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.
Mathieu-Costello O, Hoppeler H, Weibel ER.Capillary orientation (anisotropy) was compared in hindlimb muscles of mammals of different size and/or different aerobic capacity (dog, goat, pony, and calf). All muscles were fixed by vascular perfusion at sarcomere lengths ranging from 1.5 to 2.7 micron. The ratios of capillary counts per fiber cross-sectional area on two sets of sections (0 and 90 degrees) to the muscle fiber axis were used to estimate capillary anisotropy and the coefficient c(K,0) relating 1) capillary counts on transverse sections (a commonly used parameter to assess muscle capillarity) and 2) capillary length per volum...
Stephens PR, Richardson DW, Ross MW, Ford TS.The anatomy of the dorsal pouch of the proximal intertarsal joint (PIJ) and its communication with the tarsocrural joint (TCJ) was studied in 15 pairs of hocks from young and mature horses. The mediolateral length of the TCJ-PIJ fenestration was 14 to 29 mm. The potential volume of the dorsal pouch of the PIJ was 3 to 5 ml, and a recess extended 10 to 28 mm medial to the medial commissure of the TCJ-PIJ fenestration. In a correlated clinical study, osteochondral fragments were identified radiographically within the dorsal pouch (category 1) or dorsal joint capsule (category 2) of the PIJ in 17...
Linke RP, Trautwein G.Tumorous amyloid deposits in the nasal mucosa of two horses differed from generalized AA-amyloidosis with respect to clinical features, organ distribution, and resistance to KMnO4 treatment. Using a panel of antibodies directed against different human amyloid fibril proteins and employing the peroxidase-anti-peroxidase (PAP) technique, we showed the described equine amyloid to be A lambda-type, as demonstrated by immunohistochemical cross-reactivity. Consequently, we identified a second amyloid class in horses and showed that immunoglobulin light-chain-derived amyloid may also be present in an...
Duckett WM, Manning JP, Weston PG.Serum samples were collected from 10 healthy geldings every 4 h for three consecutive days and the triiodothyronine (T3) and thyroxine (T4) concentrations determined by radioimmunoassay. There were significant differences in the hormone concentrations related to time. The mean (+/- sd) T3 concentration peaked around 08.00 h at a level (54.06 +/- 14.02 ng/dl) significantly (P less than .001) higher than the lowest concentration (38.71 +/- 10.81 ng/dl) around midnight. Although the highest mean T3 level was 08.00 h, this value was not significantly different from the noon and 16.00 h levels. Lik...
Zander R, Flachowsky G, Schubert R, Gruhn K.The nylon-bag method was applied for determination of the rumen degradation of dry matter and nitrogen of 15N-labelled wheat straw. For the experiment 4 wethers fitted with a rumen cannula were used. The bags containing 15N straw were introduced into the rumen and withdrawn 3, 6 or 12 h after incubation. In a second experiment the apparent 15N-digestibility of the same straw was determined in wether and pony. The dry matter disappearance varied between 6 and 23%. For 15N-labelled straw the disappearance of 15N was higher than that of total N. 12 h after incubation 71% of 15N and only 25% of to...
Houpt KA, Thornton SN, Allen WR.Six pony mares deprived of water for 24 hours showed significant increases in plasma vasopressin (2.8 pg/ml) and osmolality (9 mosmol/kg). When water was made available the ponies drank rapidly (5 of 6 drank to satiety within 90 seconds) and corrected their fluid deficits precisely. Vasopressin did not return to predehydration levels until osmolality did after 15 minutes of access to water. The horse differs from rodents and humans, but is similar to pigs in that vasopressin levels do not fall before osmolality returns to normal. Oropharyngeal factors, therefore, may not be as important in vas...
Berndtson WE, Jones LS.Testes were obtained from 47 1-20-year-old stallions during the natural breeding season. Total testicular testosterone and testosterone/g testis increased with age (P less than 0.005), and total testicular testosterone was associated with larger testis size (P less than 0.05). Neither testosterone per gram nor per paired testes were related to total Sertoli cell number (P greater than 0.05), but greater testosterone per paired testes was associated with fewer Sertoli cells per unit of seminiferous tubule length (P less than 0.005) or basement membrane area (P less than 0.02) and with a higher ...
