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.
Prevalence of equine herpesvirus type 1 latency detected by polymerase chain reaction. In this study, an improved polymerase chain reaction (PCR) was used for detection of DNA of latent EHV-1 strains from several sources. Three pairs of oligonucleotide primers spanning fragments of 333 bp, 226 bp and 268 bp of the thymidine kinase (tk) gene, and one primer pair spanning 225 bp of the glycoprotein C (gC) gene were used in specific amplifications. Primers for EHV-4 PCR were also designed. Restriction digests with TaqI confirmed the identity of tk PCR fragments from EHV-1. The sensitivity to detect PCR products was further improved by visualisation in silver-stained acrylamide gels...
Climate change: effects on culicoides–transmitted viruses and implications for the UK. Changes in the distribution and abundance of insects are likely to be amongst the most important and immediate effects of climate change. We review here the risk that climate change poses to the UK's livestock industry via effects on Culicoides biting midges, the vectors of several arboviruses, including those that cause bluetongue (BT) and African horse sickness (AHS). The major old-world vector of BT and AHS viruses, C. imicola, occurs in southern Europe and will spread further north as global temperatures increase. It is unlikely, however, that in the foreseeable future it will reach and be...
Prevalence of selected species of internal parasites in equids at necropsy in central Kentucky (1995-1999). A survey to determine current prevalence of several species of endoparasites in equids (n=350) at necropsy was conducted at the Livestock Disease Diagnostic Center in central Kentucky (1995-1999). Thelazia lacrymalis were found in 42% of the 1- to 4-year olds (n=132), which was the only age group examined for these parasites. Five- to 30-year olds (n=157), examined for Onchocerca spp. worms/lesions, had a prevalence of 24%. In > or =1-year olds (n=324), the infection rate for Gasterophilus intestinalis was 12% for second instars and 14% for third instars and for Gasterophilus nasalis was 2%...
Infection of aquatic insects with trematode metacercariae carrying Ehrlichia risticii, the cause of Potomac horse fever. We provide evidence of Ehrlichia risticii Holland, the agent of Potomac horse fever, in trematode stages found in aquatic insects collected from a pasture stream in northern California, using nested polymerase chain reaction (PCR) amplification and sequence analyses of the 16S rRNA, 51 kDa major antigen and groEL heat shock protein genes. E. risticii was detected in metacercariae found in the immatures and adults of the following insects: caddisflies (Trichoptera), mayflies (Ephemeroptera), damselflies (Odonata, Zygoptera), dragonflies (Odonata, Anisoptera), and stoneflies (Plecoptera). The pr...
Fecal shedding of Salmonella spp by horses in the United States during 1998 and 1999 and detection of Salmonella spp in grain and concentrate sources on equine operations. To estimate prevalence of fecal shedding of Salmonella spp among horses in the US horse population and prevalence of Salmonella spp in grain or other concentrate used as horse feed on equine operations in the United States. Methods: Cross-sectional survey. Methods: Horses on 972 operations in 28 states. Methods: Fecal samples were collected from horses resident at each operation. Only a single sample was collected from any individual horse; number of horses from which samples were collected on each operation was determined on the basis of number of horses on the operation. A single sample of g...
Equine viral arteritis. Equine viral arteritis (EVA) can cause prominent economic losses for the equine industry. The purpose of this review is to provide the pathologist some familiarity with the clinical history, lesions, pathogenesis, and diagnosis of EVA. EVA is caused by an arterivirus (equine arteritis virus, EAV), and the vascular system is the principal but not unique viral target. EVA has variable presentations, including interstitial pneumonia, panvasculitis with edema, thrombosis and hemorrhage, lymphoid necrosis, renal tubular necrosis, abortion, and inflammation of male accessory genital glands. EAV anti...
Occurrence of Thelazia lacrymalis (Nematoda, Spirurida, Thelaziidae) in native horses in Italy. A survey on the prevalence of Thelazia spp. in the province of Bari (Apulia region, Italy) in slaughtered native horses was conducted from June 20, 1995 to April 3, 1996. Both eyes from 409 ten-month- to 4-year-old native animals were examined. Sixty horses (14.7%) were found parasitized by Thelazia lacrymalis. Three hundred-sixty one parasite specimens (220 females, 99 males and 42 larvae) were collected with a mean count burden of 6.0-5.1 (range 1 to 20) per head. T. lacrymalis specimens were found free in the conjunctiva and behind the nictitancte, in the excretory ducts of the Harderian gl...
Immune responses and viral replication in long-term inapparent carrier ponies inoculated with equine infectious anemia virus. Persistent infection of equids by equine infectious anemia virus (EIAV) is typically characterized by a progression during the first year postinfection from chronic disease with recurring disease cycles to a long-term asymptomatic infection that is maintained indefinitely. The goal of the current study was to perform a comprehensive longitudinal analysis of the course of virus infection and development of host immunity in experimentally infected horses as they progressed from chronic disease to long-term inapparent carriage. We previously described the evolution of EIAV genomic quasispecies (C...
