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.
Daels PF, Hughes JP.The purpose of this study was to develop a contraceptive method for feral horses. The feral horse population has increased significantly in recent years despite attempts to control numbers. As in most wild animal population control programs, contraceptive methods must be easy to apply, cause minimal disruption to the social structure and be fully reversible. In the present study, we tested the effectiveness of an intrauterine device (IUD) for fertility control in mares. Six mares were fitted with a silastic O-ring-shaped IUD on July 1 of Year 1. The IUD-treated mares were turned out with 12 no...
Braun J, Hochi S, Oguri N, Sato K, Torres-Boggino F.Three experiments were conducted to evaluate the effect of different macromolecule components (egg yolk, skim milk, and BSA) in a widely employed extender for cryopreservation of horse semen. Spermatozoal motility (MOT) and the percentage of spermatozoa with an intact plasma membrane (IPM) were evaluated in frozen-thawed samples. In the first experiment (four Draft Horse stallions, four ejaculates each) a standard freezing extender containing 20% whole egg yolk was modified by replacing extender components (glucose-EDTA solution, 11% lactose solution) with an increasing volume of a skim milk d...
Marchi PR, Rawlings P, Burroughs JN, Wellby M, Mertens PP, Mellor PS, Wade-Evans AM.Purified African horse sickness virus (AHSV) was fed, as part of a blood meal, to adult females from a susceptible colony of Culicoides variipennis, established in the insectories at the Institute for Animal Health, Pirbright Laboratory, UK. The meal consisted of heparinized blood obtained from ovine, bovine, equine (horse and donkey) or canine sources spiked with AHSV serotype 9 (AHSV9). The infectivity levels observed for C. variipennis varied significantly, according to the source of the blood sample. Comparison of the protein profiles obtained from AHSV9 incubated with the individual serum...
Leo M, Kolb E, Siebert P, Dittrich H.The activity of adenosine deaminase in the cerebrum, cerebellum, brain stem, heart, skeletal muscle, lung, liver, spleen, kidney and testes of horses of the breeds Haflinger and Thüringer Kaltblut was not different from each other. In the erythrocytes and the plasma no activity of the ADA exists.
Mettenleiter EM.In this presentation, normal sonoanatomy of the horse eye will be introduced and biometrical data of 30 healthy eyes along optical axis will be presented. We used the ultrasound system Philips Diagnost R 1200 in connection with a 5 MHz linear transducer. With this equipment it is possible to visualize and measure at the unaltered eye the cornea, the anterior chamber of the eye, ciliary body, iris, lens, vitreous body, wall of the posterior globe (retina, choroid, sclera) and retrobulbar structures (optical nerve, retrobulbar muscles, orbital fat pad, bony orbita). The echographical examination...
Lennard SN, Stewart F, Allen WR.In situ hybridization, Northern blotting, and immunohistochemical techniques were used to study the expression of transforming growth factor beta 1 (TGF beta 1) in the endometrium of the mare during the first 150 days of pregnancy (term = 330-340 days). In situ hybridization using an oligonucleotide (45mer) probe, based on a homologous region within all known mammalian TGF beta 1 DNA sequences, demonstrated TGF beta 1 mRNA accumulation in the glandular and lumenal epithelial cells of the endometrium from day 33 onwards which corresponds to the time of implantation (day 33-45). Expression in th...
McKane SA, Rose RJ, Evans DL.Twenty-four Thoroughbred and twelve Standardbred racehorses aged between 2 and 6 years, presented for reported poor racing performance, underwent clinical exercise testing. During the last 10 s of exercise at each speed throughout an incremental speed exercise test on a treadmill inclined at a 10% slope, samples of arterial blood and expired gases were collected. Maximum oxygen uptake and the partial pressures of oxygen and carbon dioxide in arterial blood were determined. These values were compared between the two breeds of horses and also with reference to cytological findings of bronchoalve...
