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.
Kohn CW, Fenner WR.The neurologic form of EHV-1 infection appears to be the result of central nervous system infarction caused by vasculitis, which is initiated in endothelial cells of small blood vessels. The etiologic agent is equine herpesvirus-1, subtype 1. There is some evidence to suggest that the neurologic form of the disease actually results from reactivation of a previous infection. Whether the vasculitis that causes the central nervous system injury is the direct result of the infection or an immune response to the infection has not been determined. The clinical signs are rapid in onset, nonprogressiv...
Dunlop CI, Steffey EP, Miller MF, Woliner MJ.Cardiopulmonary function was monitored in 6 non-medicated, healthy male horses, anesthetized with halothane or isoflurane in O2 at a constant dose (1.2 times the minimum alveolar concentration). Horses were exposed once to each anesthetic agent, and a minimum of 2 weeks separated anesthetic exposures. All horses were studied in left lateral recumbency, and ventilation was mechanically controlled to induce a PaCO2 of 35 to 45 mm of Hg and an inspiratory peak airway pressure of 18 to 22 cm of H2O. After 1 hour of horse preparation, constant conditions were begun. With duration of anesthesia, car...
Hillidge CJ.The selection of lipid-soluble antibiotics capable of intracellular penetration is considered critical for the successful treatment of Rhodococcus equi pneumonia and lung abscesses in foals. Two such antibiotics: erythromycin (25 mg kg-1, three times daily) and rifampin (5 mg kg-1 twice daily) have been used in combination for this purpose at the University of Florida since 1981. Positive evidence of R. equi was present on culture of tracheal aspirates in 57 foals, most of which exhibited radiographic evidence of extensive lung abscessation. The duration of therapy ranged from 4 to 9 weeks. Mi...
Harvey KA, Morris DD, Saik JE, Donawick WJ.A 13-year-old Thoroughbred mare had a 2-week history of weight loss and intermittent fever. Examination of abdominal and pleural fluid revealed peritonitis and pleuritis. Ultrasonography of the ventral abdominal midline revealed an intra-abdominal mass. Exploratory celiotomy was performed, but the mass was not surgically excisable. The mare was euthanatized and necropsied. Histologically, the mass was determined to be a fibrosarcoma of omental origin.
DeBowes RM, Leipold HW, Turner-Beatty M.Cerebellar abiotrophy is a degenerative condition of Arabian horses that produces signs of head tremors and ataxia. Affected foals demonstrate clinical signs between the time of birth and 6 months of age. The condition is untreatable, although some animals have reportedly improved to varying degrees. The disease is believed to be inherited; however, definitive evidence is lacking at this time.
Takai S, Kawazu S, Tsubaki S.Humoral immune response to Rhodococcus equi in experimentally infected foals was studied with the enzyme-linked immunosorbent assay (ELISA) method. Class-specific antibodies were measured by ELISA in the sera of foals after intratracheal or oral inoculation with R. equi ATCC 6939 or T 48 and in the lung washings of a foal after intratracheal inoculation or of normal horses. After intratracheal or oral inoculation with R. equi, serum antibodies were first detected in immunoglobulin G (IgG) followed by IgM and IgA classes, but significant levels of IgM and IgA developed only in the foal infected...
Stewart JH, Young IH, Rose RJ, Costas L, Barko AM.The distributions of ventilation-perfusion ratios, and the effects of 100% oxygen administration on the distributions, were studied in 3 foals from 4h to 9 days of age, using the multiple inert gas elimination technique. The distributions were calculated from the pulmonary clearance of 6 inert gases following infusion into a peripheral vein of a solution containing the inert gases. The results from a total of 8 studies showed several consistent features. The major findings were (i) the absence of low ventilation-perfusion ratios, i.e. regions where blood flow was greatly in excess of ventilati...
Owen RA, Jagger DW, Jagger F.The clinical details of two cases of equine primary gastric impaction are described and the syndromes of gastric impaction and dilatation are discussed. Both cases of gastric impaction were successfully treated by gastrotomy and evacuation of the gastric contents.
Clément SF.This article discusses the clinical signs, etiology, management, and prognosis for the neonatal foal afflicted with a convulsive or allied syndrome.
Beech J.This article discusses the history and signalment, clinical signs, differential diagnosis, pathology, etiology and pathogenesis, and treatment and prevention of equine degenerative myeloencephalopathy.