Cross-sectional study of faecal shedding of Giardia duodenalis and Cryptosporidium parvum among packstock in the Sierra Nevada Range. Faecal specimens from 305 horses and mules used as packstock at one of 17 commercial or governmental (National Park Service, US Forest Service) operations were examined for Giardia duodenalis and Cryptosporidium parvum using immunofluorescent microscopy. Fourteen packstock (4.6%) were shedding G. duodenalis cysts, with herd-level prevalences ranging 0-22%. Number of packstock in the corral, size of corral and density of packstock in the corral were associated with the odds of shedding G. duodenalis cysts. None of the horses had detectable C. parvum oocysts. Assuming a sensitivity of at least 4...
Radiographic and clinical survey of degenerative joint disease in the distal tarsal joints in Icelandic horses. The prevalence of degenerative joint disease (DJD) in the distal tarsal joints and the relation between radiographic and clinical signs compatible with the disease were estimated in a population of Icelandic horses used for riding. The material consisted of 614 horses age 6-12 years (mean age = 7.9 years). Radiographs with 3 projections of each tarsus were made and a clinical examination, including palpation of the medial aspect of the distal tarsus and motion evaluation of the hindlimbs before and after a flexion test of the tarsus, was performed. Radiographic signs of DJD in the distal tarsa...
Dermatophilosis: a threat to livestock production in Ethiopia. A retrospective study of dermatophilosis was made in livestock (cattle, sheep, horses and goats) of Ethiopia under different situations. The disease was reported for the first time in sheep (8.5%), goats (3.14%) and horses (2.84%) from Ethiopia. The occurrence of the disease in cattle was significantly (p < 0.05) higher in wet (6%) than in dry (3.6%) season and in cross (26.9%) than local (3.2%) breeds. The highest prevalence (35%) was noted in cross breeds kept under poor management in the rainy season. The threat of dermatophilosis to animal production in Ethiopia is indicated. Environmen...
Ehrlichia equi infection of horses from Minnesota and Wisconsin: detection of seroconversion and acute disease investigation. Equine granulocytic ehrlichiosis (EGE) is caused by infection with Ehrlichia equi. EGE has been reported primarily in northern California, where E equi is transmitted by the tick Ixodes pacificus. Reports of EGE and the emergence of human granulocytic ehrlichia in Minnesota prompted a seroprevalence study of E equi in horses of Minnesota and Wisconsin. Tick (Ixodes scapularis) endemic areas of Minnesota and Wisconsin were compared to nonendemic regions of Minnesota. Indirect fluorescent antibody was used to detect the presence of serum antibodies to E equi. Serum samples from healthy horses, 3...
The study of cutaneous melanomas in Camargue-type gray-skinned horses (2): epidemiological survey. An epidemiological survey was made on cutaneous melanomas occurring in Camargue-type, gray-skinned horses in southern France. The population investigated was composed of 264 horses, which were selected from the Camargue horse stud registry and were allowed to be examined by the owners. The presence of tumors was inspected macroscopically according to the standardized protocols of veterinary medicine specialists, and some tumors were subjected to macroscopic histopathological examination. The results indicated that: 1) the prevalence of melanomas in the overall population was 31.4%; 2) the odds...
Characterization of trypanosome isolates from naturally infected horses on a farm in Kenya. Following an outbreak of trypanosomosis in horses on a farm in Kenya, 18 trypanosome isolates were collected from the infected animals over a period of one and a half years and cryopreserved for characterization. The characterization was done on the basis of morphology using Giemsa-stained blood and buffy coat smears, infectivity to mice, recombinant DNA hybridization, and chromosome separation by orthogonal field alternation gel electrophoresis (OFAGE). Morphologically, all the trypanosome isolates were identified as belonging to the subgenus Nannomonas, and a total of 16 out of the 18 isolat...
Occurrence of Thelazia lacrymalis (Nematoda, Spirurida, Thelaziidae) in native horses in Abruzzo region (central eastern Italy). A survey on the prevalence of Thelazia spp. in Abruzzo region (Italy) in slaughtered native horses was conducted from August 29, 1997 to August 28, 1998. Both eyes from 128 eight-month to 11 year-old native animals were examined. 50 horses (39.06%) were found parasitized by Thelazia lacrymalis. 502 specimens (371 females, 88 males and 12 larvae) were collected. In the infected horses the numbers of T. lacrymalis ranged from 1 to 48, with a mean count burden of 3.92 per head (SD = 7.79). T. lacrymalis specimens were mainly in the excretory ducts of the Harderian gland, and also in the ducts of ...
A retrospective evaluation of the causes of death of 448 insured French horses in 1995. Epidemiological studies should allow comparisons to be made of the prevalence of disease in populations from different countries, but the population characteristics and health problems in French horses are not well established. We have conducted a retrospective evaluation of the causes of death and vital characteristics of insured horses in France for the year 1995, with a view to comparison with published data from other countries. Files on 448 deceased horses were provided by nine insurance companies. Most of the animals were used for breeding (60%), followed by leisure (20%), eventing and r...
