Two new oral chemical biomarkers for coyotes.

Pentachlorobenzene (PeCB) and 1,2,3,4-tetrachlorobenzene (TeCB) were evaluated as oral chemical biomarkers when administered to coyotes (Canis latrans) during the period of 31 January to 10 August 1994. Three coyotes each received 100 mg of PeCB and three received 100 mg of TeCB, each in a mineral oil formulation. Three additional coyotes received only the mineral oil carrier. Muscle and adipose tissues, blood serum, and fecal samples were evaluated by capillary gas chromatography with electron capture detection for 120 days following administration. Residues of PeCB were detected in serum, feces, and adipose and muscle tissues for 120 days post-treatment; TeCB residues were detected in feces and serum at 1 and 8 days post-treatment and in adipose tissue at 30 days post-treatment. Residues of TeCB were not detected in muscle tissue at any point in the study.

Body size and condition of coyotes in southern Texas.

Body size and condition of coyotes (Canis latrans) from a high-density population in Webb County, Texas (USA) were analyzed for age, sex and seasonal differences during 1980 to 1986. Mean body mass was progressively greater for juvenile, yearling and adult coyotes. Males were heavier and longer than females in each age class. Indices of intraperitoneal fat deposits were similar between sexes. Juveniles continued growth from fall to spring. Adults and yearlings both lost intraperitoneal fat overwinter. Mean body mass of adults decreased overwinter but mass of yearlings did not differ significantly between fall and spring. Territorial and transient female coyotes did not differ in mean body mass, length or indices of subcutaneous fat deposits.

Borrelia sp. infection in coyotes, black-tailed jack rabbits and desert cottontails in southern Texas.

Coyotes (Canis latrans) from southern Texas were sampled for antibodies to Borrelia burgdorferi from 1980 to 1986; black-tailed jack rabbits (Lepus californicus) and desert cottontails (Sylvilagus audubonii) were sampled in 1986. Coyote fetuses, adult coyote kidneys, and black-tailed jack rabbit and desert cottontail kidneys were cultured for B. burgdorferi in 1986. Results of indirect immunofluorescent antibody (IFA) tests for B. burgdorferi in coyotes were as follows (number positive at a dilution of greater than or equal to 1:128/number tested): 1980 (0 of 30), 1981 (0 of 21), 1982 (0 of 53), 1983 (0 of 78), 1984 (47 of 97), 1985 (20 of 88), and 1986 (42 of 80). Eight of 26 black-tailed jack rabbits and two of seven desert cottontails tested in 1986 had IFA titers to B. burgdorferi of greater than or equal to 1:128. Borrelia burgdorferi was isolated from one of five coyote fetuses, three of 31 adult coyote kidneys, and two of 10 black-tailed jack rabbit kidneys in 1986. These results indicate that B. burgdorferi infection has been present in coyotes in Texas, at least since 1984 and that transplacental transmission occurs.

Transmission of Ancylostoma caninum and Alaria marcianae in coyotes (Canis latrans).

One of seven female coyotes (Canis latrans) captured in Webb County, Texas during September 1986 and confined and mated in holding facilities at Millville, Utah whelped the following spring. The maternal female (greater than 5-yr-old) and her five neonates were killed at 22 days postparturition. All were infected with adult Ancylostoma caninum and were passing eggs in their feces. Also, the neonates and maternal female were infected with immature and adult Alaria marcianae, respectively. These findings suggested that the transmammary route is an important transmission mechanism for acquisition of these species of helminths in coyotes. The lack of overdispersion in the frequency distribution of these parasites and infection of the entire litter indicated that transmission from the infected female was nonselective among the pups.

Canine distemper virus in coyotes: a serologic survey.

Serum samples from 228 coyotes were selected randomly from a serum bank assembled from Texas from 1975 to 1984 and were evaluated serologically for neutralizing antibodies against canine distemper virus (CDV). One hundred and twenty-eight (56%) of the 228 coyotes had antibody titers of greater than or equal to 1:5 against CDV (seropositive). The serologic prevalence (seroprevalence) of antibodies against CDV infection was higher in the spring (62%) than in the fall (40%). The seroprevalence of CDV in various age groups was different; 25 of 101 coyotes (25%) were seropositive at less than 1 year of age, 35 of 52 (67%) were positive between 1 and 2 years of age, and 68 of 75 (91%) were positive at greater than or equal to 2 years of age. The results indicated that CDV was enzootic in coyote populations of southern Texas, with an increasing number of seropositive coyotes noted annually. The sex of the coyote did not appear to be related to the seroprevalence against CDV.

