"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.
Garcia-Villar R, Toutain PL, Alvinerie M, Ruckebusch Y.The pharmacokinetic disposition of xylazine hydrochloride is described after both intravenous and intramuscular injection of a single dose, in four domestic species: horse, cattle, sheep and dog, by an original high performance liquid chromatographic technique. Remarkably small interspecific differences are reported. After intravenous administration, systemic half-life (t1/2 beta) ranged between 22 min (sheep) and 50 min (horse) while the distribution phase is transient with half-life (t1/2 alpha) ranging from 1.2 min (cattle) to 5.9 min (horse). The peak level of drug concentration in the pla...
Lyons ET, Drudge JH, Tolliver SC.Critical tests were conducted in 14 naturally infected equids (13 horses and 1 pony) to evaluate the antiparasitic activity of haloxon. Single doses were administered by stomach tube to 3 horses and 1 pony (60 mg/kg of body weight), by addition to the feed of 3 horses (60 mg/kg), and intraorally by powder gun to 7 horses (65 mg/kg). Haloxon was efficacious (99% to 100%) against infections of Parascaris equorum, Oxyuris equi (mature and immature), and Strongylus vulgaris at both dosage levels. Probstmayria vivipara parasites were removed in 1 horse treated at 60 mg/kg by stomach tube and S equi...
Kriek NP, Kellerman TS, Marasas WF.An isolate of Fusarium verticillioides (MRC826) that induced experimental leukoencephalomalacia, also caused acute toxicity when fed to pigs and administered per rumen fistula to sheep. Pigs developed severe pulmonary oedema while sheep manifested severe nephrosis and hepatosis. A less toxic isolate (F. verticillioides MRC602), fed to baboons, resulted in acute congestive heart failure or hepatic cirrhosis, depending on the dose. Both isolates were toxic to rats and caused similar lesions, namely, hepatic cirrhosis and intraventricular cardiac thrombosis.
Slocombe JO, McCraw BM.Twelve pony foals were reared worm-free and inoculated with Strongylus vulgaris. On day 7 after inoculation, 6 ponies were given ivermectin IM at a dose of 200 micrograms/kg of body weight and on day 28 were necropsied. Ivermectin was effective in eliminating early 4th-stage S vulgaris larvae and reducing clinical signs associated with acute arteritis. After administrative ivermectin was effective against early 4th-stage Strongylus vulgaris larvae in ponies when administered at 100, 300, or 800 micrograms/kg of body weight. The purpose of the present study was to report on a more extensive tri...
Shupe JL, Eanes ED, Leone NC.Sodium fluoride (5 mg/kg of body weight) was fed for 20 months to horses with hereditary multiple exostoses (HME), a skeletal disorder that primarily affects endochondral bones during skeletal development. Rib biopsies were performed on both HME horses not fed fluoride (control) and HME horses that were fed fluoride to obtain comparable specimens for chemical analyses and x-ray diffraction. Fluoride content of the rib from a horse fed fluoride for 20 months was approximately 20 to 30 times higher than that from a control horse. Fluoride content of the bone tumors was higher than those of norma...
Roberts MC, Sutton RH, Lovell DK.A 13-year-old Standardbred stallion presented with a unilateral mucopurulent nasal discharge and airway obstruction was found to have an extensive cryptococcal nasal granuloma. Treatment was not attempted. The stallion was destroyed 26 months later having completed 2 successful breeding seasons. The granuloma had gradually increased in size and almost completely occupied the left nasal cavity and paranasal sinuses. It was characterised histologically by fibrous and myxomatous tissue and masses of yeasts. A cryptococcal granuloma found within the wall of the jejunum could represent evidence of ...
McGuirk SM, Muir WW, Sams RA.A pharmacokinetic study was made, using 7 healthy adult horses (weighing between 400 and 560 kg) given quinidine gluconate IV and quinidine sulfate orally. The apparent volume of distribution of quinidine base was 3.10 +/- 0.79 L/kg, total body clearance was 5.49 +/- 2.40 ml/minute/kg, and plasma half-life was 6.65 +/- 3.00 hours. The systemic availability of quinidine sulfate after oral administration of a 10 mg/kg dose was 48.5 +/- 20.4%. Oral administrations of quinidine sulfate in doses of 10 mg/kg and 10 g produced peak plasma concentrations of 0.79 microgram/ml at 146 minutes and 1.47 mi...
Rose RJ.Three of the standard radiographic views of the navicular bone were assessed in normal horses and horses with navicular disease to determine the most effective radiographic positioning. Using the upright pedal view, a pastern angulation of 20 degrees from the vertical produced the optimum result when radiographs were taken using a grid. The best result using the high coronary view was obtained with an anode-film distance of 1 1000 mm, and a tube-head angle of 50 degrees from the vertical. When the special navicular view described by Morgan was examined, the most satisfactory projection was obt...
