Chronic selenium toxicosis was induced in 1-yr-old male mallard ducks (Anas platyrhynchos) by feeding selenium, as seleno-DL-methionine, in amounts of 0, 10, 20, 40, and 80 parts per million (ppm) to five groups of 21 ducks each for 16 wk during March to July 1988. All mallards in the 80 ppm group, three in the 40 ppm group, and one in the 20 ppm group died. Histologic lesions in mallards that died of selenosis were hepatocellular vacuolar degeneration progressing to centrolobular and panlobular necrosis, nephrosis, apoptosis of pancreatic exocrine cells, hypermaturity and avascularity of contour feathers of the head with atrophy of feather follicles, lymphocytic necrosis and atrophy of lymphoid organs (spleen, gut-associated lymphoid tissue, and lumbar lymph nodes), and severe atrophy and degeneration of fat. Histologic lesions in surviving mallards in the 40 ppm group, which had tissue residues of selenium comparable to mallards that died, were fewer and much milder than mallards that died; lesions consisted of atrophy of lymphoid tissue, hyalinogranular swelling of hepatoeytes, atrophy of seminiferous tubules, and senescence of feathers. No significant histologic lesions were detected in euthanized mallards in the 0, 10 and 20 ppm groups. Based on tissue residues and histologic findings, primarily in the liver, there was a threshold of selenium accumulation above which pathophysiologic changes were rapid and fatal. Pathognomonic histologic lesions of fatal and nonfatal selenosis were not detected. Criteria for diagnosis of fatal selenosis in aquatic birds include consistent histologic lesions in the liver, kidneys, and organs of the immune system. Although histologic changes were present in cases of chronic non-fatal selenosis, these were inconsistent. Consistent features of fatal and non-fatal chronic selenosis were marked weight loss and elevated concentrations of selenium in organs.

Hematological and plasma chemistry parameters were measured in 129 juvenile white storks (Ciconia ciconia), either wild or captive bred, April to June 1994. Wild storks were members of a colony in the Lozoya River Valley, Madrid, Spain. Red blood cells count, packed cell volume and hemoglobin increased significantly with age. White blood cells count, lymphocytes count and platelets decreased with age. Total solids, total proteins, fibrinogen, albumin, alpha, beta, gamma-globulins and urea increased with age. Differences between captive and wild birds were not notable.

Following a severe infectious keratoconjunctivitis (IKC) epizootic in free-ranging alpine ibex (Capra ibex ibex) in Switzerland in 1993, 19 animals were examined from six different populations. Mucopurulent exudates, reddened conjunctiva and mononuclear inflammatory cell infiltration in the conjunctiva and the limbic area were observed in mild cases. In more severe cases, lesions ranged from perilimbic neovascularization to corneal edema, erosion, ulceration and neovascularization accompanied by infiltration of neutrophils. Sometimes an iridocyclitis was observed. In the most advanced stages, the cornea was perforated and an anterior synechia was present. Lesions found in ibex affected with IKC indicated a non-generalized, specific ocular disease. The other organs investigated did not show alterations suggestive of changes induced by agents which might cause IKC, including Chlamydia spp. and Mycoplasma, spp. The microbiological findings indicate that Mycoplasma conjunctivae is the primary pathogenic agent causing IKC in this species in Switzerland.

Monitoring mule deer (Odocoileus hemionus) on a former plutonium production site along the Columbia River at the Hanford Site, Washington (USA) revealed 27 (23%) of 116 adult males had unusually shaped, velvet-covered antlers and abnormally developed testicles. We captured 32 males to examine age-class differences and the ratio of affected to unaffected deer and determine whether affected testicles were atrophic or hypoplastic. We found testicular atrophy in most deer with velvet-covered antlers, primarily in animals older than 5 yr. Deer had marked to extreme stages of testicular atrophy, indicating permanent sterility. Decreased serum levels of testosterone and compensatory increased levels of luteinizing hormone and follicle stimulating hormone were detected in all affected males; thus, the gondopituitary hormonal pathway may have responded to abnormally low levels of testosterone in the affected animals. Brucella spp. antibodies in sera were not detected and 9 (90%) of 10 affected animals were seropositive for epizootic hemorrhagic disease virus (EHDV-2) and bluetongue virus (BTV-11) as compared to 12 (63%) of 19 unaffected animals; however, signs of other infectious diseases were not observed. Testicular degeneration generally exceeded that observed with nutritional disorders and poisons in domestic species. Also, severity of the atrophy and apparent lack of other affected tissues suggested that radiation may not be responsible. Testicular atrophy in mule deer has been reported elsewhere; however, neither prevalence has been as high nor or occurrence as well confined to a specific geographical area, as that observed at the Hanford Site. Furthermore, no physiological or age-related influences were described. Documenting the status of such variables and examining their relationships to this phenomenon is a crucial step in understanding the reproductive capacity of a wild deer population.

