Captive mallards (Anas platyrhynchos), fed an all-grain diet for up to 5 months during the winters of 1991 to 1992 and 1992 to 1993, developed lesions of squamous metaplasia; some had no detectable hepatic vitamin A. Vitamin A deficiency in mallards was defined as hepatic levels of retinyl palmitate <2 μg/g liver. Lesions were found only in ducks with low levels of hepatic vitamin A, but not all ducks with these low levels of hepatic vitamin A had histological lesions. The prevalence of lesions in the esophagus was greatest cranially and caudally and less common in the central region. Palatine salivary glands rarely were affected. Mallards with liver stores >600 μg of hepatic retinyl palmitate per g liver, fed a diet deficient in vitamin A were unlikely to become deficient over a 5 month period. Birds fed an all-grain diet had significantly lower vitamin A concentrations in their liver compared to those fed an all-grain diet with vitamin A added. Liver weight, when corrected for body size, did not affect vitamin A concentration. Serum retinol levels were conserved over a large range of hepatic vitamin A levels but levels below 300 μg retinol/1 were useful in detecting vitamin A deficiency in captive mallards. Based on the findings, the presence of lesions provides a conservative measure of vitamin A status in ducks and tissue levels should be measured in instances when mallards have questionable vitamin A status.

Vitamin A status of wild male mallards (Anas platyrhynchos) overwintering in Saskatchewan, Canada was determined. Vitamin A levels <0.2μg hepatic retinyl palmitate/g liver, occurred in 6% and 25% of male mallards sampled in 1991 to 1992 and 1992 to 1993, respectively. There was no temporal trend in vitamin A levels over either winter. Squamous metaplastic lesions, commonly associated with vitamin A deficiency in domestic animals, were not observed in any bird; hence, they were not a good indicator of vitamin A status in wild mallards. Serum retinol was not a good indicator of vitamin A status in wild mallards. Many mallards in good body condition had low vitamin A levels; thus, we propose that good body condition and ample fat stores are not indicative of overall health of the bird.

Cysts containing one or more physalopterid larvae were found commonly in the gastric tissues of snakes (Elapidae) and in all five families of lizards (Agamidae, Gekkonidae, Pygopodidae, Scincidae and Varanidae) in Western Australia. Snakes had been collected from many locations in tropical and arid Western Australia between 1912 and 1976, and lizards from the Great Victoria Desert between September 1978 and March 1979. Most cysts occurred in the submucosa; others were found within stomach muscle, and subserosally on the external stomach surface. Encysted and apparently viable larvae were associated with minimal host inflammatory response. Encysted dead and degenerating larvae occurred in cysts with inflammatory cell infiltrates, principally in snakes.

Gizzards from 64 hunter-shot Canada geese (Branta canadensis) were collected in southern Illinois (USA) in December 1991 and January 1992 to determine the prevalence and intensity of gizzard nematodes. Three species of gizzard nematodes were recovered: Amidostomum anseris, Amidostomum spatulatum, and Epomidiostomum crami. The prevalence of infection was 98%. Mean intensity was 17.8 nematodes per host and was significantly greater for immature geese (40.3 nematodes/host) than for adult geese (10.9 nematodes/host). The intensity of both A. anseris and E. crami was greater in immature geese, but even the most heavily infected birds did not display serious lesions. Despite a dramatic increase in the population of geese, mean intensity in adult geese was similar to mean intensity reported from earlier studies at the same site. Mean intensity in immature geese in 1991 and 1992 was greater than in earlier studies.

Lynx (Felis lynx) carcasses were collected during the 1989 to 1990 through 1992 to 1993 trapping seasons in Alaska (USA). Seven areas were represented. Tongue samples were removed from 1,065 carcasses. Specimens were examined for the presence of Trichinella nativa larvae by means of enzymatic digestion. Overall prevalence was 21%. Both prevalence and number of larvae per gram of host tissue were directly related to age of the host. Age-specific prevalence ranged from 4% for kittens up to 59% for lynx 5 yr of age and older. For infected lynx, intensity ranged from 0.27 larvae per gram of host tissue for kittens up to 2.35 larvae per gram for lynx 3 yr of age and older. Location-specific prevalence ranged from 19% to 27%. Year-specific prevalence ranged from 13% to 26%. Prevalence in both males and females was 21%.

