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.
Voss KA, Norred WP, Plattner RD, Bacon CW.Currently there is no convenient bioassay to determine the potential toxicity of corn naturally contaminated with Fusarium moniliforme. A short-term bioassay would be useful for future investigations aimed at isolating as yet unidentified toxins produced by this fungus. Two groups of five male Sprague-Dawley rats were each fed one of two F. moniliforme contaminated corn samples, designated CS-1 and CS-2, that were associated with separate field cases of equine leukoencephalomalacia (ELEM). A control group, also consisting of five male rats, was fed uncontaminated seed corn. All animals survive...
Shamis LD, Bramlage LR, Gabel AA, Weisbrode S.Arthrotomies of middle carpal joints were done on 13 horses, and a 1-cm partial thickness, round defect was made on the radial facet of both third carpal bones. In one joint, 1-mm diameter 1-cm deep holes were drilled within the defect, and one joint was used as a control. horses were assigned to 2 groups--group 1 (n = 6 horses), 5 drill holes; group 2 (n = 7 horses), 11 drill holes. At 1 and 3 weeks after surgery, differences between joints in synovial fluid total protein values, WBC counts, or results of mucin precipitate tests were not significant (P = 0.005). Physically and radiographicall...
Cymbaluk NF, Christison GI, Leach DH.Eighteen weanling horses were assigned to two treatments: limited or ad libitum feed intake. Growth and feed utilization were evaluated over a 78-wk period. Ad libitum-fed horses gained 24% more (P less than .05) weight than limit-fed horses. Total BW was distributed into 57% fore and 43% hind weight and did not differ between groups regardless of dietary treatment or age. Net gain and ADG in wither height of ad libitum-fed horses exceeded (P less than .05) that of limit-fed horses over 78 wk. Ad libitum-fed horses consumed 19, 44 and 34% more digestible energy (DE) than indicated in 1978 NRC ...
Ray AC, Kyle AL, Murphy MJ, Reagor JC.In addition to the 3-striped blister beetles (Epicauta temexa and E occidentalis), other sources of equine cantharidin toxicosis were identified at the Texas Veterinary Medical Diagnostic Laboratory and included E albida and E attrivittata and the previously incriminated E pardalis and E pennsylvanica. Improved methods for diagnosing cantharidin or blister beetle toxicosis involve partial purification of urine and gastric content extracts, using silica cartridges, followed by analysis, using capillary gas chromatography/mass spectrometry. During a 26-month period, 53 episodes of cantharidin to...
Furuoka H, Ito H, Hamada M, Suwa T, Satoh H, Itakura C.The endocrine cell components in the pancreatic islets of the following 4 pancreatic regions of the horse were investigated by immunohistochemical methods: lobus pancreatis sinister (left lobe); lobus pancreatis dexter (right lobe); and 2 regions of Corpus pancreatis (body), the duodenal lobe which lies along the cranial duodenal flexure and descending duodenum, and the intermediate lobe which is situated around the portal vein. The islets in the left and intermediate lobes contained a central mass of glucagon cells surrounded by insulin cells, a few somatostatin cells and sporadic pancreatic ...
Adams GP, Ginther OJ.We evaluated the efficacy of intrauterine plasma infusion in mares as a treatment for infertility caused by endometritis and distinguished the effects of intrauterine infusion of plasma vs saline solution. Forty-three subfertile mares were randomly assigned to 1 of 3 treatment groups: untreated controls (n = 14), those treated by saline infusion (n = 14), and those treated by plasma infusion (n = 15). Reproductive status was assessed daily by transrectal ultrasonography. Uterine aspirates and biopsy specimens were obtained 8 days after ovulation for cytologic and histologic evaluation, and mar...
Sweeney CR, Leary HJ, Ziemer EL, Spencer PA.Water vapor-saturated air was delivered to 12 healthy, housed horses for 2 hours daily for 5 days. Treatment had no effect on tracheal mucus transport rate, bronchoalveolar lavage total and differential cell counts, blood cell counts, or plasma fibrinogen concentration.
Rossmanith W, Horvath E.After electrophoretic separation in SDS-PAGE structural proteins of the virus of Equine Infectious Anemia (EIA) were easily blotted by the semi-dry-blotting method onto nitrocellulose filters. Strips of these filters were used for antibody demonstration, and positive reactions thereof were intensified by a biotin-avidin-peroxidase system. Sensitivity of this system was so high as to allow readable interpretation of bands up to the dilution of 1:6,400 of a strongly positive serum. Frequently this procedure allowed to make a firm diagnostic Western-Blot diagnosis on far weaker equine sera. Inter...