Damm JB, Voshol H, Hård K, Kamerling JP, Vliegenthart JF.The carbohydrate chains of equine fibrinogen were enzymatically released by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F. The oligosaccharides obtained were fractionated by a combination of FPLC and HPLC and analyzed by 500-MHz 1H-NMR spectroscopy. Four monosialo and four disialo diantennary N-acetyllactosamine type of carbohydrate chains occur: (formula; see text)
Passaniti A, Roth TF.Ferritin was purified from chicken liver by two different methods: gel filtration on controlled-pore glass beads, and immunoaffinity chromatography employing a chicken ferritin-specific monoclonal antibody that did not cross-react with horse spleen ferritin. This antibody recognizes intact ferritin and an oligomeric 240 kDa form of the molecule after protein transfer to nitrocellulose, but not the 22 kDa chicken ferritin subunit. Chicken liver ferritin purified by these methods exhibited reduced migration on non-denaturing polyacrylamide gels compared with horse spleen ferritin. These results ...
Edlund PO, Bowers L, Henion J.Monitoring steroid use requires an understanding of the metabolism in the species in question and development of sensitive methods for screening of the steroid or its metabolites in urine. Qualitative information for confirmation of methandrostenolone and identification of its metabolites was primarily obtained by coupled-column high-performance liquid chromatography-tandem mass spectrometry. The steroids and a sulphuric acid conjugate were isolated and identified by their daughter ion mass spectra in the urine of both man and the horse following administration of methandrostenolone. Spontaneo...
Moreno-Millan M, Delgado Bermejo JV, Lopez Castillo G.An X-trisomy has been detected in an intersexuality Spanish-bred horse by using G- and C-banding methods. The external characteristics and the behavioural and physiological irregularities of the horse are described. This is the first time that an association between an X-trisomy and a case of intersexuality has been reported in any domestic animal.
ter Laak EA, Fennema G, Jaartsveld FH.Contagious Equine Metritis (CEM) was detected in the Netherlands for the first time in 1987. A total number of five mares (Dutch saddle-horse) were infected in three separate outbreaks. The origin of the infection could not be determined in any of the cases. As the isolates of the causal organism, Taylorella equigenitalis, showed auto-agglutination, diagnosis was difficult. Therefore, an indirect immune fluorescence test as used to diagnose the second isolate. Five strains were isolated, which all were resistant to streptomycin. The prevalence of CEM since 1981 is summarised. The importance of...
Pirhonen A, Linnala-Kankkunen A, Mäenpää PH.Protamine 1 and two protamine 2 variants were isolated from stallion sperm and separated by acetic acid-urea gel electrophoresis. After electroblotting onto polyvinyldifluoride filters, their amino-terminal amino acid sequences were determined by pulse-liquid peptide sequencing. The sequences of the two protamine 2 variants are homologous but slightly different in length and amino acid composition and indicate for the first time the existence of two different genes for this protamine species.
Satoh K, Nakao T, Nagai F, Kano I, Nakagawa A, Ushiyama K, Urayama O, Hara Y, Nakao M.Monoclonal antibodies against horse kidney outer medulla (Na+ + K+)-ATPase were prepared. One of these antibodies (M45-80), was identified as an IgM, recognized the alpha subunit of the enzyme. M45-80 had the following effects on horse kidney (Na+ + K+)-ATPase: (1) it inhibited the enzyme activity by 50% in 140 mM Na+ and by 80% in 8.3 mM Na+; (2) it increased the Na+ concentration necessary for half-maximal activation (K0.5 for Na+) from 12.0 to 57.6 mM, but did not affect K0.5 for K+; (3) it slightly increased the K+-dependent p-nitrophenylphosphatase (K-pNPPase) activity; (4) it inhibited p...
