Serologically negative birds and mammals of species, known from other studies to be exposed naturally to St. Louis encephalitis (SLE) virus in Memphis, Tennessee, and other selected species were inoculated experimentally with strains of SLE virus to determine their potential as natural hosts. Mosquitoes (Culex sp.) were allowed to feed on some of the inoculated vertebrate species, held for 14 days, and tested for SLE infection. The cardinals (Richmondena cardinalis), robins (Turdus migratorius), and baby chicks (Gallus gallus) all became viremic; 97% of the bobwhites (Colinus virginianus) and 20% of the Japanese quail (Coturnix coturnix) became viremic. No viremia was detected in raccoons (Procyon lotor), opossums (Didelphis virginiana), or adult cotton rats (Sigmodon hispidus). Only 20% of cottontail rabbits (Sylvilagus audubonii), 50% of wood rats (Neotoma mexicana), and 75% of hamsters (Mesocricetus auratus) but all the young cotton rats and least chipmunks (Eutamias minimus) were susceptible. Robins had the highest titered viremia but were viremic for the shortest period of time. Bobwhites had lower peak viremia titers but for a longer duration. Biologic differences in the response of some vertebrates to different SLE strains were noted. Culex pipiens quinquefasciatus mosquitoes readily became infected after feeding on viremic cardinals. Comparisons of the experimental data with information obtained from field investigations provided a better understanding of the contributions of the various vertebrate species to the transmission and maintenance of SLE virus in nature.

Small mammals were trapped in northeastern Alberta, Canada during 1976. Blood samples from these animals were tested for virus by inoculation of suckling mice. Blood clots from two deer mice yielded isolates of the same virus. The virus was related antigenically to a number of flaviviruses which have been isolated from mammals in Central America and North America and was related most closely to Modoc virus. Physical, chemical, and biological properties of the virus were similar also to those of Modoc virus. It did not produce illness or death in deer mice inoculated in the laboratory. Neutralization tests indicated that 1/38 (3%) red squirrels (Tamiasciurus hudsonicus), 3/35 (9%) least chipmunks (Eutamius minimus), 13/109 (12%) deer mice, and 3/50 (6%) humans were infected naturally. This is the first reported evidence of infection of red squirrels and chipmunks with a Modoc-like virus. These data extend the range of Modoc-like viruses northward by 1,500 km and comprise the first isolate from mammals in the boreal forest of Canada.

Seventeen species of mammals and seven species of birds from Ossabaw Island, Georgia, were tested for vesicular stomatitis (VS) neutralizing antibodies. Seropositive results were restricted to mammals with six of 17 species testing seropositive for VS (New Jersey type) neutralizing antibodies. Seropositive species included: raccoons (Procyon lotor), white-tailed deer (Odocoileus virginianus), feral swine (Sus scrofa), cattle (Bos taurus), horses (Equus caballus), and donkeys (Equus asinus). All tests for VS (Indiana type) were negative.

A recent outbreak of rabies in raccoons, Procyon lotor (L.), in Loudoun County, Virginia (1981–82), prompted a study of the epidemiology of the disease. Parameters studied included the occurrence and movement of the disease over time, sex and age relationships, and behavior patterns of raccoons. During the 18 mo, 427 raccoons were tested, of which 75% were infected with rabies virus. Interpretation of rainfall data and the subsequent spatial occurrence of infected raccoons within the county indicated a cause and effect relationship. The submission rate of female raccoons was greater than that of males. The female raccoons (adult and juvenile) were also found to be infected with the virus more often than the males. Behavior of infected raccoons in a rural environment was similar to those observed in the southeastern United States during earlier epizootics of rabies. The presence of a skunky odor on infected raccoons may be a characteristic of raccoon rabies.