Monahan CM, Chapman MR, French DD, Taylor HW, Klei TR.Moxidectin was tested as an oral gel formulation during a controlled test performed to evaluate dosages against equine gastrointestinal parasites. Four groups of ten ponies were used. Ponies ranged from 1 to 20 years of age and were naturally infected in southern Louisiana or Mississippi. Fecal exams and fecal cultures were performed on all ponies to determine the strongyle egg counts and the percent distributions of large and small strongyles. Following these determinations, ponies were allocated to replicates of four ponies to provide an even distribution of strongyle infection, age, weight ...
Gillis C, Sharkey N, Stover SM, Pool RR, Meagher DM, Willits N.Results of studies in human beings and other species have indicated that aging significantly influences the strength, modulus of elasticity, and energy storage ability of tendon. We wanted to determine the effects of aging on the material and ultrasonographic properties of equine superficial digital flexor (SDF) tendon. Ultrasonographic measurements of left forelimb SDF tendon cross-sectional area and mean echogenicity were made in 23 standing horses ranging in age from 2 to 23 years. All horses had not been in work for a minimum of 6 months prior to the study. After euthanasia, left forelimb ...
Gillis C, Meagher DM, Cloninger A, Locatelli L, Willits N.Fifty Thoroughbred horses were examined. All horses had been in race training for a minimum of 4 months before examination and had worked at racing speed; 24 horses had raced. All horses were clinically sound at the time of examination. Ultrasonography was performed, using a 7.5-MHz transducer with built-in fluid offset. Videotaped images of the palmar soft tissue structures were obtained at 4, 8, 12, 16, 20 and 24 cm distal to the base of the accessory carpal bone (DACB). Images were digitized, and each image was calibrated. Values for cross-sectional area (CSA) and mean echogenicity (ME) wer...
Cuvelliez S, Rosseel G, Blais D, Salmon Y, Troncy E, Larivière N.Intravenous anesthesia in the horse: Comparison of xylazine-ketamine and xylaxine-tiletamine-zolazepam combinations. Six healthy adult horses were anesthetized twice at random with following intravenous combinations: 1.1 mg/kg of body weight (BW) of xylazine followed by 2.2 mg/kg BW of ketamine (X-K) and 1.1 mg/kg BW of xylazine followed by 1.65 mg/kg BW of tiletamine-zolazepam (X-TZ). The modifications of some cardiorespiratory parameters and the duration of anesthesia were evaluated and compared for the 2 protocols used. Few significant differences were observed between the 2 protocols in re...
Foster AP, Lees P, Cunningham FM.Platelet activating factor (PAF) mimics the effects of Culicoides antigen by inducing oedema and inflammatory cell accumulation in the dermis of horses with the allergic skin disease, sweet itch. PAF could therefore contribute to antigen-induced inflammatory changes in these horses. We now report that intravenous administration of the PAF receptor antagonist WEB 2086 (3 mg kg-1), at a dose that inhibited the vascular and cellular responses to PAF in sweet itch horses, reduced Culicoides antigen-induced oedema at 1 h by 73% and at 8 h by 71% (p < 0.05). Neutrophil accumulation and eosinophil...
Peippo J, Huhtinen M, Kotilainen T.A rapid and reliable method for sex determination of preimplantation-stage equine embryos has not been available. The aim of the present study was to find an enzyme which would distinguish sexes in the horse by finding a polymorphic restriction site between the ZFY and ZFX homologues amplified by the polymerase chain reaction (PCR). Altogether, 38 different restriction enzymes were tested using female and male DNA extracted from blood. The primers used for amplification were selected from conserved sequences between human ZFY and ZFX genes and mouse Zfy-1 and Zfy-2 genes. Nine enzymes cut the ...
Riber C, Rubio MD, Marquez F, Pinedo M, Muñoz A, Castejon F.Clinical blood chemistry was studied on 13 Andalusian horses with laminitis. Ten healthy horses were used as controls. Blood samples were taken within the first 24 hr after the onset of the disease in Obel grade 3 before any type of treatment was given. No significant differences were observed in the number of red blood cells and white blood cells between Andalusian horses affected by laminitis and healthy animals. Significant decrease in the number of neutrophils and increased number of lymphocytes were noted. A significant increase in the enzymatic activity of CPK, LDH and AST in these anima...