Four of five reindeer (Rangifer tarandus tarandus) obtained from a Besnoitia sp.-infected herd at the Assiniboine Park Zoo in Winnipeg, Manitoba, Canada, in October 1989, had evidence of mild dermatitis over the articular surfaces of carpal and tarsal joints. Cysts of Besnoitia sp., either surrounded by inflammatory reactions or without evident host response, were present within the dermis, submucosa of the nasal turbinates, periosteum, tendons, testes and hooves. The light microscopic and histochemical features of Besnoitia sp. from reindeer were indistinguishable from those of other Besnoitia spp. described in cattle, rodents and horses.The Besnoitia sp. cysts and organisms from reindeer were unique in that bradyzoite membrane micropores and cytoplasmic enigmatic bodies were not observed. Two cats were fed cysts of Besnoitia sp. but no oocysts were detected in feces for 90 days post-infection.

A competitive enzyme-linked immunosorbent assay (C-ELISA), using a group-specific monoclonal antibody against bluetongue virus (BTV), was applied to detect anti-BTV antibodies in serum samples from two llamas (Llama glama) experimentally infected with BTV serotype 10. Antibodies were detected in both llamas by 1 wk or 2 wk post-infection. Antibodies to BTV increased exponentially during the first 4 wk in both llamas and stabilized at an elevated level during the remaining 5-wk-period of the experiment. We evaluated the C-ELISA for 1,442 field sera from bluetongue-free areas, collected from 398 llamas in New Zealand as well as 451 elk (Cervus elaphus canadensis), 323 bison (Bison bison) and 270 reindeer (Rangifer tarandus tarandus) in Canada. Based on the frequency distribution of the C-ELISA values, we propose that the current negative cut-off value of 50% inhibition established for bovine field sera also can be applied to the sera from these wild ruminants. The C-ELISA values for other wild ruminant field sera collected in bluetongue-free areas of Canada from 98 native caribou (Rangifer tarandus caribou), 32 white-tailed deer (Odocoileus virginianus), 14 moose (Alces alces), and nine muskoxen (Ovibos maschatus) and 15 yak (Bos grunniens) also were less than 50%, with the exception of three caribou samples. Based on our results, we propose that the C-ELISA be used as a rapid and specific test for serodiagnosis of BTV infection in llamas and possibly other wild ruminants.

Serum samples collected from 1,396 white-tailed deer (Odocoileus virginianus) in five areas of Georgia (USA) from 1989 to 1991 were tested for precipitating and serum neutralizing (SN) antibodies to the enzootic North American epizootic hemorrhagic disease virus (EHDV) and bluetongue virus (BTV) serotypes. Precipitating antibodies to the EHDV or BTV serogroups, as detected by agar gel immunodiffusion (AGID) tests, were present in 35%, 29%, and 39% of deer sampled in 1989, 1990, and 1991, respectively. Significant differences (P < 0.05) in precipitating antibody prevalence were detected between physiographic regions during all years. Antibody prevalence consistently was highest in deer sampled from the Coastal Plain (77%), followed by the Piedmont (33%), Ridge and Valley (29%), Barrier Island (5%), and Blue Ridge (2%) regions. All AGID-positive samples were tested by SN tests for antibodies against all North American EHDV and BTV serotypes (EHDV serotypes 1 and 2, BTV serotypes 2, 10, 11, 13, and 17). Criteria for previous exposure to a specific serotype were either detection of monospecific results or clusters of positive results against that serotype. Serologic evidence of previous exposure to EHDV serotypes 1 and 2, and BTV serotypes 11 and 13 was detected during all years. Predominant serotypes varied among years. In general, evidence of exposure to EHDV serotype 2 appeared annually while exposure to BTV serotype 13 and EHDV serotype 1 decreased and increased, respectively. To determine serotype diversity prior to 1989, 134 AGID-positive white-tailed deer serum samples collected from 1967 to 1988 also were tested by SN. Evidence of exposure to EHDV serotypes 1 and 2 and BTV serotypes 11, 13, and 17 was detected.

