"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.
Hillidge CJ, Lees P.The neuroleptanalgesic drug combination of
etorphine and acepromazine (Large Animal
Immobilon; Reckitt & Colman Ltd.) was
administered i.v. at the recommended dose rate
(24 ,ug/kg etorphine and 100 pg/kg acepromazine)
to twelve Welsh Mountain ponies of 185 to 336 kg
bodyweight. Cardiovascular measurements were
made before and at pre-determined times up to
30 min after the injection. The etorphine
antagonist, diprenorphine (Revivon; Reckitt &
Colman Ltd.), was then injected i.v. (30,ug/kg)
and further measurements were obtained.
Pronounced increases in heart rate, moderate
increase...
McGuire TC, Pollara B, Moore JJ, Poppie MJ.Foals with combined immunodeficiency had normal levels of purine salvage pathway enzymes, including adenosine deaminase, nucleoside phosphorylase, and xanthine oxidase.
Lees P, Serrano L.1 The butyrophenone tranquilizer, azaperone, was administered intramuscularly, at dose levels of 0.4 and 0.8 mg/kg, to ponies and its effects on cardiovascular and respiratory functions assessed. 2 Arterial blood pH, CO2 tension (PaCO2) and O2 tension (PaO2) remained relatively constant throughout the course of action of azaperone. 3 Azaperone did not modify plasma protein concentration but venous blood packed cell volume and haemoglobin concentration were reduced by 5 to 10% for at least 4 hours. These changes were probably caused by uptake of erythrocytes into the splenic reservoir. 4 Small ...
Vaughan LC.Local disorders of bone growth form an important group of the orthopaedic problems that occur in foals. The recognition of the condition presented is essential so that the appropriate corrective measures may be instituted, and an accurate prognostication made. A knowledge of the applied anatomy of the growth plate is essential to the understanding of these cases. Consideration is given to epiphyseal separation and to angular deformity, from the point of view of diagnosis, prognosis and treatment.
Jeffcott LB, Rossdale PD.The current knowledge of the clinical signs, epidemiology and pathogenesis of abortion due to the equid herpesvirus (EHV 1) is reviewed. The relationship between the respiratory and abortigenic forms of the disease is discussed as well as the low incidence of virus abortion in the UK compared to some other parts of the world. Some practical aspects of the disease as they affect stud management are considered including methods of diagnosis, prophylaxis and the necessary action to be taken to prevent spread of infection.
Turner AS, Milne DW, Gabel AA.Long-bone fractures of 6 foals admitted consecutively to the Ohio State University Veterinary Hospital were treated successfully with ASIF dynamic compression plating. The cases included 2 foals with closed fracture of the metacarpus, and 1 foal each with open nonunion of the metatarsus, closed fracture of the radius, open fracture of the tibia, and open fracture of the ulna. Five of these foals became sound, with no deformity, so they could be trained for racing or showing. The 6th foal, a filly with nonunion, became "pasture-sound" and was scheduled for breeding. It was concluded that the dy...
Frankland AL, Morris PG, Spreull JS.Seven pieces of autologous skin were transplanted onto freshly created, full thickness skin defects on the limbs and back of a one-year-old, male, piebald, Shetland pony. The transplantations were completed in two operative sessions, the transplants on the left side were done in the first session and the right side in the second. The sizes of the transplants varied from 20 sq cm to 2 sq cm and their thicknesses from whole skin to very thin, split skin. Donor sites were both rumps and the right side of the neck. Six of the seven grafts and two thirds of the remaining graft, were accepted. Both ...
Hilmas DE, Gillette EL.The clinical records and follow-up data obtained over 13 years on the results of radiotherapy of spontaneous fibrous connective-tissue sarcomas in dogs, cats, and horses were reviewed. The results obtained from the treatment of fibrosarcomas and sarcoids of horses indicated that radiation administered with 60Co is important in the medical and surgical management of these tumors. Fibrous connective-tissue sarcomas in horses were radioresponsive. When radiotherapy was applied postoperatively, the probability of a 2-year cure approached 50% for all prescribed radiation doses of less than 2,000 to...