Vagnoni KE, Ginther OJ, Lunn DP.Chorionic girdle cells are a highly invasive subpopulation of trophoblast cells of the equine conceptus. By Day 35 (Day 0 = day of ovulation), cells of the chorionic girdle adhere to the uterine epithelium and begin to invade the endometrial wall. Invasive cells must attach to extracellular matrix proteins, secrete proteinases capable of degrading matrix, and migrate through the degraded matrix; invasion is largely dependent on the proteinase activity of the cells. The objective, therefore, was to develop an in vitro system to examine the mechanisms of equine chorionic girdle cell invasion thr...
Fazeli AR, Steenweg W, Bevers MM, van den Broek J, Bracher V, Parlevliet J, Colenbrander B.The hemizona assay (HZA) has been developed as a diagnostic test to predict the fertilisation potential of human spermatozoa. The aim of this study was to develop an HZA for stallion spermatozoa and to investigate a possible relationship between fertility and the outcome of the HZA in this species. Equine oocytes were obtained from ovaries collected at a slaughterhouse and by transvaginal, ultrasound-guided follicle aspiration. They were then denuded from cumulus cells and stored in salt solution at 4 degrees C until use. On the day of the experiments the oocytes were bisected, thus providing ...
Monreal L, Villatoro AJ, Monreal M, Espada Y, Anglés AM, Ruiz-Gopegui R.Thirty healthy male horses were allotted to 3 groups and treated blindly during 4 days. Group-1 horses received unfractioned calcium heparin (100 IU/kg of body weight, SC, q 12 h). Group-2 horses received a single dose of a low-molecular-weight heparin (50 anti-Xa IU/kg, SC) every morning, and a similar volume of saline solution every evening. Group-3 horses received the vehicle (saline solution), SC, every 12 hours. Citrated and EDTA-anticoagulated blood samples were collected before starting the medication (T-0) and once daily 3 hours after each morning injection (T-3, T-27, T-51, and T-75)....
Arriaga C, Yépez-Mulia L, Viveros N, Adame LA, Zarlenga DS, Lichtenfels JR, Benitez E, Ortega-Pierres MG.Human trichinellosis outbreaks related to horsemeat consumption have been reported in France and Italy in recent years. In order to determine if Trichinella is present in horses slaughtered at an abattoir in the State of Mexico, diaphragm muscle tissue samples (22-37 g) from 80 horses were examined by artificial digestion. Four of these samples had larvae that were characterized as Trichinella sp. by morphological criteria and as Trichinella spiralis by the polymerase chain reaction.
Kato H, Ohashi T, Nakamura N, Nishimura Y, Watari T, Goitsuka R, Tsujimoto H, Hasegawa A.Equine interleukin-1 alpha (IL-1 alpha) and IL-1 beta were molecularly cloned to establish a basis for research on inflammatory and immune responses in the horse. Equine peripheral blood mononuclear cells (PBMC) were stimulated with lipopolysaccharide (LPS), and cDNA clones of equine IL-1 alpha and IL-1 beta covering the whole coding sequences were isolated from them. These equine IL-1 alpha and IL-1 beta clones contained open reading frames encoding 271 and 269 amino acids, respectively. The deduced amino acid sequence of equine IL-1 alpha showed 71.6% and 60.2% similarity with that of human ...
Long MT, Goetz TE, Kakoma I, Whiteley HE, Lock TE, Holland CJ, Foreman JH, Baker GJ.Fetal infectivity of Ehrlichia risticii was investigated in 19 ponies that were E risticii negative on the basis of results of an indirect fluorescent antibody (IFA) test. Thirteen pregnant ponies were infected by IV administration of E risticii between 90 and 180 days of gestation. Six pregnant ponies served as noninfected controls. Each infected pony had clinical signs of equine monocytic ehrlichiosis, was confirmed to be ehrlichemic, and developed an IFA titer to E risticii. Two infected ponies became recumbent, were unresponsive to supportive care, and were euthanatized. After recovery fro...