Fackelman GE, von Rechenberg B, Fetter AW.The need for early postoperative weight bearing following fracture repair in the horse has led to investigation of various means of expediting the healing process. Bone grafting represents one means of accomplishing this, and the transplantation of autologous tissues has proven to be most useful in equine orthopedics. Acid-decalcified, frozen, allogeneic bone for grafting is easy to prepare, readily contoured, osteogenic, and elicits no obvious immune or rejection response. The most compelling reason for the use of the substance is the elimination of the need of a harvesting operation on a pat...
Lyons ET, Drudge JH, Tolliver SC.Antiparasitic activity of a micronized formulation of the benzothiazole compound, tioxidazole, at the dose rate of 11 mg/kg, was evaluated by the critical test method. Drug was given by stomach to 3 horses and on feed to 3 horses. Excellent removal activity was found for Strongylus vulgaris (100%) in 5 naturally infected horses, S edentatus (91% to 100%) in 5 horses, small strongyles (88% to 99%) in 6 horses, immature Oxyuris equi (100%) in 5 horses, and Parascaris equorum (100%) in 5 horses (a 6th horse had 10 small specimens present at necropsy). There was no measurable activity against bots...
Snow DH, Baxter P, Whiting B.The pharmacokinetics of meclofenamic acid were studied in Thoroughbred horses and in ponies. After intravenous (i.v.) administration of either 2 mg/kg or 4 mg/kg sodium meclofenamate the elimination half-life was of the order of 0.9 h while the volume of distribution was found to be 0.128 litre/kg. Elimination was in accordance with a one-compartment model. Following oral administration of either meclofenamic acid (4 mg/kg) or sodium meclofenamate (4 mg/kg) a much longer terminal half-life than that calculated for Kel from i.v. data was found. This anomaly indicated that the 'flip-flop' phenom...
Sarkar DK, Smith GC, Fink G.We have investigated the effect of manipulating central catecholamines on the timing of puberty (as assessed by vaginal opening) in female rats and the surge of luteinizing hormone (LH) and gonadotropin releasing hormone (GnRH) induced by pregnant mare serum gonadotropin (PMSG) in immature female rats. Manipulation of the catecholamines was carried out with either 6-hydroxydopamine (6-OHDA) administered with or without either desipramine (DMI) or pargyline, or alpha-methyl-p-tyrosine (alpha-MPT). The neonatal administration of 6-OHDA delayed puberty, an effect which was potentiated by pretreat...
Okoh AE.Between 1944 and 1977, the distribution of confirmed cases of rabies in farm livestock in Nigeria were 15 in cattle, 8 in goats, 4 each in sheep, pigs and horses and two in donkeys respectively. The less-cared-for pastoralist sheep - dogs as well as stray dogs have so far been the sole propagating animal species of rabies to farm livestock although wild fauna have been suspected. The fact that cases are sporadic and lower incidence of livestock rabies is generally reported than the number that actually occurs makes the formulation of a definite control measures difficult. The need to educate n...
Rommel FA, Sahu SP.Intrauterine inoculation of pony mares with the bacterium that is the causative agent of contagious equine metritis (CEM) resulted in clinical disease. A humoral immune response could be detected by agglutination and complement fixation (CF), and in some cases precipitating antibody was found by immunodiffusion tests. Agglutinating antibody was the most reliable serological indicator of overt infection and was detected in 8 ot 28 mares after initial intrauterine inoculation of 3-4 x 10(5) bacteria. Seventy percent of mares given a second inoculation and all mares given a third inoculation of 3...
Strigazzi A, Bianchi M.The dimensional distributions of the adipocytes in Equus caballus in many subjects and in many regions have been studied: such distributions turn out to be in good approximation galtonian ones. Furthermore, all the logarithm populations of the cell diameters have significantly the same variance. The used statistical methods (ANOVA two way with replications, and TUKEY -test) indicate an extremely significant different among the various regions (the smallest cells are in the supra-orbital fossa, the greatest ones are in the abdominal subserous floor).
Pointelli E, Santa-maria MA, Caretta G.A total of 1267 microfungi, including 35 Myxomycetes, were recorded from the fecal samples of the 60 horses; of these 395 were found on 20 saddle-horse feces, 363 on 20 race-horses and 509 on 20 working horses. Eighty two species representing 53 genera were recorded; of these 7 were Zygomycetes, 18 Ascomycetes, 1 Basidiomycetes and 25 Fungi Imperfecti: 2 Myxomycetes. Common coprophilous fungi are in decreasing order Pilobolus kleinii, Saccobolus depauperatus, Mucor hiemalis, Lasiobolus ciliatus, Podospora curvula, Petriella guttulata, M. circinelloides, Coprinus radiatus, Dictyostelium mucoroi...
