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.
Dennis VA, Klei TR, Miller MA, Chapman MR, McClure JR.Ten helminth-free pony foals divided into three groups were used in this study. Eight foals were each experimentally infected per os with 50 Strongylus vulgaris infective larvae weekly for 4 weeks, at which time one foal died of acute verminous arteritis. The remaining seven foals subsequently received 50 S. vulgaris infective larvae every 2 weeks for an additional 20 weeks. Four of the infected foals remained untreated (Group 1) and three of the infected foals were given ivermectin at 8, 16 and 24 weeks post initial infection (Group 2). Two foals served as controls (Group 3). Foals in Group 1...
Weber JA, Woods GL.This article reviews the capabilities of transrectal ultrasonography for determining the distribution of fluid and tissue within stallion accessory sex glands. Emphasis is placed on describing the normal ultrasonographic appearance of the accessory sex glands, excurrent ducts, and pelvic urethra of stallions during rest, after teasing, and after ejaculation and using this information to detect glandular abnormalities.
McDonnell SM.This article includes a brief description of the reproductive patterns and specific behaviors comprising courtship and copulation in equids. The author then focuses on breeding behavior of the domestic stallion. Descriptions of normal breeding behavior under a variety of domestic management systems, comments on sexual behavior of donkeys and exotic equids, and the most common types and treatments of sexual behavior dysfunction are included.
Legrottaglie R, Agrimi P.Electrophoretic analysis in polyacrylamide gel (PAGE) of the equine rotavirus 106/88/LI/EQ, isolated from the diarrhea of an 18 day old foal was compared to the bovine strain NCDV. There was a notable difference in the migration of some segments of the viral RNA. Bands 2 and 3 of the equine rotavirus comigrated while there was a clear separation of segments 7, 8 and 9. Moreover, the migration of segments 1, 4 and 5 revealed a lower molecular weight than the corresponding segments of NCDV.
Divers TJ, Timoney JF, Lewis RM, Smith CA.A 12-year-old thoroughbred gelding died from diffuse global glomerulonephritis, 3 months after a lower respiratory infection from which Streptococcus zooepidemicus was isolated. Immunopathological studies (immunofluorescence, immunodiffusion, immunoperoxidase testing and immunoblotting) indicated the presence of an immune reactant renal disease associated with IgG antibody and streptococcal antigens.
Hurtgen JP.The breeding soundness evaluation of a stallion is a thorough investigation of a stallion's libido, mating ability, and semen quality. The evaluation should include historical data about the medical aspects of the horse's performance and breeding career, observations and breeding behavior characteristics, collection and evaluation of semen, tests to determine freedom from infectious or contagious disease, and production of foals free of genetic defects. This information should allow the examiner to anticipate the impact of the stallion on the reproductive efficiency of a group of mares. The br...
Love CC.Ultrasonographic examination of the testis, epididymis, and spermatic cord of the stallion can be used to enhance the routine breeding soundness evaluation of the stallion. Normal ultrasonographic anatomy of the testes and associated structures are presented to aid the clinician in differentiating abnormalities of these structures.
Willoughby R, Ecker G, McKee S, Riddolls L, Vernaillen C, Dubovi E, Lein D, Mahony JB, Chernesky M, Nagy E.The response of horses exposed to three common respiratory viruses was studied by measuring tracheal mucociliary clearance rates in the trachea. Tracheal clearance rates (TCR) were determined before, during illness and following recovery in horses exposed to equine rhinovirus (ERhV-2), equine influenza virus (EIV) and equine herpesvirus (EHV-4) by means of lateral scintigraphs made following an injection of technetium-99m sulphide colloid into the tracheal lumen. In six horses exposed to ERhV-2, TCR remained within normal limits. Exposure to EIV resulted in reduced TCR in six of seven horses, ...
