Infectious diseases in horses encompass a range of illnesses caused by bacteria, viruses, fungi, or parasites. These diseases can affect various systems within the equine body, leading to symptoms that range from mild discomfort to severe systemic illness. Common infectious diseases in horses include equine influenza, strangles, equine herpesvirus, and West Nile virus. These diseases can be transmitted through direct contact with infected animals, contaminated surfaces, or vectors such as insects. Understanding the mechanisms of transmission, pathogenesis, and immune response is essential for effective prevention and control. This page compiles peer-reviewed research studies and scholarly articles that explore the epidemiology, diagnosis, treatment, and management of infectious diseases in horses.
Fernie DS, Cayzer I, Chalmers SR.A passive haemagglutination test (PHT) which has been developed for the detection of antibodies to the contagious equine metritis organism (CEMO) in serum is described. Samples from each of 30 mares with metritis were positive with titres in the range 256 to 4096. Samples from each of 239 clinically normal mares and 30 colts and fillies believed not to have been exposed to CEMO were negative with titres of less than 256, the majority of samples (97 per cent) showing a titre of 32 or less.
Dietz WH, Peralta PH, Johnson KM.The clinical and laboratory findings in ten humans infected with Venezuelan equine encephalitis virus, subtype I-D, are described in this report. Clinical and laboratory data indicate that, in contrast to equine infections, human infection with these enzootic virus strains (I-D) is similar to human infection with epizootic strains (I-ABC). In most cases there was an abrupt onset of fever, muscle pain, and vomiting. Virus was recovered from sera obtained during the first 3 days of illness. Lymphopenia occurred in all patients, and neutropenia occurred in three. No sequelae of these infections w...
Hughes JP.Contagious Equine Metritis (CEM) is a highly contagious venereal disease of horses caused by a fastidious, Gram-negative coccobacillus which grows best on chocolate agar under microaerophilic conditions (5-10% CO2). Clinically, the disease is characterized by a copious watery-to-mucopurulent, vaginal discharge two to ten days after breeding by an infected stallion (11, 13). Shortened estrous cycle lengths are common and may be the only indication of endometritis in some instances (7). Inapparent carriers of the disease in both the mare and stallion make control of the disease more difficult. O...
Charman H, Long C, Coggins L.Three structural proteins of equine infectious anemia virus were purified, labeled with 125I, and utilized in radioimmunoassays with horse sera and antisera to heterologous retroviruses. Whereas radioimmunoassay titers for the major protein, p25, were 500- to 1,000-fold higher than titers in immunodiffusion, for clinical purposes these two procedures were equivalent. Antibodies to two low-molecular-weight proteins, p12 and p10, were also found in infected horses, but with a lower frequency and lower titers. As a rule, only sera positive for p25 also contained antibody to p12 and p10. Antisera ...
Fretz PB, Babiuk LA, McLaughlin B.The serological results from this study clearly show that both equine influenza and equine rhinopneumonitis viruses were present during spring and autumn epidemics of respiratory disease on Western Canadian racetracks. Approximately 11% of the horses showed significant convalescent titres to influenza while 9% showed significant convalescent titres for equine viral pneumonitis. It was noted in our study a positive vaccination history corresponded with a reduction in the severity of the respiratory infection.
Issel CJ, Adams WV.In 1975, a survey was conducted in East Baton Rouge Parish, Louisiana, to determine the prevalence of equine infectious anemia. Using the agar gel immunodiffusion test, 94 of 1,398 horses (6.7%) were found to be infected. Infection rates were especially high in areas where clinical cases of equine infectious anemia had been diagnosed. Clinical signs compatible with the disease were noted in 1 of the 94 seropositive horses. The sample set of 1,398 horses represented 22% of the census population obtained during the 1971 Venezuelan equine encephalomyelitis vaccination campaign.
Cinco Del Fabbro M, Dougan R, Jelincic A, Piacentini I.The macroagglutination test, according Mailloux, was investigated for its feasibility in the rapid diagnosis of human and animal leptospirosis. Suspected sera examinated by Mailloux test, were also examinated by Complement Fixation and Microagglutination; the results suggest that: Mailloux macroagglutination is the serological test of choice, for screening of animal and human sera, mostly if it is not needed to know the infecting serovar.
