Topic:Disease Prevalence
Disease prevalence in horses refers to the frequency and distribution of various diseases within equine populations. Understanding disease prevalence is essential for identifying health trends, assessing risk factors, and implementing effective disease management and prevention strategies. Common diseases affecting horses include equine influenza, equine herpesvirus, strangles, and equine infectious anemia. The study of disease prevalence involves collecting and analyzing data from veterinary reports, field studies, and laboratory diagnostics. This page compiles peer-reviewed research studies and scholarly articles that investigate the patterns, causes, and implications of disease prevalence in horses, providing insights into equine health management and epidemiology.
Epizootic lymphangitis in horses: a review of the literature. Epizootic lymphangitis is a relatively common infectious disease of horses and other liquids in certain parts of the world. The infection rate varies according to the geographic area and the age of the animal. The disease is most commonly characterised by a cord-like appearance of the subcutaneous lymphatic and cutaneous pyogranulomas, the discharge from which contains spherical or pear-shaped bodies of the causal agent, Histoplasma farciminosum. Diagnosis can be made by the demonstration of typical organisms in stained smears, culture and tissue sections. Serological tests and a skin hypersen...
Prevalence of antibodies to Neospora caninum in horses in North America. Serum samples from 296 horses slaughtered for food in the United States were tested for antibodies to Neospora caninum by the Neospora-agglutination test (NAT). Antibodies were found in 69 (23.3%) horses with titers of 1:40 (19 horses), 1:80 (19 horses), 1:100 (3 horses), 1:200 (7 horses), 1:400 (4 horses), and 1:800 (17 horses). This is the first serologic survey for N. caninum antibodies in horses.
Control of equine piroplasmosis in Brazil. The importance of equine piroplasmosis control in endemic countries has increased in recent years and plays an important role to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Babesia equi or Theileria equi and Babesia caballi) in Brazil--a country where the disease occurs endemically--in different climatic conditions, and to evaluate the results of a strategy for tick control in order to decrease infection rates. Blood samples were taken from 720 horses on 28 farms from different regions and su...
Genetic and antigenic diversity among eastern equine encephalitis viruses from North, Central, and South America. Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lin...
Epidemiological aspects of Babesia equi in horses in Minas Gerais, Brazil. The prevalence of Babesia equi in two climatic regions of Minas Gerais state was determined using the indirect fluorescent antibody test (IFAT) with blood samples obtained from horses in two slaughterhouses. Of 399 samples, 241 (60.4%) showed a positive reaction. Anti-B. equi antibody was detected in every county studied, the prevalence being 59.7% for horses in the area where the temperature rises above 18 degrees C in winter and 61.4% in the area where it remains below 18 degrees C, indicating that climatic variation has no substantial effect on the prevalence of the infection in Brazil. Blo...
Association of Ixodes pacificus (Acari: ixodidae) with the spatial and temporal distribution of equine granulocytic ehrlichiosis in California. This study was conducted to determine if the biology of certain ticks associated with horses regulates the spatial and temporal distribution of equine granulocytic ehrlichiosis (EGE) in California north of Monterey County. We compared the spatial and temporal distribution of EGE cases with the seasons of activity and life histories of ticks that infest horses. Spatially, cases collected from equine veterinarians clustered around each other in a manner different from the way in which control cities of practice were distributed, with foci limited to the Sierra Nevada and coastal foothills. Cases...
Ticks and antibodies to Borrelia burgdorferi from mammals at Cape Hatteras, NC and Assateague Island, MD and VA. Results of a survey for ixodid ticks and/or serum antibodies to Borrelia burgdorferi from 14 species of small to large mammals from eastern coastal areas of the United States are presented. Most samples were obtained from July 1987 through June 1989 (excluding December-March) at 3 locales: Assateague Is. National Seashore, Worcester Co., MD., and Accomack Co., VA. (approximately 38 degrees 05' N 75 degrees 10' W), and Cape Hatteras National Seashore, Dare Co., NC (approximately 35 degrees 30' N 76 degrees 35' W). Hosts sampled included opossums (Didelphis virginiana), least shrews (Cryptotis p...
Serologic prevalence of Sarcocystis neurona, Toxoplasma gondii, and Neospora caninum in horses in Brazil. To determine serologic prevalence of Sarcocystis neurona, Toxoplasma gondii, and Neospora caninum in horses in Brazil. Methods: Prevalence survey. Methods: 101 Thoroughbreds in Brazil. Methods: Blood samples were obtained from horses and tested for serum antibodies against S neurona by use of an immunoblot procedure with culture-derived S neurona merozoites as antigen, and for serum antibodies against T gondii and N caninum by use of a modified agglutination test with formalin-preserved tachyzoites and mercaptoethanol. Results: Antibodies against S neurona and T gondii were detected in 36 and ...
