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At least 217 records · Page 12Linked to original sources
PubMed2004

Antibodies to selected pathogens in free-ranging terrestrial carnivores and marine mammals in Canada.

Antibody titres to selected pathogens (canine adenovirus [CAV-2], feline herpesvirus [FHV], phocine herpesvirus [PHV-1], canine distemper virus, dolphin morbillivirus [DMV], phocine distemper virus [PDV], parainfluenza virus type 3 [PI3], rabies virus, dolphin rhabdovirus [DRV], canine coronavirus, feline coronavirus, feline leukaemia virus, Borrelia burgdorferi and Toxoplasma gondii) were determined in whole blood or serum samples from selected free-ranging terrestrial carnivores and marine mammals, including cougars (Fellis concolor), lynxes (Fellis lynx), American badgers (Taxidea taxus), fishers (Martes pennanti), wolverines (Gulo gulo), wolves (Canis lupus), black bears (Ursus americanus), grizzly bears (Ursus arctos), polar bears (Ursus maritimus), walruses (Odobenus rosmarus) and belugas (Delphinapterus leucas), which had been collected at several locations in Canada between 1984 and 2001. Antibodies to a number of viruses were detected in species in which these infections have not been reported before, for example, antibodies to CAV-2 in walruses, to PDV in black bears, grizzly bears, polar bears, lynxes and wolves, to DMV in grizzly bears, polar bears, walruses and wolves, to PI3 in black bears and fishers, and to DRV in belugas and walruses.

Adenoviruses, Canine↗
PubMed1995

Occurrence of rabies in a wolf population in northeastern Alaska.

Nine Alaskan wolves (Canis lupus) were found dead during spring and summer 1985; five of seven animals tested for rabies virus were positive. The 1985 epizootic altered annual den use patterns by wolves in northeastern Alaska, but did not appear to affect population size. We propose that rabies in arctic wolves may be more common than previously thought.

Alaska↗
PubMed2006

Echinococcus granulosus (Cestoda, Taeniidae) in the Iberian wolf.

The intestinal contents of 27 Iberian wolves (Canis lupus signatus) from Spain were screened for the presence of the taenid cestode Echinococcus granulosus. Four animals were found positive (15% prevalence). The intensity of parasitation was variable (mean 71, range 1-147 E. granulosus per host). Gravid individuals were found in all wolves positive with the parasite. Molecular characterization of the parasite material showed that the wolf strain belongs to the G1 genotype. According to the results, we conclude that the Iberian wolf takes part in the maintenance of the life cycle of this zoonotic parasite in Spain and that this fact could have public health relevance.

Animals↗
PubMed2003

Echinococcus granulosus in Finland.

Echinococcus granulosus is shown to occur in eastern Finland in a sylvatic cycle involving wolves (Canis lupus) as the definitive host and reindeer (Rangifer tarandus tarandus) and probably also elk (Alces alces) and the wild forest reindeer (Rangifer tarandus fennicus) as intermediate hosts. Even though the prevalence of E. granulosus in reindeer has increased in recent years, it is still very low (<0.013%). The results suggest, however, that the reindeer is a good sentinel animal to show the contamination of soil with Echinococcus eggs. This is the first report of wolves acting as a definitive host for E. granulosus in northern Europe. The parasite seems to be quite common in the Finnish wolf population, with a prevalence of approximately 30% in both intestinal and faecal samples. The present results and previous ones indicate that E. granulosus infection has not spread to dogs in the reindeer herding area.

Animals↗
PubMed2004

Study on the ecological distribution of alveolar Echinococcus in Hulunbeier Pasture of Inner Mongolia, China.

A study on the ecological distribution of alveolar Echinococcus was carried out in the Hulunbeier Pasture of Inner Mongolia, China during 1998 and 1999. Animals examined included wolves (Canis lupus), red foxes (Vulpes vulpes), sand foxes (Vulpes corsac), domestic dogs (Canis familiaris), Microtus brandti, Meriones unguiculatus, Citellus dauricus, Allactaga sibirica, Phodopus sungorus and Ochotona daurica. Three wolves were found to be infected with E. granulosus. Two sand foxes were infected with E. multilocularis. The majority of infections of alveolar echinococcus was found in M. brandti. Based on the structure of metacestodes found in the livers of naturally infected M. brandti, 3 main variants were observed. Type I had small alveolar cysts with thin cyst walls. Type II had a larger cyst with a thick cyst wall. Infection of laboratory mice with the gravid segments isolated from the naturally infected sand foxes led to the formation of mature Type I alveolar metacestodes in the lungs and Type II metacestodes in the livers of infected animals, respectively.

