Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Baggot JD, Love DN, Stewart J, Raus J.The absorption and disposition kinetics of gentamicin were compared at two dosage levels (2 and 4 mg/kg bodyweight [bwt]) in one- and three-month-old foals. Following intramuscular (im) injection of single 2 mg/kg bwt doses, the drug was absorbed rapidly and produced peak serum concentration (18.2 mu 5.3 +/- g/ml, n = 8) at 30 mins. Much wider variations were associated with the amount of drug absorbed and the serum gentamicin concentrations after administration at the higher dosage level. The half-life of gentamicin was similar in the one-month-old (3.7 +/- 1.7 h, n = 8) and three-month-old (...
Tenter AM, Friedhoff KT.The sensitivity and specificity of the complement fixation (CF) test for the diagnosis of Babesia infections in equines was assessed, using the indirect fluorescent antibody (IFA) test as a reference. Antibodies were first detected between 11 and 20 days post infection (dpi) in the CF test and between 7 and 14 dpi in the IFA test in ponies infected experimentally with B. equi (USDA strain). The CF test became negative in four of five ponies 63-174 dpi although B. equi was demonstrated microscopically in two of these four ponies up to 364 and 455 dpi. The IFA test remained positive up to 476 dp...
Reinemeyer CR, Herd RP.The large intestines of 6 horses were divided by length into 12 segments, and each segment was washed and weighed. At least 5% by weight of each segment was examined by mural transillumination, and encysted cyathostome larvae were counted. Total numbers of larvae in each segment were calculated. Encysted larvae (98%) were present in the proximal 7 segments of the large intestine (cecum and proximal 75% of the ventral colon), and 2% were present in the distal 25% of the ventral colon and entire dorsal colon. Encysted larvae (6%) were located in the dorsal colon of 1 heavily infected horse. Larv...
Weiland G.The increasing horse trade requires a reliable immunodiagnosis of equine piroplasma infections due to import restrictions imposed by various countries, including the United States of America. It was the aim of our investigations to establish the suitability of serological tests for the detection of parasite carriers and, eventually, to differentiate between Babesia caballi and B. equi infections. The investigations were carried out on 11 ponies with experimentally-induced B. caballi and/or B. equi infection. The infections were confirmed by the demonstration of parasites in blood smears 2-13 d...
Slocombe JO, McCraw BM, Pennock P, Ducharme NG, Baird JD.Twenty pony foals (reared worm free), 6.5 to 10 weeks of age, were inoculated with Strongylus vulgaris and allocated to 5 groups, each with 4 foals. One week after inoculation, 1 group of 4 foals was given oxfendazole (OFZ) at a dosage rate of 10 mg/kg of body weight, another group was given 2 such treatments 48 hours apart, and a 3rd group was given a placebo. All treatments were administered by stomach tube. Three weeks later, foals were euthanatized and necropsied in a test for efficacy against early 4th-stage larvae. Oxfendazole was 80% and 94.9% effective against early 4th-stage S vulgari...
Ryan PL, Friendship RM, Raeside JI.Estrogen production in vitro was compared for Leydig cells from cryptorchid and scrotal testes in boars and stallions. Animals with natural and experimental cryptorchidism were used. Purified Leydig cells were prepared from testes of mature animals by collagenase treatment and Percoll density gradients. After incubation for 3 hours (1 X 10(6) cells), estrone sulfate and estrone in the media were measured by direct radioimmunoassay. Androstenedione and testosterone in media extracts also were determined. Cells from the abdominal testis of unilateral cryptorchid boars and stallions showed impair...
Stegmann GF.The effect of abnormal body position on cardiovascular and pulmonary function in the awake and anaesthetised horse is reviewed. Parameters such as pulmonary shunt, lung volumes, blood gases and alveolar-arterial oxygen partial pressure differences are discussed. Withholding food for 24 hours and mechanical ventilation may be used to improve blood gas values associated with abnormal recumbency during anaesthesia. During prolonged recovery, horses should be encouraged to adopt sternal recumbency.
Johnson L.A new approach to quantification of Sertoli cells is described. The number of Sertoli cells per testis was calculated from the number of spermatids per testis, the number of spermatids per Sertoli cell apex, and the correction for the lifespan of spermatids enumerated per testis. To evaluate this method under different physiological conditions, testes from 28 adult (4-20-year) stallions obtained in the nonbreeding season (December-January) and from 28 adult stallions in the breeding season (June-July) were compared. Number of Sertoli cells per gram parenchyma was similar between seasons. Howev...
