Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Smith BL, Auer JA, Watkins JP.Four horses, 2 to 17 years old, were treated for unilateral avulsion fractures of the tibial tuberosity. Two horses were treated successfully with tension band wiring or plating in combination with lag screw fixation. One horse was euthanatized because of implant failure during recovery and one was euthanatized on day 11 because a longitudinal fracture of the tibial tuberosity occurred through the plane of the screws used for stabilization.
Wheeler SJ.Single teased fibre studies were made on samples of the lateral palmar nerve from 16 horses of mixed age and size which had no evidence of neuromuscular disease. Significant proportions of abnormal fibres indicative of axonal degeneration/regeneration and demyelination/remyelination were identified. Measurements of internodal length and fibre diameter were made. Internodal length was shown to be related to fibre diameter, changes in this relationship being mainly influenced by the incidence of abnormal fibres rather than by the age of the horse. Information about the incidence of abnormal fibr...
Irvine CH, Sutton P, Turner JE, Mennick PE.Plasma progesterone concentrations were measured in 179 mares bled on alternate days commencing with a positive pregnancy diagnosis on Days 17 to 18 after ovulation and concluding on Days 42 to 45. During this period 17 mares (10 per cent) lost their pregnancies, 11 before Day 25. In 15 mares the timing of the pregnancy loss could be determined with adequate accuracy; in only one did a decline in progesterone precede the loss. Thus pregnancy loss between Days 17 and 42 was rarely caused by a fall in plasma progesterone.
Attenburrow DP, Flack FC, Portergill MJ.The technique of impedance plethysmography is described and its application to observation of lung volume changes in the horse at exercise is discussed. The results from horse at rest show that there is a close relationship between rate of lung volume change (flow rate) and the associated impedance changes during both inspiration and expiration. Impedance changes during exercise were related to inspiration and expiration by observation of associated respiratory sounds. Artefacts related to technical difficulties are also indicated.
Harrison LA, Squires EL, Nett TM, McKinnon AO.Natural GnRH and its analog have potential for hastening ovulation in mares. A study was conducted to evaluate the efficacy of a GnRH agonist given either as an injectable or s.c. implant for induction of ovulation in mares. Forty-five seasonally anestrous mares (March) were assigned to one of three groups (n = 15/group): 1) untreated controls; 2) i.m. injection of the GnRH agonist buserelin at 12-h intervals (40 micrograms/injection for 28 d or until ovulation) and 3) GnRH agonist administered as a s.c. implant (approximately 100 micrograms/24 h for 28 d). Six mares per group were bled on d 0...
Kotze SH, Van Aswegen G.The ileocaecal junctions of 5 horses and 2 donkeys were examined by using antisera to the following peptides: somatostatin, glucagon, gastrin, neurotensin, vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide Y (NPY). Antisera to somatostatin, neurotensin and NPY demonstrated endocrine cells in the ileal- and caecal parts of the ileocaecal junction, while immunoreactivity for glucagon was demonstrated in endocrine cells of the ileal part only. Nerve cell bodies showing immunoreactivity to SP, VIP, CGR...
Hunt DA, Snyder JR, Morgan JP, Stover SM, Pool RR, Pascoe JR.Femoral neck and proximal epiphyseal lengths were measured in 37 femurs from 19 cadaver foals that were 1 day to 12 months old to determine the applicability of a human interfragmentary compression system to equine femoral capital physeal fractures. Because components of the implant system are available only in fixed sizes, its use was possible in foals older than 5 weeks of age, but not in younger foals. The 135 degree angle plate conformed best to the equine femur. Femoral capital physeal fractures were created surgically and repaired with the implant system in three foals. Fracture stabilit...
Kotzé SH, Soley JT.The ileocaecal junction mucosal surface morphology of 5 horses and 1 donkey was examined using scanning electron microscopy and light microscopy. Based on differences in surface morphology, the junction could be divided into 4 distinct regions. The distal extremity of the ileum was characterized by the presence of typical finger-like villi followed by a narrow zone displaying short, stubby villi which gradually merged into a 3rd region representing the true transitional zone between the small and large intestine. In this region the villi fused, forming low ridges arranged in circular, semi-cir...
