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PubMed1991

Food caching in captive coyotes: stereotypy of action sequence and spatial distribution of cache sites.

This paper describes some aspects of the food caching behaviour of four captive coyotes. Detailed observations of the actions used by coyotes to cache food revealed them to be strikingly similar to those previously described for timber wolves. The similarities included the identity of the movements used, their temporal sequencing, and their susceptibility to interruption. This suggests that there exists a stereotypy across canids in the action sequences used in caching. Second, an examination of the distribution of cache sites revealed that each coyote scattered cache sites widely within a wooded region of their enclosure and preferentially in terrains close to exposed tree roots.

Animals↗

PubMed1991

Analysis of coyote mitochondrial DNA genotype frequencies: estimation of the effective number of alleles.

A restriction-site survey of 327 coyotes (Canis latrans) from most parts of their North American range reveals 32 mitochondrial DNA (mtDNA) genotypes. The genotypes are not strongly partitioned in space, suggesting that there is high gene flow among coyote subpopulations. Consequently, each new geographic location added to the study has a decreasing probability of containing a mtDNA genotype that had not been previously discovered. This being the case, by using Monte Carlo sampling experiments, we can estimate the total number of genotypes that would be found if all possible localities were surveyed. This estimate of total genotypic variability agrees qualitatively with estimates based on theoretical considerations of the expected number of alleles in a stable population. We also predict effective population sizes from genotype data. The accuracy of these estimates is thought to be dependent on the fact that coyotes are not highly genetically structured, a situation which may apply to highly mobile species.

Alleles↗

PubMed1985

Antifertility effect of busulfan and procarbazine in male and female coyotes.

Antifertility effects of two cytostatic agents, busulfan and procarbazine, were evaluated using 43 captive breeding pairs of adult coyotes. Nineteen pairs served as untreated controls. Only the male or female of remaining pairs was treated. Females received either 8 mg busulfan/kg or 6 mg procarbazine/kg just prior to onset of the breeding season. Males were treated once with either 8 mg busulfan/kg just before onset of breeding or with 4 mg busulfan/kg or 6 mg procarbazine/kg about 1 mo before onset of the breeding season. Uterine implantation sites were counted in females of all breeding pairs postpartum via laparotomy. Busulfan given to males at 4 mg/kg or to either females or males at 8 mg/kg significantly reduced implantation sites compared to untreated controls. Thus, busulfan may be successful in controlling population in coyotes in the field where both the male and female of a breeding pair may ingest the compound. However, multiple doses at a lower rate would be preferred because dosages greater than 10 mg/kg resulted in mortality. Although procarbazine has a mode of action similar to busulfan, doses of 6 mg procarbazine/kg did not reduce implantation sites or disrupt normal spermatogenesis. Increased doses need to be evaluated before effectiveness of procarbazine for coyote population control can be determined.

Animals↗

PubMed2003

Reconstructing the spread of Dirofilaria immitis in California coyotes.

Dirofilaria immitis is a filarial nematode parasite that is currently widely enzootic in dog and coyote (Canis latrans) populations of California. Weak historical evidence suggests that the initial focus of D. immitis in California occurred 3 decades ago in the Sierra Nevada foothills (SNF) and spread to other parts of California thereafter. However, this hypothesis is difficult to evaluate because of the lack of epidemiological studies on heartworm in California before 1970. We investigated this hypothesis by comparing D. immitis prevalence in coyotes between initial (1975-1985) and current (2000-2002) surveys in the SNF and 2 coastal regions. In the SNF, prevalence of heartworm was not significantly different between initial (35%, n = 169) and current (42%, n = 60) surveys (P = 0.17), suggesting the existence of a stable enzootic focus in the initial survey period. In contrast, current prevalence was 4 times higher than initial prevalence in the northern Coast Range foothills (44 vs. 10%; n = 119, 107; P < 0.001) and in the south San Francisco Bay foothills (32 vs. 8%; n = 31, 59; P = 0.005), suggesting that initial surveys were made during the early stages of colonization. Dirofilaria immitis prevalence, intensity, and abundance was similar in a coastal location in Mendocino County between 1994-1996 and 1999-2002, suggesting some degree of stability in this enzootic focus. Collectively, these findings support the hypothesis that D. immitis established itself initially in California coyotes living in the SNF and subsequently expanded its range of enzootic foci in central California.

Animals↗

PubMedDate not supplied

Seroepidemiology of Bartonella vinsonii subsp. berkhoffii infection in California coyotes, 1994-1998.

The prevalence of antibodies to Bartonella vinsonii subsp. berkhoffii in coyotes (Canis latrans) in California ranged from 51% in central to 34% in southern and 7% in northern California. Seropositive coyotes were more likely to be from coastal than inland counties (p clustered distribution of Bartonella seropositivity in coyotes suggests that B. vinsonii subsp. berkhoffii infection is vectorborne. Further investigation is warranted to evaluate which arthropods are vectors and what the mode of transmission is from wildlife to domestic dogs and possibly humans.

