Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Brown PJ, Clayton HM.The pathological changes associated with the migration through the liver of P. equorum larvae were investigated. Twenty pony foals were killed at intervals of 2 to 185 days after a single infection with 160 or 8000 P. equorum eggs and 4 pony foals were killed at intervals of 94 to 144 days after twice weekly infections of 50 eggs from birth. At post-mortem examination the macroscopic changes included the development of focal haemorrhages and small, white diffuse or nodular lesions.
Microscopic lesions were found mainly around the portal triads and consisted of infiltration by cells, including...
Putt W, Fisher RA.In this paper we describe seven enzymes, NP, GOTM, PGM2, alpha FUC, PEP A, ADA and MPI which are found in the white cells of horses, including 39 British crossbred ponies and 16 crossbred horses, 30 Mongolian ponies and 10 Icelandic ponies. Two of these enzymes--alpha FUC and MPI--were polymorphic in all the populations of horses studied and could prove useful as additional markers in the paternity testing of horses. PEP A and GOTM were also polymorphic in two of the populations studied and could be used as further markers in these populations.
Gay CC, Speirs VC, Christie BA, Smyth B, Parry B.Six horses, which had a foreign body obstruction of the small colon showed abdominal pain of progressing severity and intestinal tympany. On rectal examination the caecum and large colon were distended with ingesta and gas but the obstructing mass could be palpated in only 3 cases. All horses had elevated indirect blood pressure and in 3 there was also fluid distension of the stomach. Only one horse had known access to foreign material in the diet, but a further 3 were related to an exceptionally dry climate period. Five of the 6 horses recovered following surgery.
Powell DG, Whitwell K.Following an outbreak of CEM in England during 1977 a Code of Practice was introduced to control the disease in 1978. The Code recommended a bacteriological screening programme for Thoroughbred mares and stallions and improved standards of hygiene on the stud farm. As a result of the implementation of the Code a number of asymptomatic carrier mares was detected. Stallions which had transmitted CEM in 2977 and were treated did not transmit the disease during 1978. Two small outbreaks of CEM were reported during the 1978 breeding season.
Grieve RB, Moore BG, Bradley RE.A critical test was performed to evaluate the anthelmintic properties of an injectable butamisole formulation and to compare the efficiency with that of a commercially available piperazine-thiabendazole anthelmintic. The test was done in 10 horses and 15 ponies with naturally acquired parasitic infections. Butamisole was administered at the dose level of 2.5 or 3.75 mg/kg of body weight by either subcutaneous or deep intramuscular injection. Given at the dose level of 2.5 mg/kg, butamisole was highly effective (99%) against Strongylus vulgaris and moderately effective (49%) against Parascaris ...
Maxwell JA.A 9-year-old mare exhibiting signs of colic late in pregnancy was presented. Uterine torsion was diagnosed and corrected by caesarean section. A live foal was delivered and the mare survived the surgical interference.
Dodman NH, Waterman AE.The rapid intravenous administration of the butyrophenone tranquilliser, azaperone, at a dose rate of 0.29-0.57 mg/kg body weight resulted in the immediate onset of excitement and ataxia of varying degree in over half the animals. The severity of the reaction appeared to be related to the size of the animal. Other side effects such as salivation, sweating, muscle tremor and vocalisation were also observed. The possible causes of this paradoxical reaction to the tranquilliser are discussed.
Woodley SL, Burns PJ, Douglas RH, Oxender WD.This study was designed to test if oestradiol treatment would prevent or delay luteolysis in mares. Mares (5/group) received 0, 0.1, 1.0 or 10.0 mg oestradiol-17 beta daily from the day of ovulation until the next ovulation or for a maximum of 32 days. This treatment did not prevent luteolysis which occurred 15.8, 16.8, 15.8 and 17.3 days after the previous ovulation for the mares treated with 0, 0.1, 1.0 and 10.0 mg oestradiol respectively. Although oestradiol treatment failed to alter oestrous behaviour after luteolysis, daily treatment with 10.0 mg oestradiol prevented follicular growth and...
