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Capillaria hepatica infection was diagnosed by histologic examination in 21 of 71 (30%) coyotes in Louisiana. All infected coyotes were at least 1 year old, and most (19 of 21) were more than 2 year years old. Capillaria hepatica was not found in any livers from 31 red foxes and 20 gray foxes examined.
Translocation of a rabies variant from one area to another has been identified increasingly in the United States. During November and December 1994, rabies was diagnosed in five dogs from two associated kennels in Florida; in addition, two other dogs being kept at one of the kennels died with suspected, but unconfirmed, rabies. Rabies virus recovered from the five dogs was identified as a variant not previously found in Florida but endemic in coyotes (Canis latrans) in south Texas. The suspected source of infection was translocation of infected coyotes from Texas to Florida. This report summarizes the findings of an investigation of these cases by the Alachua County Public Health Unit, the Florida Department of Health and Rehabilitative Services, and CDC.
Individual sporocysts containing 4 sporozoites were shed in the feces of dogs, foxes, and raccoons after ingestion of bovine tissue infected with Sarcocystis fusiformis bradyzoites. No sporocysts were shed by cats, monkeys, swine, skunks, ferrets, rats, guinea pigs, or rabbits after ingestion of similar bovine tissue. The shedding of sporocysts by dogs that had ingested tissue from a bovine experimentally infected with sporocysts from coyotes indicated that both canids were definitive hosts for the same species of Sarcocystis. After oral inoculation wtih sporocysts from dogs previously fed infected bovine heart, a calf became infected; but sheep, swine, rats, mice, rabbits, and monkeys did not. These results show the narrow specificity of the asexual stages of this parasite for the bovine intermediate host and the wider, though still restricted, host range of the sexual stages of this parasite for coyotes, dogs, foxes, and raccoons, the definitive hosts.
The persistence and interrelationships of a recurrent group of intestinal helminth species in a coyote population from southern Texas were determined; data were collected at 4-yr intervals (1979, 1983, and 1987). The a priori expectation was that a defined recurrent group of helminth species persisted over time and that the respective helminth species were stable in terms of their abundances. The Fager index and subsequent recurrent group analysis indicated a small group of taxonomically unrelated recurring species of helminths that always demonstrated affinities with each other and occasionally with certain of the remaining species. Although there were differences across host subpopulations delineated by sex and age, temporal changes reflective of extrinsic environmental variables acting on certain helminth species appeared to have the greatest effect on recurrent group size and structure. Three of the 8 common intestinal helminth species (Ancylostoma caninum, Oncicola canis, and Alaria marcianae) occurred in all recurrent groups. Thus, there was temporal persistence of a small recurrent group of dominant helminth species that formed the basis of the intestinal helminth community in this coyote population.
Ixodes pacificus is the main tick vector for transmission of Anaplasma phagocytophilum and Borrelia burgdorferi to large vertebrates in California. The present study was undertaken in I. pacificus-infested counties in California to examine spatial and temporal relationships among A. phagocytophilum and B. burgdorferi-exposed coyotes with vegetation type and climate. The overall A. phagocytophilum and B. burgdorferi seroprevalences were 39.5% (N=215) and 18.9% (N=148), respectively, with no association with sex. PCR for A. phagocytophilum and B. burgdorferi was negative in all blood and kidney samples. Increased seroprevalence was a positive function of rainfall. Ehrlichial seropositivity was increased in blue-oak foothill pine, montane hardwood, and redwood vegetation regions, and decreased in coastal sagebrush and cropland. Increased exposure to B. burgdorferi occurred in blue oak woodland.
The duration and stereotypy (in terms of duration) of three actions, stand-overs (SO), generalbites (GB), And scruff-bites (SB), were measured during social play and agonistic interactions in infant eastern coyotes (Canis latrans). The rate of biting was also calculated. We found: (1) SO's and GB's lasted a significantly shorter time during play; (2) when performed during playful interactions, all three acts showed more stereotypy; (3) there was no significant difference between the rates of occurrence of biting during the two situations. A discussion of the 'exaggerated' nature of play behaviour is presented, particularly concerning the form of motor actions that are used during this activity.
Reproductive tracts of 24 female coyotes hand-reared for behavioral research were examined by laparotomy following the 1977-78 breeding season. Litter counts revealed 51 whelps with 10 of the 24 females while examination by laparotomy indicated 83 uterine swellings in 18 of the same 24 females. The laparotomy proved to be an effective, relatively precise procedure and gave a 39% increase in data acquisition.