Serum samples were collected from white-footed mice (Peromyscus leucopus) and raccoons (Procyon lotor) during 1983, 1984, and 1990 through 1993 in Connecticut (USA) and were tested in enzyme-linked immunosorbent assays (ELISA) against whole cell Borrelia burgdorferi sensu stricto (strain 2591) and the following recombinant antigens of this spirochete: p41-G (an immunogenic epitope of flagellin), outer surface protein (OSP)A, and OSPB. Antibodies were most frequently detected when whole cell antigen was used in the analyses. Reactivity to highly specific recombinant antigens also occurred and was particularly helpful in verifying B. burgdorferi infection. Geometric mean antibody titers for assays with whole cell antigen ranged from 453 to 2,363 and were at least two-fold higher than geometric means calculated for tests with recombinant antigens, which ranged from 226 to 640. With greater sensitivity, an ELISA with whole cell antigen is preferred for determining presence of antibody in sites enzootic for Lyme borreliosis. However, use of highly specific recombinant antigens, particularly OSPA and OSPB, in an ELISA can provide supportive information in ecological studies of this disease.

We determined if the ear biopsy location affected detection of Borrelia burgdorferi when either culture or the polymerase chain reaction (PCR) was used among 50 white-footed mice (Peromyscus leucopus), live-captured in a Lyme disease enzootic area in Maryland (USA) between March and October of 1991 and 1992. The infection status of individual mice was determined by organ culture; ear biopsy samples were obtained from the peripheral and central part of the ear for detection of B. burgdorferi by culture and by PCR. Overall, B. burgdorferi was cultured from one or more tissue samples in 33 (66%) of 50 captured mice. Among infected mice, B. burgdorferi was detected by culture in 29 (88%) of 33 peripheral and 28 (85%) of 33 central ear biopsy samples. By PCR it was detected in 24 (73%) of 33 peripheral and all 33 central samples (P = 0.002). Detection of B. burgdorferi by culture was independent of the ear biopsy location; however, the organism was detected by PCR with greater frequency in central ear biopsy samples as compared to peripheral samples. Agreement between culture and PCR was moderate (Kappa = 0.64) on peripheral ear samples and excellent (Kappa = 0.79) on central samples. We propose that when ear biopsy samples are used to detect B. burgdorferi by PCR in wild-caught P. leucopus, removal of biopsy samples from the central part of the ear will achieve maximum sensitivity and will achieve the highest concordance between assays when both culture and PCR of ear biopsy samples are conducted in parallel.

We evaluated drug resistance and R plasmids of 554 strains of Escherichia coli isolated from feces of migratory waterfowl, including whistling swans (Cygnus columbianus), pintails (Anas acuta) and black-tailed gulls (Larus crassirostris) collected from the San-in District, Japan, between each November and March, 1983 to 1984, 1984 to 1985, and 1985 to 1986. Seven antimicrobial agents were tested: dihydrostreptomycin (DSM), kanamycin, spectinomycin, ampicillin (ABPC), oxytetracycline (OTC), chloramphenicol, and sulfadimethoxine (SDMX). Many strains were resistant to several drugs; in particular, all strains were resistant to SDMX. Both multiple drug resistant strains and drug resistance patterns occurred most frequently in strains isolated from whistling swans, followed by black-tailed gulls, and pintails, respectively. Of 233 strains, 128 (55%) carried transmissible R plasmids. The drugs with the largest number of resistance patterns observed were, in descending order, OTC, DSM, ABPC, and SDXM.

We determined how long Pasteurella multocida could survive in experimentally-exposed freshwater snails. Physa virginea were collected from the Sacramento National Wildlife Refuge, Glenn County, California (USA), an enzootic site for avian cholera. Exposure to water containing up to 10⁷ P. multocida per ml did not produce observable changes or mortality in snails. A minimum of 84 P. multocida per snail was necessary for detection among the normal snail bacterial flora. When snails were exposed to P. multocida in vials containing 10⁷ bacteria per ml, P. multocida was detected for up to 72 hours in snails. When uninoculated snails were placed in aquaria containing 10⁶ P. multocida per ml, P. multocida was not detected within the snails; further, P. multocida was detected in the water for only 24 hours at this level. Based on these results, we propose that P. virginea is not an effective reservoir for P. multocida.