Allison MJ, Cook HM.Rates of oxalate degradation by microbes in gastrointestinal contents from rabbits, guinea pigs, swine and a horse increased after additional of oxalate to diets. A similar response was previously observed with ruminal microbes from cattle and sheep. Bacterial that utilize oxalate for growth appear to be selected by increased levels of dietary oxalate.
van Nie CJ, van der Kamp JS.A case of tricuspid atresia in a premature foal associated with large atrial septal and ventricular septal defects is reported. This anomaly is compared with other cases in horses as reported in the literature. As tricuspid atresia in horses is usually not diagnosed so that relatively few cases have been reported, a classification similar to that of human anomalies is not possible. It is suggested that the present malformation is due to abnormal development of the atrioventricular canal. The factors involved in the pathogenesis of this abnormal development are obscure.
Woods PR.Skin lesions can be associated with many internal diseases. Most organ systems seem to have conditions in which skin lesions can develop. Treatment of the skin lesions in such a situation is palliative. The underlying internal disease must be addressed for resolution of the skin lesions to occur. It is important to view the skin as an integral communicating part of the body and not just as the skin.
Scardia A, Mariani Pimenta EL, Ross Russell RI, Jones GJ, Staffieri F.The aim of this study was to evaluate the validity of the SpO/FiO diagram in estimating gas exchange in horses under general anaesthesia. In this prospective, controlled clinical study were included 10 horses under general anaesthesia. FiO was progressively reduced with the following steps: 0.6, 0.4, 0.3 and 0.21; SpO was recorded at each step. An arterial blood sample was collected at the steps of 1.0 and 0.21, to calculate intrapulmonary shunt with the Fshunt formula. The Fshunt value calculated at 0.21 FiO was defined as "Fshunt 0.21", the one calculated at 1.0 FiO as "Fshunt 1.0". The FiO ...
Brooks DE, McCoy DJ, Martin GS.Uterine rupture was diagnosed in 2 postpartum mares with hemorrhagic vaginal discharge. Both mares had abdominal pain, as evidenced by pawing, kicking at the abdomen, or attempting to roll. Peritoneal fluid analysis was useful in establishing a diagnosis. One mare had many RBC in the peritoneal fluid and was anemic; this mare was managed medically with oxytocin, antibiotics, and blood transfusion. The mare was able to raise her foal to weaning age. The second mare had many RBC, degenerate neutrophils, and intracellular and extracellular bacteria in peritoneal fluid. Surgical repair of the uter...
Cartee RE, Cowles WR.To determine the lines of maximum extensibility of the skin over the equine carpus, round puncture wounds were made 2.0 cm apart over the carpal area of 5 horses (7 carpi). The direction of elongation of the round puncture wound was observed and photographed. Lines of maximum extensibility that occurred over the surfaces of the equine carpus were determined to be proximal to distal, except in a small area over the accessory carpal bone where a state of anisotropism existed. In an immobilized carpus, direction of a surgical incision was not as important as it was in a mobile carpus, in which th...
O'Grady SE, Dryden VC.A club foot or flexural deformity may affect a horse at any stage of life from neonate through adulthood. The emphasis of this article is on defining and recommending the appropriate farriery for flexural deformities involving the deep digital flexor tendon and the distal interphalangeal joint. Clinical management of the flexural deformity is influenced by the severity, duration, and etiology of the club foot as well as the degree and source of lameness. Also discussed is the management of mismatched hoof angles, which remains a controversial subject for both farrier and veterinarian.
Kudrnáčová M, Langrová I, Maršálek M, Jankovská I, Scháňková S, Brožová A, Truněčková J.The occurrence of Hypoderma diana (Diptera: Hypodermatidae) in a herd of 15 horses was observed during a 4-year period (2010-2013) in northwest Bohemia. During this period, infestation by the warble fly H. diana increased from 12.5% in 2010 to 53.3% in 2013. Nodules were observed on the neck, back, stomach, legs, and head. The incidence of H. diana was probably influenced by the presence of a specific host mouflon (Ovis orientalis musimon).
Kirschvink N, Reinhold P.In veterinary medicine, upper airway resistance deserves a particular attention in equines athletes and brachycephalic dogs. Due to the anatomical peculiarities of the upper airway and/or pathological conditions, significant alterations of performance and/or well being might occur in horses and dogs. Physiological specificities and pathological changes of the lower respiratory tract deserve a major attention in other species.