Staempfli HR, Prescott JF, Brash ML.Four groups of two ponies, free of fecal Salmonella and Clostridium cadaveris, were treated as follows: Group A, control group; B, single nasogastrically administered dose of lincomycin (25 mg/kg) followed 48 h later by 3 L of C. cadaveris (10(9) organisms/mL); C, the same dose of lincomycin as group B; D, the same dose of C. cadaveris as group B on each of three occasions at 12 h intervals. Groups A and D remained healthy, but groups B and C developed severe colitis 48-56 h (B) or 72 h (C) after administration of lincomycin. Three ponies were euthanized and one in group B died. Clostridium ca...
Vandenbossche GM, Bouckaert S, De Muynck C, Mommens G, Van Zeveren A, Remon JP.The bioavailability and pharmacokinetics of ibuprofen, a nonsteroidal antiinflammatory drug, was studied in healthy Shetland ponies. Ibuprofen was administered IV, as a suspension, and as a solid solution oral paste to ponies from which food was withheld. The suspension paste was also administered to ponies that received hay and water ad libitum. Both formulations had an absolute bioavailability of about 80%. Bioavailability was not influenced by feeding.
Gunn HM, Fraher JP.The incidence of sarcocysts was examined in postural, propulsive and respiratory muscles from 74 horses ranging in age from mid-gestation to 14 years post-natal. Cryostat sections were stained for myosin adenosine triphosphatase (ATPase) at pH 9.5 and the type of muscle fibre containing sarcocysts was identified. Sarcocysts were found in muscles from three animals, all aged 1 year or more. Counts showed that they displayed no preference for any particular muscle. However, fibres with a high activity for myosin ATPase were preferentially colonized. Transverse sectional profiles of sarcocysts sh...
Golenz MR, Knight DA, Yvorchuk-St Jean KE.Nasogastric infusion of a human enteral feeding preparation was effective in reversing hyperlipemia in an anorectic miniature horse with an esophageal laceration. The nutrient preparation was delivered every 4 hours by gravity flow through a 12 F enteral feeding tube. Within 48 hours of initiating enteral nutrition, the hyperlipemia had resolved. Signs of intolerance to the preparation were not observed, and further weight loss was prevented. The use of a human enteral formula was a convenient and successful alternative for the treatment of hyperlipemia in the horse.
Dart AJ, Snyder JR, Pascoe JR, Farver TB, Galuppo LD.The signalment, clinical and laboratory findings of surgical conditions, treatment, and outcome of 102 cases of descending colon disease in horses were reviewed. Abnormal conditions were categorized as enteroliths, impactions, strangulating lipomas, fecaliths, foreign body obstruction, volvulus, nephrosplenic entrapment, and other conditions. Eleven breed categories of horses were seen during this period. Arabians, ponies, and American miniature horses were more predisposed to descending colon disease than other breeds (P less than 0.05). Female horses and animals greater than 15 years old wer...
Stick JA, Arden WA, Robinson RA, Shobe EM, Roth RA.Effects of 1 hour of colonic volvulus and 3 hours of reperfusion on concentrations of thromboxane (TXB2) and prostacyclin (6-keto-PGF1 alpha) in portal, pulmonary arterial, and jugular blood were determined by radioimmunoassay to assess the site of production and clearance of these eicosanoids from the circulation in 5 anesthetized ponies. Colonic volvulus had no significant effect on mean arterial pressure or TXB2 concentrations, but significantly (P less than 0.05) increased 6-keto-PGF1 alpha concentrations in all blood samples. Immediately after colonic reperfusion, all eicosanoid concentra...
Jasko DJ.This article outlines a basic method for conducting a stallion semen evaluation. After the removal of the gel fraction of the ejaculate, semen gel-free volume is determined, and any abnormality in appearance is noted. Concentration of sperm cells in semen can be determined with the use of either a hemacytometer or spectrophotometer after appropriate dilution of raw semen. The percentage of progressively motile sperm is evaluated promptly after collection of semen with the use of a phase-contrast microscope. The total numbers of sperm and progressively motile sperm in the ejaculate are calculat...
