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.
Kent MG, Schneller HE, Hegsted RL, Johnston SD, Wachtel SS.The XY Sex Reversal Syndrome of the horse is a condition associated with female or intersexual development in genetic males. In our previous study, 38 sex reversed XY mares were classified according to behavior, gross clinical phenotype, gonadal status, and H-Y phenotype. Four classes were described, ranging from potentially fertile female (Class I) to virilized intersex (Class IV). In the present study, serum testosterone concentrations were measured in 29 sex-reversed XY mares, 3 normal mares and 3 normal stallions. Serums were obtained during the breeding season (March-August), and were sto...
Merkens HW, Schamhardt HC.Force plate data from walking horses were used to evaluate the locomotion of a group of six horses during experimentally induced lameness in a forelimb or a hindlimb. By tightening or loosening screws in modified horseshoes the resulting pressure pain on the sole enabled induction and release of three different degrees of supporting lameness within a period of 2 h. The ground reaction force (GRF) patterns of the different recording sessions were compared with control data of the same horse as well as with the 'standard' horse data using a quantitative evaluation procedure involving 93 GRF para...
Jones RS, Payne-Johnson CE, Seymour CJ.A NUMBER of post general anaesthetic complications are
known to occur in the horse and are well documented (Heath
1981). These include post anaesthetic forelimb lameness o r
ischaemic myopathy (so-called 'radial paralysis') (Trim and
Mason 1974) and spinal cord degeneration (Brearley, Jones,
Kelly and Cox 1986). The only postoperative respiratory
complication which has been documented in the horse is
postoperative hypoxaemia (Gillespie, Hall and 3 1 e r 1969;
Waterman, Jones and Richards 1982).
In a report of the post mortem examinations of 185 injured
human patients who died followi...
Kwiatkowski S, Sturma L, Dai MR, Tai HH, Watt DS, Tai CL, Woods WE, Weckman TJ, Yang JM, Wood T.We have developed and evaluated a one step enzyme-linked immunosorbent assay (ELISA) test and a particle concentration fluorescence immunoassay (PCFIA) test for acepromazine as part of a panel of pre- and post-race tests for illegal medications in racing horses. These tests are rapid, sensitive and economical and development of the tests occurred in less than seven months. The ELISA test detects acepromazine with an I-50 of about 150 pg/ml. In vivo, it readily detects the presence of acepromazine or its metabolites in equine blood and urine from 8 to 72 hours or longer, respectively, after adm...
Pilsworth RC, Webbon PM.Five horses, all two year old Thoroughbreds, presented with acute onset hindlimb lameness following moderate to fast exercise. The use of a hand-held scintillation detector after Tc99 MDP injection greatly aided the diagnosis of tibial stress fractures in these horses. Radiological findings were subtle, involving only periosteal new bone and callus at the fracture site. In two cases this took several weeks to develop but in three others was present at the onset of lameness, indicating insidious pre-fracture bone pathology. The site of the most obvious radiological signs was constant in all fiv...
Honnas CM, Wheat JD.Transnasal, axial division of the aryepiglottic fold was performed to correct entrapment of the epiglottis in 20 sedated, standing horses, using a hooked bistoury and topical anesthesia. Presenting complaints included decreased exercise tolerance or loss of racing performance, abnormal respiratory noise, and coughing. The surgical procedure was technically easy to perform with a minimum of instrumentation. The horses were rested an average of 18 days before race training or riding was resumed. Evaluation of racing records or contact with owners indicated that most affected horses competed succ...
Scotti E, Jeffcott LB.An in vitro study on the calcaneus of adult horses (n = 5) and foals (n = 10) was carried out using radiographic photodensitometry, single photon absorptiometry, transmission ultrasound velocity and chemical analysis. Data for trabecular bone content, ash, calcium and phosphorus levels were obtained. As techniques for assessing bone quality, ultrasound velocity was not sufficiently sensitive nor accurate and radiographic photodensitometry was found to be limited value. Photon absorptiometry was both accurate and reproducible, although some variation in bone mineral content and bone mineral den...