Epidemiology of EHV-1 and EHV-4 in the mare and foal populations on a Hunter Valley stud farm: are mares the source of EHV-1 for unweaned foals. The prevalence of EHV-1 and EHV-4 antibody-positive horses was determined using a type specific ELISA on serum samples collected from 229 mares and their foals resident on a large Thoroughbred stud farm in the Hunter Valley of New South Wales in February 1995. More than 99% of all mares and foals tested were EHV-4 antibody positive, while the prevalence of EHV-1 antibody positive mares and foals were 26.2 and 11.4%, respectively. Examination of the ELISA absorbance data for the individual mares and foals suggested that the EHV-1 antibody positive foals had been infected recently with EHV-1 and...
Epidemiological studies of equine herpesvirus 1 (EHV-1) in Thoroughbred foals: a review of studies conducted in the Hunter Valley of New South Wales between 1995 and 1997. Sero-epidemiological studies conducted between 1995 and 1997 on two large Thoroughbred stud farms in the Hunter Valley of NSW showed clear evidence of EHV-1 infection in foals as young as 30 days of age. Similarly, serological evidence suggested that these foals were infected with EHV-1 from their dams or from other lactating mares in the group, with subsequent foal to foal spread of infection prior to weaning. These studies also provided evidence of EHV-1 infection of foals at and subsequent to weaning, with foal to foal spread of EHV-1 amongst the weanlings. These data indicated that the mar...
Prevalence of antibodies to Sarcocystis neurona, Toxoplasma gondii and Neospora caninum in horses from Argentina. Sera from 76 horses from Argentina were examined for antibodies to Sarcocystis neurona, Toxoplasma gondii and Neospora caninum. Antibodies to S. neurona were found in 27 (35.5%) of 76 horses using immunoblots with culture derived merozoites as antigen. Antibodies to T. gondii were found in 10 (13.1%) of 76 horses by using the modified agglutination test with formalin-fixed tachyzoites and mercaptoethanol; titers were 1:25 (two horses), 1:50 (six horses), 1:100 (two horses), and 1:200 (one horse). Antibodies to N. caninum were not found in any of the 76 horses by the use of N. caninum agglutina...
Cyathostominae (Nematoda) parasites of Equus caballus in some Brazilian states. Thirty six horses from nine Brazilian states (Goiás, Minas Gerais, Pará, Maranhão, Piauí, Paraíba, Pernambuco, Rio Grande do Norte, and Ceará) were examined for infections by small strongyles. The following species were identified: Cylicocyclus nassatus, C. insigne, C. brevicapsulatus, C. leptostomum, C. radiatus, C. ultrajectinus, C. ashworthi, Cylicostephanus goldi, C. calicatus, C. minutus, C. longibursatus, Petrovinema poculatum, Coronocyclus coronatus, C. labiatus, C. labratus, Cyathostomum catinatum, C. pateratum, C. alveatum, Parapoteriostomum euproctus, Cylicodontophorus bicorona...
Seroepizootiological survey of Japanese encephalitis virus and Getah virus in regional horse race tracks from 1991 to 1997 in Japan. A sero-epizootiological survey was conducted for Japanese encephalitis virus (JEV) and Getah virus (GeV) at 10 to 20 regional horse race tracks from 1991 to 1997 in Japan. It was observed that geometrical mean (GM) antibody titer to JEV and GeV was 10 to 50 times higher than others at several race courses (RCs) almost every year. Of them, several race horses showing high antibody titer, which were suggested to be infected with the virus, were also observed in this survey. These data suggested that the viruses have spread among race horses almost every year in Japan, although, fortunately, no h...
Historical perspective of cyathostomes: prevalence, treatment and control programs. Small strongyles are highly prevalent in horses and can be found worldwide. Even though over 50 species of these parasites have been described, about 10 species comprise the bulk of the total number present in horses. Efforts to control small strongyles and other equine internal parasites have been undertaken for many years. Some of the early medications and control measures provided questionable activity against endoparasites; whether effective or not, they could be detrimental to the horse. Beginning in the early 1900s, scientific effort was used to evaluate activity of antiparasitic compoun...
Vector competence of three Venezuelan mosquitoes (Diptera: Culicidae) for an epizootic IC strain of Venezuelan equine encephalitis virus. Experimental studies were undertaken to evaluate the vector competence of selected mosquito species [Aedes taeniorhynchus (Wiedemann), Culex declarator Dyar and Knab, and Mansonia titillans (Walker)] from northwestern Venezuela for the epizootic (IC) strain of Venezuelan equine encephalitis (VEE) virus that was responsible for the 1995 outbreak of VEE in this area. Ae. taeniorhynchus was highly susceptible to infection (94% of 35), and 89% had a disseminated infection. Virus-exposed Ae. taeniorhynchus that refed on susceptible hamsters readily transmitted virus, confirming that this species wa...
Isolation of Salmonella organisms from the mesenteric lymph nodes of horses at necropsy. To determine the prevalence of Salmonella infections in horses at necropsy. Methods: Cross-sectional prevalence survey. Methods: 102 horses. Methods: Mesenteric lymph nodes were collected from horses that were necropsied. Horses had died or were euthanatized because of severe disease or at the request of the owner. Twenty-eight of the horses were racehorses euthantized following acute catastrophic injuries on the racetrack. Mesenteric lymph nodes were submitted for Salmonella culture via direct plating of tissue specimens on MacConkey agar and by use of 4 enrichment culture techniques that use...