We determined the prevalence of mycoplasma infection in breeding mallard (Anas platyrhynchos) and canvasback (Aythya valisineria) hens and their broods from the central United States (1988 to 1990); and wintering American black duck (Anas rubripes) and mallard hens from the eastern United States (1990 to 1993). Mycoplasmas were isolated by culturing tracheal swabs from 656 live birds and tissue samples from 112 dead waterfowl. Nine (18%) of 51 mycoplasma isolates were identified as Mycoplasma anatis; M. anatis was recovered from four mallards, a black duck, and a gadwall (Anas strepera) duckling. Nineteen (37%) of 51 mycoplasma isolates were identified as Mycoplasma cloacale; these isolates were obtained from mallard, canvasback, and black duck adults, and from a mallard duckling. Additional unspeciated mycoplasmas were isolated from mallards, black ducks, and one canvasback.

To determine the prevalence of European Bat Lyssavirus 1 (EBL1), antibodies plasma samples were obtained from 175 serotine bats (Eptesicus serotinus) from four colonies in southern Spain between September of 1991 and September 1992. Five bats were detected with EBL1 virus in one colony in 1989. The prevalence of antibodies rose to 74% in one of the colonies studied (Villarrasa) in the spring of 1992. After a few months the prevalence declined to under 10%. Individuals with a high antibody level in the spring (up to ED₅₀ = 280) had very low titers or no antibodies in the following summer and autumn.

The role of white-tailed deer (Odocoileus virginianus) in the epizootiology of anaplasmosis in the southeastern United States was examined through retrospective and prospective serosurveys and by experimental infection studies. No serum antibody reactive to Anaplasma marginale was detected with an indirect fluorescent antibody (IFA) assay from any of 1,376 free-ranging deer sampled from 1968 through 1990 from 13 states and Puerto Rico. Thirty-one additional deer from three bovine anaplasmosis enzootic premises also were negative by IFA and Giemsa-stained blood films. Three captive deer given A. marginale intravenously developed antibodies 38 to 41 days post-inoculation (DPI) and remained seropositive for the duration of the study (161 to 287 DPI). At 42 DPI, rickettsemias of approximately 0.0001% infected erythrocytes were observed in all three deer using a DNA probe; low rickettsemias (maximum 0.01%) persisted through 56, 63, and 87 DPI, respectively. One deer had a recrudescent infection from 126 to 146 DPI (maximum rickettsemia 0.001%). We believe that white-tailed deer in the southeastern United States, even though susceptible to A. marginale infection, are not exposed naturally, even at enzootic sites. Furthermore, white-tailed deer did not develop rickettsemias sufficient to support mechanical transmission by biting flies, which is believed to be the primary means of anaplasmosis transmission in this region.

Blood samples were collected from the bill sinus of nine free-living platypuses (Ornithorhynchus anatinus) within 12 min of capture of each and again after 1 to 12 hr, New South Wales, Australia, 1981 to 1988. In seven animals which were not anesthetized, there was a significant (P < 0.01) fall in lymphocyte count between the two samples. The reduction ranged from 10 to 58% of the initial lymphocyte count and caused a significant reduction in the total white cell count (P < 0.05). Both the neutrophil and the lymphocyte counts increased in two platypuses which were anesthetized with ether prior to collection of the second blood sample. We propose that the peripheral blood lymphocyte count is a simple means of monitoring the stress response of non-anesthetized, newly-captured platypuses and may be a useful adjunct to behavioral observation.

Ten black bears (Ursus americanus) were immobilized with orally administered carfentanil citrate. The total carfentanil dose was mixed with 5 to 20 ml honey and given incrementally to captive bears. The bears ranged in weight from 80 (estimated) to 233 kg. Total carfentanil doses ranged from 0.7 to 3.0 mg, resulting in dosages of 6.8 to 18.8 μg carfentanil/kg. Mean (±SD) times from estimated 80% mixture consumption to sternal recumbency, and first safe human contact were 7.7 ± 2.3 min and 19.7 ± 5.6 min, respectively. Undesired side effects of immobilization were muscle rigidity, bradypnea, and oxygen desaturation. All bears received diazepam to alleviate muscle rigidity and were insufflated with oxygen during immobilization. Nine immobilizations were considered satisfactory or good. The bear receiving 6.8 μg carfentanil/kg, the lowest dosage used, was very excited during induction and required intravenous (IV) ketamine to permit safe examination. Immobilization was reversed with 100 mg naltrexone/mg carfentanil administered (75% subcutaneous, 25% IV). Bears recovered to full mobility in 6.3 ±1.9 min. Five bears vomited post-recovery but no episodes of renarcotization were observed.

