Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Squires EL.Twinning is a major cause of abortion in mares. Although early management of twins is quite successful, twins that remain after 40 days are difficult to manage. This article reviews the current knowledge of the use of transvaginal ultrasound probe for elimination of twins. Several techniques are presented, as well as discussion on the best time during gestation for this technique to be used.
Buonomo FC, Ruffin DS, Brendemeuhl JP, Veenhuizen JJ, Sartin JL.Effects of exogenous pST and bST on metabolic and growth factor variables were examined in three studies with lighthorse mares (455 to 545 kg). In Study 1, eight mares received five s.c. injections of bST or pST (30 mg/d). In Studies 2 and 3, five mares received one s.c. injection of a prolonged release formulation designed to deliver 500 mg of bST (Study 2) or pST (Study 3) over 14 d. Blood samples were collected for several days before injection to establish baseline values, at frequent intervals during treatment, and for several days thereafter. In all studies, blood urea nitrogen concentra...
Asari M, Sasaki K, Miura K, Ichihara N, Nishita T.To elucidate locations of cytosolic carbonic anhydrase isoenzyme (CA-I, CA-II, and CA-III)-positive epithelial cells in equine male reproductive organs. Methods: Descriptive and immunohistochemical study. Methods: 4 clinically normal male horses. Methods: The testis (seminiferous tubules, rete tubules), epididymis (initial, middle, and terminal segments), proximal and distal portions of the ductus deferens, ampulla ductus deferentis, seminal vesicle, prostate, and bulbourethral gland were excised from euthanatized horses after administration of an overdose of pentobarbital. The tissue specimen...
Zierz J, Wintzer HJ.To judge acute processes of pain objectively the results are told of a determination of adrenaline and noradrenaline in the plasma of 30 horses suffering from pain. Besides a scheme basing on an awarding of points is developed to ascertain changes of physiological and ethological parameters caused by pain. These results in changes of behaviour are compared to results determined by laboratory experiments. Concerning pain of medium and high level a relation to the concentration of catecholamines is noticed. Therefore the total of certain clinical observations is suitable for graduating acute pai...
Soma LR, Uboh CE, Rudy JA, Smith MS.To examine, in horses, the disposition and excretion of the active metabolite 6-methoxy-2-naphthylacetic acid (6MNA) of the nonsteroidal anti-inflammatory prodrug nabumetone. Methods: Pharmacokinetic analysis of 6MNA after oral administration of nabumetone and IV administration of 6MNA. Methods: Using a crossover design, 5 horses were orally administered 3.7 mg of nabumetone/kg of body weight. After a 3-week washout period, 4 horses were administered 2.5 mg of 6MNA/kg, IV. Results: Absorption of nabumetone from the gastrointestinal tract and its metabolism to 6MNA had a median appearance half-...
Graham JK.This article describes some of the basic methodology for conducting stallion semen evaluations. Not all of these assays will likely be conducted on every semen sample collected. Routine evaluations should include determination of semen volume, sperm concentration, and an estimation of the percentage of progressively motile sperm, at a minimum. Other assays can be used if a seminal problem is discerned at the beginning of the breeding season or after a stallion has recovered from an illness or injury. Additionally, laboratory assays are particularly important to conduct on cryopreserved spermat...
Merkt H.A stallion got fatal injuries by kicks of a maiden mare because a so called "panic hook" untied spontaneously. The use of such hooks to secure mares during mating should therefore not be recommended.
Squires EL.Equine oocytes obtained either by transvaginal ultrasound-guided follicular aspiration or from slaughterhouse ovaries can be matured in vitro. This generally requires culture in TCM-199 containing serum and hormones for 30 to 36 hours. With this protocol, approximately 50% to 60% of the oocytes are at metaphase-II at the end of the culture period. At least some of these oocytes appear viable based on production of fertilized eggs either through in vitro fertilization or fertilization in vivo of a recipient mare. The success of producing equine embryos in vitro is still extremely low. More than...
Topper MJ, Prasse KW, Morris MJ, Duncan A, Crowe NA.To adapt and characterize a human ELISA kit to quantify thrombin-antithrombin III (TAT) complexes in horses, and to evaluate TAT as a marker for hypercoagulation in horses. Methods: 29 clinically normal horses used as controls, and 4 ill horses used to evaluate assay for known causes of hypercoagulation. Methods: A commercially available human sandwich-type ELISA kit with 2 antibodies against human thrombin and antithrombin III that bind selectively to their corresponding TAT antigenic sites was used. Equine TAT standards were made from purified equine thrombin and antithrombin III. Proteins d...