Persson SG, Ullberg LE.The rate of disappearance of Evans blue dye from the blood after an intravenous injection was studied in young foals, between 4 and 105 days of age. This was found to be age dependant, especially during the first month, the initial dye disappearance being much faster than in the adult horse. This would mean an overestimation of plasma volume, using the single sampling technique, of about 5% during the first day of life, i.e. negligible from a practical point of view considering the standard error of estimation. The effect of exercise on the venous haematocrit was studied, too, in foals less th...
Kenney RM, Condon W, Ganjam VK, Channing C.The histological features and hormonal content of follicular fluid of antral follicles during oestrus were correlated. As a result it was possible to characterize several categories of viable and atretic follicles. A seemingly important stage in maturation appeared to be at 3 cm in diameter since follicular oestrogens and androgens underwent a 3-fold increase in concentration at that size. Evidence was obtained to suggest that oestrogens are anti-atretogenic. However, a drop in oestrogens was not the cause of atresia since degeneration commenced when levels were high. Contrary to the concept t...
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...
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.
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...
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.
Meyers SA, Rosenberger A, Orpneck K.Three protein bands with hyaluronidase activity and molecular masses of 87, 48 and 43 kDa were isolated from purified equine sperm plasma membranes. Indirect immunofluorescence was used to assess sperm labelling patterns using a polyclonal antibody to sperm hyaluronidase. In ejaculated spermatozoa, surface-associated hyaluronidase was localized to the posterior head region of 98 +/- 2% of spermatozoa (n=10). Epididymides were isolated from mature stallions (n=5) and divided into caput, corpus and cauda epididymides in separate Petri dishes. The epididymidal tubules were dissected and washed us...
Smetzer DL, Senta T, Hensel JD.Each of nine horses was treated with amphetamine alone, with atropine alone, and with amphetamine and atropine in combination. Cardiac effects of these drugs were studied by electrocardiography during resting and exercising states and immediately after exercise. Although each treatment increased heart rate significantly during the resting state, only the amphetamine plus atropine treatment increased heart rate significantly during exercise. Decrease in heart rate immediately after exercise differed significantly for each treatment; the most rapid decrease in heart rate was found after the amph...
Zizzadoro C, Caruso M, Putignano C, Crescenzo G, Ormas P, Belloli C.The effects of endotoxin on β-adrenergic-mediated relaxation were investigated in the equine digital artery (EDA). Possible involvement of cyclooxygenase-2 (COX-2) in endotoxin-induced effects and basal EDA β-adrenoceptor functionality was also evaluated. Endothelium-intact (e(+)) and/or -denuded (e(-)) EDA rings were incubated overnight with lipopolysaccharide (LPS), LPS+NS398 (selective COX-2 inhibitor) or NS398 alone. Vessel rings were then mounted in organ baths and relaxant responses to isoproterenol (ISOP) recorded on U44069-induced pre-contraction. Response to ISOP was further evaluat...
Bombardi C, Grandis A, Gardini A, Sorteni C, Clavenzani P, Chiocchetti R.The activity of the gastrointestinal tract is regulated through the activation of adrenergic receptors (ARs). Since data concerning the distribution of ARs in the horse intestine is virtually absent, we investigated the distribution of β2-AR in the horse ileum using double-immunofluorescence. The β2-AR-immunoreactivity (IR) was observed in most (95%) neurons located in submucosal plexus (SMP) and in few (8%) neurons of the myenteric plexus (MP). Tyrosine hydroxylase (TH)-IR fibers were observed close to neurons expressing β2-AR-IR. Since β2-AR is virtually expressed in most neurons located...
Snow DH, Douglas TA.The absorption characteristics of a new paste preparation of phenylbutazone were studied in ponies and thoroughbreds. The results suggested that at a similar dose rate of 5 mg/kg greater bioavailability results from the paste than from a powder preparation. Delivery of an accurate dosage of the paste was not possible using the multidose applicator. Repeated administration of the paste preparation (5 mg/kg twice daily) indicated that it is more toxic to both ponies and thoroughbreds than a powder preparation. In addition to the toxic manifestations previously reported, a neutropenia developed d...
