An avian influenza virus isolate, A/Mallard/Ohio/184/86 (H5N1), was evaluated for its effects on reproduction in isolation-reared adult mallard ducks (Anas platyrhynchos) and growth rate in juvenile mallards after intravenous inoculation. There was a significant decrease in egg production in the experimental group during the first week after inoculation, but it returned to the normal production level during the second week. No effect was seen on egg weight, shape, or fertility. Ducklings receiving this influenza virus isolate did not differ from controls in their rate of growth.

Lyme disease, caused by the spirochete Borrelia burgdorferi, is endemic in the northeast, north-central, and Pacific coastal states of the United States. The eastern chipmunk (Tamias striatus) is found throughout the disease-enzootic regions except along the Pacific coast, and may serve as an important reservoir host in some locations. To characterize their potential as a host, 11 adult chipmunks were inoculated with 10⁵ spirochetes from strains of B. burgdorferi isolated from Peromyscus leucopus and Ixodes scapularis in a hyperendemic area of Westchester County, New York (USA). All inoculated chipmunks became infected. Spirochetemias were detected by isolating spirochetes in Barbour-Stoenner-Kelly media in eight of eight chipmunks, and lasted for 2 to 5 days. Spirochetes were isolated from the ears of all animals, starting at 1 wk and for ≤4 mo, and from various internal organs at 133 days post-inoculation. Laboratory-reared larval I. scapularis ticks became infected with spirochetes after feeding on two of the inoculated chipmunks.

The prevalence of Clostridium botulinum type C (% of positive sediment samples) was determined in 10 marshes at Sacramento National Wildlife Refuge (SNWR), located in the Central Valley of California (USA), where avian botulism epizootics occur regularly. Fifty-two percent of 2,200 sediment samples collected over an 18-mo period contained C. botulinum type C (both neurotoxic and aneurotoxic) which was present throughout the year in all 10 marshes. The prevalence of C. botulinum type C was similar in marshes with either high or low botulism losses in the previous 5 yr. Marshes with avian botulism mortality during the study had similar prevalences as marshes with no mortality. However, the prevalence of C. botulinum type C was higher in marshes that remained flooded all year (permanent) compared with marshes that were drained in the spring and reflooded in the fall (seasonal). The prevalence of C. botulinum type C declined in seasonal marshes during the dry period. Similar declines did not occur in the permanently flooded marshes.

To understand the role of bighorn sheep (Ovis canadensis) in the epidemiology of anaplasmosis, we recovered a field isolate from a suspected enzootic area in southern California (USA). Whole blood was collected from three desert bighorn sheep (Ovis canadensis nelsoni) and inoculated into a susceptible splenectomized domestic sheep, calf and a susceptible spleen-intact bighorn sheep. No infection occurred in the calf, but a detectable infection developed in both the domestic sheep and bighorn sheep 24 days after inoculation. The infection in both domestic and bighorn sheep resulted in severe clinical disease but was resolved with the use of tetracycline. Using monoclonal antibodies and DNA probes, we confirmed that the isolate was Anaplasma ovis.

Using an indirect immunofluorescence assay, we determined the prevalence of Anaplasma-reactive antibody in three herds of bighorn sheep, each a different subspecies and occupying a different habitat in California (USA). Antibodies to Anaplasma spp. were identified in none of twenty California bighorn (Ovis canadensis californiana) sampled from the Mt. Baxter herd, 11 of 17 peninsular bighorn (O. canadensis cremnobates) sampled in the Santa Rosa Mountains, and all 20 desert bighorn (O. canadensis nelsoni) sampled at Old Dad Peak/Kelso Mountains. Based on an assay and an adsorption technique, the titers most likely were due to Anaplasma ovis. The presence and species of tick vectors in each of the habitats, and the presence or absence of deer or livestock were identified as factors potentially influencing seroprevalence of antibodies.