Alef M, Oechtering G.The continuous fiberoptical measurement of the mixed venous partial oxygen saturation is described. It is an enrichment of the diagnostical possibilities in veterinary medicine. In the horse it is of great interest, because disturbances of the pulmonary gas exchange and the myocardial function are common in the anaesthetised horse, and reliable methods of assessing the cardiac output are rare. Using this monitoring technique in nearly 100 equine high risk patients facilitated insight into the complex changes of the pulmonary, cardiac and circulatory function in the anaesthetised horse. The reg...
Raudsepp T, Frönicke L, Scherthan H, Gustavsson I, Chowdhary BP.Human chromosome specific libraries (CSLs) were individually applied to equine metaphase chromosomes using the fluorescence in situ hybridization (FISH) technique. All CSLs, except Y, showed painting signals on one or several horse chromosomes. In total 43 conserved chromosomal segments were painted. Homoeology could not, however, be detected for some segments of the equine genome. This is most likely related to the very weak signals displayed by some libraries, rather than to the absence of similarity with the human genome. In spite of divergence from the human genome, dated 70-80 million yea...
Otte K, Rozell B, Gessbo A, Engström W.A cDNA for equine insulin-like growth factor I (IGF I) has been isolated by reverse transcriptase-polymerase chain reaction and subsequently sequenced. The sequenced fragment contained 465 bp including the coding regions for the signal peptide, the entire mature protein, and 4 amino acids into the E-peptide. Like its human counterpart, the mature equine IGF I peptide contains 70 amino acids and was 100% homologous between horse and man. The 49-amino-acid signal peptide had the threonine in position 26 of the human signal peptide substituted by isoleucine. The nucleotide homology across the ent...
Wada R, Fukunaga Y, Kanemaru T, Kondo T.Five pregnant mares, at between 6 and 8 months gestation, were experimentally infected with the Bucyrus strain of equine arteritis virus (EAV). Of the five mares, four aborted and one died. The pathogenesis of the abortions was studied, using histopathologic techniques, tissue immunofluorescence and virus isolation. Common microscopic lesions in the maternal reproductive organs indicated myometritis with a degeneration of the myocytes and an infiltration of the mononuclear cells. Epithelial cells of the endometrial gland showed sporadic degeneration. Lesions in the fetal tissue included an atr...
Riddolls LJ, Byford GG, McKee SL.The biological and imaging characteristics of technetium-99m imidodiphosphate (Tc99m-IDP) were measured in 4 horses once and in 1 horse twice. All computational results are expressed with 95.5% (mean +/- 2 SD) confidence limits. The clearance half-time of the radiopharmaceutical from the blood was 29.6 +/- 2.3 min. The percentage of the administered dose circulating in the whole-blood volume at 4 h was 3.9 +/- 0.8%. The Tc99m-IDP radioactivity confined at the plasma fraction of the whole blood at 4 h was 85.3 +/- 1.6%. At 8 h, approximately 45 +/- 16% of the dose administered had been excreted...
Patterson JS, Maes RK, Mullaney TP, Benson CL.An immunohistochemical (IHC) assay was developed for the detection of eastern equine encephalomyelitis (EEE) virus antigen in formalin-fixed, paraffin-embedded tissues. All cases of EEE diagnosed at the Michigan State University Animal Health Diagnostic Laboratory from 1991 through 1994 were evaluated. The diagnosis was based on histopathologic examination of the brain and confirmatory virus, isolation. Sections of cerebrum from 26 equids and 5 birds were assessed by IHC. Histologically normal brain tissues from 2 horses and 1 pheasant and brain tissues from 2 cases of equine neurologic diseas...
Daly JM, Lai AC, Binns MM, Chambers TM, Barrandeguy M, Mumford JA.Evolution of equine influenza a H3N8 viruses was examined by antigenic and genetic analysis of a collection isolates from around the world. It was noted that antigenic and genetic variants of equine H3N8 viruses cocirculate, and in particular that variants currently circulating in Europe and the USA are distinguishable from one another both in terms of antigenic reactivity and genetic structure of the HA1 portion of the haemagglutinin (HA) molecule. Whilst the divergent evolution of American and European isolates may be due to geographical isolation of the two gene pools, some mixing is believ...
Muylle S, Simoens P, Lauwers H.It is generally considered that the age of a horse can be determined by examining its incisor teeth. However, the criteria used to determine age from dental configurations differ widely. The existence of this variety of rules and guidelines was the challenge for the present examination. Detailed descriptions of the incisor teeth of 212 horses of registered age were recorded and the results were compared with the age criteria of various authors. The time at which teeth were shed and the appearance of dental stars seemed to be more reliable features than the disappearance of the cups. The disapp...