Nyman G, Frostell C, Hedenstierna G, Funkquist B, Kvart C, Blomqvist H.The effect of selective mechanical ventilation of dependent lung regions were studied in anaesthetized horses (mean weight 486 kg) in dorsal recumbency. Blood-gas measurements were performed with the horse in the lateral position during spontaneous breathing (before selective intubation) and in dorsal recumbency during spontaneous breathing, general mechanical ventilation, and spontaneous breathing + selective mechanical ventilation. Arterial oxygen tension (PaO2) was 32.3 kPa in the lateral position during spontaneous breathing with a high inspired oxygen fraction (FlO2 greater than 92%). In ...
Blythe LL.Methodology for the neurologic examination in the equine species is described. Information is organized to assist the reader in defining neurologic deficits and in localizing lesions to the major subdivisions within the central or peripheral nervous system. Numerous examples of deficits are presented to assist the reader in recognition of common neurologic disease states.
Skalka B.The occurrence of equi-factor antibodies in sera of mares and their foals was studied on two horse breeding farms, one of which (Farm A) had a positive and the other (farm B) a negative history of R. equi infection of foals. The equi-factor neutralization (EFN) and the reverse Elek-Ouchterlony (REO) precipitation were used as assays. On Farm A, 25 mares positive in both tests (EFN+ REO+) and 25 mares negative in both tests (EFN- REO-) was chosen. On Farm B, a group of 25 EFN- REO+ mares and a group of 25 EFN- REO- mares were studied. The first serum samplings in mares were 1 week ante partum a...
Woolcock JB, Mutimer MD, Bowles PM.Normal horses of all ages regularly show evidence of having responded immunologically to R. equi, thus adding serological support to epidemiological evidence that this organism is a normal intestinal inhabitant. More animals from "diseased" farms show a stronger antibody response when compared with foals from "healthy" farms. Various serological tests have been used to detect evidence of infection and to relate antibody level to severity of disease. Anti-R. equi IgG antibody levels, as measured by ELISA, are raised significantly during natural infection. Clinical severity of pneumonia can be c...
Barragry TB.The avermectins were introduced in 1981 and constitute a potent new class of anthelmintic agents. They are naturally-derived products of microbial action displaying an exceptionally wide range of antiparasitic efficacy against internal and external parasites of domestic animals. This paper reviews their isolation and chemistry, mechanism of action, chemical efficacy and safety in cattle, sheep, swine, horses and dogs.
Watrous BJ.Head tilt in the horse is commonly a sign of either central or peripheral vestibular disease. The confirmation of vestibular disease is based on physical findings, including results of cranial-nerve function evaluation and observation of stance, posture, and gait. Further localization is made by ancillary tests such as cerebral spinal fluid analysis, electrodiagnostic testing, and radiography. The normal anatomy and physiology of the vestibular system, the abnormal clinical signs demonstrated during physical examination, and the various etiologies are discussed.
Richardson DW, Nunamaker DM, Sigafoos RD.Arthrodesis of the metacarpophalangeal joint was attempted in 9 adult horses, using a new external skeletal fixation device and autogenous cancellous bone graft. Four horses had excellent results, 2 horses had fair results, arthrodesis failed in 2 horses, and 1 horse fractured the third metacarpal bone. The advantages of the technique included minimal surgical trauma to the area of injury, immediate rigid fixation of the metacarpophalangeal joint, and access for treatment of soft-tissue lesions at the site of injury. Although pin loosening and pin-track infection were complications when the de...
Stewart RH, Griffiths JP.In spinal cord disease of horses, a complete history, neurologic examination, and adjunctive diagnostic procedures are very helpful in establishing a tentative diagnosis; however, a definitive diagnosis may be difficult or impossible to establish antemortem. Medical management should be initiated with full consideration of possible etiologies and knowledge of the effects and consequences of medical therapies. This article discusses the drugs commonly used in the management of spinal cord disease and the rationale for their use.
MacLachlan NJ.The histologic appearance of the ovaries and persistence of corpora lutea vary considerably among domestic animals, particularly between spontaneous and induced ovulators. The seasonally polyestrous mare has a variety of unique characteristics in ovarian structure and general reproductive function. Among the anomalies of ovarian development is the bovine freemartin with gonads containing a mixture of male and female elements. A variety of ovarian cysts occur in domestic animals, and persistent corpora lutea with associated reproductive perturbations occur in several species. Ovarian tumors are...