Milne EM, Doxey DL, Gilmour JS.Serum total lipids, lipoprotein fractions, triglycerides, cholesterol, phospholipids and free fatty acids were measured in horses with acute, subacute and chronic grass sickness (equine dysautonomia) and in colic cases. The values were compared with those of normal grazing and stabled horses. A marked individual variation occurred, but total lipids, triglycerides and free fatty acids were significantly higher than normal in grass sickness and colic cases with cholesterol was significantly higher than normal in grass sickness cases only. Pre-beta lipoprotein was significantly increased in colic...
Nixon AJ.Periarticular anatomy and techniques for arthroscopic access to the equine elbow were studied in six joints from cadavers. Caudomedial and craniolateral approaches were evaluated subsequently in 11 anesthetized horses. The caudomedial approach was made between the flexor carpi radialis and flexor carpi ulnaris muscle bellies. Most of the caudal articular surfaces of the humeral condyles, the caudal perimeter of the radius, and the trochlear notch and portions of the anconeal process of the ulna could be identified. The voluminous caudal joint capsule cul-de-sac proximal to the anconeal process...
Edington N, Bridges CG.Two groups each of six sibling ponies were exposed to sequential infections with equid herpesvirus 1 or 4 (EHV-1 or EHV-4) at four or five month intervals. Two exposures to EHV-4 did not significantly reduce virus shedding or pyrexia when the ponies were subsequently exposed to EHV-1. However, two sequential infections with EHV-1 completely protected against challenge with EHV-4. Virus neutralising antibody in each group did not increase until 21 days after primary exposure and was subtype specific. However, complement fixing antibody rose within seven days after inoculation with EHV-1, and 14...
Wheeler SJ.This study aimed to establish a clinically reproducible method of evaluation of sensory nerve conduction in the horse and to provide reference values in a group of normal horses. Age-related changes in the sensory nerve conduction velocity were of particular interest. Sensory nerve conduction was performed in the lateral palmar nerve. The results revealed an increase in velocity over the first year of life and a subsequent decrease in velocity in older horses. The effect of age must be considered if results from horses in which peripheral nerve disease is suspected are to be interpreted correc...
De Waal DT.Babesia caballi, isolated from a horse that originated from South West Africa/Namibia, was transmitted transovarially by adult Hyalomma truncatum. B. caballi proved to be highly infective for adult H. truncatum. Forty-five per cent of ticks feeding on a reacting animal with an extremely low parasitaemia became infected. In spite of a low parasitaemia, the ticks were severely affected by the parasite. Seventy per cent of the infected ticks either died during oviposition or after laying only a few eggs. The features of the infection in horses were: a prepatent period of 10 days, very low parasit...
Pyörälä S, Kotilainen T, Silvennoinen P, Hänninen U, Mero M, Kaartinen L.Serum tinidazole concentrations were monitored in five clinically healthy adult horses after intravenous (i.v.) and oral administration of the drug (15 mg/kg and 25 mg/kg, respectively). After i.v. administration, the mean residence time was 7.0 h, the elimination half-life 5.2 h and the body clearance rate 1.6 ml/min/kg. The distribution volume was found to be 660 ml/kg. After oral administration, the mean residence time was 8.5 h, the absorption half-life 1.1 h and the bioavailability essentially 100%. In view of the in-vitro sensitivities of various anaerobic bacteria, a dosage of 10-15 mg/...
Reeves MJ, Vansteenhouse J, Stashak TS, Yovich JV, Cockerell G.A study was undertaken to evaluate the significance and mechanism of reperfusion injury in the equine large colon following 1 h of haemorrhagic strangulation obstruction (HSO) or ischaemic strangulation obstruction (ISO) and to assess the effect of treatment with dimethyl sulphoxide (DMSO). ISO or HSO were created 40 cm from the pelvic flexure and maintained for 60 mins under general anaesthesia. Normal saline or 20 per cent DMSO (1 g/kg bodyweight) was administered intravenously 10 mins prior to the end of the ischaemic period. Four groups of four horses in a 2 x 2 factorial design were used....
