Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Van der Lugt JJ, Coetzer JA, Jordaan P, Marlow CH.Tyzzer's disease was diagnosed histologically in two foals, a 4-week-old Thoroughbred cross and a 6-week-old Arabian foal. Clinically both foals were in good health prior to a short illness lasting only a few hours. The liver lesions in both foals were characterized microscopically by multiple foci of necrosis. Variable numbers of elongated slender intracytoplasmic bacilli resembling Bacillus piliformis were demonstrated within hepatocytes bordering the necrotic foci.
Duncan SG, Meyers KM, Reed SM, Grant B.This experiment was designed to establish a model for the study of gastrointestinal disturbances as a result of prolonged endotoxin uptake in the horse. The hepatic portal vein of 7 horses was catheterized (through flank incisions) to give chronic hepatic portal infusions of lipopolysaccharide (LPS, endotoxin). Lipopolysaccharide was infused at a rate of 1 microgram/kg of body weight/hr for 24 hours. Two of the horses were infused with saline solution for 12 hours before LPS infusions were given. Lipopolysaccharide was shown to affect behavior and hematologic and coagulation values. The 1st ho...
Haddad NS, Pedersoli WM, Ravis WR, Fazeli MH, Carson RL.Gentamicin (GT) was administered IM to 6 healthy mature mare ponies at a dosage of 5 mg/kg of body weight every 8 hours for 7 consecutive days (total, 21 doses). Two venous blood samples were collected before (trough) and at 1 hour (peak) after the 5th, 10th, 14th, and 19th doses. An endometrial biopsy was done of each mare on days 4 and 7. On the 7th day, just before the 21st administration of GT, base-line blood samples were collected, and 22 blood samples were collected over a period of 48 hours after GT was given. The mares were catheterized on the 7th day, and urine was collected for 24 h...
Selim SA, Soliman R, Osman K, Padhye AA, Ajello L.Isolation of Histoplasma farciminosum from five horses, showing typical signs of histoplasmosis farciminosi (epizootic lymphangitis) was successfully attempted. The mycelial form of H. farciminosum was isolated on Sabouraud dextrose agar enriched with 2.5% glycerol, brain heart infusion (BHI) agar enriched with 10% horse blood and PPLO dextrose glycerol agar. The last medium proved to be the most effective, both for primary isolation and subculturing of the fungus. It was found that on primary isolation, the lag phase of the mycelial form of the fungus was relatively long, involving 4-8 weeks ...
Romagnano A, King WA, Richer CL, Perrone MA.A technique is described for the preparation of banded chromosomes from early equine embryos cultured for less than 10 h in a medium containing bromodeoxyuridine. In addition to standard Giemsa staining and C-banding, chromosomes thus prepared can also be R-banded by either the RBA or the RB-FPG methods. This technique is rapid, repeatable, and limits cell loss, making it ideal for the preparation of early embryos.
Hunt JM, Gerring EL.Prostaglandin E1 was infused intravenously (25, 50 and 75 ng/kg/min) in three ponies. Changes in gastrointestinal mechanical and electrical activity were recorded from chronically implanted strain-gauge force transducers and electrodes. Dose-dependent responses were obtained: there were significant decreases in electrical spiking activity in the stomach, left large colon and small colon, with a corresponding decrease of activity in the left dorsal colon mechanogram. The small intestine was also affected, showing a decrease in both contraction rate and amplitude, which was more marked in the pr...
Muwanga LC, Dove AF.We report the frequency with which horse riders with a significant head injury present to a large accident and emergency department. We have also recorded details about the use of headwear and conclude that horse-riding is associated with a serious risk of head injury and 'protective' headwear may not always protect.
Johnson L.Seasonal variation in number of spermatogonia and germ cell degeneration was evaluated to determine which mechanism might explain seasonal differences in daily sperm production per testis (DSP/testis) or per g parenchyma (DSP/g) in stallions. Comparing 28 adult stallions (4 to 20 yr old) in each of the nonbreeding (December-January) and breeding (June-July) seasons, the population of type A spermatogonia was more than two times greater (P less than 0.01) in the breeding season. While the number of type B spermatogonia also was elevated (P less than 0.01) in the breeding season, the number of t...
Crawford AM, Mills JN.Venoms of the tiger snake and brown snake were procoagulant, in vitro, when tested with cat, dog, horse and wallaby plasma. In the absence of calcium and phospholipid the coagulant activity of tiger snake venom was minimal. In contrast, brown snake venom alone had marked procoagulant activity. This activity, however, was enhanced by the presence of calcium and phospholipid. Death adder venom exerted an anticoagulant effect. Apparent species' differences in susceptibility to the coagulant venoms were noted. However, the probable explanation of these differences was attributed to variation in th...
