Topic:Wildlife
The interaction between wildlife and horses encompasses various ecological, behavioral, and health-related aspects. This topic explores the relationships and dynamics between horses and their natural environments, including interactions with other wildlife species. These interactions can influence behavior, habitat use, and resource competition. Additionally, wildlife can impact equine health through the transmission of diseases and parasites. This page gathers peer-reviewed research studies and scholarly articles that investigate the ecological roles, behavioral patterns, and health implications of wildlife interactions with horses.
Identification of reptilian and amphibian blood meals from mosquitoes in an eastern equine encephalomyelitis virus focus in central Alabama. Uranotaenia sapphirina, Culex erraticus, and Cx. peccator were collected in an enzootic eastern equine encephalomyelitis (EEE) virus focus in central Alabama (Tuskegee National Forest) from 2001 to 2003 and analyzed for virus as well as host selection. EEE virus was detected in each species every year except 2003, when pools of Cx. peccator were negative. Most (97%) of the 130 Cx. peccator blood meals identified were from ectothermic hosts; 3% were from birds. Among blood meals from reptiles (approximately 75% of the total), 81% were from Agkistrodon piscivorus (cottonmouth); all amphibian blo...
Prevalence of agglutinating antibodies to Sarcocystis neurona in raccoons (Procyon lotor) from an urban area of Virginia. Equine protozoal myeloencephalitis is the most important protozoan disease of horses in North America and is usually caused by Sarcocystis neurona. Natural and experimentally induced cases of encephalitis caused by S. neurona have been reported in raccoons (Procyon lotor) and raccoons are an intermediate host for this parasite. A 3-yr-long serological survey was conducted to determine the prevalence of agglutinating antibodies to S. neurona in raccoons collected from Fairfax County, Virginia, a suburban-urban area outside Washington, D.C. Samples from 469 raccoons were examined, and agglutinat...
Cytology of the normal and abnormal choroid plexi in selected domestic mammals, wildlife species, and man. A cytologic study of the choroid plexi of animals and humans was carried out using impression smears (imprints, imp) to understand better the cellular changes that occur in the cerebrospinal fluid in the case of disease. The samples, totaling 756 imp were from 11 dogs (239 imp), 10 horses (219 imp), 1 mule (23 imp), 3 cattle (69 imp), 1 sheep (19 imp), 2 pigs (39 imp), 1 deer (20 imp), 4 monkeys (22 imp), and 7 humans (106 imp). The samples came from individuals clinically free of neurologic disease, as well as from a few abnormal cases. Six of the 7 humans had no history of neurologic disease...
Detection of Anaplasma phagocytophilum in animals by real-time polymerase chain reaction. The aim of this study was to detect Anaplasma phagocytophilum in wild and domesticated animals and to identify the phylogenetic relationships of different strains of this bacterium. We adapted six published conventional methods targeting 16S fragments for real-time polymerase chain reaction. Initial screening of samples from 419 animals found 37 Anaplasma positives, later confirmed with several different primers and a TaqMan probe. We also performed DNA quantification and melting curve analysis. The nucleic acid of Anaplasma sp. was detected in a higher percentage of cases in members of the de...
Review of horses in Paleoindian sites of the Americas. Analysis of the morphological characters in North and South American horses present during Paleoindian time indicates that at least eight Equus ecospecies occurred in North America. In South America, Equus had radiated into four ecospecies, Hippidion had one, and Onohippidium had three geographically separate ecospecies. These species are found in archeological deposits ranging from ca. 13,000 to 8,000 yr B.P., in tropical habitats as well as in the high Andean and Patagonian colder ecotopes.
Absence of effects from immunocontraception on seasonal birth patterns and foal survival among barrier island wild horses. Despite a large body of safety data, concern exists that porcine zonae pellucidae (PZP) immunocontraception--used to manage wild horse populations--may cause out-of-season births with resulting foal mortality. Our study at Assateague, Maryland indicated the effects of immunocontraception on season of birth and foal survival between 1990 and 2002 on wild horses from Assateague Island. Among 91 mares never treated, 69 (75.8%) of foals were born in April, May, and June (in season). Among 77 treated mares, 50 (64.9%) were born in season. Of 29 mares foaling within 1 year after treatment (contracep...
Avian host preference by vectors of eastern equine encephalomyelitis virus. An important variable in the amplification and escape from the enzootic cycle of the arboviral encephalitides is the degree of contact between avian hosts and mosquito vectors. To analyze this interaction in detail, blood-fed mosquitoes that were confirmed vectors of eastern equine encephalomyelitis (EEE) virus were collected in 2002 from an enzootic site in central Alabama during the time this virus was actively transmitted. Avian-derived blood meals were identified to the species level of the host, and the proportion derived from each species was compared with the overall composition of the ...