Binhazim AA, Harmon BG, Roberson EL, Boerner M.During routine necropsy of a 28-year-old horse with intestinal volvulus, numerous hydatid cysts were discovered in the liver. Viable protoscolices of Echinococcus granulosus were obtained from the cyst. As a 4-year-old, this horse had been imported from an area that is enzootic for equine hydatidosis.
Chuma T, Le Blois H, Sánchez-Vizcaíno JM, Diaz-Laviada M, Roy P.The major core protein, VP7, of African horsesickness virus serotype 4 (AHSV-4), the aetiological agent of a recent outbreak of the disease in southern Europe, was expressed in insect cells infected with a recombinant baculovirus containing a cloned copy of the relevant AHSV gene (S7). Analyses of its biochemical and antigenic properties confirmed the authenticity of the protein expressed. The high-level expression of VP7 under the control of the strong polyhedrin promoter of Autographa californica nuclear polyhedrosis virus induced disc-shaped crystals in infected insect cells. This enabled u...
Hormanski CE, Truax R, Pourciau SS, Folsom RW, Horohov DW.The in vitro stimulation of peripheral blood mononuclear cells (PBMC) with interleukin 2 (IL-2) results in the development of potent cytotoxic effector cells, referred to as lymphokine-activated killer (LAK) cells. LAK cells are capable of lysing a wide variety of autologous, allogeneic and xenogeneic tumor cells. The exact mechanism of target cell recognition by LAK cells remains unknown. LAK cell activity has been reported for a variety of domesticated species except the horse. We report here that IL-2-stimulated equine PBMC, which fail to lyse either human or murine tumor cell lines, exhibi...
Douglas RH, Umphenour N.Routine measurement of estrogens, testosterone, T4, insulin, FSH, and LH at least four times per year (e.g., during each of the four seasons) may improve the efficiency of stallion management. Benefits may not be realized in the short term but will provide valuable historical data on individual stallions that, when added to other data, will improve ability of management personnel to initiate early treatment and delay or slow declining fertility. This ability will be greatly improved as more data and products become available. There appears to be a relationship between low total estrogen concen...
Morris DD, Crowe N, Moore JN.The purpose of this study was to determine if a structurally novel dual inhibitor of arachidonic acid metabolism, SK & F 86002, would inhibit the endotoxin-induced production of tumor necrosis factor (TNF) activity by equine peritoneal macrophages. Equine peritoneal macrophages were variously pretreated for 0, 0.5 and 2 h with SK & F 86002 at 10(-9) to 10(-4) molar final concentrations or were left untreated. Then, the macrophages were cultured in vitro in the presence of endotoxin (5 ng/mL). Supernatant media were collected after 4 h and stored at -70 degrees C until assayed for TNF a...
Quirk KS.There are myriad problems that can arise when training the novice stallion for natural service. Many problems can be avoided by proper early training of the novice stallion. In the final analysis, common sense should prevail. The major ally of common sense is patience. One should keep in mind that the goal is to have a stallion behave in a disciplined manner, allowing for his expression of libido and effective mounting, intromission, and ejaculation. This is accomplished through judicious training and, as with any training process, takes some time and work. Proper training will help circumvent...
Conboy HS.Although the act of breeding is instinctive to the stallion, the use of a phantom mare and AV represent an unnatural element to this act. The use of these devices, as well as proper breeding manners and etiquette, must be taught to the stallion. The novice stallion usually learns these techniques rapidly and is quite manageable if proper restraint is used during training. Positive reinforcement for good behavior is essential. The ultimate goal in training the novice stallion is to develop an individual that will enter the breeding area with controlled enthusiasm, develop an erection and gracef...