Morris DD, Whitlock RH, Corbeil LB.An equine antiserum to core lipopolysaccharide was produced by inoculation of 6 horses with a boiled cell bacterin made from the J-5 mutant of Escherichia coli O111:B4. The antiserum immunoglobulin G titer to J-5 mutant E coli, as determined by enzyme-linked immunosorbent assay, was 1:15,006. Pooled serum prepared before inoculation (preimmune serum) had a J-5 immunoglobulin G titer of 1:350. The J-5 antiserum was tested for its protective efficacy in sublethal endotoxemia in 14 horses. Four horses served as nontreated controls and were given nothing before endotoxin challenge exposure (10 mic...
Puotunen-Reinert A, Huskamp B.A retrospective study on surgical cases of colic in horses (n = 216) revealed that 42 (19.4%) developed post-surgical diarrhoea. Salmonella spp. were isolated in 6 (16.2%) of the cases (n = 37) exhibiting diarrhoea. In 35.7% of the cases (n = 42) recovery from surgery was disturbed by other complications; 23.8% (10/42) died, 2 of which from primary acute diarrhoea due to salmonellosis. Most of the outbreaks of diarrhoea occurred in winter and spring. From the associated variables examined, the duration of colic signs revealed a significant difference between the cases which developed acute pos...
Maitho TE, Lees P, Taylor JB.The disposition of phenylbutazone (4.4 mg/kg), administered intravenously to six Welsh Mountain ponies, was described by a two-compartment open model. Pharmacokinetic parameters were not significantly different after morning dosing in comparison with afternoon dosing. When phenylbutazone (4.4 mg/kg) was administered orally to the same ponies, marked variations in time to peak concentrations were produced with different feeding schedules. When access to hay was permitted before and after dosing, the mean time to peak concentration was 13.2 +/- 1.2 h and double peaks in the plasma concentration-...
Naughton GK, Mahaffey M, Bystryn JC.All of 24 animals (dogs, cats, and horses) with vitiligo were found to have antibodies to pigmented cells that could be detected by specific immunoprecipitation of radioiodinated, detergent-soluble surface macromolecules, and by indirect immunofluorescence on viable cells. These antibodies were not detected in 17 normal animals of the same species. The antibodies were directed to an 85-kDa surface antigen selectively expressed by pigmented cells that was not present on nonpigmented control cells. These observations suggest that vitiligo in animals is an autoimmune disease mediated to pigmented...
Ríha J, Minár J, Skaloud J, Janes K, Králík O.Dipterous blood-sucking insects (horseflies, black flies, gnats, midges) have negative impacts on the performance of draught horses in forest enterprises. For the protection of these animals, the following preparations were applied at the interval of 24 hours: diethyltoluamide, Oxamat (N,N-diethyloxamine acid, USSR) and Stomoxin (synthetic pyrethroid, product of the firm Wellcome, England). In the course of 66 working days, the performance of test animals treated with 10% water emulsion of diethyltoluamide increased by 49.25 cu. m. of skidded wood, i.e. by 0.74 cu. m. wood per horse/day (21.65...
Verschooten F, Picavet TM.Desmitis of the fetlock annular ligament was diagnosed in 30 horses during a period of eight years. Most of the horses had been lame for a prolonged period and had chronically distended digital flexor tendon sheaths. Air tendograms demonstrated thickened palmar or plantar annular ligaments. In 25 horses the ligament was cut longitudinally; of these, 16 horses returned to full work without any difficulty and one became sound after a second operation. Follow up time varied from three months to seven-and-a-half years. None of the five untreated horses returned to work.
Orr JA, Erichsen DF, Shirer HW, Allen PL, Payne PA.The aim of this study was to determine whether increases in ventilation would occur during intravenous acid infusion even if systemic arterial pH was held constant. In six awake ponies, HCl (500 ml, approximately 0.312 M) was infused into the right atrium at a total dose of 1.0 meq/kg over 18 min while an equivalent dose of NaOH was infused into the left heart to restore systemic arterial pH to normal. Total ventilation increased at the onset of the infusion and remained elevated although systemic arterial pH was normal to slightly alkaline. The increase in ventilation during the initial 2 min...
Ruoff WW, Baker DC, Morgan SJ, Abbitt B.DIABETES mellitus is an uncommon disease in the horse and,
when reported, is frequently secondary to Cushing’s disease
(King, Kavanaugh and Bentinck-Smith 1%2; Loeb, Capen
and Johnson 1966; Tasker, Whiteman and Martin 1966;
Baker and Ritchie 1974; Pauli, Rossi and Straub 1974; Moore,
Steiss, Nicholson and Orth 1979). Diabetes mellitus, associated with chronic pancreatitis, was reported in a horse with
hyperglycaemia, glycosuria and ketonuria (Jeffrey 1969).