Animals↗
PubMed2002

Noninvasive molecular tracking of colonizing wolf (Canis lupus) packs in the western Italian Alps.

We used noninvasive methods to obtain genetic and demographic data on the wolf packs (Canis lupus), which are now recolonizing the Alps, a century after their eradication. DNA samples, extracted from presumed wolf scats collected in the western Italian Alps (Piemonte), were genotyped to determine species and sex by sequencing parts of the mitochondrial DNA (mtDNA) control-region and ZFX/ZFY genes. Individual genotypes were identified by multilocus microsatellite analyses using a multiple tubes polymerase chain reaction (PCR). The performance of the laboratory protocols was affected by the age of samples. The quality of excremental DNA extracts was higher in samples freshly collected on snow in winter than in samples that were older or collected during summer. Preliminary mtDNA screening of all samples allowed species identification and was a good predictor of further PCR performances. Wolf, and not prey, DNA targets were preferentially amplified. Allelic dropout occurred more frequently than false alleles, but the probability of false homozygote determinations was always < 0.001. A panel of six to nine microsatellites would allow identification of individual wolf genotypes, also whether related, with a probability of identity of < 0.015. Genealogical relationships among individuals could be determined reliably if the number of candidate parents was 6-8, and most of them had been sampled and correctly genotyped. Genetic data indicate that colonizing Alpine wolves originate exclusively from the Italian source population and retain a high proportion of its genetic diversity. Spatial and temporal locations of individual genotypes, and kinship analyses, suggest that two distinct packs of closely related wolves, plus some unrelated individuals, ranged in the study areas. This is in agreement with field observations.

Animals↗
PubMed2005

Severe inbreeding depression in a wild wolf (Canis lupus) population.

The difficulty of obtaining pedigrees for wild populations has hampered the possibility of demonstrating inbreeding depression in nature. In a small, naturally restored, wild population of grey wolves in Scandinavia, founded in 1983, we constructed a pedigree for 24 of the 28 breeding pairs established in the period 1983-2002. Ancestry for the breeding animals was determined through a combination of field data (snow tracking and radio telemetry) and DNA microsatellite analysis. The population was founded by only three individuals. The inbreeding coefficient F varied between 0.00 and 0.41 for wolves born during the study period. The number of surviving pups per litter during their first winter after birth was strongly correlated with inbreeding coefficients of pups (R2=0.39, p<0.001). This inbreeding depression was recalculated to match standard estimates of lethal equivalents (2B), corresponding to 6.04 (2.58-9.48, 95% CI) litter-size-reducing equivalents in this wolf population.

Animals↗
PubMed2005

SNPs in ecological and conservation studies: a test in the Scandinavian wolf population.

Single nucleotide polymorphisms (SNPs) have the potential to become the genetic marker of choice in studies of the ecology and conservation of natural populations because of their capacity to access variability across the genome. In this study, we provide one of the first demonstrations of SNP discovery in a wild population in order to address typical issues of importance in ecology and conservation in the recolonized Scandinavian and neighbouring Finnish wolf Canis lupus populations. Using end sequence from BAC (bacterial artificial chromosome) clones specific for dogs, we designed assays for 24 SNP loci, 20 sites of which had previously been shown to be polymorphic in domestic dogs and four sites were newly identified as polymorphic in wolves. Of the 24 assayed loci, 22 SNPs were found to be variable within the Scandinavian population and, importantly, these were able to distinguish individual wolves from one another (unbiased probability of identity of 4.33 x 10(-8)), providing equivalent results to that derived from 12 variable microsatellites genotyped in the same population. An assignment test shows differentiation between the Scandinavian and neighbouring Finnish wolf populations, although not all known immigrants are accurately identified. An exploration of the misclassification rates in the identification of relationships shows that neither 22 SNP nor 20 microsatellite loci are able to discriminate across single order relationships. Despite the remaining obstacle of SNP discovery in nonmodel organisms, the use of SNPs in ecological and conservation studies is encouraged by the advent of large scale screening methods. Furthermore, the ability to amplify extremely small fragments makes SNPs of particular use for population monitoring, where faecal and other noninvasive samples are routinely used.