Hurd H.A total of 28 components were detected in the free amino acid (FAA) pool of hydatid fluid from primary and secondary equine cysts, secondary ovine cysts and host plasma. Examination of data from equine cysts revealed that the majority of FAAs were present in significantly greater concentrations in secondary cysts, glycine being over 30 times more concentrated. Values for total carbohydrates and glucose did not, however, differ significantly and total protein content was greater in primary cysts. Comparison of the (FAA) pool of secondary equine and ovine cysts revealed strain variation. It was ...
Henry M, Prasse K, White S.Multiple myeloma was diagnosed in a 3-month-old Quarter Horse foal with chronic weight loss, chronic bronchopneumonia, and epistaxis. The foal had pancytopenia, thrombocytopenia, and monoclonal beta-globulinemia. Bone marrow aspirates contained between 80 and 90% plasma cells.
Abrahamsen E, Hellyer PW, Bednarski RM, Hubbell JA, Muir WW.Arterial hypertension developed in a horse anesthetized for arthroscopy and lavage of an inflamed right carpal joint. Anesthesia was induced with xylazine HCl, butorphanol, guaifenesin, and thiamylal Na and was maintained with halothane in oxygen. Arterial hypertension and tachycardia developed within 15 minutes after a pneumatic tourniquet was placed 8 to 10 cm proximal to the right carpus and inflated to 800 mm of Hg. The surgical procedure was expedited, halothane was discontinued and anesthesia was maintained with guaifenesin to facilitate bandaging. Heart rate decreased from 72 to 42 beat...
Matsui K, Sugano S.Intrinsic heart rate (IHR) and autonomic nervous tone (ANT) were measured using the young and the adult of horses, cows, pigs, goats and chickens in order to elucidate species differences in a decrease of resting heart rate (RHR) with growth or age. The IHR and ANT were estimated from the changes in heart rate after the administration of atropine and/or propranolol. The IHR in all species decreased progressively with an increase in body weight from young to adult, and moreover the ANT altered toward the direction of parasympathetic predominance by a decrease in sympathetic tone and/or an incre...
Doonan GR, Brown CM, Mullaney TP, Brooks DB, Ulmanis EG, Slanker MR.Several hundred Michigan horses were accidentally exposed to varying levels of monensin. Severity of effects was proportional to the level of feed contamination; sudden death resulted on at least two premises. Acute signs of cardiovascular impairment occurred on one premises having received feed containing over 200 grams of monensin per tonne. Gross and histological postmortem lesions consisted of acute myocardial necrosis. Although only circumstantially confirmed, investigations led to the suspicion that the source of poisoning was a ration formulation error in a feedmill in southwestern Onta...
Troyer D, Howard D, Leipold HW, Smith JE.Southern blot analysis of equine DNA's digested with the restriction endonuclease Hinfl hybridized with a 32 PdCTP labeled human VNTR probe revealed a highly polymorphic pattern of restriction fragments upon autoradiography. The horses were unrelated individuals of the quarter horse breed. This heterologous probe can thus be used in the equine species for individual identification and pedigree analysis.
Edwards DJ, Brownlow MA, Hutchins DR.Urine and blood samples were taken at the same time from normal adult horses presented for routine investigations to establish reference values for a variety of parameters reported to be useful in the clinical evaluation of renal function. Blood biochemical values were consistent with previous studies and had well-defined normal ranges. Parameters representing urine concentration and electrolyte excretion however, varied widely reflecting the ability of the healthy kidney to change the composition of urine in response to differences in environment and management. Percent creatinine clearance r...
Prater PE, Patton CS, Held JP.Pleural effusion, secondary to a metastasis from a malignant hepatoblastoma, was diagnosed in a 3-year-old Appaloosa gelding. Severe hemorrhagic transudate in both pleural cavities resulted in acute onset of labored breathing, tachypnea, tachycardia, and jugular vein pulsation. Results of ultrasonography and radiography of the ventral lung field and cranial portion of the abdomen initially were nondiagnostic, as were results of cytologic examination of peritoneal fluid and tracheal wash specimens. Moderately high serum gamma-glutamyl transferase and alkaline phosphatase activities, despite nor...