Other reported cases were not examined fully to determine the
underlying cause of hyperglycaemia (Jorgenson 1921 ; Wilkinson 195...
Tobin T, Chay S, Kamerling S, Woods WE, Weckman TJ, Blake JW, Lees P.Phenylbutazone is an acidic, lipophilic, non-steroidal anti-inflammatory drug (NSAID). It is extensively metabolized in the horse. The metabolites so far identified, oxyphenbutazone, gamma-hydroxyoxyphenbutazone, account for some 25-30% of administered dose over 24 h. The plasma half-life of phenylbutazone and termination of its pharmacological action are determined primarily by its rate of hepatic metabolism. Phenylbutazone acts by inhibiting the cyclooxygenase enzyme system, which is responsible for synthesis of prostanoids such as PGE2. It appears to act on prostaglandin-H synthase and pros...
Day MJ, Penhale WJ.Skin biopsies from 47 dogs, 6 cats and 5 horses with suspected autoimmune skin disease were submitted for immunofluorescence from 1978 to 1985. These cases were predominantly Western Australian in origin, although a number were also referred from Queensland and Victoria. In 5 dogs, 2 cats and 2 horses immunoglobulin binding to intercellular cement substance and/or basement membrane was demonstrated by direct immunofluorescence. Antinuclear antibody was also demonstrated in several of these cases. Immunofluorescence was used in combination with histopathological examination to confirm the clini...
Jacob RJ.Preliminary experiments have revealed that several laboratory and wild-type strains of the equine herpesvirus (EHV) triad were temperature-sensitive for growth when assayed at 39 degrees C. The efficiencies of plating (EOP) observed were 10(-2) for both EHV 1 and 2, and 1 X 10(-6) for EHV 3. The EOPs were determined by plaque assays which compared titrations at 34 degrees C and 39 degrees C on equine fetal dermal fibroblast cells. Growth yield experiments, assayed at 34 degrees C, reflected those EOP's, but did not indicate any difference in yields when infected cultures were incubated at 34 d...
Galey FD, Twardock AR, Goetz TE, Schaeffer DJ, Hall JO, Beasley VR.Twelve horses, with acute laminitis (primarily in the forefeet) at 12 hours after intragastric dosing with an aqueous extract of black walnut (Juglans nigra) heart-wood, were studied. The distribution of perfusion of blood to the foot and to outlined regions within the foot was quantified, using gamma scintigraphy of regionally infused 99mTc-labeled macroaggregated albumin, before and 12 hours after extract administration. Horses 1 to 3 were not studied further. Perfusion was quantified again for horses 4 to 12 at 84 hours after extract administration. At the onset of acute laminitis, horses 7...
Krumrych W, Danek J, Markiewicz H, Gołyński M.The aim of this study was to analyze the chemiluminescence (CL) of peripheral blood in clinically healthy horses of different sexes and ages. The tests were carried out on 119 half- -breed horses, representing various forms of use (66 recreational horses and 53 sport horses). The test material was peripheral blood, which was collected under resting conditions, i.e. before physical activity related to the use of these animals. In the blood samples, spontaneous and stimulated CL with zymosan and phorbol myristate acetate were determined. It has been found that regular training effort increases t...
Drudge JH, Lyons ET, Tolliver SC.In 1973-1974, 4 controlled tests were performed in pony foals (n = 17) raised parasite-free and experimentally infected with Strongyloides westeri. Administration of infective larvae by stomach tube in 1 test resulted in low-grade infections and tended to invalidate the test. Intraoral and percutaneous (intra-aural) administration of larvae resulted in suitable test infections for 1 and 2 tests, respectively. A paste formulation of dichlorvos at 36.3 mg/kg of body weight removal from 4 ponies. Treatment of 4 the dosage rate of 44 mg/kg was consistently effective (greater than 99% to 100%) for ...
Lee OJ, Koch TG.Inflammation-associated disorders are significant causes of morbidity in horses. Equine single-donor mesenchymal stromal cells (sdMSCs) hold promise as cell-therapy candidates due to their secretory nonprogenitor functions. This has been demonstrated by mononuclear cell suppression assays (MSAs) showing that sdMSCs are blood mononuclear cell (BMC) suppressive in vitro. sdMSCs derived from umbilical cord blood are of clinical interest due to their ease of procurement, multipotency, and immunomodulatory ability. Due to the inherent donor-to-donor heterogeneity of MSCs, the development of robust ...