Animals↗

PubMedDate not supplied

Naturally occurring Ehrlichia chaffeensis infection in coyotes from Oklahoma.

A nested polymerase chain reaction assay was used to determine the presence of Ehrlichia chaffeensis, E. canis, and E. ewingii DNA in blood samples of free-ranging coyotes from central and northcentral Oklahoma. Of the 21 coyotes examined, 15 (71%) were positive for E. chaffeensis DNA; none was positive for E. canis or E. ewingii. Results suggest that E. chaffeensis infections are common in free-ranging coyotes in Oklahoma and that these wild canids could play a role in the epidemiology of human monocytotropic ehrlichiosis.

Animals↗

PubMed2000

An apparatus for studying operant activity of captive coyotes.

We describe a portable apparatus designed to examine the free-operant food preferences of captive coyotes in their home kennels. Because lever-pressing for food access was the dependent variable, we measured food preference independently of food ingestion. Using successive approximation, we trained 8 out of 19 coyotes (42%) to use the apparatus. This percentage is similar to training rates for dogs. We used fixed and variable ratio schedules of reinforcement to further test 4 of the trained coyotes. All 4 produced response curves similar to those of other species on similar schedules of reinforcement.

Animals↗

PubMed1977

Sarcocystis hemionilatrantis (Sp. N.) life cycle in mule deer and coyotes.

Fifteen coyotes (Canis latrans) shed sporulated sporocysts in their feces after eating freshly ground skeletal muscles from a mule deer (Odocoileus hemionus hemionus) infected with microscopic-sized cysts of Sarcocystis. Sporocysts were shed intermittently from 12 to 36 days after ingestion of the infected meat. Sporocyst size averaged 14.4 X 9.3 mum. Eleven mule deer fawns orally inoculated with these sporocysts became infected and 9 of 11 died between post-inoculation days (PID) 27 and 63. Clinical signs of anorexia, weight loss, pyrexia and weakness were evident prior to death. A calf (Bos taurus) and two lambs (Ovis aries) orally inoculated with these sporocysts did not become infected and remained healthy throughout the experiments. Similarly, uninoculated control animals consisting of three mule deer fawns, two lambs and one calf remained healthy during the experiment. Preliminary histologic examinations conducted on selected tissues from all animals revealed microscopic-sized schizogonous stages in macrophages, between muscle fibers and near blood vessels in the esophagus, heart, biceps femoris, semi-membranosus, diaphragm and tongue from seven of eight fawns which died between PID 27 and 39. Developing or mature muscle cysts were not found in fawn tissue until PID 60. Sarcocysts were found in the three infected fawns examined after this time. Muscle cysts or earlier schizont stages were not found in tissues from the inoculated or uninoculated calves and lambs. A single muscle cyst was found in one control fawn; the other two control fawns were negative for both muscle cysts and other schizogonous stages. These results established that the life cycle of this species of Sarcocystis can be completed with coyotes as the definitive host and mule deer as the intermediate host. Based on the demonstrated host specificity and earlier findings, the name Sarcocystis hemionilatrantis is proposed for this parasite of mule deer and coyotes.

Animals↗

PubMed1979

Brucella abortus in coyotes. I. A serologic and bacteriologic survey in eastern Texas.

Prevalence of Brucella abortus serum antibodies in coyotes from east central Texas was determined by the buffered Brucella antigen (card test), rivanol, standard agglutination tube, and cold complement fixation tube tests. Eighteen percent (9 of 51) of the coyotes were positive serologically. B. abortus biotype 1 was isolated from various tissues from 7 of 43 coyotes by bacteriologic culture. Congenital transmission was found.

Animals↗

PubMed1979

Epizootic streptococcal pneumonia in captive coyotes.

Severe death loss was observed in captive coyotes, Canis latrans. Of 48 coyotes in one kennel, 22 (46%) died within a 7 day period. Cause of death was determined to be acute fibrinopurulent (bacterial) broncho-pneumonia and pleuritis. Streptococcus equisimilis was isolated from the lungs of two coyotes examined.

Animals↗

PubMed1991

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.

Age Factors↗

PubMed1992

Diseases, parasites and survival of coyotes in south-central Georgia.