Thirty stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary (Quebec, Canada) population and five animals from the Hudson Bay aboriginal hunt (Northwest Territories, Canada) were examined. Twenty one animals from the St. Lawrence Estuary had mild to severe adrenal lesions and four whales from the Hudson Bay population were affected by minimal adrenal changes. Cortical hyperplasia was observed in 24 adult beluga whales all from the St. Lawrence Estuary. Bilateral cortical cysts and cellular vacuolar degeneration were observed in the adrenal glands of 19 beluga whales from both populations. The cysts, filled with a cortisol-rich liquid, were present in both sexes. Beluga whales with adrenal cysts were significantly older than animals without cysts, and the severity of the lesions increased with age. Nodular hyperplasia of the medulla was observed in seven of the beluga whales, all from the St. Lawrence Estuary population. All lesions could be part of a normal aging process. The adrenocortical lesions might be due to stress or adrenocorticolytic xenobiotics, while the medullary hyperplasia might be caused by hypoxia or exposure to estrogenic xenobiotics.

From 1984 through 1992, staff at The Marine Mammal Center (TMMC, Sausalito, California, USA) examined 207 northern elephant seals (Mirounga angustirostris) with a condition of unknown etiology called northern elephant seal skin disease (NESSD). The skin lesions were characterized by patchy to extensive alopecia and hyperpigmentation, punctate or coalescing epidermal ulceration, and occasionally, massive skin necrosis. Microscopic lesions included ulcerative dermatitis with hyperkeratosis, squamous metaplasia and atrophy of sebaceous glands. All diseased seals were less than 2 years of age and suffered from emaciation, depression, and dehydration. Mortality from septicemia increased significantly with severity of skin ulceration. Compared to 14 apparently unaffected seals, diseased seals had depressed levels of circulating thyroxine, triiodothyronine, retinol, serum iron, albumin, calcium, and cholesterol. Levels of alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, gamma glutamyl transpeptidase, blood urea nitrogen, and uric acid were elevated. Morphometrically, diseased animals were approximately 15% smaller than normal seals of the same age. Serum and blubber concentrations of 36 polychlorinated biphenyl congeners (ΣPCB) and dichloro-diphenyl-dichloroethylene (p,p′-DDE) were negatively correlated with body mass. Mean concentrations of ΣPCB and p,p′-DDE in serum in diseased seals were elevated as compared to apparently normal seals. Etiology of this syndrome remains unknown, but the possibility of PCB toxicosis cannot be ruled out.

Histopathological examination revealed multifocal acute to chronic adrenal necrosis in 74 of 162 (45%) Pacific harbor seal pups (Phoca vitulina richardsi) dying during rehabilitation following live stranding along the coast of central and northern California (USA). Necrotic adrenal cells contained amphophilic, smudgy intranuclear inclusion bodies that were stained positive for DNA. Fifty of these seals also had lesions typical of sepsis, bacterial omphalophlebitis, pneumonia or gastroenteritis. Twenty four seals had no lesions other than thymic atrophy and occasional multifocal hepatic necrosis. Prior to death, affected seals had a marked lymphopenia. Electron microscopy revealed unenveloped intranuclear hexagonal to round viral particles approximately 100 nm in diameter, and cytoplasmic enveloped virions approximately 160 nm in diameter. These were morphologically consistent with herpesvirus. Inoculation of phocine adrenal and kidney cell lines with an adrenal tissue homogenate from affected animals produced a cytopathic effect in 5 days. Electron microscopy of cell cultures showing this cytopathic effect revealed similar viral particles to those observed in affected adrenal glands. Cases with characteristic inclusion bodies were observed in 42 of 95 (44%) male and 32 of 67 (47%) female seals. Affected animals had been in rehabilitation 0 to 63 days and were below average birth weight for this species.

Blood samples were collected from 1,042 marine mammals off the coast of Alaska (USA) and Russia during the period 1978 to 1994. Eight species of pinnipeds were represented. Sera were tested for presence of neutralizing antibodies to both the PB84 isolate of phocid herpesvirus-1 (PhHV-1) and the 7848/Han90 strain of phocid herpesvirus-2 (PhHV-2). Species-specific antibody prevalences ranged from 22% to 77% for PhHV-1 and 11% to 50% for PhHV-2. Species-specific antibody prevalences for PhHV-1 were greater than or equal to prevalences for PhHV-2. For both viruses and each host species, differences in antibody prevalences were not related to: (1) sex, (2) location of capture, or (3) year of collection. Antibody prevalence of PhHV-1 in walruses (Odobenus rosmarus) could be quantitatively predicted as a function of age. These two viruses have distinct biological properties and based on current data the epizootiology of the two viruses is different, as well. No evidence of herpesvirus-induced mortality has been detected in areas included in this survey. Based on results of this survey, neither PhHV-1 nor PhHV-2 are considered significant mortality factors in mammals which inhabit the marine environment off the coast of Alaska or Russia.

