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.
Clark ES, Becht JL.This article discusses the various drugs that affect the equine gastrointestinal tract. Drugs that alter intestinal motility, that protect the gastrointestinal tract, and that alter secretions, as well as analgesics, appetite stimulants, and orally administered antimicrobial agents are reviewed.
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.
Caprile KA, Short CR.Rational drug therapy in the foal requires a sound knowledge of the pharmacodynamics and pharmacokinetics of various drugs as well as a thorough understanding of the physiologic differences that exist between the neonate and the adult and that may serve to alter drug disposition and, therefore, drug response. A summary of these physiologic factors with emphasis on the foal is presented and is followed by recommendations regarding the applied therapeutics of various antimicrobial agents.
Greene SA, Thurmon JC, Tranquilli WJ, Benson GJ.Serum insulin and plasma glucose concentrations were determined in 8 mares. Four IV treatments were studied: xylazine (1.1 mg/kg of body weight); yohimbine (0.125 mg/kg); yohimbine (0.125 mg/kg) followed 5 minutes later by xylazine (1.1 mg/kg); and 5 ml of isotonic saline solution as a control. Blood samples were collected before (time 0) and at 5, 15, 30, 60, 120, and 180 minutes after drug administration. Serum insulin concentration decreased and plasma glucose concentration increased in mares given xylazine. Plasma glucose concentration was unchanged in control mares and in mares given yohi...
Brumbaugh GW.The goal of antimicrobial drug use is quite specific. Consideration of many microbe-related, host-related, and drug-related factors is necessary for appropriate selection and use of antimicrobial drugs in equine patients. The concepts and data presented in this article demonstrate that fact. At the risk of oversimplification, "The bug denotes the drug, and the horse directs the course."
Ho CL, Ko JL, Li CH.The peripheral opioid activity of six homologous beta-endorphins (beta-EPs) were assayed on the guinea pig ileum and the vas deferens of the mouse, the rat and the rabbit. In the guinea pig ileum assay, human beta-EP (beta h-EP) was less potent than camel, turkey, and ostrich beta-EPs, of the same potency as equine beta-EP and more active than des-acetyl salmon beta-EP. In the rat vas deferens, mammalian beta-EPs showed higher activity than those from the bird and the fish, whereas in the mouse vas deferens assay, beta h-EP is more active than those from other species. In the rabbit vas defere...
Clark ES, Semrad SD, Bichsel P, Oliver JE.Cystometrography and urethral pressure evaluations were performed in 7 horse mares and 5 pony mares before and after sedation with xylazine. Before sedation, mean (+/- SD) maximal bladder contraction pressure was 91.4 +/- 16.5 cm of H2O in horses and was 86.0 +/- 14.4 cm of H2O in ponies, and maximal urethral closure pressure was 49.1 +/- 19.4 cm of H2O in horses and 37.7 +/- 14.4 cm of H2O in ponies. A significant difference was not found between values of nonsedated vs sedated animals. Only values for threshold volume were significantly different (P less than 0.05) between nonsedated horses ...
Roussel AJ, Lin YC, Strait JR, Modransky PD.Radioimmunoassay for parathyroid hormone (PTH) in equids was performed on blood samples from healthy equids and equids with hypercalcemia and hypophosphatemia. The assay was validated for equine carboxy-terminal PTH. Manipulation of serum ionized Ca in healthy equids by infusing Na2 EDTA and CaCl2 produced an expected increase and decrease, respectively, in measurable immunoreactive PTH. Intra-assay and interassay coefficients of variation were 2.6% and 11.7%, respectively. The range of PTH valves for healthy mature horse mares and geldings maintained on pasture was less than 0.27 ng/ml to 0.9...
Clark ES, Morris DD, Whitlock RH.Esophageal pressure events during deglutition were evaluated in healthy adult animals (6 horses, 6 cattle, and 5 sheep), using a 3-side hole catheter assembly perfused with water by use of a hydraulic-capillary infusion system. The peak postdeglutition pressure, contraction time, and contraction length were determined for the cranial and caudal esophageal sphincter regions and for each functionally different region within the body of the esophagus. The percentage of deglutitions in which relaxation developed at the sphincter regions and the propagation speed (velocity at which pressure waves t...