A total of 423 serum samples representing 94 coyotes which were wild trapped in east Texas were used to compare the serologic results from five different methods for detecting antibodies to Brucella abortus. The sera were tested for Brucella spp. antibody activity by the Card (CARD), rivanol precipitation (RIV), standard agglutination tube (SAT), cold complement fixation test (CF), and enzyme linked immunosorbent assay (ELISA) methods. Each serum sample selected for this comparison demonstrated antibody activity by one or more of the five serologic methods. When the serologic results of the five different methods were compared, 143 sera were positive according to the CF test and agreement was 67.1-70.6% with CARD, RIV and SAT. The maximum agreement for CF positive was with CARD (70.6%) and the lowest agreement fro CF negative was also with CARD (56.4%). Agreement among the serologic methods for the SAT positive ranged from 69.1% (CARD) to 72.7% (RIV). Agreement between SAT and ELISA was poor with only 38.1% agreement for SAT positive and 11.3% agreement for SAT negative. Agreement between methods for CARD positive sera was poor, with a low of 43% for both SAT and ELISA, and a high of 55.6% for RIV. Agreement between methods for 149 RIV positive sera was 83.2% for CARD, 67.8% for SAT, 64.4% for CF and only 50.3% for ELISA. Agreement between methods for ELISA positive results ranged from 49.0% for RIV to 62.7% for CARD.(ABSTRACT TRUNCATED AT 250 WORDS)
The development of Sarcocystis cruzi Hasselmann (syn. S. fusiformis Railliet) meronts was studied in seven 7- to 10-day-old calves filled 4, 7, 11, 15, 22, 25 and 28 days postinoculation (DPI) with 5 x 10(7) sporocysts from feces of coyotes. No meronts were found 4 and 7 DPI. Young and intermediate meronts with 1-16 nuclei were found in endothelial cells of arteries in mesenteric lymph nodes, but not in kidneys 11 DPI. Mature meronts were noted in endothelial cells of arteries, arterioles, or capillaries of many organs of calves killed 15 to 25 DPI. No first-generation meronts were found 28 DPI. By electron microscopy, all stages of the first-generation merogony were found free within the host cell cytoplasm and not within a parasitophorous vacuole. The appearance of intranuclear spindles preceded the formation of merozoites by endopolygeny. Mature meronts measured 41.0 x 17.5 (34-50 x 15-24) microgram, contained approximately 100-350 merozoites, and had 2 to 4 relatively small residual bodies, 2.8 microgram in diameter. Merozoites measured 6.3 x 1.5 (5.5-7 x 1 microgram) and contained most of the organelles characteristically found in coccidian merozoites. Micropores were observed in merozoites, but not in young and intermediate meronts. Merozoites were seen free in the lumen of blood vessels, in intracellular areas, and free within the host cell cytoplasm.
The development of Sarcocystis cruzi was studied in an 11-day-old calf killed seven days postinoculation with 5 x 10(8) sporocysts from feces of coyotes. Uninucleate zoites were found in arteries of mesenteric lymph nodes but not in other organs. Zoites measured 4.9 x 3.0 (3.5-7.0 x 2.1-3.5) micrometers. Of the 36 zoites studied, 31 were in endothelial cells, four were in macrophages in the lumen of arteries, and one was free in the lumen of an artery. Infected endothelial cells were two to three times larger than uninfected cells. Zoites appeared structurally similar to sporozoites. The occurrence of zoites in macrophages suggests that sporozoites of Sarcocystis might use such cells to reach the site of their first merogony.
The genus Mesocestoides Vaillant, 1863 includes tapeworms of uncertain phylogenetic affinities and with poorly defined life histories. We previously documented 11 cases of peritoneal cestodiasis in dogs (Canis familiaris L.) in western North America caused by metacestodes of Mesocestoides spp. In the current study, DNA sequences were obtained from metacestodes collected from these dogs (n = 10), as well as proglottids from dogs (n = 3) and coyotes (Canis latrans Say, 1823 [n = 2]), and tetrathyridia representing laboratory isolates of M. corti (n = 3), and these data were analyzed phylogenetically. Two nuclear genetic markers, 18S ribosomal DNA and the second internal-transcribed spacer (ITS 2), were sequenced. Phylogenetic analysis of the 18S rDNA data recovered a monophyletic group composed of all samples of Mesocestoides spp., distinct from closely related outgroup taxa (Amurotaenia Akhmerov, 1941 and Tetrabothrius Rudolphi, 1819). Initial analysis of the ITS 2 data resolved 3 clades within Mesocestoides. Two proglottids from dogs formed a basal clade, a second clade was represented by tetrathyridial isolates, and a third clade included all other samples. Interpretation of these data from an apomorphy-based perspective identified 6 evolutionary lineages. We also assessed whether metacestodes from dogs (n = 4) are capable of asexual proliferation in laboratory mice. One tetrathyridial and 2 acephalic isolates from dogs proliferated asexually. Further investigation is warranted to determine which of the lineages represent distinct species and to determine the life history strategies of Mesocestoides spp.