Serum samples from Peromyscus leucopus (white-footed mouse), collected in Connecticut (USA) in 1983, 1985, and during 1990 to 1993, were analyzed by an enzyme-linked immunosorbent assay (ELISA) or indirect fluorescent antibody (IFA) staining methods for antibodies to Borrelia burgdorferi (strain 2591), Babesia microti, Ehrlichia chaffeensis (Arkansas strain), and Ehrlichia equi (MRK strain). Of the 294 serum samples tested, 160 (54%) contained immunoglobulins to one or more of these pathogens. There were antibodies to two or more etiologic agents in 77 (48%) of the seropositive mice. Although it was uncommon to detect coexisting antibodies to all four pathogens (n = 5 positive mice), E. chaffeensis-reactive antibodies or immunoglobulins to E. equi were present along with those produced to B. burgdorferi and B. microti in 24 other mice. These rodents carry antibodies to several tick-borne pathogens at numerous sites in Connecticut and may play a role in the epizootiology of ehrlichiosis as well as babesiosis and Lyme borreliosis.

Blood was collected from 878 grizzly bears (Ursus arctos) in seven geographic areas of Alaska from 1973 to 1987. An enzyme-linked immunosorbent assay procedure was used to test sera for evidence of exposure to Trichinella spp. Serum antibody prevalence ranged from 5% (10 positive of 196 tested) in the Southern Region of the state to 83% (355 of 430 tested) in the Northern Region. These major discrepancies may be a result of differing food habits of bears in the major geographic areas. Prevalence was higher in older age cohorts. Neither year-of-collection nor sex had a significant effect on prevalence.

The prevalence of Toxoplasma gondii was determined in wild mammals in the Czech Republic from 1981 to 1990. The biological prevalence of T. gondii was <1% in insectivores (n = 578), 12% in carnivores (n = 112), 1% in rodents except muskrats (Ondatra zibethicus) (n = 5,163), 24% in muskrats (n = 437), 5% in lagomorphs (n = 293), 0% in ruminants (n = 456), and 2% in wild boars (Sus scrofa) (n = 136). The seroprevalence (Sabin-Feldman dye test, titre ≥ 1:4) of T. gondii was 15% in ruminants (n = 421), and 15% in wild boars (n = 124). Antibodies to T. gondii also were found in four of 10 carnivores. Toxoplasmosis is a common infection in wild mammals from the Czech Republic, but its prevalence varies considerable according to taxonomic groups and different localities where wild mammals live.

Black fly feeding alone and in concert with Leucocytozoon spp. infection caused mortality in fledgling great horned owls (Bubo virginianus) in the Yukon, Canada 1990 to 1991. These mortalities occurred during a year of food shortage corresponding with a decline in the population of snowshoe hare (Lepus americanus), the main prey for great horned owls. We hypothesize an interaction between food availability and the consequences of host-parasite interactions.

Helminths and arthropods were collected and quantified from two black rhinoceroses (Diceros bicornis bicornis) and one white rhinoceros (Ceratotherium simum), and ticks from an additional four black and two white rhinoceroses in southern Africa. The helminths of a black rhinoceros from the Republic of South Africa and one from Namibia were quantitatively measured and recorded for each compartment of the alimentary tract. Probstmayria vivipara was the most abundant parasite in each animal. A recently described nematode, Diceronema versterae, was found in the stomach of one animal. Draschia megastoma was present in the descending colon of the same animal, but it was twice the size of similar specimens reported from equids and the typical granulomatous lesions caused by this nematode in horses were not observed. New records of other helminths from rhinoceroses include Parabronema roundi, Kiluluma sp., Kiluluma goodeyi, Kiluluma magna, Khalilia rhinocerotis, Oxyuris karamoja and Anoplocephala gigantea. The stomach bot, Gyrostigma pavesii, was collected from one black and one white rhinoceros. Ticks collected from the black rhinoceroses were Amblyomma hebraeum, Dermacentor rhinocerinus, Rhipicephalus mactdatus, Bhipicephalus muehlensi and Haemaphysalis silacea. The two white rhinoceroses were infected with A. hebraeum, D. rhinocerinus, Hyalomma truncatum, Rhipicephalus simus, Rhipicephalus appendiculatus and Rhipicephalus zambeziensis.

Carcasses of 268 ruffed grouse (Bonasa umbellus) collected in eastern Tennessee (USA) from October 1983 through February 1988 were examined between 16 January 1985 and 25 April 1988 for non-filarioid helminths. Three nematode species and one cestode species were found. The two most common parasites were the cecal worm Heterakis bonasae (81% prevalence, mean intensity ± SD of 62 ± 114) and the tapeworm Echinolepis carioca (27% prevalence, 30 ± 73 mean intensity). Age and sex of host were sufficient to predict infection by both common species. Condition of host and year and month of collection also had significant effects on prevalence. Intensity of cecal worm infection varied with age and condition of host and with region and month of collection.