Hilbert BJ, Rowley G, Antonas KN, McGill CA, Reynoldson JA, Hawkins CD.Sodium hyaluronate was injected into normal horse joints and joints that had undergone an arthrotomy and experimental cartilage damage. The elimination half-life for hyaluronic acid in normal joints was found to be approximately 96 h. The injection caused a non-significant increase (42%) in synovial fluid protein concentration and a fall in the intrinsic viscosity of the fluid. In the arthrotomy group the synovial fluid hyaluronic acid concentration fell after surgery but it was unaffected by the injection of sodium hyaluronate. An initial rise in the intrinsic viscosity of the synovial fluid ...
Van Huffel XM, Varner DD, Hinrichs K, Garcia MC, Strzemienski PJ, Kenney RM.A photomicrographic method for evaluation of stallion spermatozoal motility was developed, and spermatozoal image and velocity characteristics were defined. The photomicrographic method was compared with visual estimation of motility in the same semen sample over time. Using photomicrography, velocities and percentages of individual spermatozoal image characteristics were determined. Although there was a high correlation between results of the 2 methods, results of the photomicrographic method were more repeatable than were those of the visual method.
McClure JJ, Addison JD, Miller RI.Oral candidiasis and bacterial septicemia were diagnosed in 8 foals that had laboratory and/or pathologic evidence of immunodeficiency. Two foals suffered solely from complete failure of passive transfer of colostal immunoglobulins. Six foals had evidence of immune defects but did not meet the criteria for diagnosis of any of the currently recognized primary equine immunodeficiency syndromes. All six of these foals died or were euthanatized due to bacterial infections. One foal with failure of passive transfer recovered and the other died of a mesenteric torsion before the effect of treatment ...
Woods WE, Chay S, Houston T, Blake JW, Tobin T.Interference or 'masking' in thin layer chromatography occurs when the presence of one drug on a thin layer plate physically obscures or interferes with the detection of another drug. We investigated the ability of phenylbutazone and oxyphenbutazone to mask or interfere with the detection by high performance thin layer chromatography (HPTLC) of basic drugs used illegally in horse racing. Of fifty-five basic drugs called 'positive' since 1981 by laboratories affiliated with the Association of Official Racing Chemists (AORC), forty did not comigrate with phenylbutazone or oxyphenbutazone and cou...
Wendorff KM, Nishita T, Jabusch JR, Deutsch HF.The sequence of equine muscle carbonic anhydrase (CA-III) has been determined. The 2 reactive cysteines of the 5 such residues have been localized. A strong sequence homology to other mammalian carbonic anhydrases exists, and 91% of the residues in the equine and bovine muscle forms are identical.
Lunn DP, Peel JE.A five-year-old standardbred mare suffered a cervical oesophageal rupture subsequent to a kick. Marked cellulitis and extensive soft tissue damage resulted. Treatment consisted of creating an oesophageal fistula, local debridement and systemic antibiotics. The mare made a long but successful recovery. Treatment of oesophageal rupture in the horse is discussed.
Halnan CR.From the standpoint that cytogenetic screening in mares is seldom necessary as an aid to diagnosis of the gonadal dysgenesis syndrome, a series of double-blind trials were conducted to test the proposal that present practice failed to explore the potential for cytogenetics in clinical practice. It was demonstrated that diagnoses of infertility might be made where mares were found to be of normal phenotype by clinical examination. Such mares were found to be gonosmic mosaics. One stallion had a polymorphism of the X chromosome and had poor conception rates. It was demonstrated that the true val...
French DD, Haynes PF, Miller RI.A horse had severe granulomatous lesions of the upper airways that were attributable to Conidiobolus coronatus. Therapeutic success was documented by clinical examination of the horse 4 years after treatment by surgical extirpation and intralesional and topical use of amphotericin B.
Borst GH, Smidt WJ, Berghuis GA.The concentrations of progesterone in milk were determined in twenty-one mares to establish a diagnosis of pregnancy in an early stage (15-19 days). Progesterone levels varied from 0.0 to 4.2 ng/ml in nine non-pregnant mares and from 6.7 to 30.0 ng/ml in twelve pregnant mares. Progesterone levels were determined by an enzyme-linked immunosorbent assay (ELISA).