Wood T, Weckman TJ, Henry PA, Chang SL, Blake JW, Tobin T.Our investigation of the urine of grazing horses at the University of Kentucky shows that the mean pH level is about 7.9, and if their diet is supplemented with grain, it is about 7.4. There appears to be no significant effect of time of day or year on urine pH levels in horses. However, horses taken from pasture and supplemented with grain in a stalled environment show a slight decrease in urine pH. Additionally, we investigated the effects of storage on pH levels. Equine urine samples appear to be quite stable with regard to pH for 48h, but then show a marked increase. Urine pH can have a gr...
Hinrichs K, Riera FL.Ten mares were used to investigate the effect of administration of prostaglandin F2 alpha on uterine tubal motility, as reflected by embryo recovery from the uterus 5 days after ovulation (day 0). Mares were assigned to 3 groups: group A, uterine flush for embryo recovery on day 7; group B, uterine flush for embryo recovery on day 5; and group C, uterine flush for embryo recovery on day 5, after treatment with prostaglandin F2 alpha (10 mg, IM) on day 3. Each mare was assigned to each group once. Embryo recovery rates for the 3 groups were: A, 6 of 10; B, 2 of 8; and C, 0 of 10. The embryo rec...
Boy MG, Galligan DT, Divers TJ.Medical records of 82 horses with clinical signs of neurologic disease and histologic lesions suggestive of protozoal encephalomyelitis were reviewed. The presence of a protozoan parasite in the CNS was not influenced by prior treatment of the horse with corticosteroids. Prior treatment of horses with trimethoprim-sulfonamide alone or in combination with pyrimethamine resulted in a decreased number of horses in which a protozoan parasite was detected in the CNS at necropsy. The mean age of affected horses was 3.62 +/- 2.78 years, with male and Standardbred horses being overrepresented, compare...
Asmis R, Jörg A.Horse eosinophils preincubated with 3H-labelled acetate and stimulated with the Ca2+ ionophores ionomycin or A23187 form a radioactive compound, which we have shown to be 1-O-alkyl-2-[3H]acetyl-sn-glycero-3-phosphocholine (platelet-activating factor). We could detect no 1-O-acyl-2-[3H]acetyl-glycero-3-phosphocholine in the radioactive fraction. The formation of platelet-activating factor was strongly correlated to the generation of leukotriene C4, the main arachidonate metabolite in horse eosinophils, suggesting that platelet-activating factor and leukotriene C4 have a common precursor pool (1...
Bernard W, Reef VB, Clark ES, Vaala W, Ehnen SJ.Records of 6 horses with pericarditis were reviewed. Septic pericarditis was suspected in all horses, based on historic and clinical findings. In horses 1, 2, and 4, cytologic examination of the pericardial effusion revealed acute inflammation with severe neutrophil degeneration. In horses 3 and 5, cytologic examination of pericardial fluid revealed subacute inflammation with degenerated neutrophils, and in horse 6, chronic active inflammation, with well preserved neutrophils. In horses 1 and 3, bacteria were identified on cytologic examination of pericardial fluid. Results of microbiologic cu...
Beard WL, Robertson JT, Leeth B.Congenital frontal sinus cysts were found bilaterally in the frontal sinuses of a one-year-old miniature horse. Diagnosis was based on radiography of the head and cytologic examination of tissue aspirated from the frontal sinuses. The cysts were surgically removed, using a hinged bone flap technique bilaterally over the frontal sinuses.
May SA, Hooke RE, Lees P.Equine interleukin-1 has been produced from peripheral blood monocytes by stimulation with E. coli lipopolysaccharide. Sephacryl S200 gel filtration revealed a molecular weight of 17-18 kD. Chromatofocusing of the 17-18 kD peak identified four active fractions. Two major peaks were detected at pH 6.7 and pH 7, with smaller peaks at pH 6.3 and pH 5.9. The pI 7 molecule is probably the equine form of IL-1 beta.
Love CC, Strzemienski PJ, Kenney RM.Serum concentration of ampicillin, a semisynthetic penicillin, was measured in mares at various time intervals up to 24 hours after intrauterine infusion of 3 g of ampicillin. Blood samples were drawn immediately before infusion and at 1-, 4-, 10- and 24-hour intervals after infusion. At postinfusion hour 24, two endometrial biopsy specimens were obtained to measure endometrial concentrations of ampicillin. Blood was drawn twice as part of the 24-hour postinfusion sample collection, once before removal of the biopsy specimens and again 5 minutes after removal of the biopsy specimens. After dru...
