"Horses" is a broad topic that encompasses various aspects of equine biology, behavior, and management. This category includes studies on the anatomy, physiology, and genetics of horses, as well as their behavior, nutrition, and care. Research in this area may also cover the historical and cultural significance of horses, their roles in agriculture, sport, and therapy, and the challenges associated with their conservation and welfare. The page aggregates peer-reviewed research articles and scholarly studies that explore the multifaceted relationships between humans and horses, examining both scientific and socio-economic perspectives.
Snow DH, Ricketts SW, Mason DK.The haematological response to racing and to fast and slow training exercise was investigated in studies involving two populations of horses which differed widely in geographical location, climatic factors and management (Newmarket and Hong Kong). The well documented elevations in erythrocyte parameters were demonstrated and changing responses in leucocyte parameters, resulting in variations in the neutrophil to lymphocyte (N/L) ratio were described. It was shown that the immediate response to the anticipation or stress of exercise was a decrease in N/L ratio in association with an increase in...
Johnstone IB.Nonsteroidal anti-inflammatory drugs are commonly used in the treatment of inflammatory conditions, and have potential value in the treatment of thrombotic disease in the horse. This study compares the potency of three nonsteroidal anti-inflammatory drugs phenylbutazone, naproxen (equiproxen) and flunixin meglumine (banamine) with respect to their effects on equine platelets. Two functional responses of horse platelets were evaluated in vitro: their ability to aggregate and their ability to make available platelet factor 3 procoagulant activity. Flunixin at a concentration of 10(-6) M signific...
Ginther OJ.Fixation and orientation of the conceptus within the uterine lumen of 40 barren mares were examined by ultrasound daily on days 11-21 and at three-day intervals thereafter until day 48. The growth curve of the in situ conceptus had a distinct plateau between days 17-24, as determined by measurements of the width and area of conceptuses on the ultrasound images. The vesicle expanded at an average daily rate of 3-4 mm before the plateau and 2-3 mm after the plateau. Dramatic changes occurred in the shape of conceptus. The predominant shapes were approximately as follows: days 11-16, spherical; d...
Ginther OJ.Movement of the conceptus within the uterine lumen of barren mares was studied by daily ultrasound examinations on days 11-20 and by rectal palpation on days 15-48 (Experiment 1) and by ultrasound examinations 3 or 4 times per day at 2-4 hour intervals on days 11-16 (Experiment 2). In addition, broodfarm records were analyzed to compare side of ovulation with side of embryo attachment (Experiment 3). The vesicle was found in opposite uterine horns for 43% of the successive, daily, ultrasound examinations on days 11 and 12, 12 and 13, 13 and 14, and 14 and 15; 24% of the successive examinations...
Lees P, Creed RF, Gerring EE, Gould PW, Humphreys DJ, Maitho TE, Michell AR, Taylor JB.Five matched pairs of horses were used to investigate the effects of phenylbutazone on a range of physiological, biochemical and haematological variables. The drug was given by mouth daily for 15 consecutive days at the manufacturer's recommended dose rates to one group of horses (Group A); the second group (Group B) received equivalent doses of a placebo. For some of the measured parameters, significant changes were recorded in both groups, indicating background instability. Significant decreases in serum total protein, albumin, plasma pH, viscosity and magnesium, and an increase in albumin: ...
Thomson JR, McPherson EA, Lawson GH, Wooding P, Brown R.The chymotrypsin activity of seven batches of Micropolyspora faeni and of five batches of Aspergillus fumigatus culture extracts, prepared for inhalation challenge in horses, was assayed and was found to range between 0.29 and 1.45 units/mg protein and 0.02 and 0.20 units/mg protein respectively. Horses affected with chronic obstructive pulmonary disease (COPD) were challenged with two batches of each antigen which had different chymotrypsin activities and no significant correlations were found between the degree of response to challenge and the chymotrypsin activity of the antigens. Inhalatio...
Silberzahn P, Dehennin L, Zwaïn IH, Leymarie P.Testosterone has been identified by mass spectrometry in blood and follicular fluid aspirated from mature Graafian follicles of mares. Quantitative measurements made by gas chromatography-mass spectrometry have validated the determination of plasma testosterone made by radioimmunoassay. However, because of high levels of epitestosterone (17 alpha-hydroxyandrost-4-en-3-one) in the follicular fluid, radioimmunoassay overestimates the true concentrations of testosterone. The occurrence of testosterone in mare follicular fluid at a concentration which is two orders of magnitude higher than that in...