Held JP, Patton CS, Shires M.Osteochondroma of the distal portion of the radius was diagnosed in 3 horses with a history of lameness and distention of the common tendon sheath of the superficial and deep digital flexor tendons at the level of the carpal canal. In 2 horses, the exostosis was removed through an incision at the caudal border of the lateral digital extensor muscle above the carpal ligament.
Oijala M, Katila T.Detomidine was administered twice to six foals (14 to 94 days old) using three different doses (10, 20 and 40 micrograms/kg bodyweight intravenously) in a double blind trial. Sedation, analgesia, heart rate and clinically observed side-effects were recorded. Detomidine showed strong sedative effects at all doses tested. Sedation deepened very little by increasing the dose from 10 to 40 micrograms/kg bodyweight, but the duration of the effect was longer. Analgesia was considered good with the largest dose (40 micrograms/kg), and moderate or non-existent with the lower doses. Detomidine caused a...
Gossett KA, McCoy DJ, Jowett PL, Kearney MT.Nitrofurazone solution containing 0.2% nitrofurazone and 99.8% polyethylene glycol was given to 4 healthy horses (2 L in 2 L of lactated Ringer solution, intraperitoneally). Horses developed hypovolemia, hyperosmolality, and mixed respiratory and metabolic acidosis. These changes were largely attributable to polyethylene glycol, but a contribution of nitrofurazone cannot be excluded. Intraperitoneal infusion of nitrofurazone solution in horses is contraindicated.
Morris CM, Field HJ.Tissue specimens obtained from equine herpesvirus-1 (EHV-1), subtype 1-infected aborted foetuses were analysed for the presence of virus DNA by means of Southern blot and dot blot hybridisations. The specificity of the methods was confirmed although the sensitivity was inferior to classical techniques such as virus isolation. However, the possibility of detecting the state of the virus DNA and the ability to distinguish between subtypes were important features, and the dot blot method was shown to have potential for a rapid diagnostic test. This report demonstrates some potential practical app...
Kamerling SG, Cravens WM, Bagwell CA.1. Detomidine is a novel veterinary sedative analgesic which is thought to act by stimulation of alpha 2 adrenoreceptors. The present study was undertaken to determine the direction, time course, and dose-response relationship of detomidine on specific autonomic responses in the unanaesthetized horse. 2. Detomidine was administered intravenously to eight adult thoroughbred racehorses at doses of 0.010-0.040 mg kg-1, according to a double-blind Latin square crossover design. Cardiac and respiratory rates, pupil diameter and rectal temperature were monitored for 180 min postinjection. 3. Detomid...
Sandgren B.Radiographic examination of the tarsocrural, metacarpo- or metatarsophalangeal joints was made in 139 Standardbred horses. Most were under three years old with no history of orthopaedic problems. In the tarsocrural joint, osteochondrosis was observed in 25 (18.1 percent) of the horses (n = 138) and 14 (56 percent) of these were affected bilaterally. In the metatarsophalangeal joint, the most frequent radiographic abnormality was single or multiple bony fragments or defects at the plantar proximal end of the proximal phalanx, which was noticed in 40 (28.8 percent) of the horses (n = 139). The l...
Boero MJ, Kneller SK, Baker GJ, Metcalf MR, Twardock AR.Injury of the lateral collateral ligaments of the tarsocrural joints was diagnosed in nine Standardbred pacers. The average age was 4.9 years. The severity of the lameness varied from severe to subtle and joint effusion was seen in eight of 10 tarsocrural joints. A positive hindlimb flexion test was seen in four of six cases in which results were recorded. The identification of the site of involvement was based on a focal intense 'hot spot' seen on scintigraphy, and new bone formation seen radiographically at the anatomical sites of insertion of the long lateral collateral ligament of the tars...