Boersema JH, Eysker M, Maas J, van der Aar WM.The reappearance of strongyle eggs in faeces after treatment with ivermectin or pyrantel embonate was investigated in 22 foals, 36 yearlings, and 45 adult horses on five Dutch horse farms. The results confirmed earlier studies which showed an egg reappearance period of 9 and 6 weeks after ivermectin and pyrantel treatment, respectively. There were no differences between the egg reappearance periods of foals, yearlings, and adult horses. The mean egg counts of the yearlings were, however, consistently higher than the mean egg counts of the adult horses and foals in both ivermectin- and pyrantel...
Rezai A, Underwood JL, Jalali GR, Mathias S, Allen WR, Mowbray JF.Recurrent spontaneous abortion occurs in 1 in 500 random matings and usually results in abortion of all pregnancies. If absence of antibody to a paternally derived antigen caused abortion, the woman would be expected to make antibody to the other paternal antigen and abort only half her pregnancies. Methods: Microvesicles were prepared from equine placentae. Acid-eluted IgG antibody was eluted from the polymorphic R80K antigen and used to type the residual R80K antigen on vesicles or on peripheral blood leucocytes. Results: In several equine sibships all the half-sibs had the same paternal R80...
Weiss DJ, Richwagen K, Evanson OA.To evaluate the contribution of hematocrit and RBC deformability to pulmonary vascular pressures of racehorses. Methods: Pony lungs were isolated and right and left lungs were perfused separately with blood. The effects of changing hematocrit and of pentoxifylline treatment were evaluated. Methods: 11 healthy mixed-breed ponies. Methods: Ponies were anesthesized, blood was collected, and lungs were removed and perfused with blood at constant flow rate. Results: Increasing the hematocrit from 35% to 65% resulted in increases in pulmonary arterial pressure (53%, 45%), capillary shear stress (45%...
Johnson GC, Miller MA, Floss JL, Turk JR.The histologic and immunochemical characteristics of benign vascular tumors excised from the skin of seven young horses were evaluated. The patients were male horses of various breeds and were 16 months of age or younger at the time of presentation. Six tumors occurred on the extremities, and one was removed from the lip. Histologically, most tumors consisted of cellular nodules of varying compactness with few to many blood-filled lumina. Nodular growth separated preexisting adnexa and subcutaneous collagen. Some tumors contained or consisted predominantly of loosely packed arrays of ramifying...
Roberts H, Lopez M, Hartley M.African swine fever in the Caucasus and Leningrad regions of Russia. Equine infectious anaemia in several EU member states. Foot-and-mouth disease in Bulgaria--the first in an EU member state since 2007. Highly pathogenic avian influenza H5N1 in the Far East. West Nile virus in southern Europe. These are among matters discussed in the international disease monitoring report for October to December 2010, prepared by Defra's Food and Farming Group, Veterinary Science Team.
Zapf AM, Fey K, Büttner K, Gröf M, Staszyk C.Pituitary pars intermedia dysfunction (PPID) and dental disorders are of major concern in horses older than 15 years. Although PPID in geriatric horses and dental disorders in all age groups are well described, a connection between this endocrine disease and pathological changes in equine dental structures has not yet been investigated. In humans, periodontitis is considered to be a complication of systemic diseases like diabetes mellitus type 2, obesity and various conditions leading to an impaired immune response. In PPID, cross links to insulin and immune dysregulations are proven. The aim ...
Manley SV.The objectives of monitoring are to gain much information as possible about the anesthetized horse and to follow changes in that information, with the ultimate aim of making anesthesia and surgery as safe as possible for the horse. Information necessary to achieve that aim will vary depending on patient category. For example, a young, healthy horse undergoing a short elective procedure can be clinically well monitored by patient signs, electrocardiogram, and indirect blood pressure response. More invasive monitoring is justified and warranted if the health status of the horse is in question. T...
King JN, Gerring EL.Characteristic motility patterns were seen throughout the gastrointestinal tract in a pony prepared chronically with electromechanical recording devices after developing a simple obstruction of the small intestine. Gross distension of the stomach with fluid produced loss of gastric contractile activity and a chaotic electrogram. These changes were reversed instantaneously when the stomach was decompressed. In the jejunum, proximal to the obstruction, the unique 'colic motor complex' was observed with contractions of longer duration arranged in characteristic pulses of activity. The left dorsal...
Davis LE.Adverse drug reactions occasionally occur in the horse. The majority can be anticipated and avoided. The practicing veterinarian should understand the various types of adverse reactions as well as their mechanisms so that should such a reaction occur, the practitioner can promptly recognize the problem and institute corrective measures.
