Edward C. Ramsay

Herpesvirus Particles Associated With Oral and Respiratory Lesions in a California Desert Tortoise (Gopherus agassizii)

A 60-year-old captive California desert tortoise (Gopherus agassizii) which died in August 1990 at the University of California, Davis, California (USA), during treatment for colonic impaction had marked caseous necrosis of the oral cavity, choana, trachea, and lungs. Numerous intranuclear inclusion bodies and a large number of syncytial giant cells were seen in the oral cavity and respiratory tract along with bacterial granulomas. Pasteurella testudinis, Streptococcus veridans, and coagulase-negative Staphilococcus spp. were cultured from the lesions. Using electron microscopy, herpesvirus particles were observed in intranuclear inclusions and cytoplasm. Viral stomatitis, tracheitis, and bronchopneumonia complicated by bacterial infection were diagnosed. Although respiratory disease is common in desert tortoises, this is believed to be the first report of association with a viral infection.

NEOPLASIA IN FELIDS AT THE KNOXVILLE ZOOLOGICAL GARDENS, 1979-2003

Abstract A review of medical records and necropsy reports from 1979–2003 found 40 neoplasms in 26 zoo felids, including five lions (Panthera leo, two males and three females), three leopards (Panthera pardus, two males and one female), one jaguar (Panthera onca, female), 11 tigers (Panthera tigris, three males and eight females), two snow leopards (Panthera uncia, one male and one female), two cougars (Felis concolor, one male and one female), one bobcat (Felis rufus, male), and one cheetah (Acinonyx jubatus, female). Animals that had not reached 3 yr of age or had been housed in the collection less than 3 yrs were not included in the study. Neoplasia rate at necropsy was 51% (24/47), and overall incidence of felid neoplasia during the study period was 25% (26/103). Neoplasia was identified as the cause of death or reason for euthanasia in 28% (13/47) of those necropsied. Neoplasms were observed in the integumentary-mammary (n = 11), endocrine (n = 10), reproductive (n = 8), hematopoietic-lymphoreticular (n = 5), digestive (n = 3), and hepatobiliary (n = 2) systems. One neoplasm was unclassified by system. Multiple neoplasms were observed in 11 animals. Both benign and malignant neoplasms were observed in all systems except for the hematopoietic-lymphoreticular systems where all processes were malignant. Of the endocrine neoplasms, those involving the thyroid and parathyroid glands predominated (n = 8) over other endocrine organs and included adenomas and carcinomas. In the integumentary system, 63% (7/11) of neoplasms involved the mammary gland, with mammary carcinoma representing 83% (6/7) of the neoplasms. The rates of neoplasia at this institution, during the given time period, appears to be greater than rates found in the one other published survey of captive felids.

Cystic Endometrial Hyperplasia in Elephants

Most captive female elephants are nulliparous and aged and many have endometrial disease, factors that may hinder fertility. This study characterized the pathologic features and demographic distribution of endometrial lesions from 27 captive Asian (Elephas maximus) and 13 African elephants (Loxodonta africanus), 12- to 57-years of age. The principal lesion was marked cystic and polypoid endometrial hyperplasia (CEH), present in 67% of Asian and 15% of African elephants ranging from 26 to 57 years. The lower prevalence in African elephants likely reflects their younger age range in this study. Fourteen of 15 affected elephants with breeding information were nulliparous. These results suggest that CEH and polyps are common in aged nulliparous elephants, and the severity of these lesions may impair fertility. These findings will be useful in the interpretation of ultrasonographic findings during reproductive examinations of potential breeding cows. Also, breeding programs should focus on younger animals.

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.

Effects of Feeding on Plasma Uric Acid and Urea Concentrations in Blackfooted Penguins (Spheniscus demersus)