Johnson P.An unusual compound of small molecular weight has been detected in serum from horses with acute grass sickness by solvent extractions and thin-layer chromatography. The substance has not been detected in the serum of normal horses or cases of equine colic and apparently disappears from grass sickness serum after two to three days of clinical illness. Although this compound is found in sera which are known to possess in vivo neurotoxicity, this property could not be demonstrated in either the total chloroform extract which contains the compound or in the hydrophilic serum components remaining a...
Heath E, Aire T, Fujiwara K.A microtubular mass (MM) defect was found in the spermatozoa of 7 Standardbred stallions; 3 stallions were sons of the same sire. Two of these 3 stallions and 2 other stallions (for a total of 4 out of the 7 stallions) were considered subfertile when the defect was first observed. Fertility improved with time, either during the first breeding season or when a given stallion was used less frequently; however, the MM defect persisted, consisting of tortuous arrays of small abnormal microtubules visible only by transmission electron microscopy. The MM probably contained the protein tubulin as ind...
Giles CJ, Urquhart KA, Longstaffe JA.Clinical and laboratory findings are recorded from a series of 15 cases (aged one to 16 years) of sudden-onset chronic diarrhoea with weight loss, progressing in many cases to emaciation and death, associated with the emergence of fourth stage cyathostome (trichoneme) larvae in large numbers through the colonic and caecal mucosae. Apart from a single incident in mid-October, disease only occurred in winter and spring (January to May). Characteristic features included hypoalbuminaemia, increased alpha and beta plasma globulin levels and neutrophilia without left shift. Faecal egg counts were fr...
Brownlow MA, Turner DM, Hutchins DR.An inhalation anaesthetic apparatus for the horse is described and the physiological concepts pertaining to its design presented. The internal diameter of all breathing components is 6.2 cm with no change in cross sectional area throughout the circle system. The soda lime capacity is 25 litres (approximately 20 kg). In the horse, which is apparently predisposed to alveolar hypoventilation during inhalation anaesthesia, it is apparent that adequate anaesthetic apparatus design should be directed towards minimising resistance and dead space and providing maximal and efficient carbon dioxide elim...
Liu IK.Uterine defense against infection in the mare has been actively investigated over the past decade. Mechanisms of defense, including the role of immunoglobulins, polymorphonuclear neutrophils, and the physical ability of mares to eliminate bacteria from the uterus, are discussed.
Knight PK, Thomson PC.OBJECTIVE Compare the career profiles of a cohort of Standardbred horses that first raced as 2-year-olds with those that started their racing careers at a later age. METHOD Retrospective analysis of the racing records of all foals born in New South Wales in the 2000 foaling season. RESULTS The career records of 999 horses were analysed. Almost half (43.9%) first raced as 2-year-olds and one-third (33.9%) as 3-year-olds. The median career duration for horses that first raced as 2-year-olds was 2.93 years (interquartile range (IQR) 2.70-3.16), which was significantly greater than the median for ...
Câmara ACL, de Sousa Argenta VL, de Moraes DDA, Fonseca EF, Fino TCM, Paludo GR, Soto-Blanco B.Determining the prognosis of poisoning by plants containing pyrrolizidine alkaloids is usually challenging. This study aimed to identify important prognostic parameters that can determine the severity of spontaneous poisoning by in horses. Blood samples from 42 horses spontaneously poisoned by oats contaminated with seeds were evaluated. Complete blood counts (CBC) and serum biochemical tests [urea, creatinine, total protein, albumin, total and direct bilirubin concentrations, aspartate aminotransferase (AST), γ-glutamyl transferase (GGT), and creatine kinase (CK) activities] were performed...
Hirsh DC, Kirkham C, Wilson WD.Fifteen Escherichia coli isolates from the blood and tissue of foals with septicemia were compared with 15 from the feces of clinically normal horses. Comparisons were made with respect to survival in normal equine serum, production of aerobactin, and production of hemolysin. Isolates from the blood and tissues of septic foals were more likely to be resistant to equine serum than were isolates from feces of clinically normal horses. There were minimal differences between the isolates with respect to aerobactin and hemolysin production, almost all being nonhemolytic and aerobactin negative. Ser...
Scarlet D, Budik S, Aurich C.A new device for storage and shipping of cell cultures--the Petaka G3 cell management device--was tested for its applicability for cooled-storage of equine semen. Semen from three stallions was processed with EquiPro extender either without antibiotics (three ejaculates per stallion) or with gentamicin (250 mg/l; three ejaculates per stallion). Semen was either stored at five (anaerobic conditions) or 15 °C (aerobic conditions) in syringes or cell culture devices. Total and progressive motility, as well as membrane integrity of spermatozoa, were evaluated from days 1 to 7 after collection wit...