Seroprevalence of canine parvovirus in wild coyotes from Texas, Utah, and Idaho (1972 to 1983).

The prevalence of serum antibodies against canine parvovirus-2 (CPV-2), as measured by a standard hemagglutination-inhibition test, was determined in serum samples collected from 1,184 coyotes (Canis latrans) in Texas, Utah, and Idaho from 1972 to 1983. No evidence of parvoviral infection was found before 1979, after which seroprevalence rapidly increased to greater than 70% at all sites by 1982. There were minor differences in prevalence between age groups and among sites, but no consistent differences between sexes. The onset of CPV-2 seroprevalence in free-ranging coyotes coincided remarkably with the recognition of the clinical disease and seroprevalence in domestic dogs in the United States.

Population dynamics across selected habitat variables of the helminth community in coyotes, Canis latrans, from south Texas.

The effects of selected intrinsic variables operating on host subpopulations and of extrinsic variables across the collective host population on the distributions of 10 common helminth species from coyotes in south Texas were compared. The intrinsic variables of host sex and presence and severity of sarcoptic mange had little effect on the distributions of most helminth species. The combined influences of (1) seasonal changes across the collective host population and (2) host subpopulations delineated by age were responsible for the overdispersed distributions of Oncicola canis, Physaloptera rara, and Protospirura numidica. Overdispersion in Ancylostoma caninum, Alaria marcianae, and Spirocerca lupi populations resulted almost exclusively from the heterogeneity of factors contributing to their rates of establishment, survival, and reproduction as generated across host age subpopulations. Aggregated abundances of A. caninum and A. marcianae occurred in young hosts, but were cumulative in older animals infected with S. lupi. The hypothesis that heterogeneity within the host population, rather than across the collective host population, is the main factor generating overdispersion in natural populations was confirmed for only 3 of 10 helminth species (A. caninum, A. marcianae, and S. lupi). The effects of extrinsic factors operating across the collective host population appeared to be equal to, or in some instances of greater importance than, these forces operating over host subpopulations in determining the dispersion patterns of some helminth species (O. canis, P. rara, and P. numidica). The distributions of Taenia pisiformis, Mesocestoides lineatus, Oslerus osleri, and Toxascaris leonina were not affected, or only minimally influenced, by these intrinsic or extrinsic variables. The effects of these habitat variables on dispersion patterns are highly correlated with the life cycle and mode of transmission of the respective helminth species.

The epizootiology and pathology of sarcoptic mange in coyotes, Canis latrans, from south Texas.

An epizootic of sarcoptic mange in coyotes from south Texas, Canis latrans , was studied over a 7-yr period, 1975 through 1981. From a four-county area centered in Webb County, Texas the epizootic radiated centrifugally to include a 27-county area. The disease progressed from initial, scabby encrustations on the ischium and fore and hind legs to severe, thickened, slate-gray hyperkeratotic lesions with almost complete alopecia. There were significant decreases in alpha-globulin and albumin, significant increases in gamma-globulin, and significant decreases in fat deposits and total body weight indicative of a chronic infection with establishment of a humoral antibody response as the infection progressed in severity. Significant differences in prevalence of mange across habitat variables of host age and sex, and across seasons were related to the juvenile/adult ratio in the coyote population at any particular time because the infection progressed more rapidly in juveniles. Population dynamics and abundance of coyotes were generally unaffected by the mange epizootic. Although higher mortality was associated with mange-infected animals, this had no effect on overall mortality in the coyote population.

Notoedric mange in the bobcat, Felis rufus, from south Texas.

A fatal case of notoedric mange is described in an adult male bobcat, Felis rufus, from south Texas. This cat was extremely weak and emaciated. Skin lesions consisted of greatly thickened, gray encrustations and alopecia of the muzzle, eyes, crown, ears and parietal scalp extending down the neck to the midscapular region of the shoulders. Histologically, there was partial to complete excoriation of the stratum corneum with erosions into the stratum germinativum to the level of the dermis in some areas. Numerous specimens of Notoedres cati (Hering, 1838) were noted, usually in the stratum corneum, sometimes burrowing into the stratum germinativum. A mild dermal inflammatory response consisting principally of neutrophils and round cells was observed. Confirmed notoedric mange with clinical signs similar to the above was also observed by a local veterinarian in three bobcat kittens from the same area. These were treated with a sulfurated lime shampoo followed by VIP dip. Subsequently, they recovered without consequence. These cases emphasize the possibility of notoedric mange as a potential epizootic disease in wild felid populations.