Brown MP, Kelly RH, Stover SM, Gronwall R.Six healthy adult mares were given a single IV injection of trimethoprim (TMP)-sulfadiazine (SDZ) at a dosage rate of 2.5 mg of TMP/kg of body weight and 12.5 mg of SDZ/kg. Serum, synovial, peritoneal, and urine TMP-SDZ concentrations were measured serially over a 48-hour period. The highest measured mean concentrations of TMP and SDZ were found in the first (0.5 hour) sample of serum, synovial fluid, and peritoneal fluid. The mean peak concentrations of TMP and SDZ averaged 4.37 micrograms/ml and 21.81 micrograms/ml for serum, 2.95 micrograms/ml and 15.31 micrograms/ml for synovial fluid, and...
Barber SM, Clark EG, Fretz PB.In 2 horses with rapidly growing, locally destructive tumors of the premaxilla, there was major disruption and displacement of some incisor teeth, with radiographic evidence of disruption of the premaxilla at the base of the tumors. In horse 1, most of the tumor was removed by incising it at its base, and the tumor bed was treated cryosurgically with 3 freeze-thaw cycles, using liquid nitrogen. The area healed by 2nd intention. The tumor was found to be a benign fibroblastic tumor, possibly a fibroma. After 4 years, there has been no recurrence. Horse 2 was euthanatized on the basis of a tenta...
Platt H.The pathology of 4 cases of caecal rupture in foaling mares is described. One of these animals died suddenly, probably when rupture occurred, and 3 survived for 5 to 8 h and died from acute peritonitis.
The pathogenesis of this type of injury is discussed and it is suggested that rupture may arise from the pressure of a foetal hind foot against the caecum when distended by local tympany.
Roberts MC.Vitamin B12 and folate concentrations were determined by radioimmunoassay in groups of horses in Queensland. Highest serum vitamin B12 levels were found in supplemented performance horses. These, together with pastured horses that included pregnant and lactating mares, had significantly greater serum folate activity than permanently stabled animals. The range of red cell folate concentrations was much narrower in horses in training than from any other group. Red cell folate may be a better indicator of a horse's folate status than the serum folate value. Vitamin B12 and folate concentrations w...
Revington M.Eight hundred and sixteen blood samples were collected from horses at Sydney race tracks, 1 to 3 h before racing, and subjected to haematological analysis. Haemograms were also performed on 65 blood samples taken from horses at rest in their stalls. These were used as reference values of prerace and resting haemograms, respectively. The haemograms of 29 of the resting horses were compared with the haemograms of the same 29 horses the following day at the race track. Both samples were considered to be representative of their reference populations. In general, there was a significant increase fr...
Moore CP, Fales WH, Whittington P, Bauer L.Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and included 7 genera, with Aspergillus sp being the most prevalent. Ten of the eyes with fungal keratitis had been treated with corticosteroids. Eleven of 38 eyes had mixed bacterial and fungal infections. Clinically, the most severe cases were those in which Aspergillus and gram-negative bacteria existed in a mixed infection. On the basis of susceptibility testing,...
Bonagura JD, Pipers FS.A horse, a cow, and a dog with aortic valve vegetative endocarditis were studied by M-mode echocardiography. Echocardiographic abnormalities of the aortic valve, mitral valve, and left ventricle were observed. These features were identical to those reported in human beings with aortic valve endocarditis. Abnormalities associated with aortic valve endocarditis included irregular thickening of the valve, multiple linear echoes in the aortic root, diastolic prolapse of the aortic vegetation, and diastolic fluttering of a torn aortic valve. Some of these features were found in each animal. The con...
Tait AD, Hodge LC, Allen WR.The production of equilin and the other ring B-unsaturated estrogens by the pregnant mare is anomalous in that they are biosynthesised by a cholesterol-independent pathway. Fetal horse gonads were incubated with tritiated sodium acetate and radiochemically pure 3 beta-hydroxy-5,7-pregnadien-20-one and 3 beta-hydroxy-5,7-androstadien-17-one were isolated. A fetal gonad--placental system is proposed for equilin production, 3 beta-hydroxy-5,7-pregnadien-20-one being a precursor for 3 beta-hydroxy-5,7-androstadien-17-one in the fetal gonad and the latter being the precursor of equilin in the place...
Braun JP, Benard P, Burgat V, Rico AG.In domestic animals, Gamma Glutamyl Transferase is mainly in the kidneys, the pancreas and the intestine; its liver activity is relatively high in cows, horses, sheep and goats and very low in dogs, cats and birds. The use of plasma reference values can help to interpret the variations of serum GGT mainly in hepatobiliary diseases of cattle, sheep, goats and cholestatic disorders of dogs. Urinary GGT is a good test of kidney toxic damage.