Höglund J, Nilsson O, Ljungström BL, Hellander J, Lind EO, Uggla A.The egg output and humoral antibody response to scolex antigens of the equine tapeworm Anoplocephala perfoliata were monitored in naturally infected foals by an egg flotation/centrifugation method and an indirect enzyme-linked immunosorbent assay (ELISA). The study was performed on a stud farm in south-western Sweden between May 1994 and April 1995. Sequential blood and faecal samples were taken from 21 foals during their first summer on pasture and until tapeworm eggs were detected. Results were expressed separately for 10 and 11 foals born before and after the end of April 1994, respectively...
Elitsur E, Marsh AE, Reed SM, Dubey JP, Oglesbee MJ, Murphy JE, Saville WJ.Sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (EPM), a neurologic disease of the horse. In the present work, the kinetics of S. neurona invasion is determined in the equine model. Six ponies were orally inoculated with 250 x 10(6) S. neurona sporocysts via nasogastric intubation and killed on days 1, 2, 3, 5, 7, and 9 postinoculation (PI). At necropsy, tissue samples were examined for S. neurona infection. The parasite was isolated from the mesenteric lymph nodes at 1, 2, and 7 days PI; the liver at 2, 5, and 7 days PI; and the lungs at 5, 7, and 9 days ...
Schulman ML, Bolton LA.A sunflower-based feed supplement grossly contaminated with the seed of a Datura sp. resulted in severe signs of poisoning in 2 horses. One horse died peracutely of acute gastric dilatation and rupture following ingestion of the contaminated feed. The 2nd horse developed unresponsive paralytic ileus that led to euthanasia. Examination of the feed and gastrointestinal contents of both horses showed a high proportion of the characteristic Datura sp. seeds. The clinical signs and pathology in both cases were consistent with intoxication by the parasympatholytic alkaloid components of Datura sp.
Kosiniak K.The use of an 'open' artificial vagina made it possible to separate the individual jets in the ejaculate of the stallion. A total of 132 jets were collected in this way from twenty-one ejaculates. After macro- and microscopic examination and sperm counting, glycerylphosphorylcholine (GPC), ergothioneine and fructose levels were determined for every jet. The values obtained for the first three jets were similar and accounted for about 76% of all spermatozoa, and 70% of GPC. These jets also contained the highest concentration of ergothioneine and fructose.
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.
Tesarowski DB, Viel L, McDonell WN, Newhouse MT.The purpose of the study was to administer therapeutic aerosol generated by metered-dose inhalers to horses exhibiting clinical signs of heaves using a compact inhalation device developed for human medicine. It was fitted to a custom face mask in order to study the effect of an inhaled beta 2-agonist, fenoterol. Pulmonary function testing was performed on six horses following an acute exacerbation of heaves, characterized by tachypnea, wheezes, crackles, and spasmodic cough. Horses inhaled fenoterol in 1 mg increments administered as one 200 microgram puff every 5-10 s with the recording of da...
Maher O, Puchalski SM, Drake C, le Jeune SS.To evaluate the sensitivity and specificity of abdominal computed radiography (CR) for the diagnosis of enterolithiasis in horses and to examine how these parameters are affected by the number and anatomic location of enteroliths and by gas distension of the gastrointestinal tract. Methods: Retrospective case series. Methods: Horses ? 1 year old that underwent abdominal CR and subsequent exploratory laparotomy or postmortem examination. Methods: 3 reviewers blinded to signalment, history, clinical signs, and diagnoses separately evaluated abdominal computed radiographs of horses included in th...
Silvina Fernández A, Henningsen E, Larsen M, Nansen P, Grønvold J, Søndergaard J.An experiment was carried out in 1997 to test the efficacy of an isolate of the microfungus Duddingtonia flagrans against free-living stages of horse strongyles under conditions in the field and to assess the eventual effect of the fungus on the normal degradation of faeces. Faecal pats were made from faeces of a naturally strongyle infected horse, which had been fed fungal material at a dose level of 106 fungal unit/kg bwt. Control pats without fungi were made from faeces collected from the same animal just before being fed fungi. Faecal cultures set up for both groups of faeces to monitor th...
Wolf L.The locomotor system requires normal movement for normal function. Movement restrictions of soft tissues and joints stimulate nociceptive pathways in the corresponding vertebral segment. Reflex-induced alterations of sensory and motor neuron activity within the segment lead to detrimental changes within many of the tissues associated with and distant from the area. Manual therapy is utilized in both diagnosis and treatment of tissue and joint movement restrictions. Early recognition and treatment of dysfunction in the equine athlete prevents permanent pathology and facilitates performance exce...