Hoffman AM, Baird JD, Kloeze HJ, Rosendal S, Bell M.Mycoplasma felis was identified as the cause of acute pleuritis in 2 show-jumping horses. The pleural exudate was proteinaceous, contained large numbers of neutrophils, and had a markedly increased lactate concentration. M. felis was isolated in pure culture from pleural fluid. Rising serum antibody titers to M. felis as well as a precipitous decline in titers to equine influenza virus were demonstrated in both horses. Pleural effusion in both horses and a pneumothorax detected in one of the horses resolved following a single drainage of pleural fluid and intravenous fluid, antibiotic, and ana...
Baggot JD.Veterinary and human pharmacology differ principally in the range of species in which drugs are used and studied. In animals, as in humans, an understanding of the dose-effect relationship can be obtained by linking pharmacokinetic behaviour with pharmacodynamic information. Studies of different classes of drugs support the assumption that the range of therapeutic plasma concentrations in animals is generally the same as in humans. The requirement for species differences in dosage or administration rate (dose/dosage interval) may be attributed to variations in pharmacokinetic behaviour or phar...
Love CC.Semen collection techniques in the stallion have evolved considerably over the last 70 to 80 years and are used today primarily for artificial insemination. Semen can be collected from stallions that are otherwise unable to breed, allowing continued use of valuable animals. There are many options for collection of semen from stallions that present with ejaculatory dysfunction (see the article by McDonnell elsewhere in this issue.) Although there are many advantages to the use of artificial breeding, the collector must understand each step of the collection procedure as well as stallion prefere...
Stewart DR, Addiego LA, Pascoe DR, Haluska GJ, Pashen R.Equine relaxin has been previously determined in a small number of pregnant Thoroughbred mares. To better define the normal pregnancy pattern of relaxin, the current study reports on a much larger number of mares. It also was designed to determine if all equids have the same gestational pattern of relaxin secretion. Plasma samples were collected weekly in 24 Standardbred mares, every 7-10 days in 10 pony mares, and daily in late pregnancy from 16 burros. Standardbreds had higher concentrations of relaxin than that reported for Thoroughbreds during most of gestation and did not exhibit the midp...
McDonnell SM.In summary, important events of ejaculation include emission of sperm and the accessory gland fluids into the urethra, simultaneous closure of the bladder neck, and forceful ejaculation of the combined semen through the urethra. Emission and bladder neck closure are primarily alpha-adrenergically mediated thoracolumbar sympathetic reflex events with supraspinal modulation. Ejaculation is a sacralspinal reflex mediated by the pudendal nerve. In stallions, the most common ejaculation disorders are emission and ejaculation failure, and urine contamination of semen. Rare disorders are azoospermia ...
Plata-Madrid H, Loch WE, Youngquist RS, Thompson DL, Bennett-Wimbush KG, Wilkerson C, Bouchard G, Smith MF, Braun WF, Aveiro JJ.Twenty-two pony mares were used in a project designed to determine the effectiveness of different treatments in controlling FSH, follicular development and synchronization of estrus and ovulation. Mares in Group 1 (n=8) received daily oral altrenogest (0.044 mg/kg); those in Group 2 (n=7) received daily altrenogest (0.044 g/kg) and, during the last 4 days of treatment they received steroid-free follicular fluid, (15 cc) intravenously (I.V.) two times a day; Mares in Group 3 (n=7) received daily intramuscular (I.M.) injections of progesterone (80 mg) and estradiol valerate (7 mg). All treatment...
Nielsen SS, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ.... () was identified among the most relevant antimicrobial-resistant (AMR) bacteria in the EU for cattle and horses in previous scientific opinions. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9, and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome...
Dorman D.The central nervous system's extrapyramidal system provides involuntary motor control to the muscles of the head, neck, and limbs. Toxicants that affect the extrapyramidal system are generally clinically characterized by impaired motor control, which is usually the result of basal ganglionic dysfunction. A variety of extrapyramidal syndromes are recognized in humans and include Parkinson's disease, secondary parkinsonism, other degenerative diseases of the basal ganglia, and clinical syndromes that result in dystonia, dyskinesia, essential tremor, and other forms of tremor and chorea. This cha...