Persistence of inclusion body disease of cranes virus (IBDCV) was determined by monitoring virus shedding, serum antibody and in vitro cultivation of trigeminal ganglia from cranes. Samples were collected from captive cranes surviving the outbreak in 1978 and from cranes inoculated with the virus. Tissues and fluids from eggs of cranes that survived the outbreak were also tested for virus. Latent IBDCV was found in the trigeminal ganglion of one crane that was exposed to the virus in 1978. Spontaneous or induced (cyclophosphamide and dexamethasone) reactivation of viral shedding was not detected in any cranes tested. Five of six experimentally inoculated cranes died with lesions of an inclusion body disease, but virus was isolated from only three of them. One crane shed detectable levels of IBDCV prior to death. The surviving crane developed a transient antibody response without evidence of viral shedding, after five exposures to the virus. A latent infection was not detected in this crane. Serum antibody titers of cranes that survived the outbreak declined from 1980–1982. No virus was isolated from the eggs. Although IBDCV is capable of persisting in a latent form in the trigeminal ganglia of cranes, the low frequency of viral shedding suggests that this virus may be only a sporadic problem.

During studies on the etiology of puffinosis, a disease of the Manx shearwater, 1 to 4% of full-grown birds were found to have dry, non-pigmented lesions on the webs of the feet. Poxvirus infection was detected in six of seven full-grown birds with such lesions. The lesions contained large encapsulated inclusions which were packed with mature and immature poxvirus particles. Poxvirus infection was not apparent in shearwater fledglings during puffinosis epizootics, and its spatial distribution was not related to that of puffinosis. The results indicate that poxvirus infection produces a mild, self-limiting disease in shearwaters and is not the cause of puffinosis.

Studies were conducted from April through August during 1974 and 1975 on 30 randomly selected trapping sites in Wall Doxey State Park, Holly Springs National Forest, and 1.6 km south of the park in Marshall County, Mississippi to provide information on the occurrence of ticks involved in the maintenance and transmission of spotted fever-group rickettsiae in nature. Of 365 animals (14 species) collected, 186 (51%) were parasitized by 4,169 ticks. Species of ticks collected included: (1) Dermacentor variabilis; (2) Amblyomma americanum; (3) Rhipicephalus sanguineus; (4) Haemaphysalis leporispalustris; and (5) Ixodes texanus. Of 2,105 ticks examined, 116 (5.5%) were positive for rickettsia-like organisms.

Two studies of brucellosis in wildlife on farms where the brucellosis infection prevalence in cattle was known are reported. On a research farm, 233 feral animals of 22 mammalian species and 12 of seven avian species were trapped during three time periods. Sixty were studied before cattle were introduced, 128 were studied while 501 cattle infected with Brucella abortus were calving and aborting, and 60 specimens were collected 20 mo after the last infected cow calved. Selected tissues from 229 wild animals were cultured and sera from 138 were examined using the brucellosis card, standard tube agglutination (STA), 2-mercaptoethanol (2-ME) and rivanol (RIV) tests. Brucella abortus was not recovered from any animals sampled prior to cattle being introduced and all sera collected were negative. Brucella abortus was isolated from four opossums (Didelphis virginiana) and one raccoon (Procyon lotor) in the group of animals trapped during the calving period. Three serums were tested and had STA titers ranging from 1:100 to 1:200. Of 68 sera only one had antibodies. Brucella were not isolated from 59 animals trapped after the calving period and only one of 42 serums had antibodies. On regional cattle farms, 243 wild animals were trapped. Brucellae were not isolated from 223 animals which were cultured. No serums had significant titers. The data from this study suggest opossums and raccoons can be infected from cattle but are unlikely to maintain the infection.

Several wild olive baboons from a single troop in the Masai Mara Game Reserve, Kenya were observed to be lethargic and emaciated. Five were trapped and tuberculin tested by intradermal inoculation of 0.1 cc (100 IU) mammalian old tuberculin in the upper eyelid. Two of the five showed positive reaction at 72 hr and were examined at necropsy. Gross lesions in both animals consisted of multiple nodules with caseation in the lung, spleen and tracheobronchial lymph nodes. There were multiple granulomas throughout the lung, spleen and the lymph nodes. Tissues were cultured on Lowenstein-Jensen media with and without pyruvic acid. Isolates were typed as Mycobacterium bovis.