A major weakness of the Baermann funnel technique for extracting nematode larvae from feces is the funnel. As many as 67% of Parelaphostrongylus tenuis first-stage larvae lodged on the sloping surface of glass Baermann funnels. The number of larvae collected after 24 hr was not significantly correlated with total numbers in the samples, whether feces were supported over tissue paper or over window screening. Instead, we collected about 8 times as many larvae and achieved a significant relationship between larvae collected and the total numbers present when pelleted fecal material was submerged over screening in vertical-sided beakers. The methodology of this more efficient and more accurate way of estimating numbers of protostrongylid larvae is described. Most larvae were located on and in the mucous layer covering fecal pellets and readily left fresh pellets emersed in water; 72% of these larvae left after 6 min and only 11% remained after 1 hr. Larvae in water at room temperature sank as fast as 6 cm/min, but those close to a vertical glass surface sank more slowly (97% sank 18.5 cm in 105 min).

The first epizootic of edwardsiellosis, caused by Edwardsiella tarda, is described. The epizootic occurred in the Chesapeake Bay, Maryland (USA) during the summer and autumn of 1994, and affected wild adult striped bass (Morone saxatilis). Clinical signs included numerous irregular coalescing hemorrhagic ulcers on the body and fins that were distinctly malodorous. Internally, the body cavity was filled with abundant yellowish or sanguinous mucoid fluid, and the visceral organs had multiple tiny white foci. The intestines contained thick white opaque mucus. Histopathological lesions included ulcerative dermatitis, cardiac endothelial hyperplasia, and necrotic foci and granulomata in multiple organs. A bacterium isolated in pure culture was characterized taxonomically and serologically as the wild-type or classical biotype of E. tarda. In infectivity trials, it was pathogenic for striped bass, gilthead seabream (Sparus aurata), and turbot (Scophthalmus maximus) with an LD₅₀ of about 10⁵ cells; however, the isolate was non-virulent for mice (LD₅₀ > 10⁸ cells). The isolate also was resistant to the bacteriolytic activity of normal fish skin mucus.

One hundred and nineteen Merriam's wild turkeys (Meleagris gallopavo merriami) and 31 domestic chickens coexisting on a ranch in west-central Colorado (USA) were surveyed for mycoplasmosis by serologic and cultural methods. Although no clinical signs were apparent in any wild turkeys tested, 51 (43%) had positive rapid plate agglutination (RPA) reactions for M. gallisepticum (MG) and/or M. synoviae (MS); 37% of 56 adults and 48% of 63 subadults were classified as positive reactors to MG and/or MS. No turkeys tested in 1992 (n = 61) and 17 (29%) of 58 turkeys tested in 1993 were RPA-positive for M. meleagridis (MM). Hemagglutination inhibition (HI) test results were negative for MG, MS and MM as were most enzyme-linked immunosorbent assay (ELISA) test reactions (MG = 99%, MS = 93%, MM = 87%). Immunoblotting showed mild to moderate reactivity to MG proteins in 49% of 41 samples tested. Most chickens were strongly positive for MS by RPA (81%), HI (58%) and ELISA (87%); 48% also were positive for MG by RPA but all were MG-negative by HI and ELISA. No pathogenic mycoplasmas were isolated from either group of birds. Mycoplasma gallopavonis was commonly identified from the wild turkeys, and M. gallinaceum was isolated from both the chickens and wild turkeys. In a transmission study conducted in 1994, disease-free domestic turkeys failed to seroconvert when co-housed with wild turkeys from this population that were RPA-positive for MG. Collectively, the results of this study were inconclusive regarding the status of pathogenic mycoplasmas within this wild turkey population.

The standard tube agglutination test (STAT) and the complement fixation test (CFT) were used to assess the seroprevalence of antibodies to Brucella spp. in caribou (Rangifer tarandus) from three populations on Baffin Island, Canada. During late winter from 1983 to 1986, sera from 17 of 40 North Baffin (43%), 11 of 33 Northeast Baffin (33%) and 12 of 82 South Baffin (15%) adult caribou had antibodies in the STAT at 1:50 or the CFT at 1:5. Seroprevalence increased as caribou matured with one (4%) of 25 calves, four (13%) of 31 yearlings, and 40 (26%) of 155 adult caribou being positive. However, seroprevalence did not differ with sex in any age class. Positive antibody titers were higher in adult females sampled in May, 3 to 4 wk before parturition, than in adult females sampled in late March and April. The strength of positive titers did not differ with the time of sampling among adult males. Pathologic signs of brucellosis were found in three (13%) of 23 caribou that were assumed to have active infections (caribou with CFT titers > 1:160). Brucella suis biovar 4 was isolated from 24 (60%) of 40 caribou from which lesions were submitted. Between 1986 and 1990, the annual incidence of reported human (Homo sapiens) cases averaged 3.4 (34:100,000) on Baffin Island.

