The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Wright IM.The clinical features are reported from 118 horses (mean age 9.2 years) which were diagnosed as suffering from navicular disease using predetermined criteria. The animals were used for a variety of purposes and had been lame for periods between 1 and 72 months. The majority of cases (84.7%) had been treated using various techniques before evaluation. The severity of lameness was related to the duration of clinical signs: 78% of horses were bilaterally affected but there was no left:right limb predominance. Broken foot/pastern axes were recorded in 75% of horses while 45% also exhibited mediola...
Troedsson MH, Liu IK, Ing M, Pascoe J, Thurmond M.The electrical myometrial activity of three mares with a documented increased susceptibility to chronic uterine infection (CUI) and three mares considered to be resistant to CUI was investigated. Electrodes were surgically implanted in the myometrium of the mares and electrical activity was monitored by a Grass polygraph. Oestrus was determined by transrectal ultrasonography of the reproductive tract and teasing of the mares with a stallion. Findings were confirmed by blood progesterone concentrations 35 mm was detected, the uterus was infused with a genital strain of 5 x 10(6) Streptococcus ...
Wright IM.Dorsoproximal-palmarodistal oblique, lateromedial and palmaroproximal-palmarodistal oblique radiographic projections were used with standard techniques to examine 118 horses with clinical signs of navicular disease. All radiological features which have previously been reported as significant changes in the navicular bones of horses with navicular disease were recorded. Comparisons were made between these features in lame limbs and sound limbs in unilaterally lame horses and most lame limbs and least lame limbs in bilateral but asymmetrically lame animals. Their relationship to the degree of la...
Greet TR, Bathe AP.This paper describes the use of a linear stapling device as an aid to unilateral ovariectomy in nine mares with granulosa thecal cell tumours. The intraoperative and postoperative complications are described and follow up details on each case are presented.
Zaruby JF, Livesey MA, Percy DH.This clinical report describes an 8-year-old Thoroughbred mare that was presented for evaluation of a chronic, unilateral nasal discharge. Findings on physical examination, radiology, and video-endoscopy supported a clinical diagnosis of ethmoidal hematoma. After surgical ablation of the mass a defect was detected in the cribriform plate. At necropsy a 1.5 cm aperture was identified in the left cribriform plate allowing direct communication between the fundus of the nasal cavity and the cranium. Histology of the mass identified tissue consistent with an adenocarcinoma. History of profuse epist...
McCulloch J, Williamson SA, Powis SJ, Edington N.It has been suggested that EHV-1 infection may perturb immune responsiveness in the natural equine host. The mechanism underlying this phenomenon is not clear, but disturbances of circulating leucocyte populations could contribute. In order to objectively assess the nature of the haematological changes provoked by EHV-1 infection, two groups of conventionally-maintained Welsh mountain ponies were challenge-infected intra-nasally with the Ab4 isolate of EHV-1. These groups were controlled by similarly-sized groups of non-infected ponies. All data generated was subjected to rigorous statistical ...
Kaji Y, Taniyama H, Matsukawa K, Okada H, Tsunoda S, Tagami M, Akita H.Nodular hepatic lesions caused by larval Echinococcus multilocularis were found in a four-year-old female thoroughbred race horse born and raised in Hokkaido. Before detection of the infection, the infected animal was transported around Honshu for racing. The present disclosure of hydatidosis in a race horse raises concern over the potential danger of spreading the infection throughout Japan by horses possibly infected in Hokkaido.
Johnson PJ, Goetz TE.A 10-month-old Standard-bred colt was examined because of weight loss, fever, and extensive subcutaneous edema of the ventral aspects of its trunk. Diagnosis of granulomatous enteritis was based on D-xylose malabsorption, hypoproteinemia, and rectal mucosal biopsy. Campylobacter fetus subsp fetus was cultured from jugular venous blood when the horse was admitted to the hospital and 24 hours later. Appropriate antimicrobial agents and glucocorticoids failed to effect clinical remission. After euthanasia, granulomatous enteritis was confirmed at necropsy but C fetus subsp fetus was not isolated ...
Hoffman AM, Viel L, Prescott JF.Despite the high incidence of distal respiratory tract infection of undetermined cause on farms, to our knowledge, the microbiologic effects of conventional antimicrobial treatment for this condition have not been studied. We evaluated the possible pathogenic role of bacterial isolates from the distal airways of foals with clinical respiratory tract disease, by correlating changes in their numbers (increase or decrease) with clinical, endoscopic, and pulmonary cytologic signs of disease resolution during treatment with antimicrobial drugs. We also determined qualitative changes in in vitro ant...
Lyons ET, Tolliver SC, Drudge JH, Granstrom DE, Collins SS.During the period 28 February-1 July 1992, fecal samples were collected and examined for eggs of Strongyloides westeri once from each of 382 horse foals (364 Thoroughbreds, 16 Standardbreds, one Lippizaner, and one draft-type horse) in central Kentucky. Ages of the foals at the time of sampling ranged from 7 to 63 days (mean 22 days). The nine farms in the study were considered to have overall excellent deworming programs. None of the foals had been treated with an antiparasitic compound before the study. Eggs of S. westeri were found in 6% (22 of 382) of the foals on 78% (7 of 9) of the farms...