In a survey of avian blood parasites in Costa Rica, 51 (11%) of 479 birds sampled were infected by at least one species of hematozoan. Fourteen of the 60 species of birds in the survey were examined for the first time. Infections were most common in ramphastids and emberizids and infrequent in other taxa. Among resident species, infections were more commonly detected during the wet season when most birds breed than during the dry season when few birds breed. Infections caused by Haemoproteus sp. were most common, while Plasmodium sp., Leucocytozoon sp., Trypanosoma sp., and microfilarial infections were rare. The intensity of the 40 Haemoproteus infections in adult birds was low, with a mean ± SE of 12.5 ± 3.7 infected cells per 10,000. Haemoproteus infections did not undergo seasonal changes in intensity.

We conducted a study of the population dynamics, movement, and diseases of white-tailed deer (Odocoileus virginianus) in Cades Cove, Great Smoky Mountains National Park, Tennessee (USA) from 1980 to 1984. During the study 590 blood samples were collected from 518 deer, with some deer recaptured one or two times. The estimated percent of the herd sampled each year ranged from 8% to 28%. We also collected serum samples from 56 cattle pastured in Cades Cove.

Deer and cattle sera were tested using the microagglutination test for the presence of antibody to the following serovars of Leptospira: pomona, hardjo, grippotyphosa, icterohemorrhagiae, and canicola. One hundred and six deer (21%) were seropositive for only one of the serovars. We found that 57 (11%) of the deer had antibodies to serovar hardjo, 33 (6%) were positive for antibodies to serovar pomona, 15 (3%) were positive for antibodies to serovar icterohemorrhagiae, and one deer had antibodies to serovar canicola.

Age class and sex of deer were associated with antibody presence. Adult (≥1.5 yr) male deer were more likely to have antibodies than the other age class and sex groups (P = 0.001).

In recaptured deer, similar titers were found in samples from one deer taken 807 days apart. Titer declined below the screening dilution level (1:250) after 37 days in one deer.

Serum antibodies to influenza A viruses and paramyxoviruses were detected in Adelie penguin (Pysoscelis adeliae) and Antarctic skua (Stercorarius skua maccormicki) sera in the Ross Sea Dependency. An avian paramyxovirus was isolated from a penguin cloacal swab.

Sera from 22 (13 wild and nine captive) European brown bears (Ursus arctos) from Croatia were tested to 18 viral and rickettsial agents. Serologic evidence of exposure was found to the following agents (number positive/number examined): Bhanja virus (3/15), Tahyna virus (3/15), West Nile virus (4/15), Naples sandfly fever virus (1/15), human adenovirus (1/22), influenza A (1/22) and B (1/22) virus, cytomegalovirus (1/22), parainfluenza virus 1 (2/22), Chlamydia psittaci (1/22), Coxiella burnetii (2/22), and canine parvovirus 2 (CPV-2) (7/22). Evidence of exposure to arboviruses was found exclusively among free-living bears. Evidence of exposure to agents usually transmitted directly was predominant among captive bears. Canine parvovirus 2 antibodies were the most frequently found antibodies and the only antibody common to both groups of bears. This may be the first report of antibodies to CPV-2 in bears.

Blood lead concentrations of juvenile American black ducks (Anas rubripes) sampled in unhunted sanctuaries of Nova Scotia (NS) and Prince Edward Island (PEI), Canada, usually were <30 parts per billion (ppb). Based on gizzard content analyses of juvenile American black ducks from hunted areas, eight (24%) of 33 flightless birds contained ingested lead shot. Blood lead concentrations were ≥100 ppb in seven of eight juveniles with ingested shot; thus we adopted blood lead concentrations 100 ppb as our threshold indicating exposure to non-background lead. The proportion of both American black ducks and ring-necked ducks (Aythya collaris) with elevated blood lead concentrations (>100 ppb) exceeded 5% in hunted areas sampled in NS and PEI combined. The Canadian Wildlife Service draft policy is to consider replacing lead shot with non-toxic shot for waterfowl and snipe hunting if 5% of American black ducks exceed a blood lead concentration of 200 ppb. American black ducks significantly (P < 0.05) exceeded this threshold but ring-necked ducks did not. The source of lead in hunted areas may have been lead shot; we recommend that it be eliminated and replaced by an acceptable non-toxic shot for waterfowl hunting. Twenty four (96%) of 25 of American black ducks overwintering in Sullivans Pond, Dartmouth, NS, contained elevated (>100 ppb) blood lead concentrations and 19 (76%) had detrimental concentrations (>200 ppb). We believe that the source of lead at Sullivans Pond was automobile emissions.