Watson ED.Incubation of blood neutrophils with uterine flushings collected from ovariectomised mares treated with oestradiol, stimulated migration under agarose, whereas flushings from mares treated with progesterone or oily vehicle, inhibited migration. After intra-uterine infusion of bacteria, however, flushings from oestradiol-treated and vehicle-treated mares inhibited migration, whereas progesterone treatment stimulated migration. Migration of uterine-derived neutrophils under agarose was less than that of blood neutrophils and was not influenced by treatment with ovarian steroids. Uterine suscepti...
McCarhey RN, Jeffcott LB, McCartney RN.Ten pairs of third metacarpal bones from Thoroughbred horses aged two to 12 years were used to estimate bone strength. Measurements of transverse cortical ultrasound velocity, cortical cross sectional area and bone mineral content were made using ultrasonic transmission velocity and single photon absorptiometry. These data were used to determine bone mineral density, compact bone density and modulus of elasticity. The results were compared with those measured by direct means or chemical analysis and satisfactory correlations were obtained between estimated and measured values. Single photon ab...
Dyson S.The carpus and metacarpus of 40 horses which were free from lameness and 40 horses with lameness associated with the metacarpophalangeal joint or more distal limb were examined radiographically (Group A). The opacity of the proximal third of the third metacarpal bone was regular, with a uniform trabecular pattern. Osseous cyst-like lesions (OCLLs) were identified in the radial carpal bone (1), the ulnar carpal bone (2), the second carpal bone (15) and the fourth carpal bone (1). Thirty-one of 638 horses (4.8 percent) with forelimb lameness had pain localised to the proximal metacarpal region u...
McDowell KJ, Sharp DC, Grubaugh W, Thatcher WW, Wilcox CJ.Cycling pony mares were bred and used to test the effect of restricted conceptus mobility on luteal maintenance (i.e. maternal recognition of pregnancy). In Experiment 1, uterine horns were ligated to restrict conceptus mobility to one uterine horn, Group 1; one horn plus the uterine body, Group 2; or one horn, the body and approximately 80% of the second horn, Group 3. Pregnancies were monitored with real-time ultrasonography. Four of five mares in Group 1 and two of four mares in Group 2 returned to estrus (Day 16.0 +/- 1.9 and 14.5 +/- 0.7, respectively) and subsequently lost the embryonic ...
Higgins JA, Klei TR, Foil LD.Culicoides variipennis were fed under controlled conditions on two ponies that exhibited seasonal changes in Onchocerca cervicalis microfilarial (mf) skin density and skin distribution. The seasonal changes did not radically affect mf ingestion. Flies were fed on the umbilicus of infected ponies by two methods: individual feeding in consecutive order at the same site, or by mass feeding. Linear regression analysis indicated that ingestion of microfilaria was independent of feeding time and engorged weight. In the individual feeding data, there was a trend toward an increased ingestion of mf as...
Satoh M, Higuchi T, Inoue S, Miyakoshi D, Gotoh T.Assessment of the cricoarytenoideus dorsalis muscle (CAD) in horses using a transesophageal ultrasound, computed tomography, or magnetic resonance imaging is available in a limited number of hospitals. This study assessed the ease of ultrasonographic imaging of the CAD using an external transcutaneous technique in horses. After confirmation of the CAD in the cadavers, ultrasonography in twenty live horses was carried out using a transcutaneous approach. In live horses, ultrasonographic imaging of the CAD was possible by pushing the larynx from the opposite side with the other hand. It is belie...
O'Callaghan MW.When performed on selected clinical cases, ventilation/perfusion scintigraphy provides valuable additional information on regional lung function that is not obtainable from conventional thoracic radiographs. This is particularly true of horses with EIPH, COPD, and those suspected of having some form of small-airway disease. For horses with EIPH, the presence of a perfusion deficit on the scan is considered a key prognostic sign, because it is likely in these cases that irreversible bronchial arterial takeover has occurred in the affected areas of lung. Findings from horses with COPD have impro...