Kortz GD, Madigan JE, Goetzman BW, Durando M.Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were determined in 8 clinically normal neonatal foals. After the foals oriented themselves and nursed the mares, they were sedated as necessary, and local anesthesia was provided for making the skin incisions. Using a technique similar to that used in human beings, an indwelling subdural catheter was placed to measure ICP. Carotid artery catheterization was used to measure arterial blood pressure. Cerebral perfusion pressure was calculated as the difference between mean arterial blood pressure and ICP. Intracranial pressure and ...
Barker SA.Advances in analytical technology now make it feasible to detect and confirm exceptionally low concentrations (pg to fg/mL) of drugs and their metabolites in equine biological fluids. These new capabilities complicate the regulatory interpretation of drug positives and bring into question the fair application of medication rules. Such approaches and policies are further complicated by the possibility that drug positives may arise from contamination of the equine environment on the backstretch of the race track. This manuscript provides data demonstrating that the general environment of the bac...
Gliatto JM, Alroy J.A horse with malignant lymphoma (histiolymphocytic) and cutaneous amyloidosis is described. The lymphoma involved the dura mater of the spinal cord and some of the peripheral lymph nodes. Multifocal amyloid deposits were present in the skin and subcutis of the ventral abdomen but not within the lymphoma cell infiltrates or in the viscera.
Kästner SB, Marlin DJ, Roberts CA, Auer JA, Lekeux P.The performance of a Fleisch No. 5 pneumotachometer (F), and two commercial ultrasonic pneumotachometers, the BRDL (B) and the Spiroson (S) systems were compared in respect to their use for determination of ventilatory parameters at rest and during lobeline-induced hyperpnoea. Five clinically healthy Thoroughbred horses were tested with the three pneumotachometers in random order. Respiratory airflow, respired gas concentrations, oesophageal pressures, pressures within the mask systems and arterial blood gases were determined before and during lobeline-induced hyperpnoea. Because measured peak...
Wafy MN, Hassan EA, El-Maaty AMA, Abu-Seida AM.Despite the extensive research on ocular ultrasonography, there is paucity of information regarding ocular biometry and color Doppler imaging of the donkey's eye. This study establishes B-scan ocular biometry and color Doppler ultrasonographic reference values in normal donkeys and describes effect of laterality, maturity and gender on ocular biometry and vasculature. Forty (80 eyes) clinically normal immature and mature donkeys of both sexes were included. Transpalpebral ocular ultrasonography was made using a 12-MHz linear transducer. Biometric ocular measurements were made including the ant...
King JN, Gerring EL.The effect of cisapride was evaluated on the normal fasting bowel motility of four ponies with chronically implanted electromechanical transducers. Cisapride was infused over 60-min periods at 0.05 mg/kg (n = 4), 0.1 mg/kg (n = 5) and 0.25 mg/kg (n = 5). It produced marked and prolonged increases in electrical and mechanical activity at all sites examined. In the stomach there was increased total contraction activity with increased contraction amplitude and a slight reduction in rate. In the small intestine there was an increase in irregular (phase II) activity with an increase in number and a...
Ishizuka T, Tamura J, Nagaro T, Sudo K, Itami T, Umar MA, Miyoshi K, Sano T, Yamashita K.Effects of intermittent positive pressure ventilation (IPPV) on cardiopulmonary function were evaluated in horses anesthetized with total intravenous anesthesia using constant rate infusions of medetomidine (3.5 µg/kg/hr), lidocaine (3 mg/kg/hr), butorphanol (24 µg/kg/hr) and propofol (0.1 mg/kg/min) (MLBP-TIVA). Five horses were anesthetized twice using MLBP-TIVA with or without IPPV at 4-week interval (crossover study). In each occasion, the horses breathed 100% oxygen with spontaneous ventilation (SB-group, n=5) or with IPPV (CV-group, n=5), and changes in cardiopulmonary parameters were ...