Descriptive epidemiologic study of disease associated with influenza virus infections during three epidemics in horses. To describe 3 epidemics of respiratory tract disease caused by influenza virus infections in a large population of horses. Methods: Cross-sectional and prospective longitudinal observational studies. Methods: All horses stabled at a Thoroughbred racetrack. Methods: During a 3-year period, descriptive information was collected as horses arrived at the racetrack and throughout race meetings. Routine observations and physical examinations were used to classify horses' disease status. Cause of epidemics was established by use of serologic testing and identification of influenza virus in nasal secr...
Role of peridomestic birds in the transmission of St. Louis encephalitis virus in southern California. In response to the 1984 St. Louis encephalitis (SLE) epidemic in the Los Angeles Basin of southern California (USA), an investigative program was initiated to evaluate the interactive components of the SLE virus transmission cycle. From 1987 through 1996 (10 yr), 52,589 birds were bled and their sera tested for SLE and western equine encephalomyelitis (WEE) virus antibodies by the hemagglutination inhibition (HAI) test. Eighty-three percent of the birds tested were house finches (Carpodacus mexicanus) (48.7%) and house sparrows (Passer domesticus) (34.6%); 1.1% of these birds were positive for...
Postmortem findings of gastric ulcers in Swedish horses older than age one year: a retrospective study of 3715 horses (1924-1996). The present study was performed to estimate retrospectively the prevalence of gastric ulceration in necropsied Swedish horses and to evaluate some potential risk factors. Horses (n = 3715) older than age one year and necropsied 1924-1996 were included. Information about breed, gender, age, season of death, clinical signs of colic, Gasterophilus larvae and documentation of diseases in different organs was recorded. Data on size, number and anatomical distribution of gastric ulcers were also obtained. The cold-blooded horses and the Standardbreds were the 2 most dominating breeds in our material...
[Validation of an indirect immunoenzyme assay for the detection of antibodies against Trypanosoma evansi in horses in Argentina]. An indirect enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Trypanosoma evansi was evaluated using 90 different sera, obtained from naturally-infected horses. As negative controls, 218 sera from the T. evansi-free zone of Argentina, and 90 uninfected sera from the enzootic zone were used. The results of the ELISA were expressed in terms of percent positivity (PP) when compared with a positive primary reference serum, obtained from a horse experimentally-infected with T. evansi. The inter-assay coefficient of variation (CV), expressed as PP, was 44.7% for the negative con...
Detection of trypanosome DNA in serologically positive but aparasitaemic horses suspected of dourine in Ethiopia. A field study of horses was conducted in the province of Bale, Ethiopian highlands. A rapid questionnaire analysis indicated that dourine, known as "Dirressa", is a major health problem of equines in this area. A total of 121 horses suspected of dourine were examined by use of clinical, parasitological, serological and DNA based techniques. Incoordination of hindlegs (76%), swelling of external genitalia (48.8%) and emaciation (39.7%) were the most common clinical signs observed. Using the haematocrit centrifugation technique (HCT), no trypanosomes were detected in blood, genital washes or tis...
Rabies surveillance in the United States during 1998. During 1998, 49 states, the District of Columbia, and Puerto Rico reported 7,961 cases of rabies in nonhuman animals and 1 case in a human being to the Centers for Disease Control and Prevention, a decrease of 6.5% from 8,509 cases in nonhuman animals and 4 cases in human beings reported in 1997. More than 92% (7,358 cases) were in wild animals, whereas > 7.5% (603 cases) were in domestic species (compared with 93% in wild animals and 7% in domestic species in 1997). Decreases were evident in all of the major contributing species groups, with the exception of skunks and bats. The relative cont...
Survey on equine cryptosporidiosis in Poland and the possibility of zoonotic transmission. The present study was undertaken to investigate the prevalence of Cryptosporidium infection in horses used for recreational riding as well as in humans. A total of 106 faecal specimens from horses raised in 4 localities of western Poland and 6 stool samples from 3 persons who had constant or sporadic contact with horses were screened microscopically for oocysts using modified Ziehl-Neelsen staining. Enzyme immunoassay (EIA) was additionally used for the detection of coproantigen in human stool samples as well as in 43 randomly selected horse faecal samples. The overall infection rate of horses...
Effect of prophylactic administration of hyperimmune plasma to prevent Rhodococcus equi infection on foals from endemically affected farms. The effect on foals of prophylactic administration of hyperimmune plasma to prevent R. equi infection was investigated on three farms at which R. equi infection was endemic. Sixteen foals between 10 and 39 days of age were intravenously given 1-21 of hyperimmune plasma. ELISA antibody titres against R. equi were significantly increased and maintained at high levels for over 30 days in most of the recipient foals. The prevalence of R. equi infection was 6.3% (1/16) in the foals that received the immune plasma, and 26.3% (5/19) in the control foals not given the immune plasma on the three farms....