During an avian cholera epornitic, between December 1982 and January 1983, 58 dead, 23 sick, and 106 hunter-killed lesser snow geese (Chen caerulescens caerulescens) were collected at Delevan National Wildlife Refuge, Colusa County, California, USA. Fifty-one of the dead and sick geese were infected with Pasteurella multocida. Lead concentrations in the livers ranged from <1 to 253 parts per million (ppm) (dry weight). Lead concentrations in the kidneys ranged from <1 ppm to 547 ppm (dry weight). Snow geese with >30 ppm lead, considered diagnostic of acute lead poisoning, had significantly (P < 0.05) lower heart weights and a smaller band of heart fat, compared to geese with tissue lead concentrations of <30 ppm. Tissue lead concentrations in geese dying from avian cholera generally were lower than concentrations in hunter-killed geese, but the differences were not significant for either kidney (P = 0.08) or liver (P = 0.30) tissue.

Histopathological and mycological studies were made on mycotic gastritis in juvenile ayu, Plecoglossus altivelis. The disease occurred 5 days after the transportation of fish from a hatchery pond to two rearing ponds of Tochigi Prefectural Fisheries Experiment Station, Tochigi, Japan. The pyloric region of the stomach was red. Numerous fungal hyphae penetrated into the stomach wall. Seven fungal isolates were obtained from the lesions. Three isolates were identified as Saprolegnia diclina Type 1. Based on histology, hyphae were most numerous in the pyloric stomach, but also penetrated abdominal adipose tissue, the pancreas, spleen, kidney, swim bladder, gonad, and liver. In some cases, the hyphae penetrated trunk muscles.

A Napoleon fish (Cheilinus undulatus) was infected with both an acid-fast bacterium and an imperfect fungus. This is the first report of an acid-fast bacterial infection in Cheilinus undulatus, and the first observation of an imperfect fungus in the swim bladder of a tropical marine fish.

A debilitated adult female moose (Alces alces) shot east of the MacKenzie River, Northwest Territories, Canada, had large fluctuant masses over both carpi. Only the forelimbs were available for examination. Carpal pathology included bilateral bursitis and osteomyelitis of subjacent bone. In addition severe osteomyelitis with fractures was observed in the left lateral and right medial digits. Brucella suis biovar 4 was isolated from the right medial first phalanx. This is believed to be the first reported case of infection with this organism in a wild moose. The bacterium is common in caribou (Rangifer tarandus) in the region.

Serum samples from 665 hunter killed black bears killed in 1989 to 1992 throughout Pennsylvania (USA) were tested for Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Toxoplasma gondii antibodies were found in 535 of 665 (80%) bears. Considering the highest dilutions at which antibodies were detected, prevalences were 10% at 1:25, 37% at 1:50 and 33% at 1:500. No significant difference in antibody prevalence was found between males (79%) and females (80%), but a significant difference was found between juvenile (65%) and adult (83%) bears.

A study was undertaken on wild animals to determine the seroprevalence of animal leptospirosis in Korea. Using the serum microagglutination test for 19 serogroups, it was shown that two of 26 rats (Rattus rattus) had antibodies to Leptospira canicola. When data for domestic animals were included, the most prevalent (nearly 50%) serogroup was Leptospira canicola.