Kearns CF, McKeever KH, Malinowski K.Adipose tissue plays complex role(s) in metabolic and endocrine control. To date, little work has been done in the horse regarding adipocytokines. Objective: This study was conducted to determine whether therapeutic levels of chronic beta-agonist administration, exercise, or both could alter their concentrations. Methods: A total of 23 standard-bred mares were divided into four experimental groups: clenbuterol (2.4 microg.kg(-1) bw twice daily for 8 wk) plus exercise (8 wk, 20 min.d(-1) at 50% VO2max; CLENEX; N = 6), clenbuterol only (CLEN; N = 6), exercise only (EX; N = 5), and control (CON; ...
Cockerell GL, MacCoy DM.This report provides a general overview of the pathobiology of neoplasia, and an update on the clinicopathological manifestations of lymphosarcoma, mastocytoma, histiocytoma, melanoma, sarcoid and circumanal gland tumors in domestic animals. Neoplasia represents a continuum of events from reversible hyperplasia to irreversible and pathological changes in tissue growth patterns. In some instances the causes of this disease process have been identified, but the etiology of the majority of naturally occurring neoplasms remain unknown. Surgical excision is the preferred treatment for tumors, but i...
Naidoo V, Gehring R.An overview of reports of suspected adverse drug reactions received by the Veterinary Pharmacovigilance and Medicines Information Centre during the period March 2001 to February 2002 is given. A total of 77 reports were received. The majority of reports involved suspected adverse reactions that occurred in dogs and cats. Most products implicated in the reports were Stock Remedies. The products were predominantly administered either by veterinarians or trained paraveterinary professionals. Although the majority of reports were received from veterinary pharmaceutical companies, the proportion of...
Grandy JL, Hodgson DS, Dunlop CI, Chapman PL, Heath RB.The cardiopulmonary effects of intravenous (i.v.) administration of the sympathomimetic drug ephedrine during two different levels of halothane anesthesia [end-tidal concentration of 1.37% (light anesthesia) and 2.1% (deep anesthesia)] were studied in eight horses. Anesthesia was induced and maintained using only halothane in O2. Ventilation was controlled to maintain a Paco2 of 38-42 mmHg. Following instrumentation and stabilization of the horse at the halothane concentration being studied, baseline measurements of cardiac output (Q), arterial blood pressure (AP), pulmonary artery pressure, h...
Mehdizadeh Gohari I, Boerlin P, Prescott JF.NetF-producing type A Clostridium perfringens, a pathotype of C. perfringens, causes necrotizing enteritis in neonatal foals and necrotizing and hemorrhagic enteritis in dogs. Recent core genome multilocus sequence typing study revealed that netF+ C. perfringens strains belong to two distinct clonal populations (clonal complexes I and II). There are no reports on susceptibility to antimicrobial drugs of isolates from this pathotype. The susceptibility to 13 different antimicrobial drugs of 49 netF+ strains recovered from foals or dogs with necrotizing enteritis in Canada, the United States, an...
Moeller S, Patan-Zugaj B, Däullary T, Tichy A, Licka TF.Laminitis is associated with failure of the suspensory apparatus of the distal phalanx (SADP) connecting the distal phalanx to the hoof wall. The specific aim of this study was to examine in vitro whether thinning of the hoof wall leading to increased deformability influences the damage of the laminar tissue created by loading of the hoof. Paired cadaver forelimbs from twelve horses were used. For each pair, the hoof wall from one hoof was thinned by 25%; this was ascertained by radiography. The contralateral hooves were used as controls. In a material testing machine, hooves were loaded in a ...
Marchant EA, Semevolos SA.The marginal transitional zone is peripherally located within the diarthrodial joint, and represents the interface of articular cartilage, periosteum, and the fibrous joint capsule. The purpose of this study is to characterize the protein expression of matrix and molecular regulators in the marginal transitional zone of foals having osteochondrosis (OC) compared to normal foals. Several families of proteins with known roles in cartilage and bone development are investigated, including matrix molecules, Wnt signaling, apoptotic factors and paracrine cell signaling molecules. Our results demonst...