Immonen I, Cuervo-Arango J.The reproductive management of mares for frozen semen artificial insemination (AI) can be costly and labor intensive. Predicting the exact time of ovulation can be challenging even when ovulation-inducing drugs are used. The main objective of this retrospective study was to determine whether there was an effect of interval between examinations to detect ovulation on likelihood of pregnancy and early embryonic loss in mares after postovulatory breeding with a single straw of frozen/thawed semen. The second objective was to determine the efficacy of two different drugs (human chorionic gonadotro...
Groman EV, Schultz RM, Engel LL, Orr JC.In the reduction of 17beta-hydroxy-5alpha-androstan-3-one to the 3beta-alcohol, horse liver alcohol dehydrogenase utilizes the 4-pro-R hydrogen of NADH whereas the 3(17)beta-hydroxysteroid dehydrogenase of Pseudomonas testosteroni utulized the 4-pro-S hydrogen. These observations provide an exception to the rule proposed by Alworth and Bentley that with regard to the paired methylene hydrogens at C-4 of NADH and NADPH "the stereospecificity of a particular reaction is fixed and does not vary with the source of the enzyme preparation". It is also apparent that for these two enzymes, the selecti...
Naden J, Squires EL, Nett TM, Amann RP.The pituitary response to exogenous GnRH was studied in 8 colts of Quarter Horse phenotype from 32 to 96 weeks of age. Colts were from dams treated daily from Day 20 to 325 of gestation with (1) 2 ml neobee oil per 50 kg body weight (controls); or (2) 2 ml altrenogest per 50 kg body weight. GnRH challenges (5 micrograms/kg body weight) were administered every 8 weeks from 32 to 96 weeks of age to estimate pituitary content of LH. Blood samples were collected every 20 min for 4 h before GnRH and 15, 30, 45, 60, 90, 120, 180, 240 and 360 min after GnRH. Serum concentrations of LH and FSH were de...
Dice PF, Cooley PL.This report involves a retrospective study of five horses with an unusual form of progressive peripheral corneal ulcers. These ulcers were located at the perilimbal region of the cornea and spread both centripetally to mid periphery and circumferentially. Lipping of the epithelial edge was observed often. The depth ranged from superficial to mid stroma. Patients ranged from two and a half to eight years, both sexes, and were referred after a variety of antibacterial therapy. Histories were similar in that all ulcers were initially located adjacent to the limbus in one or more quadrants. No tra...
Smith HL, Rosenblatt AJ, Suen WW, Owen H, Ahern BJ.A 6-week-old Thoroughbred filly was presented for evaluation of an expansile mass overlying the right nasal passage and causing respiratory stertor. On skull radiographs, there was a loculated, soft tissue-opaque mass identified dorsal to the right upper premolars and effacing the right nasal cavity. Computed tomography (CT) revealed a locally extensive mass with relatively benign characteristics located centrally on the tooth root apices of the deciduous second premolar (506). The mass extended axially into the right nasal cavity, occluding the meatuses and causing displacement of the nasal s...
Sugita S, Oki H, Hasegawa T, Ishida N.Estimation formulas for the morbidity of horses infected with equine influenza virus by linear regression, logistic regression and probit transformation were developed, using data from the outbreak at the Sha Tin Racing Track in Hong Kong in 1992. Using these formulas, we estimated the equine influenza virus morbidity rates at training centers belonging to the Japan Racing Association (JRA) in October 1997 and in October 1998. In 1998 JRA started a new vaccination program, and every horse must now be vaccinated twice per year. At that time, the vaccine included two US lineage virus strains, th...
Marais J.The vascular architecture of the dermal laminae was studied by scanning electron microscopy of vascular corrosion casts. Ultrastructurally, the laminar vasculature consisted of arterioles, capillaries, venules and veins, arranged in a sheet-like network. Through the laminae, arterioles ran parallel to the solar surface and branched at two levels to form a continuous arteriolar arcade, parallel to the hoof wall. Capillaries originating from these arcades formed hairpin loops joining the marginal vein prior to forming an axially situated venous network. Additional capillaries were also given off...
