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.
Brook D, Schmidt GR.A case of pre-renal azotaemia is described in a 12 year old pony resulting from oesophageal obstruction of 8 days duration. Blood urea nitrogen, creatinine, calcium, inorganic phosphate, sodium, potassium, chloride and bicarbonate concentrations were monitored throughout the recovery period. After relief of the obstruction normal blood concentrations were quickly restored.
Vivrette SL, Irvine CH.Acyclic mare given oestradiol for 3 days to simulate the preovulatory plasma oestradiol surge showed a non-significant 37% decrease in plasma LH during treatment. When GnRH analogue injections were given with oestradiol on Days 1--3, oestradiol had no effect on each GnRH-induced LH increase, but LH increases were more prolonged following subsequent GnRH injections on Days 4--7 when oestradiol was no longer being given. A much greater prolongation of LH release occurred when the course of GnRH injections was commenced after oestradiol treatment ceased; the LH response was almost identical to th...
Merkt H, Jacobs KO, Klug E, Aukes E.An evaluation of the foaling rate achieved in the Hannoverian breed in Germany between 1815 and 1973 showed that during this period no improvement of the reproductive rate was achieved. The decennial foaling percentage remained within 50--60% except for those decades which included the two World Wars and their aftermaths. The annual foaling percentage remained maximal until the number of mares covered/stallion rose above 80 and it also remained high throughout the reproductive life of the stallion. Only in the oldest stallion (32 years) was there a significant lowering of fertility.
Mia AS, Koger HD.Serum concentrations of arginase, glutamic pyruvic transaminase (SGPT) and glutamic oxaloacetic transaminase (SGOT) in dogs, cats, horses, cattle, sheep and pigs were determined before and after oral administration of CCl(4) at doses known to cause hepatic necrosis. Following CCl(4) administration, serum concentration of arginase and SGOT increased to a level of diagnostic significance in all animals. SGPT increased markedly in dogs and cats and marginally in 1 of 3 cattle and 2 of 3 pigs. In the surviving animals, the serum concentration of arginase returned to normal range much earlier than ...
Günzel AR, Merkt H.Of 383 mares showing clinical evidence of suspected early fetal resorption between 20 and 60 days after mating, 217 were treated with a single injection of 200 mg CAP (a synthetic progestagen); the remaining 166 mares served as untreated controls. Treatment had neither a beneficial nor a detrimental effect on the continuation of pregnancy. Conception rates following loss of the conceptus were higher in lactating than in non-lactating mares. No increase in number of twin or deformed foals was evident in the treated animals.
Garcia MC, Freedman LJ, Ginther OJ.A working hypothesis for the regulation of LH secretion in the mare is postulated which involves the following two components: (1) a primary central nervous system (CNS)-pituitary component which is responsible for a basal circannual LH rhythm, entrained to an environmental 'Zeitgeber' (most probably photoperiod) and independent of ovarian influences, and (2) a secondary ovarian (steroidal) component which modifies the primary rhythm during the ovulatory season. This hypothesis does not seem to apply in its entirety to FSH secretion; the CNS-pituitary component is demonstrable within the first...
Hyland JH, Bristol F.Oestrus was synchronized in 116 mares by means of an i.m. injection of prostaglandin F-2 alpha (Day 0) and of fluprostenol (a PG analogue) on Day 16. Mares were then randomly divided into three groups. Group A mares (N = 30) were given 2500 i.u. hCG I.M. ON Day 20 and artificially inseminated on Day 21 without detection of oestrus. Group B mares (N = 32) were given 2500 i.u. hCG i.m. on Day 20 and inseminated on Days 21 and 23, also without oestrus detection. Group C mares (N = 54) were teased on Days 18, 19, 21, 23 and 25 and inseminated on Days 19, 21, 23 and 25 while they were in oestrus. S...
Yamamoto M, Tanaka Y, Sugano M.1. Changes in lipid components of lipoproteins during incubation of horse serum at 37 degrees C were investigated. In non-incubated serum, cholesterol and lecithin existed predominantly in alpha-lipoprotein or in high-density lipoprotein (HDL). Lysolecithin was mainly associated with the fraction with density above 1.21. 2. When serum was separated into alpha- and beta-lipoproteins by the heparin precipitation method after 1 hr incubation, the decrease in alpha-lipoprotein free cholesterol and lecithin was about four times that in beta-lipoprotein counterparts. 3. When serum lipoproteins were ...
Webb AI, Weaver BM.Seventeen horses were dissected and their organs and tissues weighed. The results of these dissections are presented together with comparisons of the data with that already available in the literature. Predictive equations for organs and tissue weights are also given which were derived by comparison of linear and allometric regression models using 4 different body weight indices.