Urasawa S, Urasawa T, Ishizawa F, Taniguchi K.Bovine and equine sera were screened for poliovirus-reactive immunoglobulins (PRIgs) by means of neutralization and precipitation reactions with type 1 poliovirus. Bovine serum B1826 and B36 were found to contain such PRIgs from their reactivity to various PRIgs-resistant mutants of type 1 poliovirus origin. Neutralization and precipitation reactions with six mono-specific antibodies obtained by absorbing antiserum with each of the six different PRIgs-resistant virus mutants revealed that three antibodies were active in precipitation reaction while the others were substantially ineffective. On...
Cabañes FJ, Abarca L, Bragulat MR, Calvo MA.The ability of 17 strains of Epidermophyton to perforate hair in vitro using the Ajello & Georg's test procedure and a modification of Lu's method has been studied. Following the Ajello & Georg's test procedure only E. stockdaleae perforated hair. Sporadically some strains of E. floccosum perforated horse hair. We noted as well unusual perforations originated from inside to outside of the hair. By the other technique, all strains, excepting E. floccosum var. nigricans in child hair, perforated hair. E. floccosum showed these perforations later than E. stockdaleae.
Kastelic JP, Adams GP, Ginther OJ.Luteal progesterone was removed by an injection of prostaglandin F2alpha or bilateral ovariectomy on Day 12 of pregnancy in pony mares. The embryonic vesicle remained mobile in the uterus until loss occurred on Days 13, 13, 15, or 19 in four prostaglandin-treated mares and Days 15, 17, 19, or 26 in four ovariectomized mares. Exogenous progesterone given daily, starting on Day 12, maintained pregnancy until Day 40 in five of five prostaglandin-treated and three of four ovariectomized mares. During two-hour mobility trials on Day 14, embryonic vesicles in mares without luteal or exogenous proges...
Payne SL, Salinovich O, Nauman SM, Issel CJ, Montelaro RC.Comparisons of peptide and oligonucleotide maps of glycoproteins and RNA from nine isolates of equine infectious anemia virus (EIAV) that were generated during parallel infections of two Shetland ponies revealed that each isolate was structurally unique. Each EIAV isolate contained a unique subset of variant peptides, oligonucleotides, or both, indicating that structural variation in EIAV is a random and noncumulative process and that a large spectrum of possible EIAV variants can be generated in infected animals.
Weaver AD.The case records of 13 horses with acquired incarcerated inguinal hernia in January-August 1983, were reviewed. Nine cases were in stallions. The remaining four involved eventration 5-48 hours following castration. Ages ranged from 1-17 years. Horses showed a variable degree of colic. Bowel was felt to pass through the internal inguinal ring on rectal examination in most cases. The physical features of the scrotum varied considerably. Resection of ischemic jejunum and/or ileum was necessary in three horses. Two horses were euthanized at surgery (one with bilateral ischemic jejunum, one with bo...
Squires EL, McKinnon AO.Because the reproductive performance of mares is lower than that of any other domesticated species, hormone therapy is important in ensuring fertility and proper management of pregnancy. Current techniques of hormone therapy are discussed.
Berrocal A, van den Ingh TS.The pathological findings in three cases of equine phycomycosis in Costa Rica are described. Two cutaneous (Pythium sp) and one nasal lesion (Conidiobolus) were observed.
Wells M, Gaffin SL.Passive immunotherapy with anti-lipopolysaccharide hyperimmune equine plasma (Anti-LPS) is effective in treating experimental Gram-negative bacterial infections. The bactericidal activity of anti-LPS towards five different Pseudomonas species, including two multiresistant Pseudomonas aeruginosa isolates was tested here, as well as the ability of anti-LPS to inhibit the quantitative chromogenic limulus amoebocyte lysate (LAL) assay. Anti-LPS caused a mean reduction of 84.4 +/- 3.2% (P less than 0.001) in the number of colony forming units (cfu) of all isolates, whereas saline and complement ina...
Thurmon JC, Benson GJ.The purpose of this article is to review the use of selected anesthetics and anesthetic adjuncts in horses. Emphasis is placed on the pharmacologic bases of their use.