Turner JE, Irvine CH.Administration to mares of the anabolic steroid, methandriol, at the maximum recommended dose (300 mg every 3 weeks) for 1 1/2 years had no effect on reproductive characteristics except for suppression of GnRH-induced LH release and a tendency to suppress basal LH levels and the height of the ovulatory LH surge. A 4-fold increase in dosage caused marked suppression of basal LH, the LH surge, and GnRH-induced LH release. Other reproductive responses were minimally affected. There were no behavioural effects, and no changes in weight occurred when mares were compared with matched controls. Small...
Page AE, Stills HF, Horohov DW.Multiple hypotheses into the age-based susceptibility of animals to Lawsonia intracellularis exist, including the decline of passively acquired antibodies. Objective: To determine whether the decline in passively acquired antibodies in horses is responsible for the age predilection of equine proliferative enteropathy (EPE). Additional objectives included examination of various risk factors for the development of EPE as well as the determination of naturally occurring attack rates for clinical and subclinical EPE. Methods: Prospective, multifarm field study. Methods: A total of 369 mare and f...
Tischner M.Artificial insemination (A.I.) of mares in Poland has not yet been widely applied. Initial attempts were made by research groups between 1945 and 1955 but A.I. of mares was only introduced into the normal practice of A.I. Centres during 1964-67. Intensive research into methods for preserving stallion semen in liquid nitrogen has been undertaken since 1968. Of the total of 3734 mares artificially inseminated in Poland since 1945, 350 were inseminated with frozen semen. The slow progress of A.I. in horses is imputed to the small numbers of people involved in the work, to the conservation of the ...
Voigt G.The author informs on up to date identification methods of horses. The implantation of passive transponders is a practicable method for marking of horses. Because it gives less pain to horses, this method is to prefer. Stress inflicted on horse is minimal, it compares to a intramuscular injection. The reliability of the system in use has so far been very high. Members of ISO have voted overwhelmingly in favor of a standard for electronic identification of animals. From now on, countries and user organizations can make use of this technique to identify animals and if used can rely on the fact t...
Maxwell L, McCarrel TM, Hay S, Cole C.The antifibrinolytic agent aminocaproic acid (ACA) is occasionally used prior to episodes of intense training in racehorses suffering from exercise-induced pulmonary hemorrhage. Although a previous study indicated that the drug is cleared rapidly in horses, some racetrack practitioners claim that recent adverse analytical findings for ACA in postrace samples were from ACA administrations 5-7 days before the race. The purpose of this study was to re-examine the pharmacokinetics of ACA in horses to address this apparent conundrum. Eight exercise-conditioned thoroughbred horses were administere...
Kaneene JB, Miller R, Ross W, Gilbert L.Data from two 12 month prospective monitoring programs that followed management, economics and animal health from randomly-sampled equine operations in Michigan were used to determine patterns of health maintenance. Health maintenance measures were grouped, and average uses per year were computed for the most-common measures reported: respiratory, Potomac Horse Fever, neurological and multiple-system vaccinations, deworming, and general farrier work. Factors examined for potential association with health maintenance measure use were numbers of equids and horse-days on the operation, average ag...
Yamada K, Araki M, Tokushige H, Fujiki R, Sakai S, Tateno O, Mashita S, Kusano K.Equine scintigraphy has been legally permitted in Japan since 2009; however, it has not yet been a routine modality for horses. One reason is the legal regulations concerning the disposal of contaminated bedding. However, overseas, the bedding after scintigraphy can be disposed following radioactivity decay, but this is not allowed in Japan. Therefore, beddings are required to stored permanently in a controlled area, implying that large amounts of beddings such as straw would be kept untreated, which is quite unpractical. This may cause a hospital owner to hesitate to construct an equine scint...
van der Harst MR, Rijkenhuizen AB.The prognosis of ruptured collateral ligaments of the metacarpophalangeal or metatarsophalangeal joint in horses is usually considered to be poor, especially for future athletic performance. The main problem is the development, due to joint instability, of osteoarthritis, which may result in persistent lameness. In this paper a surgical technique is described in which joint stabilisation is realised by using a polypropylene mesh as a substitute for the ruptured ligaments, with the subsequent application of a cast for 7 weeks. The technique was successfully performed in 2 horses with ruptured l...