Rabies surveillance in the United States during 2002. During 2002, 49 states and Puerto Rico reported 7,967 cases of rabies in nonhuman animals and 3 cases in human beings to the Centers for Disease Control and Prevention, an increase of 7.2% from the 7,436 cases in non-human animals and 1 case in a human being reported in 2001. More than 92% (7,375 cases) were in wild animals, whereas 7.4% (592) were in domestic species (compared with 93.3% in wild animals and 6.7% in domestic species in 2001). Compared with cases reported in 2001, the numbers of cases reported in 2002 increased among all major reporting groups with the exception of swine and ro...
[Blood feeding sources and peridomiciliation of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Psychodidae, Phlebotominae)]. A precipitin test was employed to study the alimentary tract content of Lutzomyia longipalpis in the intra- and peridomiciliary environments in the municipality of Raposa, Maranh o State, a transmission area for visceral leishmaniasis or kala azar. Out of 2,240 female sandflies captured, 547 (24.4%) had fed on vertebrate blood, with the following proportions: avian (87.9%); rodent (47.2%); human (42.4%); canine (27.6%); opossum (26.6%); and equine (22.5%). Based on a survey of 120 human dwellings, chickens were found to be the most common domestic animals in the peridomicile (28.3%), followed ...
Laminitis in Przewalski horses kept in a semireserve. Semireserves were created by the European Conservation Project for scientific research in preparation for reintroduction in the wilderness. They are defined as enclosures large enough to carry a group of Przewalski horses throughout the year without any additional feeding. The semireserve offers diverse opportunities for significant scientific research. As part of a general screening program, the hoof development in a group of Przewalski horses was investigated in the semireserve Schorfheide near Berlin. Since the foundation of this semireserve in 1992, veterinary treatment was not necessary w...
Epidemiology of leptospirosis: observations on serological data obtained by a “diagnostic laboratory for leptospirosis” from 1995 to 2001. Serological data on leptospira infection were reported and discussed. From 1995 to 2001, the blood serum samples of 9885 domestic and wild animals and humans, living in Northern and Central Italy, were examined by the macroagglutination test (MAT) employing bratislava, ballum, canicola, grippotyphosa, icterohaemorrhagiae, pomona, hardjo and tarassovi serovars as antigens. Considering sera with > or = 1:400 antibody titers as positive, 674 (6.81%) animals scored positive. Sheep, horses, pigs and dogs gave the highest number of positive responses, particularly against the serovar bratislava and,...
Prevalence of antibodies to Neospora caninum, Sarcocystis neurona, and Toxoplasma gondii in wild horses from central Wyoming. Sarcocystis neurona, Neospora caninum, N. hughesi, and Toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. The source of infection for N. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for S. neurona, N. caninum, and T. gondii, respectively. Seroprevalence of these coccidians in 276 wild horses from central Wyoming outside the known range of the opossum (Didelphis virginiana) was determined. Antibodies to T. gondii were found only in 1 of 276 horses tested with the modified agglutination test using 1:25, 1:50, ...
Long-term study of Cryptosporidium prevalence on a lowland farm in the United Kingdom. A longitudinal sample survey testing for Cryptosporidium in livestock and small wild mammals conducted over 6 years (1992-1997) on a lowland farm in Warwickshire, England, has shown the parasite to be endemic and persistently present in all mammalian categories. Faecal samples were taken throughout the year and oocysts concentrated by a formal ether sedimentation method for detection by immunofluorescence staining using a commercially available genus specific monoclonal antibody. Cryptosporidium parvum was identified by morphology and measurement of modified Ziehl-Neelsen stained oocysts. C. m...
Surveillance results from the first West Nile virus transmission season in Florida, 2001. After West Nile virus (WNV) was first detected in Florida in July 2001, intensive surveillance efforts over the following five months uncovered virus activity in 65 of the state's 67 counties with 1,106 wild birds, 492 horses, 194 sentinel chickens, and 12 people found infected with the virus. Thirteen of 28 mosquito isolations came from Culex mosquitoes. As seen in the northeastern United States, wild bird mortality was the most sensitive surveillance method. However, unlike the predominantly urban 1999 and 2000 epizootics, the Florida transmission foci were rural with most activity detected ...
Transmission of eastern equine encephalomyelitis virus in central Alabama. A site near Tuskegee, Alabama was examined for vector activity of eastern equine encephalomyelitis (EEE) virus in 2001. More than 23,000 mosquitoes representing 8 genera and 34 species were collected during a 21-week period, and five species, Culiseta melanura, Aedes vexans, Coquillettidia perturbans, Culex erraticus, and Uranotaenia sapphirina, were examined for the presence of virus using a nested reverse transcriptase-polymerase chain reaction for EEE virus. Each species was infected at various times of the mosquito season (May-September) with different minimum infection rates (MIRs). Culis...
