Infectious disease serologic survey in free-ranging Venezuelan anacondas (Eunectes murinus)

Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.

Control of reproduction and sex related behaviour in exotic wild carnivores with the GnRH analogue deslorelin: preliminary observations

The GnRH analogue deslorelin, in long-acting implants, was used in an attempt to temporarily control reproduction or aggression in wild carnivores in southern Africa and the USA. In the southern African study, 6 mg deslorelin was administered to cheetahs (eight females, four males), one female leopard and wild dogs (six females, one male) housed in groups, and 12 mg deslorelin was administered to two lionesses. None of the animals became pregnant after deslorelin administration apart from one wild dog that was mated at the initial treatment-induced oestrus. Two wild dogs and one lioness came into oestrus 12 and 18 months after deslorelin administration, respectively, thus demonstrating that the anti-fertility effects of deslorelin are reversible. Two lionesses and four cheetahs underwent oestrus without allowing mating 2-14 days after treatment. Simultaneous administration of progestins to three bitches and one lioness did not suppress oestrus. Male cheetahs had no spermatozoa on day 82 after treatment and did not impregnate two untreated females. Of three untreated female wild dogs housed with treated males, only the first female to enter oestrus (21 days after deslorelin administration) became pregnant. One month after treatment, plasma testosterone concentrations of male dogs were at basal values. In the USA study, three male sea otters that had been treated with 6 mg deslorelin ceased antagonistic behaviour and blood testosterone concentrations and size of the testes were still sharply reduced 24 months after treatment. Male red (n = 7) and grey (n = 5) wolves received 6 mg deslorelin in December 1998 but no effects on seasonal spermatogenesis and behaviour were observed. In a black-footed cat, sperm production, libido and aggressiveness decreased in response to treatment with 3 mg deslorelin and penile spines were not observed within 3 months after treatment, but were observed again 4-6 months later. Treatment of female red (n = 5) and grey (n = 5) wolves with deslorelin in December 1999 triggered preseason oestrus and mating, which were followed by one abortion and one successful pregnancy. Contraception was achieved in female Fennec foxes (n = 7) and two lionesses, which was observed in the foxes by an absence of increases in faecal progesterone concentrations. In two male bush dogs, administration of 3 mg deslorelin once or twice was insufficient to suppress reproductive function or behaviour.

Serum antigen 85 levels in adjunct testing for active mycobacterial infections in orangutans

Diagnosis of active mycobacterial disease in orangutans (Pongo pygmaeus) has been impeded by high levels of non-specific intradermal skin test reactivity to mycobacterial antigens. This may be due in part to cross reactivity between antigens, tuberculin concentrations used or other species-specific factors. Antigen 85 (Ag85) complex proteins are major secretory products of actively growing mycobacteria, and measurement of serum Ag85 could provide a method for determining active mycobacterial infections that was not dependent on host immunity. Serum Ag85 was measured by dot-immunobinding assay using monoclonal anti-Ag85, purified Ag85 standard and enhanced chemiluminescence technology in coded serum samples from 14 captive orangutans from a zoo in Colorado, 15 semi-captive orangutans in Malaysia, and 19 free-ranging wild orangutans in Malaysia. Orangutans from Colorado (USA) were culture negative for Mycobacterium tuberculosis and M. avium, although all had laboratory suspicion or evidence of mycobacterial infection; median serum Ag85 was 10 microU/ml (range, <0.25-630 microU/ml). Of the semi-captive orangutans, six were skin test reactive and two were culture positive for M. avium on necropsy. Median serum Ag85 for this group was 1,880 microU/ml (0.75-7,000 microU/ml), significantly higher than that of Colorado zoo or free-ranging Malaysian orangutans. Median serum Ag85 in the latter group was 125 microU/ml (range, 0.75-2,500 microU/ml). These data suggest that suggest that additional studies using more specific reagents and more samples from animals of known status are appropriate.

