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.
Pierson RE, Sahu SP, Dardiri AH, Wilder FW.Contagious equine metritis was reproduced experimentally in 6 pony mares. The disease was characterized by rapidly developing cervicitis and by varying amounts of exudate. The exudate, apparent as early as 48 hours after inoculation, drained from the cervix as a tenacious, mucopurulent discharge for several days, then rapidly disappeared. In all mares, the clinical disease cleared within several weeks of inoculation, without treatment.
Tzipori S, Walker M.A rotavirus, morphologically similar to other known rotaviruses, was demonstrated in the faeces of 5 foals with diarrhoea on two properties. Four of these 5 samples produced specific intracytoplasmic fluorescence in cell culture when reacted with calf rotavirus antiserum conjugate. Sixteen affected foals from both properties were depressed, did not suckle and became recumbent. Most had a watery diarrhoea which lasted for 3 days and resulted in some dehydration and loss of body condition. Sick foals were separated from their mothers following the onset of diarrhoea and given fluid therapy and a...
Woode GN, Bew ME, Dennis MJ.Inoculation at birth with a live attenuated strain of a bovine rotavirus isolated in the USA (scourvax-reo) induced protection in five gnotobiotic calves seven to 21 days later against a UK isolate of pathogenic bovine rotavirus. However, no protection was induced in three calves challenged three to five days after vaccination. There was a close antigenic relationship demonstrated between the two bovine rotavirus isolates. In contrast only one of three gnotobiotic calves inoculated with foal rotavirus, and one of three with human rotavirus, were protected against bovine rotavirus challenge. Pr...
Braverman Y, Boorman J.Very low infection rates (less than 3%) were obtained when Aedes aegypti mosquitoes ingested blood contained 5.8--6.5 log10 MLD50/0.02 ml African horse sickness virus (AHSV). When A. aegypti mosquitoes were inoculated intrathoracically with virus, however, high infection rates were achieved. Mosquitoes infected by inoculum failed to transmit virus to embryonated hens eggs by bite, and virus could not be detected in membrane or blood when inoculated mosquitoes were allowed to engorge on uninfected blood through a chick skin membrane. It was concluded that the mosquito A. aegypti is unlikely to ...
Allen PZ, Heidelberger M, Rappaport IA, Ward GM.Serial bleedings were obtained from two mules during prolonged immunization, one with type XXV the other with type VIII pneumococcal vaccine. IgGa, IgGb, IgGc, IgB, IgG(T) and IgM present among purified Pn anti-XXV and Pn anti-VIII immunoglobulin isolated from various bleedings were identified by use of rabbit anti-equine heavy chain specific reagents. Radioimmunodiffusion with 14C-labelled type XXV pneumococcal capsular polysaccharide and horse and donkey reagents with species specificity directed against donkey or horse IgGa respectively, demonstrated both parental horse and donkey IgGa heav...
Dawson FL, Benson JA, Croxton-Smith P.Serum agglutination tests, anti-globulin tests, and complement fixation tests were carried out on sera taken over a period of 98 days from two fillies experimentally infected with the contagious equine metritis organism. The pattern, and significance in diagnosis, of these results is discussed. All 3 tests showed positive titres in the acute phase of experimental disease; reactions in the complement fixation test persisted longest.
McCraw BM, Slocombe JO.Pony foals inoculated with infective Strongylus edentatus larvae were examined at necropsy from ten to 72 weeks postinfection. At ten weeks postinfection larvae were visible retroperitoneally in the liver and flanks and were recovered from the ligaments of the liver. The fourth molt was detected at 16 weeks postinfection and larvae were also recovered from the wall of the cecum at this time. By 40 weeks adult S. edentatus containing eggs were found in the contents of the cecum and colon. While many larvae migrate to remote parts of the body, it is likely that only those that attain the base of...
Murray DR, Ladds PW, Campbell RS.Lesions encountered in a clinicopathological study of cutaneous lesions resembling 'swamp cancer' from horses in North Queensland included 37 cases of subcutaneous phycomycosis, 5 of which were also infected with Habronema sp larvae. In addition 9 cases of primary cutaneous habronemiasis, 58 sarcoids, 12 fibromas, 8 fibrosarcomas, 10 squamous cell carcinomas, 4 haemangiomas, 3 melanomas, 1 papilloma, 1 palpebral adenocarcinoma and 7 cases of simple granulation were diagnosed. Subcutaneous phycomycosis resulted in the most extensive lesions. These were rapidly growing and provided the poorest p...
Platt H, Atherton JG, Simpson DJ.Four pony mares were readily infected with the organism of contagious equine metritis by intracervical inoculation and one by coitus with an infected stallion. Infected mares developed an acute endometritis with local destruction of the endometrial epithelium. In 2 experimentally infected mares, infection appeared to have been spontaneously eliminated from the genital tract within 3 to 4 weeks. A third mare however remained persistently infected in the clitoral fossa over a long period and was a symptomless carrier. Four pony stallions were readily infected in the urethral fossa and the organi...
Jahrling PB, Hesse RA, Metzger JF.A radioimmunoassay (RIA) procedure is described for measuring antibodies to alphaviruses in human and other mammalian sera. The test employed protein Abearing Staphylococcus aureus as a solid-phase immunoadsorbent for (3)H-labeled viruses complexed with immunoglobulin G. Using antibodies produced in humans and guinea pigs, the RIA procedure clearly differentiated among antibodies to Venezuelan, western, and eastern equine encephalomyelitis viruses. Sensitivity of the RIA depended on the concentrations of labeled viruses employed. The dilution of serum that effected binding of 50% of the (3)H-l...
Rice NR, Simek S, Ryder OA, Coggins L.Equine infectious anemia virus (EIAV) recently has been shown to possess a high-molecular-weight RNA genome and a virion reverse transcriptase. We completed the demonstration that EIAV is a retrovirus by showing the presence of proviral DNA in equine cells infected in vitro, but not in normal horse DNA. These studies were performed by using a highly representative cDNA probe synthesized by the virion polymerase. It was found that this cDNA reassociated extensively, and with high thermal stability, with either viral RNA or DNA extracted from infected cells, but showed no detectable reassociatio...
Thompson DB, Spradborw PB, Studdert M.Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.