Domestic sheep were sighted at different times from 1991 to 1993 on four Nevada (USA) ranges occupied by bighorn sheep. Nasal and pharyngeal swab samples were collected from both sheep species and cultured to determine if any strains of Pasteurella spp. were shared on range conditions after contact of the two species. Pasteurella spp. were isolated from all 38 bighorn sheep and 16 of 17 domestic sheep included in this study. The isolates were characterized on the bases of species, biotype, serotype, biogroup, and restriction enzyme analyses (REA) as well as ribotyping of bacterial DNA. A P. haemolytica biotype 3, biogroup 11 isolate from a domestic sheep had biochemical, REA, and ribotype profiles which were identical to those of isolates from three bighorn sheep on the same range. None of the other isolates were found to be common to the two sheep species. Disease was not detected in any of the bighorn populations. However, bighorn sheep populations were extirpated on two ranges while increasing on the other two, including the range on which P. haemolytica biotype 3, biogroup 11 strain was isolated. Declining sheep numbers were not correlated with the presence of any one strain of Pasteurella spp from the sheep.

We examined the effects of simulated stress on susceptibility of Rocky Mountain bighorn sheep (Ovis canadensis canadensis) neutrophils to Pasteurella haemolytica leukotoxin in a blocked, crossover experiment. Ten captive-raised bighorn sheep were sampled 10 hr after separate administrations of long-acting adrenocorticotrophic hormone (ACTH) gel and normal saline (control). We then compared in vitro leukotoxin-dependent neutrophil death rates after exposure to culture supernatants from four unique P. haemolytica isolates (one from domestic and three from bighorn sheep). Simulated stress effects were evidenced by elevated (P = 0.002) mean plasma Cortisol concentrations, more neutrophils (P = 0.037), and fewer lymphocytes and eosinophils (P ≤ 0.043) in ACTH-treated bighorn sheep. Maximum leukotoxin-dependent neutrophil death rates were ≥61% for three of four P. haemolytica isolates tested. For all three cytotoxic isolates, neutrophil death rates at 150 μg/50 μl supernatant were about 1.13 times higher (P = 0.0001) after bighorns received ACTH; for two of these, overall neutrophil death rates were higher (P ≤ 0.001) in ACTH-treated bighorn sheep. Although variable leukotoxin production among P. haemolytica strains appeared principally responsible for differences in leukotoxin-dependent neutrophil death rates, susceptibility of bighorn sheep neutrophils to leukotoxin was increased by prior exposure to elevated plasma Cortisol concentrations. It follows that if similar processes occur in neutrophils and alveolar macrophages in vivo, they could contribute to greater susceptibility of stressed bighorn sheep to pneumonic pasteurellosis.

In order to determine the susceptibility of deer to infection with bovine viral diarrhea virus (BVDV), four mule deer (Odocoileus hemionus) fawns and one white-tailed deer (O. virginianus) fawn were inoculated intranasally with the New York-1 strain of BVDV originally isolated from cattle. None of the animals developed clinical signs of illness. Virus was isolated from white blood cells from four fawns on one or more occasions from day 2 through day 15 post-inoculation (PI) indicating that infection and systemic spread of BVDV had occurred. In addition, virus was isolated from nasal swabs from three fawns, one to three times, from day 2 through day 8 PI. Four fawns had virus neutralizing antibody titers to two strains of BVDV prior to inoculation and all developed greater than four-fold increases in virus neutralizing antibody titers by 3 wk PI. No gross lesions of bovine viral diarrhea were detected at necropsy approximately 3 mo PI. A variety of nonspecific lesions were detected by histopathology. Based on these findings, mule and white-tailed deer are susceptible to infection with BVDV. Isolation of virus from nasal swabs is evidence that BVDV could be transmitted by deer via direct contact.

In vitro and in vivo infections were conducted to determine if the epizootic hemorrhagic disease (EHD) and bluetongue (BT) viruses would replicate in peripheral blood mononuclear (PBM) cells of white-tailed deer (Odocoileus virginianus). All of the North American EHD and BT viruses (EHD virus serotypes 1 and 2, and BT virus serotypes 2, 10, 11, 13, and 17) replicated in vitro in cultures of white-tailed deer PBM cells. However, this replication appeared to be monocyte-dependent and was not enhanced by lymphocyte blastogenesis induced by the addition of concanavalin A. In white-tailed deer infected with either EHD virus serotype 2 or BT virus serotype 10, virus could be isolated consistendy from PBM cells only from postinfection day 4 through 8, although they remained viremic through post-infection day 21. In deer, highest viral titers were associated with the erythrocyte fraction, and in no cases did viral titers detected in the platelet, PBM cell or polymorphonuclear cell fractions approach titers observed in whole blood. In the in vitro infections of white-tailed deer erythrocytes, the EHD and BT viruses were associated with pits in the erythrocyte membrane. This association may be important in the long-term viremia observed in deer.