Serologic testing, radio-telemetry and post-mortem diagnostic evaluations were used to investigate survival and causes of mortality among 17 coyotes (Canis latrans) in south-central Georgia (USA). Prevalence of canine heartworm (Dirofilaria immitis) microfilariae was lower (P = 0.057) among fall-captured (22%) than among winter-captured (75%) coyotes. Prevalence of heartworm was higher among adults than juveniles in the fall, but no significant difference was detected between animals captured in winter. Antibodies were found against canine parvovirus (65%), canine parainfluenza virus (59%), infectious canine hepatitis virus (41%), and Toxoplasma gondii (18%). Antibodies were not found to Brucella canis, canine coronavirus, five serovars of Leptospira interrogans, or canine distemper virus. Seroprevalence of canine parvovirus was lower (P = 0.009) among fall-captured animals (33%) than winter-captured animals (100%). The Kaplan-Meier estimate of annual survival was 0.500 for all animals. Juvenile survival did not differ (P = 0.79) from adult survival, but male survival (S = 0.217) was lower (P = 0.11) than female survival (S = 0.804). Two of nine (22%) mortalities were human-caused, one was due to concurrent canine parvovirus and canine distemper virus infections, one animal died of trauma, two were considered natural mortalities of unknown cause, and no cause of death could be determined for the remaining three animals. Natural mortality may be significant for coyotes in south-central Georgia, although there was no apparent link between exposure to pathogens and the animals' subsequent fate in our small sample.

Animals↗

PubMed1996

Winter poisoning of coyotes and raptors with Furadan-laced carcass baits.

Three bald eagles (Haliaeetus leucocephalus), a red-tailed hawk (Buteo jamaicensis), and two coyotes (Canis latrans) found in a field in north-central Kansas (USA) in December 1992 were poisoned by flowable carbofuran (Furadan 4F) placed on sheep (Ovis aries) carcasses to kill coyotes. The carbofuran was placed on the carcasses in October 1992, but the coyotes and raptors apparently were killed in late December. Thus, flowable Furadan can cause direct and secondary deaths of wildlife under some circumstances for at least 60 days following placement.

Animal Welfare↗

PubMed1996

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.

Adipose Tissue↗

PubMed1998

Viral antibodies in coyotes from California.

Prevalence of antibodies against canine parvovirus (CPV), canine distemper virus (CDV), and canine adenovirus type 1 (CAV) were determined among 152 coyotes (Canis latrans) at the Naval Petroleum Reserves (NPRC; California, USA) from 1985 to 1990. Overall prevalence of antibodies to CPV, CDV, and CAV was 66%, 37%, and 68%, respectively. Prevalence of CPV and CDV varied significantly among years. Antibody prevalence did not differ between sexes for any disease, but did vary significantly among age classes and was lowest for pups (< 1-yr-old). Among pups, antibody prevalence increased with age for all three diseases. Coyotes are a potential source of viral exposure for endangered San Joaquin kit foxes (Vulpes macrotis mutica), but variation in coyote abundance did not appear to influence antibody prevalence among kit foxes.

Adenoviridae Infections↗

PubMed1999

Naturally occurring hepatozoonosis in coyotes from Oklahoma.

Nine of 16 free-ranging coyotes (Canis latrans) from central Oklahoma (USA) had naturally acquired infections of Hepatozoon americanum. Infections were confirmed by recognition of tissue stages closely resembling H. americanum in skeletal and cardiac muscle. At the time coyotes were collected they were infested with a variety of ticks, including adult Gulf Coast ticks (Amblyomma maculatum). We propose that the high prevalence of H. americanum in this small sample of free-ranging coyotes and the ability of these same animals to harbor adult populations of A. maculatum is an important component of the epizootiology of canine hepatozoonosis in North America.

Animals↗

PubMed2000

Muscular sarcocystosis in coyotes from Oklahoma.

In a recent survey in Oklahoma (USA), 52 free-ranging coyotes were examined for the presence of sarcocysts. Two of these coyotes were found infected with sarcocysts in skeletal muscle. By light microscopy, the cyst wall was thin and smooth. Ultrastructurally, the cyst wall had minute villar protrusions. The sarcocysts were 14.4 to 50.4 microm wide and 46.8 to 99 microm long. This is the first report of Sarcocystis sp. sarcocysts in the skeletal muscle of coyotes.

Animals↗

PubMed1988

Evaluation of praziquantel against induced Nanophyetus salmincola infections in coyotes and dogs.

Efficacy of praziquantel against Nanophyetus salmincola, the trematode vector of salmon poisoning disease, was determined in coyotes (n = 29) and dogs (n = 25). The 10- to 14-week-old animals were fed fish or fish kidneys that contained metacercariae of N salmincola. To prevent salmon poisoning disease, all animals were treated with tetracycline on days 8 and 9 after they were fed fish. Ten days after ingestion of infected fish, 19 coyotes and 12 dogs were treated once with praziquantel, administered SC or IM, at dosages between 6.68 and 38.73 mg/kg of body weight. Within 8 days after treatment, the numbers of trematode eggs in feces and trematodes recovered from the small intestine were reduced by greater than 99% when compared with untreated controls. Signs of drug toxicosis were not observed. On the basis of these results, praziquantel at doses approved for use in dogs against cestodes was highly effective against N salmincola in coyotes and dogs.

Animals↗