Hong CB, Donahue JM, Giles RC, Petrites-Murphy MB, Poonacha KB, Roberts AW, Smith BJ, Tramontin RR, Tuttle PA, Swerczek TW.Pathologic and microbiologic examinations were performed on 1,211 aborted equine fetuses, stillborn foals, and placentas from premature foals in central Kentucky during the 1988 and 1989 foaling seasons to determine the causes of reproductive loss in the mare. Placentitis (19.4%) and dystocia-perinatal asphyxia (19.5%) were the 2 most important causes of equine reproductive loss. The other causes (in decreasing order) were contracted foal syndrome and other congenital anomalies (8.5%), twinning (6.1%), improper separation of placenta (4.7%), torsion of umbilical cord (4.5%), placental edema (4...
Burrows GE, Morton RJ, Fales WH.Gram-negative bacterial isolates (635) obtained from routine submissions to the Oklahoma Animal Disease Diagnostic Laboratory during 1983-1987 were tested for antimicrobial susceptibility. Minimal inhibitory concentrations (MICs) were determined for the following antimicrobials using commercially prepared microdilution assay materials: ampicillin, cephalothin, chloramphenicol, erythromycin, gentamicin, kanamycin, oxytetracycline, penicillin G, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, and tylosin. Results for isolates from cattle, dogs, horses, and pigs are presented. In only a fe...
Hoffman AM, Viel L, Juniper E, Prescott JF.Respiratory tract infections are prevalent in foals, yet the frequency with which the distal airways are affected in clinical episodes of respiratory tract disease has not been evaluated to our knowledge. The objective of the study was to determine the incidence of distal respiratory tract infection (DRTI) in foals on a sample of Thoroughbred breeding farms (n = 10) in Ontario. In a pilot study, clinical criteria commonly used to select foals for antimicrobial treatment (detection of abnormal lung sounds, plus nasal discharge, cough, fever, tachypnea, and/or lethargy) were found to segregate f...
Ansar Ahmed S, Furr M, Chickering WR, Sriranganathan N, Sponenberg DP.Immunological, clinical, and pathological investigations were conducted on a horse with lymphosarcoma. The immunological status was investigated by measuring the level of antibodies by single radial immunodiffusion test and the ability of lymphocytes to proliferate in response to mitogens. Multiple immunological abnormalities were noted in this horse. They were; (1) decreased IgM, IgG, and IgA levels in the serum despite hyperproteinemia; (2) increased in-vitro spontaneous lymphoproliferation which reflects augmented mitosis; (3) decreased lymphoproliferative response to T cell stimulants (e.g...
Sellers RF, Maarouf AR.Cases of western equine encephalitis in horses in 1987 in western USA and Manitoba, Canada were examined by backward trajectory analysis of winds. Culex tarsalis mosquitoes infected with western equine encephalitis virus could have been carried on southerly winds from Texas and Oklahoma to northern USA and from there to Manitoba. The presence of the Polar front over North Dakota and Minnesota at the end of July would have led to the landing of Cx. tarsalis in Montana and Wisconsin and prevented further carriage into Manitoba. Temperatures in southern Texas during the winter months (average dai...
Waelchli RO, Känzig M, Gygax A, Corboz L, Rüsch P.A total of 368 uterine swabs were taken from mares in heat (n = 202) and from mares that were not in heat (n = 166). From 72 of the mares, two swabs were taken; one during either seasonal anoestrus or dioestrus, and one during oestrus. Swabs were taken during anoestrus/dioestrus in 94 other mares and during oestrus in the remaining 130 mares. Bacteriological cultures were done aerobically and classified as negative, insignificant or significant. There was a trend for more positive cytological specimens during oestrus than during anoestrus/dioestrus. The proportions of significant cultures were...
Thein P, Darai G, Janssen W, Bergle RD, Strube W, Floss G.From spring 1990 to summer 1991 we investigated 21 horses with clinical symptoms of EHV-infection by means of serological and virological methods including DNA-hybridization to identify the causative agents. The results indicated that, as already reported by us, EHV4 may also cause the paralytic form of the infection. The possibility of double infection with EHV4 and EHV1 cannot be excluded. In 3 out of 21 affected horses we could investigate brain tissue and/or spinal fluid by Dotblot hybridization with EHV1 and EHV4-DNA. The investigated samples of all three horses showed hybridization with ...
Ross MW, Sponseller ML, Gill HE, Moyer W.Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone (MT3) caused an acute onset of lameness in 5 horses; however, 3 of the horses had historical and radiographic or scintigraphic evidence of chronic tarsal and metatarsal disease before fracture. The pathogenesis of dorsoproximolateral fracture of MT3 remains unclear, but the fracture may occur as a result of the formation of abnormal bone in the proximal aspect of MT3. The prognosis for racing in horses with this fracture appears to be guarded.