Abstract Preprandial and postprandial plasma uric acid concentrations were evaluated in 12 healthy blackfooted penguins (Spheniscus demersus). Five male and 7 female penguins were fasted overnight, and blood was collected the next morning. Four days later, the same group of birds was given a morning feeding of fish ad libitum. Each birds food consumption was recorded over a 2-hour feeding period. A blood sample was collected from each bird after removal of the fish (0- to 2-hour postprandial sample) and again 4 hours later (4- to 6-hour postprandial sample). Plasma samples were analyzed for uric acid and blood urea nitrogen (BUN) concentrations. In the 8 birds that consumed food during the 2-hour feeding period, plasma uric acid concentrations were significantly higher in both the 0- to 2-hour and 4- to 6-hour postprandial samples than in the preprandial samples. Uric acid concentrations were significantly lower in the 4- to 6-hour postprandial samples than in the 0- to 2-hour postprandial samples. Preprandial uric acid concentrations were <10 mg/dl, and 0- to 2-hour postprandial concentrations were >13.4 mg/dl (mean concentration = 21.2 mg/dl). No significant differences were found between preprandial and postprandial BUN concentrations. In penguins, uric acid concentrations must be measured after a fast to avoid a possible misdiagnosis of renal disease or gout.

SEROLOGIC SURVEY OF DOMESTIC FELIDS IN THE PETEN REGION OF GUATEMALA

Abstract Blood samples were analyzed from 30 domestic cats (Felis domesticus) from the Petén region of Guatemala to determine the seroprevalence of common pathogens that may pose a potential risk to native wild felids. Eight of the cats had been vaccinated previously; however, owners were unable to fully describe the type of vaccine and date of administration. In addition, blood samples were obtained from two captive margays (Leopardus wiedii). Samples were tested for antibodies to feline immunodeficiency virus, Dirofilaria immitis, feline panleukopenia virus, feline herpesvirus, feline coronavirus, canine distemper virus, and Toxoplasma gondii and for feline leukemia virus (FeLV) antigen. Fifty percent or more of the cats sampled were seropositive for feline herpesvirus (22 of 30), feline panleukopenia (15 of 30), and T. gondii (16 of 30). Five cats were positive for FeLV antigen. Both margays were seropositive for feline coronavirus and one was strongly seropositive to T. gondii. All animals were seronegative for D. immitis. This survey provides preliminary information about feline diseases endemic to the Petén region.

A COMPARISON OF CARFENTANIL/XYLAZINE AND TELAZOL®/XYLAZINE FOR IMMOBILIZATION OF WHITE-TAILED DEER

From October 2001 to January 2002, captive free-ranging white-tailed deer (Odocoileus virginianus) were immobilized with a combination of carfentanil citrate and xylazine hydrochloride. From this study, we selected a dose of carfentanil/xylazine for the purpose of comparing immobilization parameters and physiologic effects with those of a combination of tiletamine and zolazepam (Telazol®) and xylazine. Animals were initially given intramuscular injections of 10 mg xylazine and one of four doses of carfentanil (i.e., 0.5, 1.0, 1.5, and 2.0 mg). A carfentanil dose of 1.2 mg (x̄±SD=23.5±3.2 μg/kg) and 10 mg xylazine (0.2±0.03 mg/kg) were selected, based on induction times and previously published reports, to compare with a combination of 230 mg of Telazol® (4.5±0.6 mg/kg) and 120 mg xylazine (2.3±0.3 mg/kg). Time to first observable drug effects and to induction were significantly longer for deer treated with carfentanil/xylazine than with Telazol®/xylazine (P<0.01). Hyperthermia was common in deer immobilized with carfentanil/xylazine, but heart rate, respiration rate, and hemoglobin saturation were within acceptable levels. Degree of anesthesia of deer immobilized with Telazol®/xylazine was superior to deer immobilized with carfentanil/xylazine. The combination of 120 mg of naltrexone hydrochloride and 6.5 mg of yohimbine hydrochloride provided rapid and complete reversal (1.9±1.1 min) of carfentanil/xylazine immobilization. Animals immobilized with Telazol®/xylazine had long recovery times with occasional resedation after antagonism with 6.5 mg of yohimbine. The combination of carfentanil and xylazine at the doses tested did not provide reliable induction or immobilization of white-tailed deer even though drug reversal was rapid and safe using naltrexone and yohimbine.

Oral induction of anesthesia with droperidol and transmucosal carfentanil citrate in chimpanzees (Pan troglodytes).