King WA, Bezard J, Bousquet D, Palmer E, Betteridge KJ.Confusion exists as to whether the oocytes of the domestic horse are ovulated at the first meiotic metaphase (MI) or the second (MII). In this study eight oocytes were collected from the preovulatory follicles of 16 mares 36 h after human chorionic gonadotropin CG treatment. Six of the eight oocytes were judged to be at MII by the presence of the first polar body and this judgement was confirmed by semithin sectioning in one. Of the two that had no polar body, one was found to be at MII after fixation for chromosomal analysis and the meiotic stage of the other remained undetermined. Since all ...
Morris DD, Bruce J, Gaulin G, Whitlock RH.Granulocyte transfusions (GT), 0.98 X 10(9) neutrophils/kg of body weight, were performed on 7 healthy pony foals between 2 and 7 days old. The mean neutrophil count of the foals was significantly (P less than 0.05) greater than base line (4,830 +/- 1,260/microliter) 1 hour after GT (8,870 +/- 3,350/microliter) and was similar to base line by 15 to 18 hours after GT (6,550 +/- 2,310/microliter). Leukocyte concentrates (LC) used for GT were harvested from clinically normal adult horses by continuous-flow centrifugation leukapheresis (CL), 3 to 6 hours after hydrocortisone sodium succinate was a...
Martens RJ, Martens JG, Renshaw HW, Hietala SK.The opsonic capacity of serum containing R. equi-specific antibody was compared with antibody-deficient sera using luminol-dependent chemilumenscence (LDCL) and bactericidal assays. These assays incorporated peripheral blood polymorphonuclear neutrophilic leukocytes (PMNL) exposed to R. equi opsonized with neonatal equine pre-colostral serum (control) or serum from foals with R. equi infections (principal). All sera were complement inactivated at 56 degrees C for 30 min. Bacteria were obtained from the lung of a foal with R. equi pneumonia. Neutrophils were obtained from one adult horse for LD...
Harland MM, Fedele C, Berens v Rautenfeld D.Horses are highly susceptible to lymphedema. Knowledge of the morphological components of lymphatic collectors is therefore essential to understanding the function of the lymphatic system. A better knowledge of the lymphatic system allows the development of more effective treatments against lymphedema. The composition of hypodermal and deep lymphatic collectors was investigated with immunohistochemical staining, using antibodies against proteins of the collector walls from the skin in the hind limbs of 10 healthy horses. Lymphatic collectors can be subdivided into passive (elastic fibers) and ...
Prado TM, Schumacher J, Kelly GM, Henry RW.The urethral fold of 30 mares was split transversely into dorsal and ventral shelves, and the ventral shelf was used to help create a urethral extension. The dorsal shelf was stretched caudally and sutured to the roof of the extension so that it covered at least the cranial half of the extension. For 20 mares, a relaxing, vaginal incision was created cranial to the external urethral orifice to enable the dorsal shelf to be retracted further caudally. Ten of the 30 mares (33.3 per cent) developed a defect, but none developed a defect in that portion covered by the dorsal shelf of the urethral f...
Gideon L.Esophageal anastomosis was performed on 2 foals after resecting a midcervical stricture. Nasogastric tube alimentation and antibiotic therapy allowed these foals to recover, and they matured to useful performing horses. These cases demonstrated a feasible and successful surgical management regimen for the strictured esophagus.
Rannamäe E, Andrianov V, Järv E, Semjonov A, Haak A, Kreem J.The remains of a horse's hind foot - a third metatarsal bone and three phalanges - were found in a presumed waste pit of a prosperous medieval household in Viljandi, Estonia, dated from the second half of the 13th to the beginning of the 15th century. The metatarsal bone had been broken during the horse's lifetime and showed evidence of partial healing. Using archaeological, zooarchaeological, morphological, microscopic, densitometric and radiographic analyses, we investigated the bones and the healing process in order to understand animal treatment in a medieval urban context. Our results sho...
van Proosdij R, Mulder C, Reijm M, Bontkes H, von Blomberg M, van der Kolk H.It has been suggested that gluten may play a role in equine inflammatory small bowel disease (ISBD). Previous work showed an association between equine gluten-sensitive enteropathy and IgA antibodies to tissue transglutaminase (TGA) in serum. The purpose of this study is to investigate the prevalence of IgA antibodies to TGA in a group of healthy non-gluten-free sport ponies and to present a case of tentative gluten-sensitive enteropathy and dermatitis in a horse. Blood samples were obtained from 40 healthy jumping ponies. The ponies comprised 12 mares, 8 stallions, and 20 geldings with an ave...