Gross and histopathologic lesions in the eyes of a blind coyote, Canis latrans, collected in King County, Texas are discussed. The animal was in good condition and its age estimated at 7 years. The left globe presented with a superficial corneal erosion, a small punctate erosion, and an apparent lenticular opacity. Histologically, there was a mild anterior uveitis and lenticular degeneration with thickening of the anterior lens capsule, cataractous cortex with Morgagnian globules and bladder cells, and a dense nucleus. The right eye was a firm phthistic globe with thickened extraocular muscles and opaque cornea. Histologically, this presented as an adherent leucoma with partial loss of intraocular contents (retina, iris, and lens), intraocular bone undergoing haematopoiesis, a small granulomatous lesion with foreign body adjacent to the optic nerve in the dural sheath, and gliosis of the optic nerve. The loss of this eye probably resulted from a penetrating injury of the globe with partial loss of intraocular contents. Lesions noted in the eye may be interpreted as an acquired lenticular degeneration of the complicated type.
Ketamine and xylazine were combined to provide anesthesia for coyotes. The drugs were tested in eight adult animals divided equally by sex. A dosage combining 5.5 mg./kg. of each drug provided effective anesthesia for periods from 45 to 60 min.
Fifty-five of 66 (83%) coyote pups from bitches vaccinated against canine parvovirus (CPV) were seropositive for CPV antibodies at birth. The CPV antibody titer in the pups declined with a half-life of 6.7 days until by the 8th week, only two of 41 (5%) pups were seropositive for CPV antibodies. At 8 wk, 41 of the pups were vaccinated against CPV (killed feline origin vaccine), but only one of 37 (3%) was positive for CPV antibodies at 11 wk. The 8-wk-old pups were either too young to respond to the CPV vaccine; they had sufficient undetectable, maternally-derived CPV antibodies to block active immunization; 3 wk was not a sufficient time for an immunological response from the pups; or the vaccine was poorly antigenic. Twenty of the 66 pups (30%) were seropositive for canine coronavirus (CCV) antibodies at birth, and all but three of the 20 were whelped from bitches that were also seropositive for CCV antibodies. Vaccination of females prior to whelping appeared to provide protection to their pups from CPV-induced mortality.
Serum from 72 wild coyotes (Canis latrans) in southeastern Colorado (USA) was collected and analyzed for prevalence of antibody to canine parvovirus (CPV) and canine distemper virus (CDV) from 1985 to 1988. The prevalence of antibodies to CPV and CDV was 71% and 57%, respectively, for the 4 yr of the study. Prevalence of antibody to CPV did not differ among years, between sexes, or with age. Prevalence of antibody to CDV did not differ among years or between sexes, but was significantly higher in adults (62%) than juveniles (33%). Prevalence of antibodies against CPV and CDV in southeastern Colorado was comparable to results reported in other serologic surveys in the western United States.
From 1980 to 1984, 267 coyotes (Canis latrans) from Tennessee were examined for helminth parasites. Hearts were examined for the presence of Dirofilaria immitis, diaphragms for Trichinella spiralis, and digestive tracts for other helminths. Six species were found including 5 nematodes (D. immitis, Physaloptera rara, Trichuris vulpis, Ancylostoma caninum, and Toxascaris leonina) and 1 cestode (Taenia pisiformis). Univariate and multivariate statistical techniques were used to assess parasite prevalence and intensity. For prevalence data, a matrix of correlation among characters was computed, and the first 3 principal components were extracted from the original distance matrix. These accounted for 93.7% of the variation in the character set. Three-dimensional projections of localities showed spatial variability on each component. Significant relationships were found between principal component I and longitude, component II and latitude and mean January temperature, and component III and mean July precipitation and mean January actual evapotranspiration. For intensity data, no spatial variability was determined.
During 1975 to 1977, serum samples were collected from 101 adult coyotes (Canis latrans) captured in northcentral Kansas. Ten samples were seropositive by microagglutination testing and six of those samples were seropositive for multiple serovars. Titers for Leptospira interrogans serovars grippotyphosa, pyrogenes, djasiman, butembo, and pomona were demonstrated.
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.