Anderson WI, King JM, Rothwell JT.Segmental atresia of the transverse colon was observed at necropsy in a neonatal foal. The dorsal and ventral components of the large colon were fused, and ended blindly. The small colon was collapsed and completely closed at its cranial end. The right and left dorsal and ventral colons were fused into one blind-ended tube. Histologically, eosinophilic intranuclear inclusion bodies demonstrative of Equine Rhinopneumonitis were present in the thymus.
Kelso TB, Hodgson DR, Visscher AR, Gollnick PD.Several biochemical components of the white portion of the gastrocnemius (WGM), plantaris (PM), and soleus (SM) muscles of the rat and middle gluteal (MGM) muscle of the horse were compared based on wet and dry weight, protein, and total creatine concentrations ([TCr]). The water content was similar for the rat hindlimb muscles, however, the concentrations of protein, ATP, phosphocreatine (PCr), creatine, and glycogen ranked as SM less than PM less than WGM for all reference bases except total creatine. In contrast, concentrations of ATP, creatine, and PCr were similar in all muscles studied w...
Huxtable CR, Chapman HM, Main DC, Vass D, Pearse BH, Hilbert BJ.A severe paretic syndrome accompanied by intense neuronal lipofuscinosis is described in sheep and horses exposed to Trachyandra divaricata. This is a newly recognised toxic hazard for grazing livestock in the coastal region of the south west of Western Australia. Animals appear to become affected over a period of weeks when summer conditions induce a scarcity of alternative feed. The disease is discussed in relation to its recent documentation in South Africa where the plant is indigenous.
Manohar M.It has been reported in exercising ponies that O2 supply to all regions of the brain increased primarily due to a large increment in CaO2 and it was implied that this may reflect a generalized increase in brain metabolism during strenuous exercise. Splenectomy ameliorates the rise in CaO2 observed with exercise in ponies. Thus, the objective of the present study was to examine changes in regional brain blood flow and O2 supply of splenectomized ponies with sub-maximal and maximal exercise and to compare these data with previous observations in normal ponies. It was reasoned that in the absence...
Bürger HJ, Bauer C.In order to confirm benzimidazole resistance as recommended at a workshop of the Commission of the European Communities the isolate 'E' of cyathostome strongyles originating from a stud where benzimidazole resistance had been demonstrated by egg hatch tests and by egg count reduction tests was investigated in two series of critical tests. Each of 11 foals reared strongyle-free was infected with 130,000 third stage cyathostome larvae. One animal remained untreated, two pairs of foals were treated with paste formulations of the (pro)benzimidazoles cambendazole (20 mg/kg bodyweight) or febantel (...
Watkins SB, Watney GC, Hall LW, Houlton JE.After premedication with intravenous xylazine 30 ponies were anaesthetised for castration under field conditions with intravenous ketamine, thiopentone or methohexitone. The duration of anaesthesia was adequate for surgery and the times taken to stand were similar in each group. The recovery of the ponies after ketamine was quieter than after either of the barbiturates and this may be an advantage when skilled assistance is lacking. However, all the anaesthetics appeared to be suitable for performing minor surgery in the field.
Enbergs H.Measuring serum or plasma levels of progesterone can be used to determine if conception has occurred in horses. If the mare's progesterone level is below 2 ng/ml 18 days after mating has occurred, conception has not taken place. This method can be used as an addunct to genital examination, and it can be used to determine if hormonal irregularities are present in mares who have not been able to conceive.
Clegg PD.A mature thoroughbred-cross gelding developed chronic severe hindlimb lameness. Despite intensive clinical investigation, the diagnosis of infective arthritis of the coxofemoral joint was difficult, and a definitive diagnosis was reached only after synoviocentesis of the joint. The horse was euthanased and examined thoroughly post mortem but no definitive aetiology for the condition was discovered.
This year's Association of Veterinary Students' congress was held at the University of Liverpool, and included a varied programme, with subjects ranging from the role of large-scale production systems in dairy farming and fertility practices in horses to the importance of recognising and talking about mental health problems within the veterinary profession. Jordan Sinclair, editor of the Journal of the Association of Veterinary Students, reports.