Stratton LG, Corstvet R, Brown J, Corley L.K. pneumoniae capsule type 68 infused into the uterus of 4 mares was recovered up to 15 weeks after inoculation. The insertion of a tampon for 10 min was more effective than a swab technique in detecting the organism in the uterus. The clitoral fossa and the urethral orifice when sampled by the swab technique were also found to be infected for a comparable period. K. pneumoniae was isolated from the clitoral specimens more often and more consistently than from either urethral or uterine specimens.
Swerczek TW.Contagious Equine Metritis (CEM) was initially reported during the 1977 breeding season in England (Crowhurst, 1977) and Ireland (Timoney, Ward & Kelly, 1977. The disease has also been diagnosed in France and Australia (Huges, Bryden & MacDonald, 1978). The first occurrence of CEM in the United States followed the importation or 2 stallions from France late in 1977 which resulted in an outbreak early in the 1978 breeding season (Swerczek, 1978). Mares usually develop clinical signs of CEM 8--10 days after being covered by an infected stallion, when a copious, greyish discharge is seen. Other m...
Thomson GW, McCready R, Sanford E, Gagnon A.In the foaling season of 1977, five vaccinated horses in a Standardbred breeding stable were affected with herpesvirus myeloencephalitis. Respiratory and abortigenic forms also occurred in other individuals on the premises. Equine herpesvirus type 1 was isolated from the brain of one case of myeloencephalitis and from lungs of two aborted fetuses. Twelve of 16 horses demonstrated fourfold or greater increases in titres to equine herpesvirus type 1.
Monath TP.The arthropod-borne encephalitides are an important cause of equine and human morbidity in the Americas. Between 1975 and 1978, 6970 human cases of arboviral encephalitis were reported in the United States of America; however, this represents only a fraction of the true incidence. St Louis encephalitis (4824 cases), California encephalitis (1035 cases), and western equine encephalitis (WEE, 947 cases) accounted for 98.5% of all reported infections. Approximately 1000-4000 cases of equine encephalitis occur annually in the United States, the majority due to WEE. In tropical America, important o...
Hazard GH, Hughes KL, Penson PJ.Contagious equine metritis (CEM) was first diagnosed in Australia in August 1977 and it has since been found on 6 farms in 3 states, having been isolated from about 24 mares and 2 stallions. Details are given of the epidemiology and control procedures used to combat CEM on one farm. Difficulty was experience in successfully treating one infected stallion; this was thought to be associated with inadequate cleaning and treating of the diverticulum of the urethral fossa. Introduction of the disease has had far-reaching consequences and may well result in the adoption of routine bacteriological te...
Powell DG, Whitwell K.Following an outbreak of CEM in England during 1977 a Code of Practice was introduced to control the disease in 1978. The Code recommended a bacteriological screening programme for Thoroughbred mares and stallions and improved standards of hygiene on the stud farm. As a result of the implementation of the Code a number of asymptomatic carrier mares was detected. Stallions which had transmitted CEM in 2977 and were treated did not transmit the disease during 1978. Two small outbreaks of CEM were reported during the 1978 breeding season.
Hemida MG, Alhammadi M, Daleb A, Alnaeem A.African horse sickness virus (AHSV) is one of the most devastating viral diseases of the family Equidae. Infection with AHSV threatens not only the Saudi equine industry but also the equine industry worldwide. This is due to the high morbidity and mortality rates among the infected population of up to 100%. The World Organisation for Animal Health (OIE) lists AHSV among its notifiable diseases; this requires Member Countries to monitor the situation with regard to AHSV very carefully in order to avoid the spread of the virus. The OIE also suggests the systematic monitoring of AHSV in the equin...
Sonmez K, Gurel A, Takai S.The aim of the present study was to develop an immunocytochemical procedure for the early detection and demonstration of Rhodococcus equi in smears of tracheal aspirates taken from live foals in field conditions. Tracheal wash samples were collected from thoroughbred foals, aged 1-5 months and located in studs around Bursa and Istanbul, Turkey. Some foals were suspected of having R. equi infection on the basis of clinical examination (n=56) and others were unaffected control animals (n=54). Serum samples were also collected from each foal for testing for the presence of R. equi-specific antibo...
Harrison S.While the importance of religious and magical healing practices in the Late Middle Ages is well established, the ritual aspects of veterinary medicine have so far not been thoroughly explored. This article addresses this lacuna through analysis of a corpus of charms, prayers, and other rituals that were used to cure a group of devastating contagious diseases that afflicted horses: animals that were often afforded complex, professional medical care in this period. It considers the semantic aspects and common features of this group of disease rituals alongside discussions of contagious illness i...