Yamamoto M, Tanaka Y, Sugano M.1. The lipid composition of serum and liver and some properties of serum lecithin: cholesterol acyltransferase of the horse were investigated. 2. Phospholipids and cholesterol were the major components of serum lipids and the concentration of triglyceride was considerably low. The concentration of liver lipids was comparable with that of other mammals. 3. Fatty acid composition of serum cholesterol ester resembled that of the 2-position of lecithin, except palmitic acid. 4. The activity of serum cholesterol esterifying enzyme was found to be 0.03-0.09 mumol/hr per ml. There was an equimolar de...
Rose RJ, Ilkiw JE, Martin IC.The effects of prolonged strenuous exercise on arterial and venous oxygen tension, carbon dioxide tension, pH, bicarbonate, standard bicarbonate, base excess, haemoglobin, packed cell volume and total plasma protein were studied in 36 horses during a 100 km endurance ride. There were significant changes in many parameters when pre-ride values were compared with both mid-ride and end of ride values. The prominent changes were the development of dehydration and a metabolic alkalosis. At the mid-ride sampling time those horses with higher heart rates had a greater degree of metabolic alkalosis th...
Sharp DC, Vernon MW, Zavy MT.Oestrous behaviour, ovarian follicular development, ovulation and changes in hair coat were observed in Pony mares which were unoperated, sham-ganglionectomized control or bilaterally superior cervical ganglionectomized. Surgery was performed during the winter anoestrus (1975--1976). Reproductive patterns in all groups were similar during the first breeding season (1976) after operation but in ganglionectomized mares the onset of the next breeding season (date of first ovulation in 1977), the pattern of follicular development, date of first oestrus and pattern of hair coat changes were all sig...
Evans MJ, Irvine CH.Deeply acyclic (seasonally anovulatory) mares were treated with GnRH or a GnRH analogue to induce follicular development and ovulation. Courses of GnRH (3--4) were administered at approximately 10-day intervals to reproduce the gonadotrophin surges which precede ovulation in the normal cycle. Exogenous progesterone was administered in an attempt to reproduce the luteal phase pattern. Induced serum FSH concentrations were comparable to those causing follicular development in the normal cycle, but induced LH levels were lower and of shorter duration than those of the periovulatory surge. Three o...
Matthews AG.Evidence is presented to suggest that the acidic prealbumin esterases in horse serum represent a protease-inhibitory protein. The esterase activity may arise from residual enzymic activity of the bound protease.
Zavy JT, Mayer R, Vernon MW, Bazer FW, Sharp DC.Uterine flushings were collected from 30 non-pregnant Pony mares on Days 8, 12, 14, 16, 18 or 20 after oculation. Mares were allowed a recovery period of one oestrous cycle and were mated at the next oestrus. They were then ovario-hysterectomized on days which corresponded to the day of the oestrous cycle to which they were assigned. Uterine flushings were analysed for total recoverable protein and acid phosphatase activity. Least squares analysis indicated a status X day interaction for total protein (P less than 0.10) and acid phosphatase activity (P less than 0.005) in which the latter was ...
Evans JW, Hughes JP, Neely DP, Stabenfeldt GH, Winger CM.Jugular blood samples were obtained from 8 mares at 5- and/or 20-min intervals for 2 to 5 days during various phases of the oestrous cycle for plasma LH determination. An episodic release pattern was observed in 1 of 3 mares sampled during the ovulatory period. One mare had one secretory burst and the other mare had several periods of fluctuating plasma LH concentration. During dioestrus, episodic secretions were observed in 2 mares sampled 11 to 13 days before and, in 1 mare, 9 days after ovulation. During the 2 to 5-day period before ovulation, episodic secretion was not observed (3 mares) b...
Butterfield RM, Matthews RG.Data from 937 Thoroughbred mares, when analysed as a single population, showed no significant difference between the activity of the right and left ovaries and the frequency of location of 35-day pregnancies in the right and left uterine horns. Nor were any differences shown when the data were analysed in years or sire groups. However, significantly more ovulations occurred in the right ovary in September and December and in the left ovary in October and November. Whereas the left and right ovulations were equal in lactating and dry mares, there was a highly significant increase in the number ...
Flood PF, Betteridge KJ, Irvine DS.Six samples of blastocoele fluid recovered between 10 and 22 days gestation were tested in human clinical radioimmunoassay systems measuring total oestrogens and total androgens. The results were erratic but in 5 cases measurements for oestrogen equivalent to between 1000 and 70,000 pg/ml and for androgen between 1000 and 85,000 pg/ml were recorded. Cells from two blastocysts were cultured in medium 199 with and without horse serum. When the used media were assayed, values equivalent to at least 8000 pg oestrogen/ml were obtained on 7 of 11 occasions. In 9 of 11 samples the androgen concentrat...