Ostrowski SR, Gunter EW, Matte TD.During the course of an investigation into community lead poisoning near a secondary lead smelter in Jamaica, blood lead and zinc protoporphyrin levels were measured in 8 exposed and 6 (3 Jamaican, 3 US) unexposed donkeys and mules. The blood lead levels of 6 animals in the contaminated area ranged from 7.5 to 33 micrograms/dl (mean = 17.6 micrograms/dl), compared to 1.8 and 2.4 in unexposed Jamaican animals. More striking was the difference in zinc protoporphyrin levels; all 8 exposed donkeys and mules had values between 900 and 1890 micrograms/dl, compared with a range of 34-46 micrograms/dl...
Ohshima K, Satake S, Ono M, Ajito T, Okada K, Numakunai S.A pathological study was performed on osteoarthrosis detected at autopsy in 20 horses whose ages ranged from 21 days to 17 years old. They were asymptomatic on the joints except in 3 animals, and autopsied after death or sacrificed due to accidental fracture or other diseases. Lesions of osteoarthrosis were recognized in all horses, which tended to increase in incidence and severity according to age. Lesions were concentrated at hinged joints such as the elbow, fetlock, and hock. Synovial fossae and ulcerative lesions were observed on each opposite articular cartilage, forming the so-called mi...
Manohar M.The present study was carried out on seven healthy ponies to examine the extent of blood flow in various inspiratory and expiratory muscles at rest and during maximal exertion as well as to determine the proportion of cardiac output needed to perfuse respiratory muscles during these conditions. Tissue blood flow was studied with 15 micron-diameter radionuclide-labeled microspheres injected into the left ventricle during steady conditions. The inspiratory and expiratory muscles comprised 2.41 and 3.05% of body weight, respectively, and received 6.17 and 3.75% of the cardiac output at rest. With...
Vernon MW, Strauss S, Simonelli M, Zavy MT, Sharp DC.The binding of prostaglandin (PG) F-2 alpha to corpora lutea (CL) from pregnant and non-pregnant Pony mares was examined. Studies of the rates of association and dissociation indicated that [3H]PGF was bound specifically and reversibly to a luteal cell membrane preparation (MP) that was isolated by high speed (100,000 g) ultracentrifugation. Various PGs and PG metabolites displaced [3H]PGF from the receptors in the following decreasing order: PGF-2 alpha greater than 13, 14-dihydro-PGF-2 alpha = 13,14-dihydro-15-keto PGF-2 alpha greater than PGD-2 greater than PGF-1 alpha = PGE-2 greater than ...
Preedy DF, Colborne GR.Metabolic and mechanical energy costs of locomotion can be combined to calculate locomotor efficiency, which is the quotient of the mechanical energy and metabolic costs. The purpose of this pilot study was to evaluate the mechanical and metabolic energy costs of locomotion at a range of 7 trotting speeds (2.5 to 6.2 m/s) on a level treadmill. A single, sound Thoroughbred horse was modelled as a system of 15 linked segments incorporating all 4 limbs, head, neck and trunk. The horse performed a continuous incremental exercise test at increasing trotting speeds while VO2 was recorded using a bre...
Stilson AE, Herring DS, Robertson JT.The radiopacity of the equine cartilaginous nasal septum and its covering mucosa seen on dorsoventral radiographs was determined to be of sufficient density to be useful in the diagnosis of any disorder of this anatomic structure. Radiographically, the frontal and nasal bones dorsally and the vomer and palatine process of the incisive bone ventrally do not completely obscure the nasal septum and its covering mucous membrane.
Liley H, Zhang J, Firth E, Fernandez J, Besier T.Population variance in bone shape is an important consideration when applying the results of subject-specific computational models to a population. In this letter, we demonstrate the ability of partial least squares regression to provide an improved shape prediction of the equine third metacarpal epiphysis, using two easily obtained measurements.
Chan CW, Collins EA.An angiosarcoma involving the right frontal and maxillary sinuses in a nine-year-old Thoroughbred mare was studied post mortem by light and electron microscopy. Important diagnostic features included malignant endothelial cells lining ill-defined vascular spaces, supported by other vasoformative elements. Rhabdomyoblasts were also found. The tumour is apparently rarely seen in the nasal passages of the horse.