Our objectives were to examine the immunity conferred by epizootic hemorrhagic disease virus serotype 2 (EHDV-2) infection in white-tailed deer (Odocoileus virginianus) and determine if this immunity was protective during challenge with homologous (EHDV-2) or heterologous (bluetongue virus serotype 10; BTV-10) virus. Trials were conducted in the fall of 1992 and 1993. In the first experiment, naive white-tailed deer were infected intradermally and subcutaneously with EHDV-2 and monitored via physical examinations, complete blood counts, a and P interferon (IFN) assays, viral isolation, and serology. Infected deer had a wide range of clinical signs in response to infection. Eleven of the 16 deer had body temperature elevations ≥0.5 C between post-infection day (PID) 4 and 8. Infected deer had decreased lymphocyte counts between PID 6 and 10 that returned to normal levels by PID 17. Severely lymphopenic animals had the most severe clinical signs; five of 10 deer with lymphocyte counts less than 1000 cells/μl succumbed to the infection. Viremia was detected in all 16 EHDV-2 infected animals by PID 4, and peak viremias occurred between PID 4 and PID 10. Three deer remained viremic until PID 56, the study endpoint. Interferon was first detected between PID 2 and 6. Peak α and β IFN levels coincided with peak viremia in 11 deer. Precipitating and neutralizing antibodies were detected in infected deer by PID 10. In the second experiment, convalescent deer were challenged subcutaneously and intradermally with either EHDV-2 or BTV-10 and similarly monitored. Virus was detected in the blood of all four deer challenged with BTV-10, but viremia was not detected in three EHDV-2-challenged deer. Temperature fluctuations, blood cell parameter changes, and IFN and antibody responses seen in BTV-10-challenged deer were similar to those seen in the initial experiment. Deer challenged with EHDV-2 had mildly increased temperatures, but minimal IFN response and lymphocyte alterations.

Twenty captive red wolves (Canis rufus), including 16 intended for release into Great Smoky Mountains National Park, Cades Cove, Tennessee (USA), and four housed at Knoxville Zoological Gardens, Inc., Knoxville, Tennessee, were evaluated for immunologic response to vaccination between June 1994 and April 1995. Wolves were vaccinated with modified-live (MLV) canine distemper virus (CDV) and canine parvovirus type-2 (CPV2). Sera were collected, and immunofluorescent staining was performed for determination of immunoglobulin titers (CDV IgM, CDV IgG, and CPV2 IgG). A capture enzyme-linked immunosorbent assay was performed for validation purposes, to confirm the reactivity of our standard diagnostic reagents with red wolf serum. All wolves produced a measurable antibody response to CDV and CPV2 vaccination. Titers against CDV and CPV2 varied widely among individual wolves, but between-litter differences in mean titers were not significant. No consistent response between the degree of response to CDV versus CPV2 vaccination was observed in individual wolves. No differences were seen between IgG responses of pups vaccinated with univalent vaccines given concurrently or during alternating weeks. Pups had an IgG response to CDV and CPV2 vaccination as early as 9 wk of age. Mean post-vaccination IgG titers against CDV were at or above the level normally measured in vaccinated domestic dogs. Mean post-vaccination IgG titers against CPV2 were below the level normally measured in domestic dogs. Adult previously-vaccinated wolves had measurable CDV and CPV2 IgG titers more than 1 yr after vaccination, but did not have significant IgG titer increases after revaccination. We conclude that red wolves are capable of producing an antibody response after vaccination with commercial canine products but that their response to CPV2 vaccination was minimal. This response can be assayed using tests developed for domestic dogs.

The effectiveness of an alpha-chloralose (AC)-corn oil suspension, an AC-margarine mixture, and AC tablets were compared for immobilizing Canada geese (Branta canadensis). Responses to AC immobilization also were compared in male and female Canada geese. There was no difference in mean time to first effects or mean time to capture between male and female geese dosed with 30 mg/kg AC in orally-administered bread baits. Recovery times (≤24 hr) also were similar between sexes. Mean (±SE) time to first effects for geese immobilized with AC tablets in bread baits (19 ± 3 min) was significantly less than mean time to first effects for geese immobilized with AC in margarine (28 ± 6 min) or AC in corn oil (32 ± 7 min) applied to bread baits (n = 12 geese/treatment). Respective mean times to capture geese immobilized with AC tablets, AC-margarine, and AC-corn oil were not significantly different at 62 ± 25, 89 ± 48, and 88 ± 30 min, respectively. Ten, 11 and, seven geese immobilized with AC tablets, AC-margarine, and AC-corn oil recovered within 24 hr, respectively; all geese recovered within 28 hr. Male and female Canada geese respond similarly to AC immobilization, at least during molt, and AC mixed with margarine or AC in tablet form is at least as effective as the presently used AC-corn oil suspension. AC tablets or AC-margarine also would be more practical for some field situations. Additional development of AC tablets will be required prior to field use for capturing nuisance waterfowl.