Derisoud E, Jouneau L, Margat A, Gourtay C, Dubois C, Archilla C, Jaszczyszyn Y, Dahirel M, Daniel N, Peynot N, Briot L, De Geoffroy F, Wimel L....No abstract available
ElWishy AB.The morphological changes which take place in the sperm during their passage
through the excurrent ducts have been studied in the bull (BRANTON and SALISBURY
1947; HANCOCK 1955; BAILY and SMITH 1958; AMANN and ALMQUIST 1962; GUSTAFSSON and CRABO 1971 ; RAO 1971) and boar (GUSTAFSSON, CRABO and EINARSSON 1970).
Such knowledge is of major importance in understanding the origin and significance
of the different sperm abnormalties as well as providing the basis for proper appraisal
of semen picture and devising useful spermiograms.
The aim of the present work is to study the morphological ch...
Leroux AJ, Schott HC, Hines MT.Ventricular tachycardia was diagnosed in a 12-year-old unconditioned Appaloosa gelding after a 3-day trail ride. Initial signs were those of abdominal discomfort, ileus, and dehydration. Medical treatment included IV administration of lactated Ringer's solution. During hospitalization, the horse developed ventricular tachycardia. Serum potassium concentrations were within reference limits; however, assessment of total body potassium stores was not performed. Resolution of the arrhythmia occurred with further fluid treatment and potassium supplementation. Cardiac arrhythmias should be considere...
Arroyo LG, Vengust M, Dobson H, Viel L.A 10-day-old quarter horse colt was presented for signs of disorientation and inability to nurse. Hydronephrosis/hydroureters, with concomitant pyelonephritis and a severe electrolytes disturbance, were diagnosed. The clinical findings closely resembled those described for a syndrome of transient pseudohypoaldosteronism in human neonates. Un poulain Quarter horse âgé de 10 jours a été présenté pour des signes de désorientation et d’incapacité à se nourrir. Une hydronéphrose/hydrouretères avec pyélonéphrite concomitante et débalancement électrolytique sévère ont été diagno...
Baran Ketencioğlu B, Yilmaz I, Tutar N, Gülmez I, Oymak FS.Sensitivity and symptoms related to animal proteins have been investigated in various occupational groups. However, data from horse farm workers are limited. We aimed to determine horse allergen sensitivity in the horse farm workers, and to evaluate its relationship with respiratory symptoms and functional parameters. A total of 110 subjects were enrolled in the study. The study group consisted of 80 horse farm workers. Face-to-face surveys, skin prick tests (SPT), and pulmonary function tests (PFT) were performed in the study group. Control group consisted of 30 healthy subjects. SPT and PFTs...
Bell K.Transferrin, albumin, 6-phosphogluconate dehydrogenase and vitamin D-binding protein polymorphisms were detected in 242 feral and domesticated Australian donkeys by polyacrylamide gel electrophoresis, starch gel electrophoresis, autoradiography, immunoblotting with specific antisera and activity staining. All four TF and two ALB variants were donkey specific while only one of the PGD variants was donkey specific. The two GC variants were electrophoretically identical to the Equus caballus F and S proteins. Available evidence suggested that the TF, ALB, PGD and GC systems are controlled by co-d...
Lucas JM, Ross MW, Richardson DW.A retrospective study of 176 Standardbred horses that had arthroscopic surgery for carpal chip fractures over a 7 year period was done in order to determine fracture location and post operative performance. Chip fractures of the proximal third carpal bone and the distal radiocarpal bone occurred with equal frequency (49.2 and 49.6% respectively), and chip fractures involving the antebrachiocarpal joint were rare. Trotters had significantly more third carpal bone lesions than radiocarpal bone lesions when compared to pacers (P = 0.0304). Seventy-four per cent of horses made at least one start f...
Heffron CJ, Baker GJ, Lee R.Videofluoroscopy was used to study the deglutition reflexin 2 horses believed, on the basis of endoscopic and clinical examination, to have normal pharyngeal and laryngeal function. The reflex was found to be the same as that described in man and in the rabbit. A feature of deglutition in the horse was the temporary increase in size of the auditory tube diverticuli (gluttural pouches) as a result of contraction of the pharyngeal muscles.