Leahy ER, Holcombe SJ, Hackett ES, Scoggin CF, Embertson RM.Limited data exist describing broodmare longevity and reproductive efficiency after surgical correction of ≥360 degree large colon volvulus (° LCV). Objective: Compare career duration and foals delivered for broodmares before and after ≥360° LCV surgery. Methods: Retrospective case series. Methods: Broodmares registered with The Jockey Club that had surgical correction of ≥360° LCV and survived to hospital discharge at Rood and Riddle Equine Hospital from 1 January 2000 to 31 December 2015 were included. Information was collected from the hospital's medical data base and The Jockey Cl...
Schumacher J, Hanselka DV.Nasopharyngeal cicatrices were observed endoscopically in 47 horses examined because of abnormal respiratory noises and/or exercise intolerance. A review of these cases revealed a correlation between cicatrization and age, sex, and the presence of other upper airway abnormalities. The age of affected horses ranged from 6 to 21 years, with a mean age of 12.7 +/- 7.8 (+/- 2 SD) years. Females were affected 2.7 times more frequently than males. Abnormalities commonly observed with a nasopharyngeal cicatrix included chondritis of the arytenoid cartilage, epiglottic deformity, and deformity of the ...
Schellenberg LM, Regenthal R, Abraham G.The present study addresses the effect of the Rho-kinase (ROCK) inhibitor Y-27632 on the β-adrenoceptor density and β-agonist-stimulated intracellular second messenger cAMP formation in primary equine bronchial epithelial cells (EBEC). Y-27632 significantly decreased the β-adrenoceptor number (B) without markedly affecting the receptor affinity (dissociation constant, K) to the radioligand [I]-iodocyanopindolol (ICYP). In contrast, Y-27632 augmented the β-agonist-stimulated intracellular cAMP production. Herein, Y-27632 markedly increased the maximal cAMP responses (E) (isoproterenol >...
Hillidge CJ, Lees P.Measurements of the rate of rise of left ventricular blood pressure (dP/dt) have been made in conscious and anaesthetised ponies. Concurrent measurements of heart rate, mean arterial pressure and left ventricular pressure were also made in order to assess their relationship to values of dP/dt. Thiopentone-halothane and thiopentone-ether anaesthesia reduced the maximal rate of rise of intraventricular pressure (dP/dt max) from conscious control levels. After correcting for variations in the loading conditions of the ventricle, the depressant effect of halothane was still apparent, but the actio...
Burns SJ, Fleeger JL.Plasma progestagens were measured in eighteen pregnant mares to establish normal levels in the first and last 90 days of gestation. Progestagens increased from 25 ng/ml at 90 days before birth to 60 ng/ml at 10 days before birth, decreased to 58 ng/ml at 5 days before, and were 3 ng/ml or less by 5 days after perturition. During the first 90 days of pregnancy, progestagens reflected luteal activity with an increase in plasma levels from Day 30 to Day 60.
Sturm RT, Lang GH, Mitchell WR.The sera of 2596 thoroughbred and standardbred racehorses from Ontario were examined by hemagglutination-inhibition for antibodies to reovirus types 1, 2 and 3. The prevalence of antibodies differed between the standardbred and thoroughbred horses and varied with the age groups within the two populations. While reovirus 1 was the principal virus type infecting thoroughbreds, all three types seemed to infect standardbred horses. Differences of these findings with data from similar studies in Europe are mentioned and the epizootiological and pathological significance of these findings are discus...
Littlejohn A, Bowles F, Maluleka W.The percentage venous admixture was calculated in 21 clinically normal horses and ponies and in 13 horses and ponies with chronic obstructure pulmonary disease (COPD). The oxygen contents of pulmonary end-capillary blood, arterial and mixed venous blood were calculated from blood and respiratory gas values and substituted in the shunt equation. The mean percentage venous admixture of the COPD subjects was significantly greater than that of the normal subjects. It was concluded that a larger proportion of alveoli in the lungs of COPD subjects were hypoventilated than that of alveoli of the norm...