Pathology of fatal West Nile virus infections in native and exotic birds during the 1999 outbreak in New York City, New York

West Nile fever caused fatal disease in humans, horses, and birds in the northeastern United States during 1999. We studied birds from two wildlife facilities in New York City, New York, that died or were euthanatized and were suspected to have West Nile virus infections. Using standard histologic and ultrastructural methods, virus isolation, immunohistochemistry, in situ hybridization and reverse-transcriptase polymerase chain reaction, we identified West Nile virus as the cause of clinical disease, severe pathologic changes, and death in 27 birds representing eight orders and 14 species. Virus was detected in 23/26 brains (88%), 24/ 25 hearts (96%), 15/18 spleens (83%), 14/20 livers (70%), 20/20 kidneys (100%), 10/13 adrenals (77%), 13/ 14 intestines (93%), 10/12 pancreata (83%), 5/12 lungs (42%), and 4/8 ovaries (50%) by one or more methods. Cellular targets included neurons and glial cells in the brain, spinal cord, and peripheral ganglia; myocardial fibers; macrophages and blood monocytes; renal tubular epithelium; adrenal cortical cells; pancreatic acinar cells and islet cells; intestinal crypt epithelium; oocytes; and fibroblasts and smooth muscle cells. Purkinje cells were especially targeted, except in crows and magpies. Gross hemorrhage of the brain, splenomegaly, meningoencephalitis, and myocarditis were the most prominent lesions. Immunohistochemistry was an efficient and reliable method for identifying infected cases, but the polyclonal antibody cross-reacted with St. Louis encephalitis virus and other flaviviruses. In contrast, the in situ hybridization probe pWNV-E (WN-USAMRIID99) reacted only with West Nile virus. These methods should aid diagnosticians faced with the emergence of West Nile virus in the United States.

Immobilization of babirusa (Babyrousa babyrussa) with xylazine and tiletamine/zolazepam and reversal with yohimbine and flumazenil

Twelve babirusa (Babyrousa babyrussa) (four females/eight males) were immobilized 30 times during a 4-yr interval. Significantly higher premedication and immobilizing doses were needed for females than for males (P < 0.05). An i.m. preanesthetic xylazine dose of 1.88 +/- 0.37 mg/kg (range = 1.20-2.12 mg/kg) was used for females and 1.22 +/- 0.16 mg/kg (range = 0.82-1.43 mg/kg) for males. After xylazine, the animals were induced with i.m. tiletamine/zolazepam; females received 2.20 +/- 0.47 mg/kg (range = 1.78-3.33 mg/kg) and males received 1.71 +/- 0.34 mg/kg (range = 1.08-2.05 mg/kg). Anesthesia was reversed with yohimbine (0.14 +/- 0.03 mg/kg; range = 0.07-0.20 mg/kg) and flumazenil (1 mg flumazenil/20 mg zolazepam) either i.m. or i.v. This anesthetic combination produced smooth induction, good relaxation, and sufficient immobilization to perform routine diagnostic and therapeutic procedures (venipuncture, hoof and tusk trims, transportation, radiographs, ultrasound examination, weight determinations, and skin biopsies). Supplemental ketamine HCl or isoflurane was administered to two animals to effectively deepen or prolong the anesthetic plane, with no resultant adverse effects.

Herpesvirus-associated papillomas in koi carp (Cyprinus carpio)

From January through November 1994, 32% (7/22) of koi carp (Cyprinus carpio) maintained in indoor aquariums developed proliferative cutaneous lesions that consisted of single to multiple 2-10-mm whitish to pink fleshy masses usually associated with fin rays. Although scaleless koi were more commonly affected (3/6) than were normally scaled koi (4/16), the difference in incidence rates was not significant (chi2 text, P > 0.05). Lesions typically resolved spontaneously in 1-3 wk, occasionally persisted for >3 mo, and recurred in several fish after 2-5 mo. Fish were otherwise asymptomatic. Wet mount preparations from lesions were densely cellular and consisted of hyperplastic epidermal cells of normal morphology without parasites or inflammatory cells. Histologically, biopsies were consistent with papillomas and were characterized by a marked benign epidermal hyperplasia without inclusion bodies or inflammatory infiltrate. Transmission electron microscopic examination revealed intranuclear and intracytoplasmic herpesvirus virions. Virus isolation attempts were unsuccessful.