Moorman GH, van Noort JH, Németh F, Breukink HJ, Gootjes P, Verzijlenberg F.A method for detection of neurectomy by electrical stimulation of the skin, distal to the neurectomy site, was tested for accuracy and feasibility. An electrical stimulation device was designed and tested to find the minimum peak voltage that would elicit a response in normal horses. Twenty seven horses were then tested at regular intervals following neurectomy and their responses recorded. Immediately following neurectomy there was an area of insensitivity with sharply defined borders extending in an arc from the back of the pastern down towards the bulbs of the heels. In the months following...
Vanderstraeten E, Bogaert L, Bravo IG, Martens A.Squamous cell carcinoma (SCC) represents the most common malignant tumour of the eye and external genitals in horses. Comparable to humans, papillomaviruses (PV) have been proposed as etiological agents of cancer in horses and recently, Equine papillomavirus type 2 (EcPV2) has been identified in genital SCCs. Hitherto it had never been demonstrated in ocular SCCs. The first goal of this study was to determine the prevalence of EcPV2 DNA in tissue samples from equine genital and ocular SCCs, genital papillomas and penile intraepithelial neoplasia (PIN) lesions, using EcPV2-specific PCR. The sec...
Suagee-Bedore JK, Hebrock S, Sundin O, Lengi AJ, Corl BA, Worth M.LinPro™ (LP) is a commercial dietary supplement marketed to increase hoof growth and quality. Ten mature (5-15 years) non-pregnant Quarter Horse mares without existing hoof quality issues were used to test the hypothesis that 32 weeks of daily supplementation with 113 g of LP would increase hoof growth rates as compared to non-supplemented controls. Hooves were trimmed at the start of the study and every 8 weeks thereafter. A mark was applied on the hoof wall surface at 2.5 cm below the junction of the hoof wall and coronary band. At each trimming, the distance between the mark and coronary ...
Dart AJ, Snyder JR, Julian D, Hinds DM.The microvascular circulation of the cecum was studied in 15 adult horses, using microangiography and light microscopy combined with gross studies and scanning electron microscopy of vascular replicas. After heparinization, the horses were euthanatized and the cecum was transected at the cecocolic junction. Blood was flushed free of the circulation with isotonic NaCl and the cecal lumen was slightly distended. In 6 horses, the vascular system was injected with a modified radiopaque medium and evaluated radiographically. Sections evaluated radiographically were also prepared for histologic exam...
Cazalet E.The paper examines the responsibilities of the veterinary surgeon in relation to the advances more recently made in the field of equine cardiology. Notwithstanding such advances it is stated that the normal established legal principles apply, in particular in relation to the preparation of certificates, namely that the veterinary surgeon must be sufficiently expert to give the opinion sought, that he must make himself fully aware of the purpose for which the certificate is required and that he must make clear the nature and limitations of any examination carried out.
Williamson JA, Dascanio JJ, Christmann U, Johnson JW, Rohleder B, Titus L.Simulation in veterinary education offers a solution for bridging the gap between observation and performance of clinical skills. An equine neck model was created that allows repetitive practice of jugular phlebotomy, intramuscular (IM) injection, and intravenous catheterization. The aim of this study was to validate the model for jugular phlebotomy and IM injection. We surveyed experienced veterinarians on the model's realism and the comprehensiveness of its features. In a randomized experimental study, we compared the learning outcomes of first-year veterinary students trained on the model (...
Gross TL, LeBlanc MM.The effect of seasonal morphologic variation of equine endometrium on histologic interpretation of periglandular fibrosis was investigated in 5 mares. Endometrial tissue was procured monthly and examined microscopically for the degree of periglandular fibrosis. A prognostic category for each mare was based on the mean number of fibrotic foci per linear field of 5.5 mm. It was found that seasonal changes reflected in endometrial glands and stroma influenced quantitative assessment of fibrosis. This occasionally resulted in a change in the assigned prognostic category. Marked nonseasonal variati...
del Junco CI, Mair TS, Powell SE, Milner PI, Font AF, Schwarz T, Weaver MP.The magnetic resonance (MR) imaging features, signalment, clinical history and outcome of 55 horses with a penetrating sole injury were evaluated. Our aim was to describe MR imaging findings within the hoof capsule, assess the utility of the technique and give recommendations for the optimal MR imaging protocol to evaluate such injuries. Data from five equine hospitals were analyzed retrospectively. The tract was more likely to be visualized in animals scanned within the first week postinjury. There was no significant predisposition based on breed, age, or gender. T2*W transverse sequences wer...