Animals↗
PubMed2004

Population response to climate change: linear vs. non-linear modeling approaches.

BACKGROUND: Research on the ecological consequences of global climate change has elicited a growing interest in the use of time series analysis to investigate population dynamics in a changing climate. Here, we compare linear and non-linear models describing the contribution of climate to the density fluctuations of the population of wolves on Isle Royale, Michigan from 1959 to 1999. RESULTS: The non-linear self excitatory threshold autoregressive (SETAR) model revealed that, due to differences in the strength and nature of density dependence, relatively small and large populations may be differentially affected by future changes in climate. Both linear and non-linear models predict a decrease in the population of wolves with predicted changes in climate. CONCLUSIONS: Because specific predictions differed between linear and non-linear models, our study highlights the importance of using non-linear methods that allow the detection of non-linearity in the strength and nature of density dependence. Failure to adopt a non-linear approach to modelling population response to climate change, either exclusively or in addition to linear approaches, may compromise efforts to quantify ecological consequences of future warming.

Age Factors↗
PubMed1998

Semen parameters and electron microscope observations of spermatozoa of the red wolf, Canis rufus.

Semen parameters were evaluated on ejaculates of a captive population of red wolves (Canis rufus) sampled over two consecutive mating seasons. A total of 31 samples from 15 animals yielded mean sperm motility of 69.6 +/- 19.4%, mean sperm density of 131 +/- 124 x 10(6) ml-1, mean total number of spermatozoa of 470 +/- 465 x 10(6) and mean percentage morphologically abnormal spermatozoa of 35 +/- 11.8%. Restricting the data to animals sampled three times or more or limiting the samples to proven breeders resulted in statistically non-significant differences in these numbers (P < 0.05). When compared with data from other canines the seminal parameters of red wolves are at the lower extremes of the range. In particular the proportion of morphologically abnormal spermatozoa (35%) is approximately twice that seen in other canine species. Light microscopic analysis of abnormal forms revealed that almost half (45%) were bent defects, another 40% were secondary defects (coiled, detached and immature) and 15% were primary defects. Electron microscopy confirmed the presence of substantial numbers of morphologically abnormal forms including double-headed and double-flagellar cells, bent or kinked forms especially in the neck region, acrosomal abnormalities and bizarre spermatids. Approximately one-third of the samples also showed the presence of white blood cells, in some cases demonstrating sperm phagocytosis (spermophagy). These results are consistent with the concept of declining sperm parameters associated with restricted gene pools in numerically limited populations. However, alternative explanations are also explored.

Animals↗
PubMed2000

Serologic survey for Toxoplasma gondii in selected wildlife species from Alaska.

Blood was collected from selected wildlife species in specific areas of Alaska (USA) during 1976-96. A modified agglutination test was used to test sera for evidence of exposure to Toxoplasma gondii. Serum antibody prevalence was 43% (62 positive of 143 tested) for black bears (Ursus americanus), 9% (11/125) for wolves (Canis lupus), 7% (22/319) for Dall sheep (Ovis dalli), 6% (14/241) for caribou (Rangifer tarandus), 1% (3/240) for moose (Alces alces), and 1% (2/241) for bison (Bison bison). A predictive model was developed to determine the effect of sex, age, location, and year of collection on antibody prevalence for each species. Prevalence was higher in older black bears, caribou, and wolves. For black bears, prevalence was highest in the southeast region of the state. For caribou, prevalence was lowest on the Alaska Peninsula.

Agglutination Tests↗
PubMed1987

Basic haematological values in carnivores--I. The Canidae, the Hyaenidae and the Ursidae.