First records of Hyalomma aegyptium (Acari: Ixodida: Ixodidae) from the Russian spur-thighed tortoise, Testudo graeca nikolskii, with an analysis of tick population dynamics

During the fall of 1995 and the spring of 1996, 77 statistically comparable tick collections, comprising 792 specimens, were made from adults of the Russian spur-thighed tortoise, Testudo graeca nikolskii, at 4 sites along Russia's Black Sea coast. These are the first tick collections reported from T. g. nikolskii since its recognition as a taxonomic entity. All ticks were determined to be Hyalomma (Hyalomma) aegyptium, a common tortoise parasite in southern Russia that in 1930 was erroneously designated the type of subgenus Hyalommasta. Male ticks were recovered from more tortoises (67) than were females (57) or immatures (14), and nymphs were seen only in the fall. Significantly more ticks parasitized male tortoises than females, perhaps because males of T. g. nikolskii have larger home ranges. However, no functional relationship was found between tortoise ventral surface area and degree of tick infestation. Like other tortoise ticks, H. aegyptium is expected to decline in concert with its increasingly threatened hosts.

Glucosuria associated with renal calculi in Asian small-clawed otters

Urine from one female and 2 male Asian small-clawed otters (Aonyx cinerea) with bilateral renal calculi, one female with unilateral calculi, and one nonaffected male were evaluated for abnormal urinary crystalloid excretion. One otter with bilateral renal calculi had cystic calculi composed of calcium oxalate monohydrate and dihydrate. The 2 affected males were littermates, as were the 2 affected females, but the 2 litters were from different parents. At the time of the study, the otters did not have clinical signs of disease. Hematologic and serum biochemical, electrolyte, and enzyme values were normal. The urinary excretion of calcium, oxalate, uric acid, phosphate, citrate, and amino acids in otters with renal calculi was similar to that of the nonaffected otter. The 4 otters with renal calculi had glucosuria but the nonaffected otter did not have glucosuria. The glucosuria, in the absence of hyperglycemia, suggested a renal tubular transport defect for glucose. Other renal abnormalities were not found.

Effect of hunters' switch from lead to steel shot on potential for oral lead poisoning in ducks

Mallards and black ducks (n = 409) killed by hunters during the 1980 and 1981 hunting seasons in Pennsylvania (Susquehanna River and Crawford County) were examined to evaluate the effectiveness of regulations that converted the studied areas from lead to steel shotgun pellets in 1977-1978. Gizzards were examined for ingested lead and steel shot, and liver specimens were analyzed for lead. Since there is no evidence to suggest that ducks preferentially ingest steel or lead shot, it was concluded that ducks with steel shot would have contained lead shot. Therefore, we concluded that the conversion to steel shotgun pellets accounted for the decreased prevalence of ingested lead shot from 11.2% to 5.6%. Toxic concentrations of lead (greater than or equal to 6 ppm, wet weight) in the liver were found in 6 of 23 ducks that contained lead shot, whereas only 2 of 386 ducks without lead pellets had toxic concentrations. It was concluded that the conversion to steel shotgun pellets in the studied areas probably has decreased the exposure of ducks to lead shot, thereby decreasing the potential for lead poisoning.

Distal extremity necrosis in captive birds

The necropsy files of the National Zoological Park and Baltimore Zoological Society were reviewed for cases of distal extremity necrosis (DEN) in birds. Nineteen cases of DEN occurred following either trauma or frostbite. Six birds developed an apparently primary type of DEN in which no predisposing factors were obvious clinically. The toes and feet were most commonly involved, and in several cases the beak was also affected. Some pathologic evidence is provided that certain cardiovascular lesions may predispose birds to DEN by compromising circulation of the extremities.