Mendoza L, Marin G.Antigens and rabbit-antisera from holotypes of Pythium insidiosum and P. destruens were prepared to elucidate their antigenic relationship. The antigens and rabbit-antisera of P. insidiosum as well as P. destruens used as a reference system showed that both shared three precipitin bands in common. The antigen and rabbit-antisera of P. destruens and P. insidiosum used as a reference system against other strains isolated from humans and animals with pythiosis, also showed three precipitin bands in common. When we used sera taken from horses with proven pythiosis against antigens of P. insidiosum...
Higuchi T, Ichijo S, Osame S, Ohishi H.In order to clarify the cause of white muscle disease (W.M.D.) in foals, tocopherol and selenium concentrations in serum and glutathione peroxidase activities in blood were measured. Examination was made on the samples from horses affected with W.M.D., the foal kept with them in the same stable, the foals kept in the stables without affected foals, and respective mares. The heavy-breed horses in Fukuoka prefecture and Tokachi district were also examined for comparison. Serum tocopherol levels of these foals were normal because after intake of colostrum. Mares of affected foals showed lower toc...
Dumasia MC, Houghton E, Jackiw M.After homogenization of testicular tissue from stallions aged 1, 2 and 5 years, the unconjugated and conjugated steroids were isolated by a combined solvent-solid extraction procedure. The conjugates were further separated into glucuronides and sulphates by chromatography using Sephadex LH-20. After enzyme hydrolysis and solvolysis of the respective conjugate classes, the three extracts, unconjugated steroids, aglycones and solvolysed sulphates, were purified by chromatography using Kieselgel 60H columns. Five fractions were resolved from each extract; an aliquot of each fraction was derivatiz...
Gibson KT, McIlwraith CW, Turner AS, Stashak TS, Aanes WA, Trotter GW.A retrospective study was made of 58 horses with open joint injuries admitted to the veterinary teaching hospital. Twenty-five (43%) were admitted within 24 hours of injury, 15 (26%) were examined 2 to 7 days after injury, and 18 (31%) were evaluated a week or more after the initial injury. The joints of the lower portions of the limbs most commonly were affected, with injuries that varied from puncture wounds to severe lacerations with soft tissue deficits. Diagnosis was made on the basis of clinical signs and results of synovial fluid analysis and radiography. Radiography was found to be an ...
Bernard WV, Reef VB, Reimer JM, Humber KA, Orsini JA.Small-intestinal intussusceptions were diagnosed in 3 foals. Cross-sectional ultrasonography through the apex of the intussusceptum revealed a target-like pattern with a thick hypoechoic rim. The thick hypoechoic rim was caused by severe edema of the entering and returning walls of the intussusceptum. At the more proximal portion of the intestines, where parietal edema was less severe, the image appeared as 2 concentric rings and an inner circular area. The outer ring and inner circular area were hypoechoic and represented the returning and the entering wall of the intussusceptum. An additiona...
Parks AH, Guy BL, Rawlings CA, Constantino MJ.A 5-year-old mare was evaluated for lameness and swelling of the right forelimb. Clinical findings, including peripheral edema, venous pulsation, palpable thrill in the cephalic vein, disparate arteriovenous oxygen tension differences between the left and right forelimbs, and Branham sign, were suggestive of arteriovenous fistula. Failure to identify the fistula by angiography was attributed to closure of the shunt during anesthesia. Surgical exploration of the affected limb to identify the shunt also was unsuccessful.
Holland RE, Sriranganathan N, DuPont L.Enterotoxigenic Escherichia coli was isolated from a 3-day-old foal with diarrhea. The isolate was distinguished from nonpathogenic E coli by determining the presence of pili and enterotoxin production. A standard slide agglutination test was performed, using pooled antisera that contained antibodies against K99 and F41 pilus antigens, K87 capsular antigen, and 0101 somatic antigen. Agglutination of the antisera occurred in the presence of the isolate. Piliation was verified by use of negative-contrast electron microscopy. Further, the isolate produced a heat-labile enterotoxin-like antigen th...