Menard L, Marcoux M, Halle G.A case of unilateral front leg lameness with bone changes in the pedal bone suggestive of osteodystrophia fibrosa cystica is reported in an eight year old crossbred gelding. The changes were diagnosed at postmortem examination. The known possible causes are briefly reviewed.
Menzies-Gow NJ, Patterson-Kane JC, McGowan CM.The clinical signs of chronic nodular panniculitis in a three-year-old mare were consistent with a diagnosis of sterile nodular panniculitis, but the mare had histopathological signs of both generalised steatitis and sterile nodular panniculitis. The mare was deficient in vitamin E and selenium.
Emmerich IU.In 2017, no new active pharmaceutical ingredients were released on the German market for horses or food-producing animals. Four established veterinary active pharmaceutical ingredients became available for additional species: the ectoparasitic Fluralaner (Exzolt®) of the isoxazoline group was additionally authorized for chickens, the macrolide antibiotics Gamithromycin (Zactran®) and Tulathromycin (Draxxin®) for sheep and the nonsteroidal anti-inflammatory drug Tolfenamic Acid (Tolfedol®) from the fenamate group for cattle and pigs. Additionally, one drug with a new combination of active i...
Sod GA, Mitchell CF, Hubert JD, Martin GS, Gill MS.To compare monotonic biomechanical properties and fatigue life of a 5.5 mm broad limited-contact dynamic compression plate (5.5-LC-DCP) fixation with a 4.5 mm broad LC-DCP (4.5-LC-DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Methods: In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Methods: Adult equine cadaveric MC3 bones (n=18 pair). Methods: MC3 were divided into 3 test groups (6 pairs each) for: (1) 4-point bending single cycle to failure testing; (2) 4-point bendi...
Alves BG, Alves KA, Hyde KA, Aguiar FLN, Souza SS, Brandão FAS, Garcia EC, Pinto Y, Gastal MO, Figueiredo JR, Teixeira DIA, Gastal EL.Ovarian tissue transplantation (OTT) is a technique well established and successfully applied in humans using mainly orthotopic or heterotopic transplantation sites. In livestock, OTT is still in its infancy and, therefore, different aspects of the technique, including the efficiency of different heterotopic OTT sites as well as the potential effect of age (i.e., young vs. old mares) in the ovarian graft quality, need to be investigated. The present study investigated the efficacy of the intramuscular (IM) or the novel subvulvar mucosa (SV) heterotopic autotransplantation sites to maintain the...
Foreman-Hesterberg CR, Foreman JH.Muscle damage can result in leakage of intracellular enzymes such as creatine kinase (CK) and aspartate transaminase (AST) into plasma. There are no controlled documentations of the effects of intramuscular antibiotic drug administration on plasma CK and AST activities in horses. The objective of this experiment was to test the hypothesis that 5 days of intramuscular procaine penicillin G injection in normal horses would result in increased plasma activities of CK and AST. Nine healthy adult horses were sampled for 7 days preceding, 5 days during, and 32 days following procaine penicillin G (2...
Ralston SL.A survey was taken of dietary management and training schedules of 54 horses competing in two 160 km endurance races. A total of 52 owners, representing 54 horses, responded to a questionnaire distributed prior to the races. Diet and training schedules were compared between horses that successfully completed the races and those that were eliminated for metabolic reasons. Horses that completed the races were 11.5 +/- 4 years old, weighed 429 +/- 4.5 kg and were ridden 61 +/- 32 km a week when training. Feed intake was reported as "free choice hay or pasture" by 34 of the respondents. Dry matter...
Milnes E, Delnatte P, Dutton CJ, Brouwer E, Cai HY, Smith DA, Peregrine AS.A 23-yr-old captive-born Przewalski's horse mare ( Equus przewalskii) was euthanized at a Canadian zoo because of severe colic resulting from rupture of a jejunal pseudodiverticulum. An incidental finding of an encysted larval cestode within a hepatic granuloma was diagnosed on histopathology. Gel-based polymerase chain reaction (PCR) on liver tissue was positive for Echinococcus granulosus sensu lato, and deoxyribonucleic acid sequencing of the PCR product was 100% homologous with Echinococcus equinus. This appears to be the first molecular confirmation of E. equinus in North America, and the...