The prevalence of Aeromonas species in feces of horses with diarrhea. Feces collected from 40 horses with diarrhea and 34 horses without diarrhea were examined to determine if an association existed between isolation of Aeromonas spp. and diarrhea. Samples were also examined for Salmonella spp., and identification of viruses and parasite ova. Neither Salmonella spp. nor Aeromonas spp. were isolated from the feces of 34 control horses. Aeromonas spp. were isolated from feces of 22 of 40 (55%) horses with diarrhea. Salmonella spp. were isolated from feces of 8 (20%) horses, and of these, 5 (12.5%) were also positive for Aeromonas spp. Twenty-nine isolates of Aerom...
Seroepidemiologic studies on Babesia equi and Babesia caballi infections in Brazil. Horses from six stud farms representing the most frequent types of horse breeding in Brazil were tested for Babesia antibodies by the IFA test. The farms are located at the tropic of Capricorn at an altitude of 472-715 m where temperatures below 0 degrees C may occur. Horses of conventional stud farms were infested with Dermacentor nitens, Amblyomma cajennense, and Boophilus microplus. Infestation with Bo. microplus was associated with direct or indirect contact of horses with cattle, and was not detected at professional stud farms. At one large professional stud farm, only D. nitens was obser...
Density of sand flies (Diptera: psychodidae) in domestic and wild animal shelters in an area of visceral Leishmaniasis in the state of Rio Grande do Norte, Brazil. The objective of the present study was to determine the association of sand flies with the presence of domestic and wild animals in the peridomiciliary area. The sand flies were collected using direct aspiration and CDC light traps placed in animal shelters. The results suggest that different sand flies species have different behavioral characteristics in an apparent preference for animal baits and that Lutzomyia longipalpis and Lu. evandroi were the most eclectic species regarding their biotope choice. Lu. longipalpis showed a distinct preference for horses and Lu. evandroi for armadillos.
Prevalence of Clostridium perfringens enterotoxin and Clostridium difficile toxin A in feces of horses with diarrhea and colic. To determine prevalence of clostridial enterotoxins in feces of horses with diarrhea and colic, and to determine whether an association exists between detection of clostridial enterotoxins in feces and development of diarrhea as a complication of colic. Methods: Prospective case series and case-control study. Methods: 174 horses with diarrhea, colic, or problems not related to the gastrointestinal tract. Methods: Horses were assigned to 1 of 4 groups: colic with diarrhea (group 1; n = 30); colic without diarrhea (group 2; 30); diarrhea without colic (group 3; 57); and control (group 4; 57). Fe...
Geographic distribution of Venezuelan equine encephalitis virus subtype IE genotypes in Central America and Mexico. Phylogenetic analysis of 20 strains of Venezuelan equine encephalitis (VEE) virus subtype IE isolated from 1961 to 1996 in Mexico and throughout Central America showed that VEE virus subtype IE was monophyletic with respect to other VEE virus subtypes. Nonetheless, there were at least three distinct geographically separated VEE virus IE genotypes: northwestern Panama, Pacific coast (Mexico/Guatemala), and Gulf/Caribbean coast (Mexico/Belize). Strains from the Caribbean coast of Guatemala, Honduras, and Nicaragua may cluster with the Gulf/Caribbean genotype, but additional isolates from the reg...
Detection of a common genotype among strains of Taylorella equigenitalis isolated from thoroughbred horses in Japan between 1994 and 1996. We examined whether or not the genotype J could be detected among 21 new strains of T. equigenitalis isolated between 1994 and 1996 in Japan since our previous report (MIYAZAWA et al. 1995). The respective pulsed-field gel electrophoretic profiles of the 21 Japanese strains, as well as those of an old EQ59 used as a reference strain after separate digestion with the two restriction enzymes, ApaI and NotI, were essentially identical but differed from those of T. equigenitalis NCTC11184T and KENTUCKY 188, respectively. Hence, the 21 strains and EQ59 appeared to have a common genotype J. Conseque...
The seroprevalence of equine trypanosomosis in the pantanal. Since little information is available on the epizootiological status of Trypanosoma evansi in South America and particularly Brazil, we evaluated equine serum samples collected in 1993, 1994, 1995 and 1997 for the presence of antibodies against this trypanosome species. Our study shows corroborative evidence about the correlation among high T. evansi seroprevalence and the rainy season in the Pantanal, Brazil. The higher seroprevalence was 79.2% in horses from a ranch located in the Nhecolândia sub-region in 1994 and the lower 5.8% in animals from the same ranch in 1997. No seroprevalence was...
Equine glanders in Turkey. In the course of an epidemiological study of glanders on a number of Turkish islands in the Sea of Marmara, 1128 horses were examined by using the intracutaneous mallein test. Thirty-five (3-1 per cent) developed an increase in rectal temperature and a swelling at the point of injection. Ten of these horses were killed and glanders was confirmed in five cases by the presence of lesions and by the immunohistological demonstration of the causative agent, Burkholderia mallei. Clinical and pathological findings indicated that in all cases the infection was restricted to the mucous membrane of the ...