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 ...
Nourian AR, Mills PC, Pollitt CC.Intraosseous (i.o.) infusion of the distal phalanx (IOIDP) as a delivery route targeting hoof lamellar tissue of standing, conscious horses was evaluated. Following sedation and regional nerve blockade in six Standardbred horses, a microdialysis (MD) probe was implanted into the hoof lamellar tissue of one forelimb. A purpose designed cannulated bone screw was introduced into the body of the distal phalanx, approximately 6 cm from the MD probe. Gentamicin solution (25 mg/mL) was infused at 20 microL/min through the bone screw for 2 h without the application of a tourniquet. MD and blood sample...
Ayliffe TR, Allen WE.PREVIOUS studies have shown that instillation of sodium benzylpenicillin into the uterine lumen of ponies in small volumes is followed by peak plasma concentrations of the antibiotic in 10to 15 mins (Allen 1978; Allen and Clarke 1978). However, the assumption that the circulating penicillin is absorbed only through the endometrium is questionable because Allen, Kessy and Noakes (1979) concluded that the intrauterine instillation of phenolsulphonphthalein was followed by absorption of the dye from the peritoneal cavity, after passage along the uterine tubes.
The present investigation was carri...
Mansell SE, Behnke MC.The nematode Onchocerca cervicalis is the most common causative agent of equine onchocerciasis; this condition is characterised by pruritus and dermatitis and is a differential diagnosis for insect bite hypersensitivity. Onchocerciasis is currently presumed of minor importance within the UK, however prevalence may increase if macrocyclic lactone use declines amid concerns about anthelmintic resistance in gastrointestinal nematodes. This survey aimed to establish O. cervicalis awareness and knowledge levels amongst UK equine veterinarians and to determine approximate numbers of UK horses affect...
Schamhardt HC, Merkens HW, Lammertink JL.Software for analysis of force plate recordings of the horse at normal walk is described. The data of a number of stance phases are averaged to obtain a representative tracing of that horse. The amplitudes of a number of characteristic peaks in the force-time curves are used to compare left and right front limbs and left and right hind limbs. The averaged tracings are plotted, default on the line printer or, via separate program, on a high quality pen plotter. A version of the program applicable for analysis of human force plate recordings, is available.
Costa HM, Silva AV, Guimarães MP.This paper describes some morphological aspects of Cylicocyclus brevicapsulatus (Ihle, 1920) (Nematoda: Cyathostominae) from Equus caballus in Brazil. The worms were studied using an optical microscope (measurements and illustrations) and a scanning electron microscope for a more detailed examination of the external morphology. The buccal capsule is very short, with a very thin wall, and the dorsal gutter is absent. Other morphological aspects are described including measurement of the spicules and gubernaculum.
Sturgeon BP, Milne EM, Smith KC.A 20 x 10 cm, lobulated mass was present in the perianal region of a 4-year-old Dales pony. Histopathology revealed an unencapsulated, loose arrangement of sheets and whorls of narrow mesenchymal cells, situated in the deep dermis. Intervening areas had a myxomatous appearance. The whorls were often arranged around a central structure resembling an axon or a vascular structure. Immunohistochemistry revealed that the elongated mesenchymal cells and central axon-like structures expressed vimentin, S-100, and neuron-specific enolase, but not pancytokeratin, glial fibrillary acid protein, and the ...
Labelle AL, Metzler AG, Wilkie DA.Neoplasia, for which surgical excision is a frequent treatment, is the most common disease of the equine nictitating membrane. There is little long-term follow-up information available to the practitioner regarding the long-term effects of nictitating membrane excision on ocular health. No information is available to compare recurrence of primary neoplasia of the nictitating membrane after excision with local or general anaesthesia. Objective: To evaluate the long-term complications of nictitating membrane resection in horses; recurrence of neoplasia of the nictitating membrane when nictitatin...