Wood T, Tai CL, Taylor DG, Woods WE, Wang CJ, Houtz PK, Tai HH, Weckman TJ, Yang JM, Sturma L.Detomidine is a potent non-narcotic sedative agent which is currently in the process of being approved for veterinary clinical use in the United States. Since no effective screening method in horses is available for detomidine, we have developed an 125I radioimmunoassay for detomidine in equine blood and urine as part of a panel of tests for illegal drugs in performance horses. Our 125I radioimmunoassay has an I-50 for detomidine of approximately 2 ng/ml. Our assay shows limited cross-reactivity with the pharmacodynamically similar xylazine, but does not cross-react with acepromazine, epinephr...
Schmidt AR.A 5-MHz transducer was used transrectally to image palpable structures in the caudal portion of abdominal and pelvic cavities of 12 horses. In 8 healthy horses, structures scanned transrectally included the left kidney, spleen, urinary bladder, urethra, accessory sex organs in the male, portions of the intestinal tract, caudal portion of the aorta, and iliac arteries, and, in small horses, the cranial mesenteric artery. The transrectal technique was used to evaluate these structures in 4 horses with clinical signs indicating intrapelvic or intra-abdominal disease. Seemingly, transrectal ultras...
Johnston JK, Divers TJ, Reef VB, Acland H.Ten horses with clinical signs consistent with cholelithiasis were evaluated. Fever, icterus, mild intermittent colic, and weight loss were reported. Clinical laboratory abnormalities included leukocytosis, hyper-proteinemia, and hyperfibrinogenemia. Gamma glutamyltransferase and liver isoenzyme of lactate dehydrogenase activities also were high. Choleliths were observed via ultrasonography of the liver in 5 of the 8 horses evaluated, and increased echogenicity of the hepatic parenchyma and dilated bile ducts were observed in all horses. Seven horses were treated medically, 5 of which died or ...
Whalley JM, Robertson GR, Scott NA, Hudson GC, Bell CW, Woodworth LM.A gene in equine herpesvirus 1 (EHV-1; equine abortion virus) equivalent to the gB glycoprotein gene of herpes simplex virus (HSV) has been identified by DNA hybridization and nucleotide sequencing. A 4.3 kbp EHV-1 PstI-ClaI sequence (0.40 to 0.43 map units) contained an open reading frame flanked by appropriate control elements and was capable of encoding a polypeptide of 980 amino acids. This had 50 to 60% identity over a 617 amino acid conserved region with the gB gene products of HSV and three other alphaherpesviruses, and 20 to 30% identity with those of human cytomegalovirus and Epstein-...
Cook BR.Twenty-five years ago Williams and Sweatman suggested that in Great Britain there are two subspecies of Echinococcus granulosus--E. granulosus granulosus and E. granulosus equinus. Echinococcus granulosus granulosus does not mature either in foxes or in horses: E. granulosus equinus will mature in either. The prepatent period of E. granulosus granulosus in the definitive host is about 42 days while that of E. granulosus equinus is about 70 days. Each subspecies has a characteristic morphology. More recently, in the course of seven experiments, dogs, red foxes (Vulpes vulpes crucigera), arctic ...
Lofstedt RM, Patel JH.In our experience, altrenogest has not always been able to exert predictable control over the estrous cycle of the mare. Therefore, we examined 12 mares that were treated with altrenogest to identify reasons for its failure to control the estrous cycle. The mares were fed altrenogest for 15 to 20 days and were examined for follicle development, ovulation, and corpus luteum formation during treatment. Through the use of real-time ultrasonography and radioimmunoassay for progesterone, we concluded that altrenogest was unable to suppress the growth of follicles to preovulatory size in some mares,...
Inzana TJ, Iritani B.A group C latex agglutination reagent, included as the negative control in the PathoDx Strep A latex agglutination test (Diagnostic Products Corp., Los Angeles, Calif), was compared with culture for rapid detection of group C streptococci (Streptococcus equi, S. equisimilis, S. zooepidemicus, and S. dysgalactiae) from swabs of veterinary specimens. The overall sensitivity of the latex test was 78%, and specificity was 97.6%. Only 25% of S. dysgalactiae isolates were detected, thereby accounting for the relatively low sensitivity. Ninety-three percent of the group C streptococci other than S. d...