The objective of this study was to determine if the potent α₂ agonist, medetomidine, and its specific antagonist, atipamezole, could be effectively used to immobilize polar bears (Ursus maritimus). Specifically, our goal was to develop a drug combination containing medetomidine that addressed some of the problems such as prolonged recovery time, non-reversibility, and poor analgesia that have been identified with the currently preferred drug combination, zolazepam-tiletamine (Telazol^® or Zoletil^®). During 1995 and 1996, 51 free-ranging polar bears along the western coast of Hudson Bay, Canada, were immobilized with a combination of medetomidine, zolazepam, and tiletamine (MZT). Immobilization with MZT was characterized by a short induction time, low volume, reliable and predictable immobilization and reversibility, adequate analgesia, and relative safety in handling for field personnel. Few adverse physiological effects were observed in any target animals with the exception of a single bear which convulsed and died shortly after it was reversed from anesthesia with atipamezole. We conclude that MZT is an effective drug combination for immobilizing polar bears. However, because of an unexplained mortality, further investigation of the physiological effects of MZT and atipamezole is warranted.

A combination of medetomidine-zolazepam-tiletamine (MZT) was used to immobilize four black bears (Ursus americanus). The drugs were used at a dose of approximately 52 μg/kg of medetomidine, 0.86 mg/kg of zolazepam, and 0.86 mg/kg of tiletamine. Induction occurred in 6.3 ± 3.3 min (mean ± SD). The combination produced minimal adverse cardiopulmonary effects. Hypertension occured in all four bears. Oxygenation and ventilation was good in three of the four bears. One bear demonstrated slight hypoxemia and hypoventilation at 15 min following drug administration. At one 1hr following drug administration atipamezole was administered at a dose of approximately 240 μg/kg. Recovery time was taken as the time from administration of the atipamezole until the time that the bear was sitting in the trap. Recovery occurred in 6.0 ± 4.1 min. MZT produced rapid, reliable immobilization in black bears with minimal adverse physiological effects. Immobilization, produced by this combination, was readily reversible with atipamezole.

We determined the prevalence and distribution of Jamestown Canyon (JC) virus antibody in white-tailed deer (Odocoileus virginianus) populations in Connecticut, USA. Sera were collected from hunter-killed deer during 1993. Antibody to JC virus was detected by enzyme-linked immunosorbent assay (ELISA) in 92 (21%) of 446 deer sera, and was uniformly distributed among geographic sites. Twenty-one ELISA-positive sera were tested and confirmed positive by plaque reduction neutralization testing. This represents the first serologic evidence of JC virus in a reservoir host population from the northeastern United States. No cross-reactivity was seen with California encephalitis, Keystone, or snowshoe hare viruses, but a varying degree of cross-reactivity was obtained with Guaroa, Jerry Slough, LaCrosse, San Angelo, and trivittatus viruses. We conclude from this investigation and previous isolations of JC virus from mosquitoes in the state that JC virus occurs enzootically in Connecticut.

One hundred fifteen samples of wolf (Canis lupus) feces were collected during 1994 to 1995 from four free-living populations of the north central Apennines Mountains, Italy. The samples were tested for canine parvovirus by antigen-capture enzyme-linked immunosorbent assay (ELISA), hemagglutination, and virus isolation. Four of these samples were positive by virus isolation as confirmed by electron microscopy. All positive samples were from Casentino Park in Tuscany. This is the first definitive observation of canine parvovirus in wolves from Europe.

An epizootic of Aujeszky's disease (pseudorabies) in four captive European brown bears (Ursus arctos) in November 1994, in the Val di Non, Trentino Region, Italy, was linked to consumption of raw pork. Affected animals had severe pruritus resulting in self-mutilation, and all four died within 24 hr after onset of clinical signs. Aujeszky's disease virus was isolated on first passage from the brain and was characterized by means of restriction endonuclease analysis. Based on these data, we believe that bears are extremely susceptible to the disease, and that wildlife managers should consider pseudorabies as a potential risk for the captive and wild bear populations.

To determine if Mycobacterium avium paratuberculosis has persisted in tule elk (Cervus elaphus nannodes) at Point Reyes National Seashore (California, USA), 100 fresh fecal samples were collected. Feces were cultured on a modified BACTEC 12B radiometric medium for detection of M. avium paratuberculosis. Four samples, coming from two separate groups of elk tested positive for M. avium paratuberculosis. Thus, a noninvasive technique was used to document the continued presence of M. avium paratuberculosis in elk at Point Reyes National Seashore. These findings document persistence of this organism for a period of at least 13 yr in a free ranging herd of elk, with a 6 yr absence of observed clinical signs.