Dyrda K, Orzołek A, Ner-Kluza J, Wysocki P.Phosphorylation and dephosphorylation of proteins are considered to be the most important processes in sperm maturation during epididymal transit. The main aim of this study was to isolate and identify phosphoproteins from the epididymal milieu obtained from reproductively mature stallions during and out of the breeding season. With the use of 1D-PAGE and nanoLC-MS/MS, we identified phosphoproteins that fulfil various functions: regulatory, transport, motility, ubiquitination, chaperone, antioxidant, apoptotic and enzymatic. Moreover, we characterized tyrosine, serine and threonine phosphoryla...
Mitchell KJ, Dowling BA, Hughes KJ, Dart AJ.A 2-day-old Warmblood colt foal was referred for evaluation of progressive abdominal distension and lethargy. Haemoperitoneum was diagnosed and a ventral midline laparotomy revealed capsular rupture, sub capsular haematoma and haemorrhage of the left kidney. Unilateral nephrectomy was performed and the foal recovered uneventfully, with no reported complications 1 year later.
Meijer P.Two cases of tetany in the horse are reported. The two patients were thoroughbreds. One was eight and the other thirteen years old. The mares were in heat and were brought to the service (stud) station to be mated. Both patients were nursing a foal. One was a four-week-old foal and the other was seven weeks old. The calcium level of the serum had dropped in the two patients, to 4.0 mg and 5.4 per ml. respectively. The magnesium level was 1.0 mg and 1.9 mg per 100 ml. respectively. The animals responded satisfactorily to intravenous infusion of calcium borogluconate and magnesium chloride. One ...
Dias DP, Teixeira LG, Canola PA, Albernaz RM, Marques JA, Neto JC.The purpose of this investigation was to evaluate surgical catheter implantation in the facial artery of horses and the long-term maintenance of such arteries using heparin and ascorbic acid as filling solution. Nine horses were implanted with a polyurethane catheter. The catheters were flushed with a heparin/ascorbic acid solution every 8h and remained patent for 25 days. Arterial blood samples were collected twice a day, and one exercise test that included serial blood samples and arterial pressure recordings was performed on a treadmill. Polyurethane catheters surgically implanted in the fa...
Nagy A, Dyson S.There are no detailed data on complications of sacroiliac (SI) joint region injections or on the variability of the methods and circumstances of injections among clinicians. Objective: To describe complications following diagnostic, therapeutic and combined SI joint region injections and the details of how these are routinely performed by a large number of clinicians. Methods: Cross-sectional questionnaire survey. Methods: Clinicians (members of American and European specialist colleges and veterinarians known to the authors), invited by email, who had performed ≥1 SI joint region injection,...
Hago BE, Vaughan LC, Plummer JM.A transmission electron microscope study was undertaken to investigate the details of the synovial tendon sheath and bursal lining in horses. The lining cells appeared to be fibroblasts and were buried in a finely granular ground substance. Generally these cells had poor cytoplasmic organelles, sparse short profiles of rough endoplasmic reticulum (RER), few scattered ribosomes and, occasionally, a poorly developed Golgi complex. However, a few lining cells appeared more active, having pronounced RER with dilated cisternane. The surface of the lining cells, particularly those with dilated RER, ...
Jastrzębska E, Wilk I.The aim of the study was to determine the effect of selected rider-related factors (riders' age and experience, type of preparatory activities, test variant) on the behaviour of recreational horses being prepared for use. Six adult, hot-blooded recreational horses were handled by two female riders that the horses knew and by another two that the horses did not know (two of them were aged 12 and two aged 30). The horses were assessed by a behaviourist for their behaviour during the pre-training activities (entering the box, grooming, cleaning the hooves, bridling, saddling up, taking a horse to...
Voermans M, Skidell J, Winberg F.Prestenotic oesophageal dilatation and stricture were diagnosed in a horse with a history of trauma in the cervical area and recurrent oesophageal obstruction. The diagnosis was established on the basis of the clinical examination, endoscopy, and positive contrast oesophagography. Conservative treatment was unsuccessful and surgical intervention was necessary. Oesophageal myectomy combined with myoplasty was performed, simultaneously relieving the dilatation and the stricture. No abnormalities were detected 8 weeks after surgery. The horse was on a normal diet and oesophageal obstruction did r...
Blythe LL.Methodology for the neurologic examination in the equine species is described. Information is organized to assist the reader in defining neurologic deficits and in localizing lesions to the major subdivisions within the central or peripheral nervous system. Numerous examples of deficits are presented to assist the reader in recognition of common neurologic disease states.