Schmidt A.Superficial mycoses caused by dermatophytes, as well as asymptomatic carriership of dermatophytes, have a high prevalence among domestic animals and pets. We examined 606 clinical specimens from skin lesions of animals with a significant tendency towards superficial mycosis due to their clinical features. Samples were obtained from horses, dogs, cats, small rodents, birds, and rabbits. The specimens were examined by microscopic and cultural techniques. Microscopically, there was no significant difference in the prevalence of structures which may develop fungal elements between the groups cultu...
Shaffer SK, Sachs N, Garcia TC, Fyhrie DP, Stover SM.To assess the motion of the proximal sesamoid bones (PSBs) relative to the third metacarpal bone (MC3) of equine forelimbs during physiologic midstance loads. Methods: 8 musculoskeletally normal forelimbs (7 right and 1 left) from 8 adult equine cadavers. Methods: Each forelimb was harvested at the mid-radius level and mounted in a material testing system so the hoof could be moved in a dorsal direction while the radius and MC3 remained vertical. The PSBs were instrumented with 2 linear variable differential transformers to record movement between the 2 bones. The limb was sequentially loaded ...
Recio P, López PG, Fernández JL, Garcia-Sacristán A.1. The presence and types of alpha and beta-adrenoceptors in the corpus cavernosum of the horse were studied in vitro by using selected ligands of adrenoceptors and isometric tension recording. 2. Noradrenaline and phenylephrine induced concentration-dependent contractions in corpus cavernosum preparations. B-HT 920 had no effect. 3. Phentolamine and prazosin produced a shift to the right of the dose-response curve of noradrenaline, while the alpha(2)-antagonist, rauwolscine had no effect on the response to noradrenaline. Phenylephrine-evoked contractions of corporal strips were significantly ...
Simpson KS, Adams MH, Behrendt-Adam CY, Baker CB, McDowell KJ.For development to proceed normally, the appropriate genes must be expressed in the correct tissues and in the correct time frame. Knowledge of gene expression during development provides information about the changes taking place within the conceptus as well as possible reasons for pregnancy failure. However, little is known about gene expression during development in the equine conceptus. In this study, we examined differences in gene expression between day 12 and day 15 equine conceptuses by suppression subtractive hybridization. This technique was used to isolate transcripts that are more ...
Bishop RC, Wilkins PA, Kemper AM, Stewart RM, McCoy AM.Nonsteroidal anti-inflammatory drug (NSAID) administration carries risks of gastrointestinal toxicity. Selective COX-2 inhibitors ("coxibs") were designed to reduce risks of adverse effects but are still associated with gastrointestinal complications in humans. The effect of coxibs on colonic inflammation and integrity in horses is unknown. The study objective was to compare the effects of the coxib firocoxib and the nonselective NSAID flunixin meglumine on ultrasonographic indicators of colonic inflammation in healthy horses. Twelve healthy adult horses were administered flunixin meglumine (1...
Giles C, Vanniasinkam T, Barton M, Mahony TJ.Equine adenovirus 2 (EAdV-2) is one of two serotypes of adenoviruses known to infect equines. Initial studies did not associate EAdV-2 infections with any specific clinical syndromes, although more recent evidence suggests that EAdV-2 may be associated with clinical and subclinical gastrointestinal infections of foals and adults respectively. In contrast, Equine adenovirus 1 is well recognised as a pathogen associated with upper respiratory tract infections of horses. In this study the complete genome sequence of EAdV-2 is reported. As expected, genes common to the adenoviruses were identified...
Black JA, Leaf G.1. The effects of cyanogen bromide on horse-heart cytochrome c and horse-heart myoglobin have been investigated. Cytochrome c yielded four fragments, of which two were haemopeptides. The two colourless peptides had amino acid compositions corresponding to those that are expected, on the basis of the sequence proposed for horse-heart cytochrome c by Margoliash, Smith, Kreil & Tuppy (1961), from cleavage at both methionine residues. Of the two haemopeptides, one was isolated and shown to be that derived from cleavage at only one methionine residue, that nearer to the C-terminus of the peptid...