Gerdes GH, Pieterse LM.Virus was isolated from the blood of horses (n = 5) showing fever and jaundice and was identified as equine encephalosis virus. In cross neutralisation tests, the isolates were shown to belong to a new serotype related to Gamil, one of the 6 known serotypes of equine encephalosis virus. The name Potchefstroom has been proposed for this new serotype.
Patteson MW, Cripps PJ.Auscultation was used to examine 545 horses for cardiac murmurs and some arrhythmias. The most significant finding was the high prevalence of right-sided holosystolic or pansystolic plateau-type murmurs compatible with a diagnosis of tricuspid regurgitation in National Hunt racing Thoroughbreds of all ages (16.4%). This condition was found in 4.7% of flat-racing Thoroughbreds, 3.7% of non-racing Thoroughbreds and Thoroughbred crosses, and in none of the ponies examined. High prevalences of left-sided early systolic murmurs (53%), left-sided early diastolic murmurs (23%), right-sided early dias...
Bayly WM, Grant BD, Breeze RG.Arterial blood gas and acid-base values during maximal exercise over a 1.2 km distance were recorded in four Thoroughbred horses before and after the chemical induction of pharyngeal lymphoid hyperplasia (PLH). Samples were collected after galloping 0.8 km and 1.2 km, immediately upon stopping and 5 mins after exercising. In only one horse was any difference noted in the pre and post PLH induction results. The horse was more hypercapnoeic at the 1.2 km mark and also took much longer to complete the gallop when it had PLH. However, it also had signs of lower respiratory disease. In the other ho...
Youngquist RS, Blanchard TL, Lapin D, Klein W.Four groups of five pony mares each were used to determine if the intrauterine infusion of EDTA-Tris solution caused adverse effects on the endometrium. The uteri of mares were infused with either saline or EDTA-Tris solution or biopsied or sham-biopsied without infusion. Acute endometritis developed in one (20%) to three (60%) mares in each group during the seven days following treatment, but there were no differences (P > 0.05) in the incidence of endometritis among the groups. Endometrial fibrosis was not evident in biopsies taken on days 14, 30 and 60 following infusion of saline or EDT...
Bridges CH, Moffitt PG.The influence of variable zinc content (29.1, 250, 1,000 and 2,000 mg/kg of dry weight) in a basic diet containing 7.7 mg of copper/kg on the ability of weanling foals to maintain normal copper balance was investigated. Serum copper and zinc concentrations were monitored, and terminal hepatic copper and zinc contents were measured in 4 weanling foals fed the basic diet containing 29.1 mg of zinc/kg and in 2 foals each fed the higher-zinc diets. Foals fed the lower-zinc diets (29.1 and 250 mg/kg) maintained normal serum copper and zinc concentrations for 14 to 15 weeks, whereas those fed the 2 ...
Liefman CE.The protection afforded by active, passive and combined active-passive methods of immunisation against tetanus was examined in previously unimmunised horses. Three groups of horses were injected; one with tetanus toxoid alone, one with tetanus antitoxin alone and one in which the tetanus toxoid and tetanus antitoxin were injected simultaneously. The protection afforded was determined by monitoring the levels of antitoxin achieved in the horses by each of these methods. The results obtained demonstrated the effectiveness of the combined active-passive method in affording rapid and prolonged pro...
Thomas RJ, Rosenthal DV, Rogers RJ.A toxoid was prepared from type B toxin of Clostridium botulinum by treatment with 0.6% formalin for 6 weeks. The toxoid was adsorbed to aluminium hydroxide and this vaccine was evaluated for safety in guinea pigs, mice and horses, and for immunogenicity in guinea pigs and horses. Neutralising antitoxin was demonstrated in adult horses receiving two 2 ml subcutaneous doses 6 weeks apart, and in a foal which suckled its vaccinated dam. Another vaccinated mare and the passively immunised foal were protected against subcutaneous injection of 1600 and 2000 mouse lethal doses of toxin per kg respec...
Barth AD, Barber SM, McKenzie NT.A two month old Thoroughbred filly was presented with signs of depression, grinding of the teeth, frothing of the mouth and abdominal pain. These signs had persisted for two weeks despite treatment with mineral oil, dioctyl sodium sulfosuccinate, meperidine and antibiotics. A variety of diagnostic tests were done, the only abnormal finding was a stress leukon. On exploratory laparotomy the stomach was dilated with fluid and gas and the pyloric canal was constricted. Pyloroplasty resulted in correction of the condition. The etiological possibilities are discussed. This is believed to be the fir...
Carmalt J, Rosel K, Burns T, Janzen E.Thirty-four mixed breed horses from two separate farms showed signs of abdominal discomfort, pyrexia and dehydration after being exposed to a new batch of 14% complete horse feed. A new batch of cattle feed from the same manufacturer resulted in dairy cows showing depression, a drop in milk production and diarrhoea. Examination of both diets revealed the presence of white kidney beans (Phaseolus vulgaris). Inclusion of raw beans of this genus in animal feeds is to be avoided.