Lisiecki P, Sobiś-Glinkowska M, Mikucki J.Under iron-restricted conditions staphylococcal strains could utilize in vitro several animals body iron sources in form of bovine haemoglobin, hemin, lactoferrin and transferrin, ovotransferrin, horse myoglobin ferritin and cytochrome C. Spectrum of utilized iron sources was not dependent on species affiliation and kind of siderophores system. Strains isolated from clinical materials utilized largest spectrum of animal iron body sources.
Trotter GW, Aanes WA.During an 8-month period, 3 horses were examined because of incomplete cryptorchid castration. Each horse had had surgery to remove 1 retained testis. In each case, the attending veterinarian believed castration had been adequately completed. History, rectal examination findings, and in 2 cases, high serum testosterone concentration were factors that led to the decision to do exploratory surgery on each horse. In each case, initial surgery had resulted in surgical removal of the tail of the epididymis, which was mistaken for testicular tissue.
Gupta AK, Singh BK, Yadav MP.Fifty aborted foetus samples were diagnosed for the presence of equine herpes virus-1 (EHV-1) by polymerase chain reaction (PCR) technique. Specific primer pair for amplification of a particular segment of EHV-1 DNA in gc region having 3 Hae III restriction endonuclease sites was used. A 409 base pair segment obtained as PCR amplification product in 9 samples was digested with Hae III to confirm the presence of EHV-1 as the infectious agent in aborted tissues. It was observed that PCR technique was more sensitive, specific and rapid than the conventional virological diagnostic methods.
Ogawa Y, Kanno M, Shimizu Y, Suzuki M, Yoshimoto T.A 56-year-old man presented with an unusual cranial penetration injury due to a horse's hoof. The CT number of the hoof was 269, and thus clearly not that of a wooden fragment or bone. An emergency operation was performed to remove the foreign body. The operation went well, and no infection developed. Eight months later he could walk unaided and had only mild disorientation.
Reck C, Menin Á, Batista F, Meira Santos PO, Miletti LC.Surra is an infectious disease caused by , which affects a large number of domestic and wild animal species. Infection control is based on rapid diagnosis followed by treatment of sick animals. This study aimed to evaluate a buffered antigen and rapid serum agglutination test (BA/Te) for the detection of anti- antibodies in serum samples of horses. For this purpose, 445 serum samples from horses were evaluated and the results compared with the diagnosis by CATT/. Our data show a sensitivity of 92%, specificity of 91% and a degree of agreement kappa () of 0.82 (95% CI: 0.771-0.877, < 0...
Waelchli RO, Ehrensperger F.Hydrops allantois was diagnosed in two Haflinger mares with severe abdominal distension. Both mares were seven months pregnant. Abortion was induced with two injections of prostaglandin six hours apart followed by further manual dilation of the cervix and administration of oxytocin the next day. There were 90 and 95 litres of fluid, respectively, in the allantoic cavities which resembled extracellular fluid with regard to concentrations of urea, creatinine, sodium, potassium, calcium, magnesium, phosphate and chloride, but not total protein. Both fetuses had severe brain abnormalities which we...
Xu Y, Zhang X, Peng P, Liu Y, Yu M, Xie L.Equine copivirus (EqCoPV) is a newly discovered parvovirus that infects equines. Currently, it is unclear whether this virus is prevalent in China. In the present study, serum samples were collected from equines in China and were processed for EqCoPV DNA detection by PCR. The results demonstrated that EqCoPV was circulating among the sampled equines, with a low detection rate of 0.94%. The genome sequence of one Chinese EqCoPV strain, UH26, was determined and used for genetic and phylogenetic analysis. The results demonstrated that UH26 has a close genetic relationship to EqCoPV strains from t...