Serologic survey of domestic animals for zoonotic arbovirus infections in the Lacandón Forest region of Chiapas, Mexico. A serologic survey in domestic animals (birds and mammals) was conducted in four communities located in the Lacandón Forest region of northeastern Chiapas, Mexico, during June 29 to July 1, 2001, with the objective to identify zoonotic arboviruses circulating in this area. We collected 202 serum samples from healthy domestic chickens, geese, ducks, turkeys, horses and cattle. The samples were tested by plaque-reduction neutralization test for antibodies to selected mosquito-borne flaviviruses (family Flaviviridae), including St. Louis encephalitis (SLE), Rocio (ROC), Ilheus (ILH), Bussuquara ...
Phylogenetic relationships of West Nile viruses isolated from birds and horses in Israel from 1997 to 2001. In November 1997, an outbreak of a neuroparalytic disease caused by West Nile (WN) virus was diagnosed in young goose flocks. Domestic geese were similarly affected in the late summer and fall of 1998, 1999, 2000 and 2001. WN viruses were also isolated from migratory and wild birds and horses in 1998-2001. A 1278 bp sequence of the envelope gene of 24 Israeli WN virus isolates was compared with those of seven isolates from Africa, Europe and New York. As a result, the Israeli isolates could then be grouped into two clusters. The 15 avian and three equine from 1997-2001 in the first cluster of ...
The prevalence and transmission to exotic equids (Equus quagga antiquorum, Equus przewalskii, Equus africanus) of intestinal nematodes in contaminated pasture in two wild animal parks. Wild equids maintained in large enclosures may suffer from helminth diseases because common hygiene practices have only limited effects on parasite populations. Weekly monitoring of helminth prevalences and pasture infestation was performed for 1 yr in several extensive maintenance systems of two wildlife parks with similar climates to determine when veterinary intervention to control parasites would be useful. We also sought evidence of natural immunogenic reactions among herds of Chapman zebras (Equus quagga antiquorum), Przewalski's horses (Equus przewalskii) and dwarf donkeys (Equus asinus...
Initiating arbovirus surveillance in Arkansas, 2001. Migratory birds could introduce West Nile (WN) virus to Arkansas. The purpose of this study was to establish a cooperative arbovirus surveillance program to monitor mosquitoes and birds in Arkansas for arboviruses. Our objectives were to: 1) perform routine, multicounty collections of mosquitoes and test them for eastern equine encephalitis, St. Louis encephalitis, and WN viruses; and 2) conduct passive surveillance by testing dead wild birds for WN virus. Arbovirus surveillance was organized by the Arkansas Department of Health, University of Arkansas, and Vector Disease Control Incorporated....
The Australian paralysis tick may be the missing link in the transmission of Hendra virus from bats to horses to humans. Hendra virus is a new virus of the family Paramyxoviridae. This virus was first detected in Queensland, Australia, in 1994; although, it seems that the virus has infected fruit-eating bats (flying-foxes) for a very long time. At least 2 humans and 15 horses have been killed by this virus since it first emerged as a virus that may infect mammals other than flying-foxes. Hendra virus is thought to have moved from flying-foxes to horses, and then from horses to people. There is a reasonably strong hypothesis for horse-to-human transmission: transmission of virus via nasal discharge, saliva and/or...
A herd-level analysis of risk factors for antibodies to Sarcocystis neurona in Michigan equids. Equine protozoal myeloencephalitis (EPM) is a neurological disease of horses and ponies caused by infection of the central nervous system with the protozoan parasite Sarcocystis neurona. A herd-level analysis of a cross-sectional study of serum antibodies to S. neurona in Michigan equids was conducted, using data collected in 1997 for study that included 1121 equids from 98 Michigan horse farms. Our objective was to identify specific herd-level risk factors associated with seropositivity. We tested associations between herd seroprevalence and various farm-management practices (including feed-s...
Ascarid nematodes in domestic and wild terrestrial mammals. The biology of the ascarid nematodes has been discussed in the context of their important economic role in farm animals, pet animals and zoo animals with special attention to carnivores and primates. In farm animals, infection with the most common roundworm of horses (Parascaris equorum) and swine (Ascaris suum) depend on many factors such as environmental conditions (larval development in the egg and egg survival), age of the host, breed, husbandry system, hygiene and treatment schedule. The monoxenic ascarids Toxocara canis and T. cati are the most important nematodes in carnivorous animals ...