Koj A, Chudzik J, Dubin A.Two proteinases (2A and 2B) purified from the granular fraction of horse blood leucocytes degrade casein (Km values 12.8 and 6mg/ml respectively) with maximum activity at pH 7.4 and in the presence of 2m-urea. Urea-denatured haemoglobin, fibrinogen, albumin and resorcin/fuchsin-stained elastin are digested at a slower rate. The enzymes hydrolyse synthetic substrates of elastase, N-benzyloxycarbonyl-L-alanine 4-nitrophenyl ester (Km 0.114 and 0.178 mM) and N-acetyl-tri-L-alanine methyl ester (Km 5.55 and 0.98 mM), but they do not hydrolyse synthetic substrates of trypsin, chymotrypsin and throm...
Drudge JH, Lyons ET, Taylor EL.Three series of critical tests were completed on a combined total of 46 horses to determine the efficacy of single doses of trichlorfon against bots, ascarids, pinworms, and large strongyles. Different formulations of trichlorfon were administered by tubing intragastrically, mixing with the daily grain ration, injecting intramuscularly, or pouring on the back at dose rates between 20 and 100 mg/kg. Administration by feeding tended to be more efficacious for removal of bots and less toxic to the horese than administration by stomach tube. In many of the tests, trichlorfon was given in the grain...
Douglas RH, Ginther OJ.Prostaglandins F were quantitated by radioimmunoassay in uterine venous plasma of anesthetized mares on day 7 of estrus, days 2, 6, 10, 14 or 18 of diestrus and days 10, 14 or 18 of pregnancy. The PGF concentration was greater (P less than .01) at day 14 of diestrus than at all other days studied. The concentrations at days 10 and 18 of diestrus and at days 10, 14 and 18 of pregnancy were greater (P less than .05) than at day 7 of estrus and days 2 and 6 of diestrus. PGF concentrations at days 10 and 14 were greater (P less than .01) for diestrous than for pregnant mares.
Allen WE.14 pregnant Welsh Mountain Pony mares were treated with progesterone in an effort to prevent pregnancy failure induced by administration of human chorionic gonadotropin (GCG). 13 of the 14 mares were treated with progesterone by injection or implant before the 38th day of pregnancy. HCG was given in 3 doses on alternate days at a dose rate of 2000 imc/day. The remaining mare was treated with HCG toward the end of the experiments to demonstrate the abortifacient property of HCG. 3 mares aborted and 1 of these was anovulatory thereafter. Further research is needed to determine the effective prog...
Bisgard GE, Forster HV, Orr JA, Buss DD, Rawlings CA, Rasmussen B.Seven ponies were subjected to carotid body denervation (CD) and two ponies were sham operated (S). Measurement of arterial blood gases and arterial blood and cerebrospinal fluid (CSF) acid-base balance were made prior to and 1,2,4,9, and 17 wks after surgery in unanesthetized animals. Resting ventilation and ventilatory responsiveness to hypoxia and NaCN infusion were assessed prior to and 2,9, and 17 wks after surgery. Alveolar hypoventilation in the CD ponies was marked 1-2 wk after surgery when VE and VA were reduced 40% and 10%, respectively, from control and PaCO2 was 12-15 mmHg above co...
Guignot F, Ottogalli M, Yvon JM, Magistrini M.The objective of this study was to perform intracytoplasmic sperm injection (ICSI) on in vitro matured equine oocytes and to improve in vitro embryonic development on Vero cells after activation of the microinjected oocytes with calcium ionophore. After maturation (23 or 40 h, 38.5 degrees C, 5% CO2), the cumulus-oocyte complexes were denuded, centrifuged and all oocytes exhibiting the first polar body were microinjected. ICSI was performed using fresh semen from three fertile stallions. Microinjected oocytes were activated with calcium ionophore A23187 (10 min, 10 microM) and cultured individ...