β hemolytic streptococcal infections, usually of group G and C, were identified in red foxes in France. In a study of 31 animals, septicemia and jaundice were found to be the main signs of the disease. Gross and microscopic lesions consisted of generalized inflammation of viscera and joints, jaundice, cellulitis and abcesses of spleen, liver, lungs and kidneys. The disease was reproduced in foxes by intramuscular inoculation of less than the minimal quantity of bacteria lethal to mice. When challenged, recovered animals were resistant to infection that proved to be lethal to control animals.

Kidney and spleen homogenates from each of 60 coho salmon (Oncorhynchus kisutch) and steelhead trout (Salmo gairdneri) were examined for detection of Renibacterium salmoninarum. The proportions of positives differed widely with the detection procedures used: in coho salmon, 5% were positive by the Gram-stain procedure, 10% by the direct fluorescent antibody test, 48% by bacteriological isolation, 65% by staphylococcal coagglutination, and 73% by counterimmunoelectrophoresis; in steelhead trout, 3% were positive by Gram-stain, 8.3% by fluorescent antibody, 17% by bacteriological isolation, and 67% by counterimmunoelectrophoresis. Renibacterium salmoninarum was not detected in either coho salmon or steelhead trout by immunodiffusion analysis.

Pooled blood samples from six white-tailed deer from the Great Dismal Swamp in Virginia were inoculated into two splenectomized deer. A moderately severe clinical reaction ensued, characterized by a hemolytic anemia, and a Babesia found in both recipient animals was presumptively identified as B. odocoilei. This is the first reported identification of this parasite in white-tailed deer in Virginia.

In August 1983, a study on parasites, diseases, and health status was conducted on sympatric populations of fallow deer (Dama dama) and white-tailed deer (Odocoileus virginianus) from Land Between The Lakes, Lyon and Trigg counties, Kentucky. Five adult deer of each species were studied. White-tailed deer had antibodies to epizootic hemorrhagic disease (EHD) virus and Leptospira interogans serovariety icterohemorrhagiae, and fallow deer had antibodies to bluetongue and EHD viruses. Serologic tests for bovine virus diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza₃ virus, and Brucella spp. were negative. One white-tailed deer had an infectious cutaneous fibroma, and one fallow deer had pulmonary mucormycosis. White-tailed deer harbored 16 species of parasites, all of which are considered typical of the parasite fauna of this host in the southeastern United States. Fallow deer harbored nine species of parasites, including eight species known to occur in white-tailed deer on the area and one species (Spiculopteragia assymmetrica) that is not. All fallow deer had inflammatory lesions in the spinal cord and/or brain that were attributed to prior infection with meningeal worm (Parelaphostrongylus tenuis), indicating that P. tenuis infections are not always fatal for this species. The apparent high rate of exposure of Land Between The Lakes fallow deer to P. tenuis without a resultant high rate of clinical cerebrospinal parelaphostrongylosis is hypothesized to be due to (1) a low prevalence and intensity of P. tenuis, (2) partial innate resistance of fallow deer, and (3) acquired immunity.

The prevalences of three helminths, Campula oblonga, Halocercus dalli and Crassicauda sp., recovered from Dall's porpoises which were net-entrapped incidentally in the vicinity of the western Aleutian Islands in the northwest Pacific are reported. Specimens of Campula oblonga were found within the bile ducts of 46% of 127 livers examined. The prevalence of hepatic trematodiasis increased with the age of the host. Pulmonary nodules associated with Halocercus dalli were noted in 71% of the Dall's porpoises. Adult H. dalli were recovered from the main stem bronchi of heavily infected lungs. Younger animals exhibited a relatively higher prevalence. Specimens of Crassicauda sp. were found within the main lactiferous canal of 69% of 29 mammary glands examined. The prevalence was highest in mature porpoises. Possible detrimental effects and the modes of transmission of the three species of parasites are also considered.