Carnevale EM, Squires EL, Maclellan LJ, Alvarenga MA, Scott TJ.In some mares with lesions of the reproductive tract, embryo collection and survival rates are low, or collection of embryos is not feasible. For these mares, oocyte transfer has been proposed as a method to induce pregnancies. In this report, a method for oocyte transfer in mares and results of oocyte transfer performed over 2 breeding seasons, using mares with long histories of subfertility and various reproductive lesions, are described. Human chorionic gonadotropin or an implant containing a gonadotropin-releasing hormone analog was used to initiate follicular and oocyte maturation. Oocyte...
Nottle BF, Tatarniuk DM, Caldwell FJ, Bell CD, Caston SS, Merkatoris PT, Gillen AM, Katzman SA.To describe the presentation, diagnosis, treatment, and outcome for horses with fibro-osseous lesions of the craniofacial complex. Methods: Retrospective multicenter case series. Methods: Thirty horses evaluated for fibro-osseous lesions of the skull from January 1, 2001 through December 31, 2019 in four centers. Methods: Medical records were reviewed for signalment, clinical presentation, histological and diagnostic imaging findings, treatment instituted, and outcome. Long-term outcome information was obtained by owner questionnaire or the medical record. Results: Diagnoses included ossifying...
Dart AJ, Pascoe JR, Snyder JR.Segmental ischemic necrosis of the descending colon associated with discrete tears of the mesocolon were diagnosed in 2 mares following foaling. After foaling, both mares had a slow onset of signs of abdominal pain and gradual deterioration of clinical status. Increases in peritoneal fluid total protein concentration and WBC count and a palpable impaction of the descending colon on examination per rectum were useful diagnostic aids. Surgical intervention was successful in one mare, but not in the other.
Coffman JR, Hammond LS, Garner HE, Thawley DG, Selby LA.A COMMON progression of chronic laminitis is ischaemic
necrosis with secondary infection a frequent complication.
For 6 years we have performed a complete blood count
(CBC) on all hospitalised horses (at the University of Missouri
Veterinary Hospital) every Monday, Wednesday and Friday.
Preliminary scrutiny of the results indicated that persistent
elevation of the total white blood cell count (WBC) and
neutrophilia was consistent with poor prognosis in horses
affected with laminitis. Because of these considerations we
decided to perform a retrospective examination of the blood
cell d...
Swor TM, Watkins JR, Bahr A, Epstein KL, Honnas CM.Previous olecranon fracture reports contain a small proportion of type 5 fractures, mostly treated with conservative therapy. Objective: To evaluate the clinical details and outcome of type 5 olecranon fractures in a large group of horses treated by tension band plate fixation and to compare results with other treatment methods. Methods: Medical records of 97 cases, including 32 (33%) classified as type 5, were reviewed. Subject details, history, radiographic findings, treatment and follow-up results (2-146 months post operatively) were recorded. Results: Treatment included open reduction and ...
Hughes KJ.Ocular manifestations may develop in many systemic diseases of horses; however, signs may not be observed unless ophthalmological examination is specifically undertaken. Recognition and assessment of ocular lesions in horses with systemic disease is desirable to facilitate diagnosis and determination of treatment options and diagnosis for both the underlying systemic disease and ocular manifestations. The purpose of this article is to review systemic diseases of horses that may have ocular signs as part of the disease process. Systemic diseases are discussed in categories of pathways for devel...
Lyons ET, Drudge JH, Tolliver SC.Critical tests were conducted in 14 naturally infected equids (13 horses and 1 pony) to evaluate the antiparasitic activity of haloxon. Single doses were administered by stomach tube to 3 horses and 1 pony (60 mg/kg of body weight), by addition to the feed of 3 horses (60 mg/kg), and intraorally by powder gun to 7 horses (65 mg/kg). Haloxon was efficacious (99% to 100%) against infections of Parascaris equorum, Oxyuris equi (mature and immature), and Strongylus vulgaris at both dosage levels. Probstmayria vivipara parasites were removed in 1 horse treated at 60 mg/kg by stomach tube and S equi...