Salonen JS, Vuorilehto L, Gilbert M, Maylin GA.Horse urine was investigated for metabolites by chromatography and mass spectrometry following the oral administration of the large animal analgesic sedative detomidine to two stallions and intravenous administration of [3H]-detomidine to a mare. Detomidine carboxylic acid and hydroxydetomidine glucuronic acid conjugate were identified in the urine after the oral doses. In addition, traces of free hydroxydetomidine were observed. About half of the radioactivity of [3H]-detomidine was excreted in the urine in 12 h after the i.v. dose (80 micrograms/kg). Most of the excretion occurred between 5 ...
Blakely JA, Blakely AA.Veterinarians commonly predict mature heart scores for yearling and 2-year-old horses to aid clients in assessing a horse's racing potential. Sixty-six thoroughbreds were assessed as a yearlings or 2-year-olds, then re-assessed as a mature horse (over the age of 3). Of these horses, 82% of the yearlings and 87% of the 2-year-olds had a correctly predicted mature heart score within one heart score range (i.e. three points).
Wilson WD, Spensley MS, Baggot JD, Hietala SK, Pryor P.The pharmacokinetics and bioavailability of ticarcillin and clavulanate were determined after intravenous (i.v.) or intramuscular (i.m.) administration of ticarcillin disodium (50 mg/kg) combined with clavulanate potassium (1.67 mg/kg) to groups of healthy foals at 3 days and 28 days of age. After i.v. administration of the combination to five foals, the disposition kinetics of ticarcillin and clavulanate were best described using a two-compartment open model. Mean plasma elimination-rate constant (beta) and clearance (ClB) for ticarcillin were significantly less (P less than 0.01), and volume...
Kosec M, Mrkun J.Methods for elimination of one of two embryos in twin pregnancies of mares were studied. Transvaginal ultrasound guided punction of yolk sac or allantoic cavity with fluid aspiration was used. Punction was done in 8 mares, pregnant between 22 and 46 days. In six cases, pregnancy did continue normally with one embryo only while in two cases, both embryos died following the procedure.
Brownlow MA, Turner DM, Hutchins DR.An inhalation anaesthetic apparatus for the horse is described and the physiological concepts pertaining to its design presented. The internal diameter of all breathing components is 6.2 cm with no change in cross sectional area throughout the circle system. The soda lime capacity is 25 litres (approximately 20 kg). In the horse, which is apparently predisposed to alveolar hypoventilation during inhalation anaesthesia, it is apparent that adequate anaesthetic apparatus design should be directed towards minimising resistance and dead space and providing maximal and efficient carbon dioxide elim...
Mullaney TP, Brown CM, Watson GL, Brandt LA.An apparently new and emerging fatal hepatic disease affecting foals is described. Characteristics included evidence of hepatic failure, marked biliary hyperplasia, hepatocellular necrosis and occasionally fibrosis. Generally, the features of the disease appear to differ markedly from other hepatic diseases of neonatal foals.
Abraham G, Broddet OE, Ungemach FR.In this study, beta-adrenoceptors of intact equine lymphocytes were identified and subclassified by (-)-[125I]-iodocyanopindolol (ICYP) binding. ICYP binding to intact equine lymphocytes was rapid, saturable (maximal number of binding sites 320 +/- 20 ICYP binding sites/cell, n = 12) and of high affinity (KD value for ICYP 14.4 +/- 1.7 pmol/l, n = 12). Binding was stereospecific as shown by the 10 times greater potency of (-)-propranolol to inhibit binding than its (+)-isomer. Beta-adrenoceptor agonists inhibited ICYP binding with an order of potency: (-)-isoprenaline >(-)-adrenaline >(-...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Fašmon Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B....Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of a feed additive consisting of vitamin K1 (phytomenadione) produced by chemical synthesis when used as a nutritional additive in complementary feed of horses at a maximum supplemental level of 14 mg vitamin K1/horse per day. The use of vitamin K1 is safe when used as a feed additive for horses under the proposed conditions of use. The use of vitamin K1 in nutrition of horses under the proposed co...