A previously undescribed species of Chloromyxum (Myxozoa: Chloromyxidae) was found in plasmodia adhering to the epithelium of the gall bladders in salamanders of the genus Eurycea (Caudata: Plethodontidae) from Arkansas and Texas (USA) in November, December, and January, 1987 to 1994. Bivalved spores of Chloromyxum salamandrae sp. n. from Eurycea multiplicata griseogaster (type host) were subspherical, with a mean size ± SD of 8.3 ± 0.3 × 7.7 ± 0.4 (7.8 to 8.8 × 7.0 to 8.2) μm (n = 20), and had a shape index (length/width) of 1.07 ± 0.03 (1.02 to 1.14). The valves measured 0.8 to 1.0 μm thick and had 10 to 12 external striations each. Each of the four polar capsules were piriform, with a mean size ± SD of 4.0 ± 0.1 × 2.6 ± 0.1 (3.8 to 4.2 × 2.4 to 2.8) μm (n = 20), and there appeared to be about four coils of each polar filament. The sporoplasm was irregular in shape and appeared to be binucleate. Adherent plasmodia observed in winter months were small, with a mean size ± SD of 31.5 ± 6.3 × 24.9 ± 2.6 (20 to 40 × 20 to 30) μm (n = 20), and contained zero to eight disporoblastic spores each. The myxozoan occurred in nine of 14 E. multiplicata griseogaster, three of eight E. multiplicata multiplicata, and two of 12 E. neotenes. This represents the first report of a Chloromyxum sp. from Amphibia in the Western hemisphere.

Caryospora simplex is reported for the first time from the feces of a captive female Kaznakov's viper (Vipera kaznakovi) in Albuquerque, New Mexico (USA). Coccidian mer-onts and gamonts were observed in the intestinal epithelial cells of another female Kaznakov's viper that died in October 1993.

We report a severe enteric infection of Sarcocystis sp. from a wild-caught bull-snake (Pituophis melanoleucus sayi). The animal was collected in October 1988 by a commercial dealer, imported into the United Kingdom during November 1988 and purchased by the London Zoo, in December 1988. The animal was not fed after capture and was anorexic from the time of purchase to the time of death in January 1989. On necropsy, the animal was emaciated and the mucosa of the proximal intestine was markedly thickened. The lamina propria was packed with oocysts, and enterocytes were parasitized by an organism which closely resembled Sarcocystis roudabushi and Sarcocystis idahoensis, two bisporocystid coccidia described previously from Pituophis melanoleucus. We propose that Sarcocystis idahoensis and Sarcocystis roudabushi are synonymous since both occur in the same host species, both invade the intestinal lamina propria and enterocytes, and sporocyst measurement ranges of both species overlap. This is the first report of death believed to be due to sarcocystosis in a naturally-infected definitive host.

The hemosporid community of 76 wild turkeys (Meleagris gallopavo silvestris) from South Carolina (USA) was examined using thin blood smears collected during January and February 1994. High prevalences and low abundances of hemosporids characterized this community. Leucocytozoon smithi and Haemoproteus meleagridis occurred in 100% and 54% of the turkeys, respectively; a Plasmodium sp. was found in one bird. Prevalence of H. meleagridis was significantly higher in juvenile turkeys than adults, but prevalences did not differ significantly among four trap sites or by host sex. Mean (±SE) intensities of L. smithi, H. meleagridis, and Plasmodium sp. were 3.4 ± 0.4, 1.8 ± 0.3, and 3.0 per 10,000 erythrocytes, respectively. Abundances of L. smithi, H. meleagridis, and Plasmodium sp. were 3.4 ± 0.4, 0.9 ± 0.2, and <0.1 ± <0.1 per 10,000 erythrocytes, respectively. Juvenile turkeys had higher rank abundance values of L. smithi than adults, whereas no differences were found among trap sites or between sexes. No differences in rank abundances of H. meleagridis were found among trap sites, host age, or host sex variables. Collectively, both common hemosporid species varied by host age, reflecting higher abundances in juvenile turkeys. Patterns of hemosporid prevalence appeared similar to patterns found in subtropical regions. Based on our data, we recommend using prevalence and abundance data to analyze the structure and pattern of hemosporid communities at the component community level.

