no bony lesions in 1995 developed radiographic signs of osteomyelitis during the study. Six snakes with bony lesions at the beginning of the study died or were euthanatized due to osteomyelitis during the study. The radiographic signs of osteomyelitis were progressive for five snakes that were serially radiographed. Only one snake with radiographic signs of osteomyelitis at the beginning of the study was still alive at the end of the study, and this animals bony lesions were more extensive at the end. Thirty-nine intestinal S. arizonae isolates, representing 13 serotypes, were obtained from the 19 snakes. Salmonella arizonae serotype 56:Z4,Z23 was isolated only once from a cloacal culture, from a snake that had no radiographic bone lesions. Twelve extraintestinal Salmonella isolates, representing two serotypes, were isolated from six snakes. All extraintestinal isolates except one were of S. arizonae serotype 56:Z4,Z23, and all isolates from bone were of this serotype. One snake with characteristic bone lesions died, and Providencia rettgeri was cultured from each of the tissues cultured, whereas no Salmonella spp. were isolated from this snake. Salmonella arizonae serotype 56:Z4,Z24 appears to have a tropism for bone and other extraintestinal sites in C. willardi and may cause a progressive, ultimately fatal disease in this species.

Chemical immobilization of rhebok (Pelea capreolus) with carfentanil-xylazine or etorphine-xylazine.

Abstract 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.

TRANSITIONAL CELL CARCINOMAS IN FOUR FISHING CATS (PRIONAILURUS VIVERRINUS)

Abstract 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.

SERUM GAMMA-GLUTAMYLTRANSFERASE AS A PROGNOSTIC INDICATOR OF NEONATAL VIABILITY IN NONDOMESTIC RUMINANTS

Abstract Rapid assessment of immune status in neonatal ruminants of endangered species facilitates early intervention in cases of inadequate passive transfer of maternal immunoglobulins. Serum gamma-glutamyltransferase (GGT) was used to evaluate suspected passive transfer status in 25 North Indian muntjac (Muntiacus muntjak vaginalis), 45 Cretan goats (Capra algagrus cretica), 20 white-lipped deer (Cervus albirostris), 25 Mhorr gazelles (Gazella dama mhorr), and 31 Soemmerrings gazelles (Gazella soemmerringi soemmerringi). Serum GGT, measured within 48 hr of birth, was compared with clinical condition at 5 days of age. Neonatal Soemmerrings and Mhorr gazelles with GGT >600 U/L were likely to survive without medical intervention, whereas GGT <400 U/L was a good indicator that the gazelle neonate would need medical intervention. Neonatal muntjac with GGT >200 U/L were also likely to survive without medical intervention. Because there is no gold standard for evaluating passive transfer status in neonatal nondomestic ruminants, it is recommended to evaluate the results of more than one diagnostic test, as well as clinical condition, in considering health status and disposition of neonatal ruminants of endangered species.

EVALUATION OF BLOOD GAS VALUES IN ANESTHETIZED SOUTHERN WHITE RHINOCEROS (CERATOTHERIUM SIMUM) VENTILATED WITH A NOVEL DEMAND VENTILATOR IN A ZOOLOGICAL PARK SETTING

Abstract Rhinoceros conservation efforts are essential to the survival of the species. One such effort is focused on using advanced reproductive technologies to produce viable northern white rhinoceros (Ceratotherium simum cottoni) embryos for implantation into southern white rhinoceros (Ceratotherium simum simum) surrogates. Anesthesia may be required to facilitate necessary procedures in these surrogate rhinoceros, but commonly reported side effects including hypercapnia and hypoxemia limit anesthetic recumbency time due to animal safety concerns. Although many interventions have been attempted, success in improving these physiologic parameters to date is mixed. The objective of this report is to describe arterial pH (pHa), blood gas (PaO2 and PaCO2), bicarbonate, base excess, lactate, and cardiovascular (heart rate, direct arterial blood pressure) values recorded in seven intubated and ventilated female southern white rhinoceros anesthetized for reproductive examinations in a zoological park setting. Anesthetic induction was accomplished using etorphine, medetomidine, butorphanol, and midazolam. The primary hypotheses were that PaO2 and PaCO2 would improve after intubation and mechanical ventilation. Induction and recovery observations were also summarized. Physiologic and laboratory data were analyzed using a mixed linear regression model using ranks. Statistical significance was set at P < 0.05. The PaO2 increased significantly (P < 0.001) following ventilation from a median value of 58 (range, 38–67) to 123 (range, 42–184) mm Hg. The PaCO2 significantly (P = 0.003) decreased from 63 (range, 55–73) to 52 (range, 30–75) mm Hg, with a corresponding improvement (P = 0.068) in pHa from 7.33 (7.25–7.34) to 7.37 (7.24–7.58) units. Intubation and ventilation improve respiratory parameters and may facilitate safe prolongation of anesthetic duration in white rhinoceros.

Repair of Horn and Frontal Bone Avulsion in a Forest Buffalo (Syncerus caffer nanus) with a Polymethylmethacrylate Dressing

Abstract A 2-yr-old female forest buffalo (Syncerus caffer nanus) presented with acute trauma to the right horn following a fight with a conspecific resulting in fracture and avulsion of the frontal bone, cornual process, horn, and juxtaposed skin. The animal was sedated for wound care and debridement followed by placement of an antibacterial-impregnated polymethylmethacrylate (PMMA) dressing. The dressing was noted to be intact on examination at day 7 post-injury, but had become dislodged and had to be replaced at day 11 postinjury. The replacement dressing ultimately fell off 68 days post-injury, revealing a healed circular scar. The use of PMMA in this case provided optimal wound care. In the 6 yr since the injury, the animal has grown a nearly normal-appearing horn, suggesting that the noncornual skin and associated skull structures may retain the ability to differentiate into a near-normal appearing horn because the entire horn apparatus in this case was avulsed.