In vitro isolation of equine piroplasms derived from Cape Mountain zebra (Equus zebra zebra) in South Africa. Twenty blood samples of zebras (Equus zebra zebra) from the Karoo National Park and the Bontebok National Park in South Africa, all seropositive for Theileria equi, were subjected to in vitro culture to identify carrier animals and to isolate the parasites. Sixteen animals had a detectable parasitaemia in Giemsa-stained blood smears examined before culture initiation, the remaining four animals were identified as T. equi carriers by in vitro culture. Cultures were initiated either in an oxygen-reduced gas mixture or in a 5% CO2-in-air atmosphere. Out of the 20 blood samples, 12 cultures of T. ...
Reversibility of action and safety during pregnancy of immunization against porcine zona pellucida in wild mares (Equus caballus). Contraceptive management of publicly valued wildlife species requires safeguards to ensure that these populations are preserved in a healthy state. In addition, reversibility of contraceptive effects and safety in pregnant animals are major concerns. A population of wild horses has been immunized against porcine zona pellucida (PZP) over a 12 year period on Assateague Island National Seashore, MD (ASIS). Mares initially received one or two 65 microg inoculations and once a year 65 microg booster inoculations, all delivered by dart. All young mares aged > 2 years were treated with PZP for 3 ...
Porcine zona pellucida (PZP) immunocontraception of wild horses (Equus caballus) in Nevada: a 10 year study. Porcine zona pellucida (PZP) immunocontraception was investigated for possible use in free-roaming wild horses in the western USA. A protocol of two injections (3-4 weeks apart) of vaccine lasting 1 year was first used and a single-injection controlled-release vaccine of 1 year duration was developed and tested in the field. Studies of a presumptive vaccine of 2 year duration were initiated. The parameters of anti-PZP antibody titre response, pregnancy testing and offspring production were used, and PZP vaccine was found to provide up to 94% infertility in free-roaming wild mares. In addition,...
Effects of immunocontraception on population, longevity and body condition in wild mares (Equus caballus). Contraception is becoming a common approach for the management of captive and wild ungulates yet there are few data for contraceptive effects on entire populations. Management-level treatment of mares with porcine zona pellucida (PZP) vaccine resulted in zero population growth of the Assateague Island wild horse population within 1 year of initiation of treatment. Contraceptive efficacy was 90% for mares treated twice in the first year and annually thereafter. For mares given a single initial inoculation, contraceptive efficacy was 78%. The effort required to achieve zero population growth dec...
Isolation of eastern equine encephalitis virus and West Nile virus from crows during increased arbovirus surveillance in Connecticut, 2000. The emergence of the West Nile virus (WNV) in the northeastern United States has drawn emphasis to the need for expanded arbovirus surveillance in Connecticut. Although the state of Connecticut began a comprehensive mosquito-screening program in 1997, only since 1999 have there been efforts to determine the prevalence of arboviruses in bird populations in this state. Herein, we report on our results of an arbovirus survey of 1,704 bird brains. Included in this report are the first known isolations of eastern equine encephalitis virus (EEEV) from crows and data on the geographic and temporal di...
Computer simulations to determine the efficacy of different genome resource banking strategies for maintaining genetic diversity. Genome resource banks (GRBs) and assisted reproductive techniques are increasingly recognized as useful tools for the management and conservation of biodiversity, including endangered species. Cryotechnology permits long-term storage of valuable genetic material. Although, the actual application to endangered species management requires technical knowledge about sperm freezing and thawing, a systematic understanding of the quantitative impacts of various germ plasm storage and use scenarios is also mandatory. In this study, various GRB strategies were analyzed using the historical data from th...
An analysis of human pathogens found in horse/mule manure along the John Muir Trail in Kings Canyon and Sequoia and Yosemite National Parks. To determine the prevalence of microorganisms that are potentially pathogenic for humans in horse/mule manure along the John Muir Trail (JMT). Methods: Random samples of horse/mule manure were collected along sections of the JMT in Yosemite, Kings Canyon, and Sequoia national parks (NP), as well as in portions of the Pacific Crest Trail (PCT) and selected JMT/PCT access trails. Convenience samples of wild animal scat found within I mile of trails were also collected. The fresh specimens were individually preserved both in 0.9% saline and polyvinyl alcohol (PVA)-containing tubes and stored at 4...
The role of birds in the ecology of West Nile virus in Europe and Africa. Surveys on wild birds conducted during the last two decades in Europe, notably Poland and the Czech Republic, to determine their infection rate with WN virus have revealed endemic foci of infection. Some species of seropositive birds were nonmigrators while others were hatchlings of migrating species. Persistently infected avian reservoirs are potential sources of viruses for mosquitoes that multiply in the temperate European zone in hot, wet summers. In the past, evidence for geographical circulation of WN viruses was based on antigenic analysis of strains from different countries while more ...