Lung tissue from 39 bottlenose dolphins (Tursiops truncatus) found dead off the U.S. Atlantic and Gulf of Mexico coasts from 1987 to 1994 was examined for the presence of morbillivirus using a reverse transcriptase polymerase chain reaction (RT-PCR) technique. Of the Atlantic cases examined, six of six were positive using this assay; 18 of 25 Gulf of Mexico cases with amplifiable RNA also were found to be positive, and eight additional specimens had no amplifiable RNA. The RT-PCR allowed the diagnosis of morbillivirus infection to be made from either sections of paraffin-embedded formalin-fixed material or from unfixed tissue. Confirmation of diagnosis was made by subsequent hybridization of the amplified products with a dolphin morbillivirus specific probe using the Southern blot technique. Application of this method to autolyzed post-mortem tissues allows diagnoses of morbillivirus infection to be made in specimens which cannot be evaluated by histologic and immunocytochemical techniques.

Eight black-backed jackals (Canis mesomelas) and seven side-striped jackals (Canis adustus) were given SAD (Berne) rabies vaccine by direct oral instillation. Three different vaccine doses were used: 10⁶³, 10⁶⁸ and 10⁷⁵ median tissue culture infectious doses. Two additional jackals were given vaccine in chicken heads. One group of jackals was challenged with a lethal dose of jackal-derived rabies virus 1 mo after vaccination and a second group 12 mo after vaccination. All 17 vaccinated jackals developed high and persistent serum neutralizing antibody titers. All challenged jackals resisted a lethal dose of rabies virus, whereas three control jackals given the same challenge succumbed to rabies.

During March 1990, a subadult raccoon found dead in northeastern Pennsylvania (USA) had gross lesions of multifocal hepatitis. Microscopically, multifocal randomly distributed areas of acute necrosis with intranuclear viral inclusions were seen in liver, spleen, adrenal glands, and tongue. Ultrastructural and immunoperoxidase results of formalin fixed liver were compatible with herpesvirus infection. This virus could be unique to the raccoon or may have been acquired from another species.

During the summer of 1986, more than 400 California gulls (Larus californicus) and ring-billed gulls (Larus delawarensis), primarily fledglings, died on an island in Lake Sakakawea near New Town, North Dakota (USA). Mortality was attributed largely to chlamydiosis. Necropsy findings in nine carcasses included splenomegaly (n = 9), hepatomegaly (n = 4), and pericarditis (n = 1). Livers from three California gulls and two ring-billed gulls, and spleens from the same five birds plus a third ring-billed gull were positive for Chlamydia psittaci by the direct immunofluorescence test. Chlamydia psittaci was isolated from separate pools of liver and spleen from one California gull and one ring-billed gull. This is believed to be the first record of epizootic chlamydiosis in gulls and the second report of epizootic chlamydial mortality in wild birds in North America.

Red-backed voles (Clethrionomys gapperi) were live trapped in northern St. Louis County, Minnesota (USA), in late September and October 1988 and experimentally inoculated with Borrelia burgdorferi. Spirochetes were isolated from most animals 14 and 28 days following inoculation. Thus, red-backed voles exposed to B. burgdorferi were susceptible to infection and could be a reservoir host, along with chipmunks (Tamias striatus) and other small rodents, in areas where white-footed mouse (Peromyscus leucopus) populations are low. No evidence of clinical disease was noted in any infected voles.

A survey of 41 mule deer (Odocoileus hemionus) and three white-tailed deer (O. virginianus) for bovine tuberculosis was conducted on a Montana (USA) cattle ranch from 2 November 1993 through January 1994. Gross and microscopic lesions typical of tuberculosis were present in tonsil and lymph nodes of the head, thorax, and abdomen of one adult female mule deer. Additionally, a single microgranuloma considered morphologically suggestive of tuberculosis was present in one lymph node of the head of a second mule deer. Mycobacterial isolates from lymph nodes of the head and thorax of the first deer were identified as Mycobacterium bovis.