Between 1986 and 1991, sera were collected from 33 roe deer (Capreolus capreolus), 24 red deer (Cervus elaphus), four fallow deer (Dama dama), two mouflon (Ovis musimon), 34 wild boars (Sus scrofa), and 48 hares (Lepus europaeus) shot in two areas of the Czech Republic. Collectively, the sera contained antibodies to Coxiella burnetii (prevalence of 12%), Francisella tularensis (4%), Brucella spp. (2%), Central European tick-borne encephalitis virus (8%), Ťahyňa (California serogroup) virus (36%), and Čalovo (=Batai) virus (23%). We propose that these mammals may play a role in maintaining natural foci of Q-fever, Ťahyňa fever and Čalovo virus infection.

From 1981 to 1991, sera of 42 European brown bears (Ursus arctos) from three areas in Croatia were tested for antibodies against 12 Leptospira interrogans serovars: grippotyphosa, sejroe, australis, pomona, canicola, icterohaemorrhagiae, tarassovi, saxkoebing, ballum, bataviae, poi, and hardjo. Diagnostic levels of antibody were found in 17 (40%) of 42 sera. Evidence of exposure to at least one of the serovars was found in seven of 14 free-ranging bears from the Lika region, four of 12 free-ranging bears from the Gorski Kotar region, zero of six orphaned cubs from the Gorski Kotar region, and six of 10 captive bears from the Zagreb Zoo. Based on the antibody titers, we implicated the following serovars: australis in five bears, sejroe in two bears, canicola in one bear, and icterohaemorrhagiae in one bear. There was a strong correlation between serovars implicated by this survey and serovars previously isolated from small mammals in Croatia.

Twenty common brushtail possums (Trichosurus vulpecula), 23 ringtail possums (Pseudocheirus peregrinus) and five sugar gliders (Petaurus breviceps) from the Blue Mountains, New South Wales, Australia were evaluated for traumatic injuries between 1989 and 1990. Ten brushtail possums and five ringtail possums were hit by motor vehicles with injuries primarily to the anterior of the body. Fifteen ringtail possums and all sugar gliders were attacked by cats. Four brushtail possums were attacked by dogs. The remaining nine possums had evidence of intraspecific fighting (n = 2) or other types of trauma. Brushtail and ringtail possums were presented primarily during their main breeding seasons. There was no sex predilection. More ringtail than brushtail possums were subadults and these were injured primarily at the time of dispersal.

A solitary mass overlying the right carpal joint region's skin in an 18-year-old female Père Davids deer (Elaphurus davidianus) was surgically excised and histologically diagnosed as a squamous cell carcinoma (SCC). The tumor was locally infiltrative, showing rather few “horn pearls” and many mitotic figures. This is the first report of a cutaneous SCC in the Père David's deer.

A white-tailed deer (Odocoileus virginianus) fawn was presented to the Southeastern Cooperative Wildlife Disease Study for examination of brachygnathia and syndactylous front feet. The hoof keratin of digits 3 and 4 was completely fused and typical sole integument covered the palmar surface between the primary digits. Based on a radiographic examination, there was fusion of the epiphyses of the first phalanges of digits 3 and 4 in both feet. In the right foot the proximal metaphyses of the first phalanges of digits 3 and 4 were fused.

Fifty-four ill or nonproductive lemmings (Dicrostonyx spp.) were evaluated for signs, lesions and causes of disease for 5 yr in a domestic colony. Parasitic granulomas caused by Encephalitozoon cuniculi were the most common finding and were seen in 22 lemmings. The disease was characterized by circling and torticollis with granulomas in many tissues, especially the central nervous system. Suppurative otitis occurred in 12 lemmings and was associated with Klebsiella pneumonia infection; circling was the common sign. Hepatic microabscesses were present in seven lemmings but a cause was not identified. Five lemmings had neoplasms and 14 had either suppurative processes, aspermia, or ovarian cysts.