Hinrichs K, Frazer GS, deGannes RV, Richardson DW, Kenney RM.Serous cystadenoma was diagnosed by histologic examination of a large ovary removed from a 16-year-old Thoroughbred mare with normal estrous cycles. Palpation and ultrasound examination per rectum had revealed an excessive number of follicles in the right ovary. The ovulation fossa was palpable on the right ovary, and the left ovary appeared to have normal activity. Plasma testosterone values were high at the time of examination (0.15 ng/ml), but decreased to normal values (0.09 ng/ml) after removal of the cystadenoma.
Collins EA.Four cases of equine lameness were treated with intra-articular polysulphated glycosaminoglycan. Two, two-year-old flat racers were treated conservatively after traumatic injury. They subsequently became lame owing to the formation of new bone and osteophytes. Two older steeplechasers were lame owing to degenerative joint disease. The four horses were treated with intra-articular injections of polysulphated glycosaminoglycans and, after three or four injections, they became clinically sound and were able to continue racing with varying degrees of success.
McAllister RA, Sack WO.A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crown-rump length (CRL) to 500-mm CRL (including a mule of 21-mm CRL). In saggital sections of the clitoris of a 480-mm CRL fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of ...
Sugiyama F, Takahashi Y, Nomura M, Ebisuda Y, Mukai K, Yoshida T.We investigated the risk factors for epistaxis in Japanese flat races over a 20-year period. The veterinary records of horses identified as having epistaxis by endoscopy on the race day, and the official racing records of all flat races from April to September between 2001 and 2020, were reviewed. The racecourses (n = 10), surface type, surface condition, race class, race distance, race year, sex, age, two training centers, ambient temperature, and body weight on race days were assessed using multivariable logistic regression (p < 0.05). Of 475,709 race starts, 616 (1.30 cases per 1000 starts;...
Moyer W.The foot is the most common source of limb pain. The problems vary from simple to quite complex. An accurate diagnosis is dependent upon a thorough and detailed knowledge of anatomy and of what is available in the way of ancillary examination techniques. The correction of most foot problems requires an appreciation of a multitude of factors and a thorough knowledge of farrier science.
Guerin G, Varewyck H, Bertaud M, Chasset P.A horse family in which a recombination occurred in the chromosome region coding for the serological specificities of the ELA complex and those of the A blood group system of a mare was further analysed by mixed lymphocyte reaction (MLR) and Southern blot hybridization. This family consisted of a stallion, a mare and five full sibs. The stallion and the mare were heterozygous for internationally recognized ELA specificities while only the mare was heterozygous for the A blood group system. MLR between all members of the family confirmed that the stallion possessed two different ELA haplotypes ...
Elsinghorst TA.In this fourth article of a series of papers listing first case reports of animal diseases published since 2000, the following six cases of horse diseases are discussed: Disseminated metastatic intramedullary melanoma. Lipoma of the extensor tendon sheaths. Meningoencephalomyelitis in a neonatal foal due to Salmonella agona infection. Neuronal ceroid lipofuscinosis. Placentitis due to Rhodococcus equi infection. Right atrial diverticulum in a foal. After a short introduction, the bibliographical data, the abstract of the author(s), and some additional information derived from the article are g...
Carrillo NA, Giguère S, Gronwall RR, Brown MP, Merritt KA, O'Kelley JJ.To determine the disposition of orally administered cefpodoxime proxetil in foals and adult horses and measure the minimum inhibitory concentrations (MICs) of the drug against common bacterial pathogens of horses. Methods: 6 healthy adult horses and 6 healthy foals at 7 to 14 days of age and again at 3 to 4 months of age. Methods: A single dose of cefpodoxime proxetil oral suspension was administered (10 mg/kg) to each horse by use of a nasogastric tube. In 7- to 14-day-old foals, 5 additional doses were administered intragastrically at 12-hour intervals. The MIC of cefpodoxime for each of 173...
White-Springer SH, Bruemmer J, Coleman RJ.A core group of 27 equine nutritionists and physiologists joined together in the late 1960s to formally address and enhance the direction of equine research, creating the Equine Nutrition and Physiology Society. In 2003, that growing society transformed into the Equine Science Society, which now serves as the preeminent, internationally recognized scientific equine organization. In recent years, it has been appreciated that equine science encompasses a wide range of focus areas, including exercise science, nutrition, genetics, reproductive physiology, teaching and extension, production and man...
Platt H.The pathology of 4 cases of caecal rupture in foaling mares is described. One of these animals died suddenly, probably when rupture occurred, and 3 survived for 5 to 8 h and died from acute peritonitis.