Goch H, Schiller B, Korbecki M.F(ab')2 fragments of horse tetanus antibodies were obtained from horse hyperimmune sera after peptic digestion. The digest was passed through a column of tetanus toxoid coupled with Sepharose 4B, F(ab')2 fragments were eluted with a solution of 5 mM HCl in 150 mM NaCl and the eluates were concentrated by ultrafiltration and lyophilized. Glycine and human serum albumin were used as stabilizing agents. Polyacrylamide gel electrophoretic mobility and molecular weight of the fragments remained unchanged after lyophilization. Freeze-dried preparations stored two months at 56 degrees C showed only a...
Raeside JI, Liptrap RM, McDonell WN, Milne FJ.Plasma levels of total oestrogens and dehydroepiandrosterone (DHA) were measured by radioimmunossay in samples taken from various blood vessels in both maternal and fetal compartments in 11 Pony mates. High concentrations of oestrogens (greater than 100 ng/ml of plasma), expressed as oestrone equivalents, were found in the fetal circulation. On both the fetal and maternal sides, oestrogen concentrations were lower in blood going to than from the placenta. DHA concentrations, on the other hand, were higher in blood flowing to the placenta from the fetus. The fetal gonads were seen as the source...
Stratton LG, Corstvet R, Brown J, Corley L.K. pneumoniae capsule type 68 infused into the uterus of 4 mares was recovered up to 15 weeks after inoculation. The insertion of a tampon for 10 min was more effective than a swab technique in detecting the organism in the uterus. The clitoral fossa and the urethral orifice when sampled by the swab technique were also found to be infected for a comparable period. K. pneumoniae was isolated from the clitoral specimens more often and more consistently than from either urethral or uterine specimens.
Marqués FJ, Hehenberger E, Dickinson R, Wojnarowicz C, Lohmann K.A 9-year-old, 1494-lb (679-kg) Quarter horse gelding in good body condition was admitted to the Veterinary Teaching Hospital, Western College of Veterinary Medicine (WCVM), University of Saskatchewan, for evaluation and treatment of acute respiratory distress. On a trail ride 26 days before presentation, the gelding had been exposed to a horse with clinical signs of an upper respiratory tract infection. The gelding performed well on the trail ride but, 4 days later, developed a mild swelling in the retropharyngeal area and a slight bilateral mucoid nasal discharge. The gelding was examined at ...
Roach J, Arango Sabogal JC, Smith K, Foote A, Verheyen K, de Mestre AM.Risk factors associated with equine reproductive efficiency have been identified along with those associated specifically with early pregnancy loss (EPL). In contrast, no studies have reported risk factors associated with abortion (loss between day 70 and 300 post-cover). Given the causes of abortion differ to those of EPL, likely too will the risk factors. A retrospective cohort study was carried out to identify risk factors associated with abortion in UK and Irish based Thoroughbreds, collecting data on 20 exposure variables over a five-year period. A generalized linear mixed model was utili...
Wakuri H, Sakuma Y, Mutoh K, Watanabe S.In 6 equine specimens of both sexes, the morphological features of the cleavage lines of the skin over the entire body were examined using a metal probe with a sharp conical point. Wounds were produced on the skin with the probe and painted with Chinese white or Indian ink. The direction of running of the cleavage lines was determined from their relationship to the long axis of each region or area of the physical structure. The cleavage lines of the head and face revealed a fixed pattern in all specimens. They were similar to those of equine fetuses of 6 to 7 months of age. A transverse patter...
Weiser MG.Using a single channel electronic cell counter and attached particle size analyzer, leukocyte size distribution histograms were determined on canine, feline, bovine, and equine blood diluted with chloride-based diluent and treated with a conventional stromatolysin. Histograms were usually unimodal, but a few were bimodal. Mean values for mean lysed leukocyte particle volume were 49.2, 51.1, 55.4, and 65.0 fl for canine, feline, equine, and bovine blood, respectively. From inspection of histograms, a lower threshold of 30 fl referenced to latex spheres was interpreted to be appropriate for coun...
Zuffa T, Bennet ED, Parkin TDH.Endurance riding is a popular equestrian sport organised at the international level by the Fédération Équestre Internationale (FEI). The sport involves prolonged exercise at speed over significant distances, which puts a substantial load on equine athletes' musculoskeletal systems and metabolism and contributes to the risk of injuries and other veterinary problems. The FEI employs a system of in-ride veterinary inspections aimed at early detection of such problems and elimination of horses unfit to continue in the ride. To date, risk factors for elimination due to irregular gait or metaboli...
Budras KD, Schiel C, Mülling CK, Patan B.The preparation of hard tissues such as the equine hoof horn for electron microscopic examination is very difficult. In particular the penetration of fixatives and chemicals used during fixation and embedding is a problem. The objective of this study was to find and implement an alternative method enabling the preparation of high-quality thin sections of hoof horn and other hard tissue, which maintains the hard tissue ultrastructure and can be used for immuno-labeling. Compared to commonly used fixation and embedding techniques, the preparation of thin sections from untreated material method s...