Basic haematological values for 32 animals of four carnivore species are reported. In six adult wolves (Canis lupus) the mean values estimated for the erythrocyte count 7.48 X 10(12)/l, haematocrit 0.465/l, haemoglobin 172.0 g/l and leukocyte counts 7.33 X 10(9)/l are given. For five young wolves, these parameters were markedly decreased, only the white cell count was raised. In 14 hunting dogs (Lycaon pictus) the mean values estimated are: erythrocyte count 9.15 x 10(12)/l haematocrit 0.435/l, haemoglobin 179.2 g/l and leukocytes 12.95 X 10(9)/l. In six striped hyaenas (Hyaena hyaena) the mean estimated values are: erythrocyte count 8.11 X 10(12)/l, haemoatocrit 0.445/l, haemoglobin 178.0 g/l and leukocytes 13.95 X 10(9)/l. Only individual values for the reported parameters are given in the Asiatic black bear (Selenarctos thibetanus). All results are compared with values derived from the literature for animals under investigation and for the domestic dog (Canis familiaris).

Animals↗
PubMed2006

Patterns of fecal gonadal hormone metabolites in the maned wolf (Chrysocyon brachyurus).

Ex situ populations of maned wolves are not viable due to low reproductive efficiency. The objective of this study was to increase knowledge regarding the reproductive physiology of maned wolves to improve captive management. Fecal samples were collected 3-5 d/wk from 12 females of various reproductive age classes (young, prime breeding and aged) and reproductive histories (conceived and raised pups, conceived but lost pups, pseudo-pregnant and unpaired). Ovarian steroids were extracted from feces and assessed by enzyme immunoassay. Concentrations of estrogen metabolites gradually increased, beginning 2-5 d before breeding, and declined to baseline on the day of lordosis and copulation. Fecal progestin metabolite concentrations increased steadily during the periovulatory period, when sexual receptivity was observed, and remained elevated during pregnancy and pseudo-pregnancy. During the luteal phase, young and prime breeding-age females excreted larger amounts of progestins than those of older age classes. Furthermore, progestin concentrations were higher during the luteal phase of pregnant versus pseudo-pregnant bitches. Profiles of fecal progestin metabolites for three singleton females were unchanged throughout the breeding season, suggesting ovulation is induced in this species. However, this finding could be confounded by age, as these females were either young or aged.

Age Factors↗
PubMed1996

Serologic survey of trichinellosis in wild mammals kept in a Mexico City Zoo.

A serologic survey of Trichinella infection was carried out to determine the prevalence of this parasitosis among wild mammals kept in captivity at the Chapultepec Zoo. This was prompted by the necropsy finding of a heavy Trichinella infection in a Canadian polar bear (Ursus maritimus) that had been kept at the Zoo for more than 11 years. The parasites recovered were identified as T. nativa (T2). A serologic study based on ELISA and Western blot analysis was performed in serum samples from two polar bears (U. maritimus), six wolves (Canis lupus); nine foxes (Urocyon cinereoargenteus); seven coyotes (Canis latrans); nine jaguars (Panthera onca); ten lions (Panthera leo); 11 tigers (Panthera tigris); six panthers (Panthera pardus); eight leopards (Panthera pardus); two lynxes (Lynx rufus); five pumas (Felis concolor); one yagouaroundi (Felis yagouaroundi); and one ocelot (Felis pardalis). In these assays, 25% and 27% of the samples studied were positive using total muscle larva extract from T. nativa (T2) or T. spiralis (T1), respectively. When T. spiralis (T1) excretory/secretory products or surface/stichosomal antigens were used, 15 and 13% positivity was obtained respectively. The reactivity rates obtained among the different groups varied from 11 to 83%, wolves having the highest infection rate. Western blot analysis of positive ELISA sera showed an antigenic recognition pattern characteristic of animals infected with Trichinella.

Animals↗
PubMed2001

Bioaccumulation of persistent organic pollutants in lichen-caribou-wolf food chains of Canada's Central and Western Arctic.