Foerner JJ, McIlwraith CW.This article attempts to address what the authors consider to be the major orthopedic problems in the racehorse, with particular attention to their treatment and prognosis. These problems include fractures, osteochondral fragments, synovitis, degenerative joint disease, tendinitis, desmitis, osteochondritis dissecans, and subchondral cystic lesions of the joints.
Sander J, Terhardt M, Janzen N.In horses, congenital defects of energy production from long-chain fatty acids have not been described so far. In contrast, inhibition of fatty acid degradation caused by the toxins hypoglycin A and methylenecyclopropylglycine from various maple species are observed frequently. These non-proteinogenic aminoacids are passed on placentally to fetuses or with collostrum or milk to newborn foals. Nevertheless, newborn foals become very rarely symptomatic. Vertical transmission apparently is not sufficient to induce clinical disease without a particular genetic constellation being present. One of t...
Suzuki K, Yamaya Y, Asano K, Chiba M, Sera K, Matsumoto T, Sakai T, Asano R.The aim of this study was to investigate the relationships between the mean concentrations of trace elements and the severity of the second-degree atrioventricular (AV) block in the mane hair of horses. Electrocardiographs of horses were continually recorded for 6 h using a holter cardiac monitor to determine dropped ventricular beats (DVBs) which can be used as an indicator of the severity of the AV block. Mane hair Ca, Cu, Mg, and Zn concentrations were measured by the particle-induced X-ray emission method. The Zn/Cu ratio and Ca concentration in mane hair were significantly and positively ...
Stampfli HR, Misiaszek S, Lumsden JH, Carlson GP, Heigenhauser GJ.The plasma proteins are a significant contributor to the total weak acid concentration as a net anionic charge. Due to potential species difference, species-specific values must be confirmed for the weak acid anionic concentrations of proteins (Atot) and the effective dissociation constant for plasma weak acids (Ka). We studied the net anion load Atot of equine plasma protein in 10 clinically healthy mature Standardbred horses. A multi-step titration procedure, using a tonometer covering a titration range of PCO2 from 25 to 145 mmHg at 37 degrees C, was applied on the plasma of these 10 horses...
Knezevic PF, Fessl L.Thrombosis of the aorta as the cause of intermittent claudication in the horse appears to be rare. Two cases out of about 10 000 horses 1973-1984 are discussed. There are various views on its aetiology, whereby haemodynamic factors and disturbances of coagulation have been mentioned as well as parasites. For treatment surgical methods should be explored in addition to medical procedures. History, diagnosis and the attempt of an aortic thrombectomy in a 12 year old thoroughbred mare are described in this paper. A standardbred stallion was left untreated on owners wish.
Pilsworth RC, Holmes MA, Shepherd M.A fracture of the pelvis in a horse can be detected scintigraphically by probe point counting. However, the pelvis is covered by a large and variable muscle mass, and is close to the urinary bladder, both of which can introduce errors. This paper describes an improved technique which uses a larger set of sampling points and analyses the data with a small computer to construct a three dimensional graph of the gamma-ray output across the pelvis, thus helping to improve the interpretation of the data. The scintigraphic plot from a normal horse, three cases of fracture (confirmed by radiography, u...
Olsen TF.A 14-year-old, quarter horse stallion was presented in lateral recumbency, unable to rise. Equine herpesvirus myeloencephalopathy was diagnosed, based on presentation, clinical signs, and the ruling out of other possibilities. After initial rapid improvements, ataxia remained, as did chronic cystitis secondary to bladder paralysis. He was euthanized after 2 months.
Brück I, Hesselholt M.The results of clinical, ultrasonic, post mortem examinations and concrement analysis of a case with nephrolithiasis in a horse are described. Problems of diagnosis, etiology and occurrence of nephroliths in the horse are discussed.
Bechert U, Rohde J, Freer H, Wagner B.SpayVac is an immunocontraceptive vaccine based on porcine zona pellucida (pZP) antigens and uses a patented liposome formulation (VacciMax or DepoVax). It has delivered single-dose, long-lasting (4-10 years) immunocontraception in several species. Previous studies have demonstrated a positive correlation between levels of pZP antibodies produced and contraceptive effect; however, individual mares that were consistently infertile did not necessarily have the highest antibody titers. The objective of this study was to identify potential differences in specific immunoglobulin G (IgG) isotype res...