Lewczuk D, Metera-Zarzycka E.Many horse breeds in the world are reserved as genetic resources; however, their characteristics seem to be insufficiently clarified, especially in terms of horse performance. Two jumping ability evaluation methods have been used to compare different types of performance breeds and on this basis their applicability for precision phenotyping has been determined. Methods: Jumping data of 186 young Polish Warmblood stallions (27 with an endangered status) bred for sport and multipurpose use was collected during their performance tests organised under identical environmental conditions following t...
Marr K, Marsh K, Hernandez L, Cunningham FM, Lees P.Leukotrienes, products of the 5-lipoxygenase pathway of arachidonic acid metabolism, possess properties consistent with their involvement in a range of inflammatory diseases. In this study the pharmacokinetics and pharmacodynamics of the selective 5-lipoxygenase inhibitor, fenleuton, have been examined in the horse. Orally administered fenleuton (four 5 mg kg(-1) doses, given once daily) was absorbed from the gastrointestinal tract, and penetrated readily into tissue cage exudate, the ratio of the plasma:exudate AUC0-48h being 0.90+/-0.02 (n=6). Ionophore-stimulated leukotriene (LT) B4 synthes...
Gaughan EM.Skeletal origins of exercise intolerance and performance failure can reside in multiple tissues. Diagnosis of injury that results in an ability to continue to exercise, yet inefficiently do so, requires familiarity with evaluation of subtle lameness and often with the specific demands of the different equine sports. Imaging is usually vital to diagnosis development and understanding of lesion influences on locomotion. Therapy is lesion dependent. Return to competitive exercise and performance is dictated by an understanding of skeletal tissue response to injury, rational progressive treatment,...
Balasuriya UBR.The primary goals of this chapter are to discuss common viral RNA isolation and purification methods that are routinely used by various diagnostic laboratories and to highlight the advantages and drawbacks of each method and to identify the most suitable and reliable method to increase the sensitivity and specificity of RT-PCR assays for the detection of equine influenza virus (EIV) in clinical specimens. Our experiences and review of literature show that magnetic bead-based nucleic extraction methods (manual and automatic) work well for isolation and purification of EIV RNA from nasal swab sp...
Orsini JA.The multiple topics summarized in this article and discussed in detail in this issue of VCNA are comprehensive and in-depth, exploring concepts and clinical experiences for state-of-the-art care of the equine foot. The research on the equine foot will translate to the clinical setting and with this the compassionate care of the horse.
Drudge JH, Lyons ET, Tolliver SC.Controlled tests of the efficacy of bot-active compounds, dichlorvos, trichlorfon, trichlorfon butonate, and carbon disulfide on the larvae of Gasterophilus intestinalis and Gasterophilus nasalis during their migratory period in the tissue of the mouth of horses and ponies were completed on experimentally induced and naturally acquired infections. Against the experimental parasitisms in pony foals, the resin-pellet formulation of dichlorvos given on the feed at the dose level of 37 mg/kg, 2 formulations of trichlorfon given by stomach tube at the dose level of 40 mg/kg, another of trichlorfon ...
Albanese V, Mereu M.Pelvic abscesses occur in horses of all ages and breeds. Although conservative management may be successful, surgical drainage may be necessary for larger abscesses or in case of secondary intestinal obstruction. The purpose of this report is to describe two cases of pelvic abscesses that were successfully drained using indwelling chest tubes, repeated lavages and targeted antibiotic treatment.
Jann HW, Cook WR.Monopolar electrosurgical cutting was used to correct epiglottal entrapment in 5 horses. The operations were carried out in the conscious animal, using topical anesthesia. The procedure required the use of a coagulation electrode designed specifically for electrosurgery, introduced through the instrument channel of a fiberoptic endoscope. The results were satisfactory and serious complications were not encountered. In 2 horses, excessive submucosal swelling developed at the site of the surgical wound, and the tumefaction took several weeks to subside in one of these horses. In both horses, the...
Charnock LN, Davidson MG, Keys DA, Gilger BC, McMullen RJ.To evaluate the normal refractive state in horses in NCSU and ECMR and determine the prevalence of naturally occurring refractive errors and their association with breed, age, coat color, iris color, sex, and geographic location. Methods: Horses from NCSU (January 2009-November 2012) and ECMR (January 2013-September 2016) underwent ophthalmic examination and streak retinoscopy. Location, color, breed, sex, and iris color were recorded. Gross and net refractive values for each meridian (horizontal and vertical), spherical refraction, astigmatism for both eyes, and anisometry were recorded, and ...