Causey RC, Paccamonti DL, Todd WJ.A total of 22 clinical streptococcal isolates, predominantly Streptococcus zooepidemicus, associated with endometritis in horses were tested for their ability to withstand the natural bactericidal properties of freshly obtained blood. During a 3-hour incubation in blood from a single horse, 8 of these isolates survived and grew, the remainder were killed. To determine whether this ability to grow extended to blood of other horses, 5 of these growing isolates were tested for their ability to grow in the blood of 5 additional horses. The same 5 horses were used for each isolate. The isolates gre...
Gauvreau GM, Young SS, Staempfli H, McCutcheon LJ, Wilson BA, McDonell WN.A valved gas collection system for horses was validated, then used to examine the relationship between the respiratory exchange ratio (RER), and plasma and muscle lactate in exercising horses. Four healthy Standardbred horses were trained to breathe through the apparatus while exercising on a treadmill. Comparisons of arterial blood gas tensions were made at 3 work levels for each horse, without (control), and with the gas collection system present. At the highest work level, the arterial oxygen tension (PaO2) was significantly lower (P < 0.05), and the arterial carbon dioxide tension (PaCO2) ...
Oge S, Oge H, Yildirim A, Kircali F.Necropsies on 43 horses, 35 donkeys and two mules slaughtered in Ankara, Turkey, revealed that 12 (15%) of the equines harboured adult Setaria equina. When blood samples were checked for microfilariae, using Knott's method and a combination of membrane filtration followed by histochemical staining for acid phosphatase (AP), only three (4%) of the animals were found to be microfilaraemic. When stained for AP, the S. equina microfilariae exhibited diffuse red staining over the entire body, including the sheath, with brighter staining around the anal and excretory pores. Application of Knott's me...
Brink P.To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. Methods: Clinical study. Methods: Three horses with chronic oromaxillary sinus fistula. Methods: After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures t...
Glaze MB, McGuire TC, Schmidt GM, Leid RW.A quantitative investigation of equine tear and aqueous humor immunoglobulins was done using normal horses and ponies as well as horses and ponies infected with Onchocerca cervicalis. The equine immunoglobulin isotypes IgGa, IgM, IgA and IgG(T) were quantitated by either single radial immunodiffusion (SRID) or radioimmunoassay (RIA). Tear immunoglobulin levels for IgGa (128 +/- 151 micrograms/ml), IgA (1,664 +/- 1,038 micrograms/ml) and IgM (106 +/- 74 micrograms/ml) were measured, while IgG(T) was not detectable. In horses with ocular inflammation the IgGa was 18-fold higher in the tears, 2,2...
Olive J, Lambert N, Bubeck KA, Beauchamp G, Laverty S.To ultrasonographically quantify experimentally induced effusion of the distal interphalangeal (DIP) joint of horses and compare results with those obtained with palpation. Methods: 8 forelimbs from equine cadavers and forelimbs of 5 mares. Methods: Preliminary ex vivo experiments were performed to validate the methods. Then, the DIP joints of the forelimbs of standing horses were serially distended with saline (0.9% NaCl) solution (1, 4, and 10 mL) by injection through an intra-articular catheter. Two ultrasonographers measured distension of the dorsal recess of the DIP joint, and 2 surgeons,...
Raisbeck MF, Garner HE, Osweiler GD.Gram negative endotoxins play a contributory role in the syndrome which results from over consumption of carbohydrates by horses and ponies. Since the antibiotic polymyxin B exerts a direct anti-endotoxin effect by chemically modifying the active lipid A moiety of endotoxin, it might be expected to protect horses after carbohydrate overload and provide a new therapeutic and experimental tool for this condition. The present study was undertaken to evaluate the effect of polymyxin B on hemostatic, hemodynamic, acid-base, and clinical aspects of the syndrome resulting from carbohydrate overload. ...
Rupić V, Bacar-Huskić L, Lojkić M, Habe F, Ergotić N.Research was carried out into the effect that different quantities and compositions of concentrated portions of meal had on certain haematological properties and on the immune response of mares in the course of hyper-immune antitetanus sera production. The experiment involved 24 Nonius and Lipizzaner cross-bred mares divided into two groups of 12 animals each, a control group and a trial group. The experiment lasted 12 months, with haematological and immunological tests being carried out every 30 days. During the course of the experiment each mare was subjected to 11 immunisation cycles, and i...