Abstract Five chimpanzees (Pan troglodytes) initially received oral droperidol sedation (1.25 mg for a juvenile chimpanzee, body wt = 18.5 kg, and 2.5 mg for adults, body wt >20 kg, range: 18.5–71 kg) followed by transmucosal carfentanil administration at 2.0 μg/kg. This preinduction regimen was developed to produce heavy sedation or even light anesthesia in order to eliminate the need for or at least minimize the stress of darting with tiletamine/zolazepam at 3 mg/kg i.m. This study was designed to assess the safety and efficacy of transmucosal carfentanil. Once each animal was unresponsive to external stimuli, or at approximately 25 min (range 24–34 min) after carfentanil administration, naltrexone and tiletamine/zolazepam (N/T/Z) were combined into one intramuscular injection for anesthetic induction. Naltrexone was administered at 100 times the carfentanil dose in milligrams. For comparison, two chimpanzees received only droperidol, 2.5 mg p.o., followed by tiletamine/zolazepam, 3 mg/kg i.m. The preinduction period for all animals receiving carfentanil was characterized as smooth, with chimpanzees becoming gradually less active and less responsive to external stimuli. Two animals became very heavily sedated at 24 and 35 min, respectively, and were hand injected with N/T/Z. The other three chimpanzees became sternally recumbent but retained some response to stimuli, and N/T/Z was administered by remote injection with minimal response. Rectal body temperatures, pulse and respiratory rates, arterial oxygen hemoglobin saturation, and arterial blood gases were measured at initial contact (t = 0 min) and at 10-min intervals thereafter. Respiratory depression was present in all chimpanzees, regardless of protocol. Mean hemoglobin saturation was 91% for both groups. Mean partial pressure of oxygen, arterial values for carfentanil-treated and control animals were 64.4 ± 7.6 and 63.5 ± 6.0 at t = 0, respectively. Only the partial pressure of carbon dioxide, arterial (Paco2) and pH showed significant differences between treated and control animals. Mean Paco2 was greater and mean pH lower for the carfentanil-treated group compared with the controls at t = 0 (58.9 ± 3.7 and 50.3 ± 3.1 for Paco2 and 7.33 ± 0.02 and 7.40 ± 0.30 for pH, respectively). The results of this study suggest that oral droperidol followed by transmucosal carfentanil can be used effectively as a premedication regimen to produce profound sedation, which limits the stress of darting during parenteral anesthetic induction with tiletamine/zolazepam in chimpanzees. The main side effect of respiratory depression appears to be adequately managed by reversing the carfentanil at the time of induction.

FUNGAL DERMATITIS IN CAPTIVE PINNIPEDS

Abstract Fungal dermatitis was diagnosed in two captive gray seals (Halichoerus grypus) and four harbor seals (Phoca vitulina) between 1992 and 1994. Trichophyton mentagrophytes, Malassezia spp., and Yarrowia (Candida) lipolytica were isolated. Erythematous, thickened, alopecic skin lesions were present on the face and on the flippers, particularly around the nail bed. The two most important environmental factors associated with development of fungal dermatitis appeared to be excessive chlorination of pool water and warm water temperature.

SALMONELLA SURVEILLANCE IN A COLLECTION OF RATTLESNAKES (CROTALUS SPP)

Abstract Over the past 15 yr, Salmonella enterica ssp. arizonae (IIIa) 56:z4,z23:- has repeatedly been isolated from individual Crotalus willardi rattlesnakes with progressively debilitating osteomyelitis at the Knoxville Zoological Gardens. In April 2004, the serotype was linked with a fatal case of septicemia in another Crotalus species in this collection. Although the association of IIIa 56:z4,z23:- with disease in this colony of C. willardi is well established, prior disease or isolation of this serotype outside of the C. willardi colony had not been documented previously, and the serotypes distribution throughout the remainder of the Crotalus collection had yet to be determined. Forty-one fecal samples were obtained from each individual (n = 36) or exhibit group (n = 5) of crotalid snakes, representing nine species, housed at the zoo. Salmonella spp. were isolated from every sample, with 21 different serotypes. The 21 serotypes were distributed among S. enterica ssp. I (24%), IIIa (9%), and IIIb (67%). Although not recovered in the primary study, S. arizonae 56:z4,z23:- was recovered from additional samples taken from two C. willardi willardi. Although the overall recovery rate of this serotype from feces has been low, it seems that its distribution among the Crotalus collection at Knoxville Zoological Gardens remains largely restricted to the C. willardi species.