The pathogenesis of this type of injury is discussed and it is suggested that rupture may arise from the pressure of a foetal hind foot against the caecum when distended by local tympany.
Kilcoyne I, Nieto J, Magdesian KG, Nottle BF.To determine the effect of a 10% dimethyl sulfoxide (DMSO) solution on the peak concentration (C ) of amikacin in the radiocarpal joint (RCJ) during intravenous regional limb perfusion (IVRLP) compared with 0.9% NaCl. Methods: Randomized crossover study. Methods: Seven healthy adult horses. Methods: The horses underwent IVRLP with 2 g of amikacin sulfate diluted to 60 mL using a 10% DMSO or 0.9% NaCl solution. Synovial fluid was collected from the RCJ at 5, 10, 15, 20, 25, and 30 minutes after IVRLP. The wide rubber tourniquet placed on the antebrachium was removed after the 30 min sample. A...
Warren A.A 5-year-old Hanoverian horse was presented for a palpable and visible mass over the frontal and maxillary sinuses. Following endoscopy and radiography surgical excision was attempted. The horse was euthanized during surgery and samples of the mass were identified as malignant anaplastic sarcoma, a seldom reported sinonasal tumor in equids. Sarcome anaplasique naso-sinusien équin infecté par Escherichia coli multirésistant aux antibiotiques. Un cheval Hanovrien âgé de 5 ans a été présenté pour une masse palpable et visible sur les sinus frontal et maxillaire. Après une endoscopie et ...
Abigail McGlennon of the Animal Health Trust and Andrea Vilela of the Redwings Horse Sanctuary describe the creation and impact of a new initiative to tackle strangles in UK horses.
Andersson L, Arnason T, Sandberg K.Investigations on relationships between biochemical polymorphism and variation in quantitative traits are of interest from the perspectives of both theoretical quantitative genetics and practical animal breeding. This subject was studied by using racing performance records of more than 25,000 horses of the Swedish Trotter breed born in the period 1970-1979. For all horses data on six blood group and nine electrophoretic loci were available. Two different performance traits were investigated. A racing performance index value was calculated for all individuals which had started in at least five ...
Magee C, McDaniel S, Turk P, Striegel N, Roman-Muniz IN.The purpose of this study was to learn how perceptions of accuracy and availability of sources affect how members of the Colorado equine industry seek both everyday information and information during an equine disease outbreak. A survey was distributed by email and social media to members of Colorado-based equine organizations. A total of 256 survey responses were obtained from individuals representing a spectrum of ages and roles in the Colorado equine industry. Survey participants predominantly identified as female (95.3%) and their industry role as a horse owner (41%) or a competitive (25.8...
Katano Y, Imai S.The effects of dipyridamole on thromboxane A2 formation by horse platelet microsomes were studied in comparison with those of imidazole, a prototype inhibitor of TXA2 synthetase and nifedipine, a calcium antagonistic vasodilator. Thromboxane A2 was synthesized by incubating PGH2 with horse platelet microsomes and was assayed on the superfused rabbit aorta. Dipyridamole induced as strong an inhibition of TXA2 synthesis as imidazole, while nifedipine was without effects. The possible beneficial clinical outcomes of this effect of dipyridamole are discussed.
Cuervo-Arango J.Prostaglandins (PGs) are essential to trigger the cascade of events that degrade the extracellular matrix of follicles leading to follicular rupture and ovulation. In mares, systemic administration of flunixin meglumine (FM), a PG synthetase inhibitor, blocks ovulation by inducing luteinized unruptured follicles (LUF). In the rat, the administration of PGF(2α) (PGF) and PGE restored ovulation in indomethacin treated animals. The mares were treated with FM 0, 12, 24 and 36 h after human chorionic gonadotrophin (hCG) administration to induce experimentally LUF (n = 15) or were left untreated (c...
Schaaf KL, Kannegieter NJ, Lovell DK.A Thoroughbred horse with bilateral laryngeal dysfunction was treated by placement of a long term tracheal cannula in order to restore full athletic function. The horse initially presented with right-sided arytenoid dysfunction that was considered to be due to a congenital malformation of the laryngeal cartilage. This was corrected by a right-sided laryngoplasty and ventriculectomy. The horse re-presented 1 year later with idiopathic left laryngeal hemiplegia. The decision was made to place a long-term tracheal cannula due to the low success rate and high complication rate associated with othe...