While biomagnification of persistent organic pollutants (POPs) in aquatic food chains is well documented, there have been few investigations of the trophodynamics of POPs in Arctic terrestrial food chains. This study presents field-collected concentration data and corresponding fugacities of various hydrophobic organic chemicals (ranging in octanol-water partition coefficients or K(OW) from approximately 10(3.8) to 10(9)) in two lichen species (Cladina rangiferina and Cetraria nivalis), willow leaves (Salix glauca), barren-ground caribou (Rangifer tarandus), and wolves (Canis lupus) from Canada's Central and Western Arctic region. The results show that, in contrast to aquatic food chains, persistent substances including beta-hexachlorocyclohexane and 1,2,4,5-tetrachlorobenzene with a K(OW) <10(5) can substantially biomagnify in lichen-caribou-wolf food chains in Canada's Central and Western Arctic. Strong positive correlations between the biomagnification factor and the octanol-air partition coefficients (K(OA)) of nonmetabolizable compounds were observed in wolves. In caribou, the biomagnification factors dropped slightly with increasing K(OA). K(OA) proved to be a better indicator of biomagnification than K(OW). Current management policies that consider only chemicals with K(OW) values >10(5) as bioaccumulative substances fail to identify substances that have the potential to biomagnify in Arctic terrestrial food chains despite a low K(OW) because of a high K(OA).

Animals↗
PubMed1993

Allozyme variability in the Italian wolf (Canis lupus) population.

Multilocus protein electrophoresis was used to estimate genetic variability in a sample of 38 Italian wolves (Canis lupus). Percentage of polymorphic loci was p = 10.0 per cent (four polymorphic loci out of 40 examined), and average observed heterozygosity was Ho = 0.028. Genotypes were in Hardy-Weinberg equilibrium. Electrophoretic analysis does not indicate a significant reduction of genetic variability at nuclear gene loci following at least one century of isolation from other European populations and demographic fluctuations suggested by recent range contraction and expansion. These findings are compared with published allozyme and mitochondrial DNA data for dogs, Canadian wolves, and introgressed wolf x coyote populations from Minnesota and Isle Royale (U.S.A.).

Animals↗
PubMedDate not supplied

[Dog as a mammalian genetic model].

Up to recently, studies on dog genetics were rather scare notwithstanding the enormous potential that the canine model can offer in the study of the genotype/phenotype relationship and the analysis of the causes of many genetic diseases, with simple or complex inheritance, that affect dogs but also the human population. This potentiality is essentially due to the natural history of dogs whose domestication from wolves dated back 15,000 years, at least. All modern dogs originated from a limited number of female wolves from Eastern Asia. By applying a combination of selections and strong inbreeding practices, humans have created over 350 breeds, each of them corresponding to a genetic isolate and altogether offering a unique panel of polymorphism never encountered in any other mammals. In this review we summarized what makes dogs an unavoidable model. Contrary to the classical models like the two yeasts, nematode, fish, fly, mouse, or rat mainly used to understand the function of genes, dog with the creation across the centuries of numerous breeds offers a unique opportunity to study the role of their alleles. We report recent data on the construction of genomic maps and on the sequencing program of the dog genome launched by the National Institute of Health (NIH). To take fully advantage of the canine model, we advocate for the systematic construction of a rich canine single nucleotide polymorphisms (SNP) ressource to perform linkage desiquilibrium studies of normal or pathological traits as well as to get insight into the genetic diversity of the canine species.

Animals↗
PubMedDate not supplied

Phylogenetic relationships, evolution, and genetic diversity of the domestic dog.

The spectacular diversity in size, conformation, and pelage that characterizes the domestic dog reflects not only the intensity of artificial selection but ultimately the genetic variability of founding populations. Here we review past molecular genetic data that are relevant to understanding the origin and phylogenetic relationships of the dog. DNA-DNA hybridization data show that the dog family Canidae diverged about 50 million years ago from other carnivore families. In contrast, the extant canids are very closely related and diverged from a common ancestor about 10 million years ago. The evidence supporting a close relationship of dogs with gray wolves is overwhelming. However, dogs are remarkably diverse in mitochondrial and nuclear genes. Mitochondrial DNA analysis suggests a more ancient origin of dogs than has been indicated by the fossil record. In addition, dogs have originated from or interbred with wolves throughout their history at different times and different places. We test the possibility of an independent domestication event in North America by analysis of mtDNA variation in the Xoloitzcuintli. This unusual breed is believed to have been kept isolated for thousands of years and may be one of the most ancient breeds in North America. Our results do not support a New World domestication of dogs nor a close association of the Xoloitzcuintli with other hair-less breeds of dogs. Despite their phenotypic uniformity, the Xoloitzcuintli has a surprisingly high level of mtDNA sequence variation. Other breeds are also genetically diverse, suggesting that dog breeds were often founded with a large number of dogs from outbred populations.

Animals↗