Sixteen species of passerine birds captured during a 2.5 yr period in Central Spain were examined for hematozoa. Haemoproteus spp., Leucocytozoon spp., Trypanosoma spp., Plasmodium spp., and microfilariae were observed. The most prevalent species were in the genus Leucocytozoon. The majority of the records are new for Spain and some represent new host records. More than one-half of the birds examined were infected with at least one parasite species. These records are similar to those reported from other areas in northern Europe and the Iberian Peninsula.

The prevalence of hematozoa in two populations of red-billed choughs (Pyrrhocorax pyrrhocorax) was sampled in 1992 and 1994 in Spain. Two blood parasites infected red-billed choughs. A species of Plasmodium, possibly Plasmodium relictum, and the piroplasm Babesia frugilegica, are described for the first time from this host. Low prevalence (1/178, <1%) of hematozoa in these populations, was evidence for a lack of effects of blood parasites on the life history and conservation of this threatened species in at least the two populations studied.

Sixteen beluga whales (Delphinapterus leucas) and fifteen ringed seals (Phoca hispida) from the western arctic region of Canada were examined for giardiasis and cryptosporidiosis. Intestinal contents from the rectum and colon were collected from animals slaughtered by Inuit hunters. A fluorescent monoclonal antibody identified Giardia sp. cysts in three of 15 (20%) seals. Thus, ringed seals are implicated as a potential reservoir for this zoonosis in the arctic.

The prevalence of antibody titers to Toxoplasma gondii in river otters (Lutra canadensis) from eastern North Carolina (USA) was investigated in a cross sectional study. Sera from 103 live trapped river otters were tested for antibodies to T. gondii using a commercially available latex agglutination kit. Forty-six (45%) of the sera were positive with titers ranging from 1:16 to >1:2,048. Adult otters (n = 78) had a seroprevalence of 47% and juvenile otters (n = 25) had a seroprevalence of 39%. Significant differences were not found between the sexes within either maturity class. The high prevalence of antibodies to T. gondii indicates that many animals in this population were exposed to the organism. This suggests handling of otters may be a zoonotic concern for fur trappers.

Two hundred and two Baylisascaris procyonis were collected from 23 (70%) of 33 raccoons (Procyon lotor) at three localities in southern coastal Texas (USA). Abundances of B. procyonis were similar among collection localities. The presence of B. procyonis in Texas is confirmed, and this record considerably extends the potential range of baylisascariasis larval migrans in North America.

Two cases of haemonchosis occurred in the Spanish ibex (Capra pyrenaica) population of the National Hunting Reserve of Tortosa and Beseit, northeastern Spain, in July 1992 and May 1993. The animals were cachectic and recumbent and had an acute hemorrhagic, macrocytic and hypochromic anemia; which was related to a high infection of 2,016 and 1,863 Haemonchus contortus, respectively, in the abomasum of the animals.

Ten Canada geese (Branta canadensis), 24 snow geese (Chen caendescens) and 22 white-fronted geese (Anser alhifrons) from coastal Texas (USA) were examined for helminths. Three cestode, seven nematode, and three trematode species were collected. Gizzard nematodes (Amidostomum anseris, A. spatulatum and Epomidiostomum crami) infected 53 of 54 birds. Gross lesions were not attributed to helminth infections and the host population does not appear to be impaired by them.

Psoroptes sp. mites and tan crusty lesions were detected in the ears of a captive Stone sheep (Ovis dalli stonei) in April 1996, after contact with infected captive Rocky Mountain bighorn sheep (Ovis canadensis canadensis). Psoroptes spp. have not been detected in free-ranging ungulates in Canada or Alaska (USA). This is the first report of Psoroptes sp. in Stone sheep, indicating their susceptibility to infection.

A 2-yr-old female brook trout, Salvelinus fontinalis, maintained at a state fish hatchery in New York (USA) was culled from the breeding stock. At necropsy, it had a markedly enlarged kidney. On histopathological examination, lymphoblastic lymphoma was diagnosed in several organs including kidney, dorsal musculature, intestines, liver, gill, pseudobranch and ovary. Origin of the tumor was uncertain, although renal involvement could have been the primary site of development.

A wild 5-yr-old red deer (Cervus elaphus) was culled from a privately owned herd because of deformed antlers, retained velvet and bilateral symmetrical testicular hypogonadism. The clinical and pathological changes seen in this deer were most consistent with congenital hypoplasia, but testicular atrophy was an alternative possibility for the etiology of their condition.

A fungal infection was identified as the cause of a high mortality rate of captive wartbiter cricket (Decticus verrucivorus) nymphs at the London Zoo (United Kingdom) in 1994. This species is threatened with extinction in the United Kingdom and the animals concerned were part of a captive breeding and reintroduction program. Following these findings, reintroductions were postponed and release sites were used only where there were no extant wartbiter crickets.