Hallebeek JM, Beynen AC.In a cross-over study with six adult horses, the effect of isoenergetic replacement of dietary glucose by beetpulp on the concentration of plasma triacylglycerols was studied. The test ration contained 25% beetpulp in the dietary dry matter. The feeding of beet pulp lowered plasma triacylglycerol concentrations (p = 0.058) in the fasting state and raised the activity of heparin-released lipoprotein lipase (LPL) (p = 0.059) and the concentration of HDL2 cholesterol (p = 0.058). In the fasting state, the plasma concentrations of free fatty acids (p = 0.073) and those of beta-hydroxybutyrate (p =...
Burrows GE, Borchard RE.Grass hay produced in the Coeur d'Alene River Basin of northern Idaho was fed to a group of 4 ponies. The hay contained Pb in concentration of 423 +/- 82 mg/kg and Cd in concentration of 10.8 +/- 1.4 mg/kg, resulting in daily exposures of the ponies to approximately 7.4 mg of Pb/kg and 0.19 mg of Cd/kg/day. The results in this group of ponies were compared with those from a group fed noncontaminated grass hay and given a daily dose of 10 mg of Pb/kg of body weight, in the form of lead acetate. Clinical toxicologic signs, hematologic changes, and blood and tissue Pb concentrations were similar ...
Nagy AM, Sathe SR, Atta AH, Hammam AMM, Hsu WH.In equine parturition, the role of progestins along with the nuclear progesterone receptor (nPR) signaling pathway in the placenta is not completely clarified. The progestins play an integral role in maintaining myometrial quiescence during the late stage of pregnancy via acting on nPR isoforms (PRA and PRB; PRB is more active than PRA). The current study aimed to determine the PRA and PRB expressions in the term equine placenta at the gene and protein levels. Six term equine placentas were used in this study. Reverse transcription polymerase chain reaction (RT-PCR) was used to quantify the mR...
Watson ED, Thomson SR, Howie AF.A steroidogenic acute regulatory (StAR) protein has been identified in several species as a probable important rate-limiting step in steroidogenesis. This protein is believed to be responsible for transporting cholesterol from the outer to the inner mitochondrial membrane. It is known that equine chorionic gonadotrophin (eCG) stimulates steroidogenesis in the corpora lutea of early pregnant mares and that eCG also upregulates StAR mRNA in bovine ovaries. In the present study, ovarian tissue from cyclic and early pregnant mares was immunostained to detect the distribution of the StAR protein. W...
Possessing high meat and dairy productivity and good reproductive and adaptive qualities to year-round grazing, the Kushum breed plays an exceptional role in the improvement of productive qualities in horse herding in Kazakhstan and the former Soviet republics. The aim of the study was to develop breeding methods for creating new highly productive breeding lines for the Kushum breed horses. The leading method was linebreeding, which is based on the systematic use of remarkable animals, the offspring of which will accumulate and develop all the desired qualities and traits. The practical signif...
Kanitz W, Schneider F, Hoppen HO, Unger C, Nürnberg G, Becker F.The aim of the study was to investigate the effect of the GnRH agonist Buserelin given on day 10 after ovulation on pregnancy rate and concentrations of progesterone and LH. Altogether 191 warmblood mares were used for two trials. Fresh or frozen/thawed semen from 27 stallions was used for A.I. In trial A 171 mares received either Buserelin (Receptal, Hoechst, Germany, 40 microg/animal) or 10 ml 0.9% NaCl (placebo). On day 16 after A.I. pregnancy diagnosis was performed by ultrasound scanning of the uterus. For statistical analysis, data were analyzed by a mixed model, with four fixed factors ...
de Waal A, Potgieter FJ.Dehydration, to varying degrees, will inevitably occur in horses participating in endurance trail rides. This water loss is directly related to the amount of body water lost through evaporative cooling, that in turn being related to the amount and rate of work performed, and to the environmental temperature and humidity. An electronic apparatus that can substitute for the conventional and time-consuming venous haematocrit was developed to measure the animals' hydration status. The mechanism of this electrometer is based upon the relationship between the red cell content and the electrical cond...