Yasine A, Ashenafi H, Geldhof P, Bekana M, Tola A, Van Brantegem L, Van Soom A, Duchateau L, Goddeeris BM, Govaere J.Trypanosoma equiperdum (T. equiperdum) causes dourine, a venereally transmitted infection in horses. Purification of semen by single layer centrifugation (SLC) has been proven to be successful in reducing venereally transmitted diseases when dealing with other pathogens. The objective of this study was to evaluate the purification of T. equiperdum spiked semen by SLC. Semen was spiked using cryopreserved T. equiperdum stabilates (Dodola strain isolate 943). In total, 6 concentrations, varying from 10 to >5 × 10 trypanosomes, were added to semen samples. Subsequently, SLC was performed ...
Hoskinson JJ, Wooten P, Evans R.Nonsurgical, percutaneous, transvenous removal of a catheter fragment embolus was performed in a 14-day-old Thoroughbred foal. A basket retrieval catheter was introduced into the jugular vein and manipulated under fluoroscopic guidance to remove the fragment from the right side of the heart. Percutaneous retrieval should be considered as an alternative to thoracotomy for retrieval of intracardiac or intravascular foreign bodies.
Bienert-Zeit A, Gietz C, Staszyk C, Kietzmann M, Stahl J, Ohnesorge B.To monitor concentrations of sulfadimidine in the paranasal sinus mucosa (PSM) of unsedated horses following IV administration of trimethoprim-sulfadimidine via in vivo microdialysis. Methods: 10 healthy adult horses. Methods: Concentric microdialysis probes were implanted into the subepithelial layers of the frontal sinus mucosa of standing sedated horses. Four hours after implantation, trimethoprim-sulfadimidine (30 mg/kg) was administered IV every 24 hours for 2 days; dialysate and plasma samples were collected at intervals during that 48-hour period and analyzed for concentrations of sulfa...
Simon V, Dyson SJ.We compared the radiographic and scintigraphic findings in the third carpal bone of horses performing different work disciplines and investigated their relationship with lameness. Horses had undergone carpal radiography including acquisition of a dorsoproximal-dorsodistal oblique (DPr-DDiO) image of the distal row of carpal bones and/or scintigraphic examination of the carpi. Cause of lameness, breed, age, and work discipline were recorded. Increased opacity in the third carpal bone was graded, ratio of radiopharmaceutical uptake calculated objectively, and increased radiopharmaceutical uptake...
Morandi F, Frank N, Avenell J, Daniel GB.99mTc-mebrofenin is used in humans and small animals to assess hepatic function. This study was undertaken to measure hepatic clearance of 99mTc-mebrofenin in healthy horses and to determine whether feed deprivation and increased serum total bilirubin (TBIL) concentration alter 99mTc-mebrofenin clearance. Plasma clearance of 99mTc-mebrofenin was determirned in 7 healthy horses at 0, 48, and 96 hours of feed withholding. Serum TBIL and nonesterified fatty acid (NEFA) concentrations were measured every 24 hours. 99mTc-mebrofenin (4.16 +/- 0.62 mCi, mean +/- SD) was injected into a jugular vein, ...
McClintock SA, Hutchins DR, Laing EA, Brownlow MA.Six adult horses with normal blood gas values, normal thoracic radiographs and free from overt signs of respiratory disease were confined in flotation tanks for periods from one to seven weeks. With one exception, they all coughed, had a variable amount of nasal discharge and, at autopsy, showed cranio-ventral alterations to their lungs which were characterised by patchy irregular areas of absorption atelectasis with or without an inflammatory reaction and an accompanying alveolar emphysema.
Iff I, Mosing M, Lechner T, Moens Y.To determine the usefulness of an acoustic device to confirm correct placement of extradural needles in horses. Methods: Prospective experimental study. Methods: Twelve adult healthy horses weighing between 434 and 640 kg. Methods: Horses were sedated, placed in stocks and subjected to caudal extradural anaesthesia using lidocaine 2%. For extradural puncture an 18 gauge Tuohy needle connected to an acoustic device via an electronic pressure transducer was used. This device allowed recording of the extradural pressure profile and the transformation of pressure changes into an audible signal. Ex...
Heinze H, Klug E.Clinical tests with synthetic gonadotrophin-releasing hormone (Hoechst) were made during the breeding seasons of 1973 and 1974, using 128 mares injected with 1-0 to 4-0 mg of the substance intramuscularly. The mares were placed in one of five groups based on ovarian condition determined by clinical evidence. Some success was obtained in the induction of ovulation in mares with inactive and sub-normally active ovaries and in a small group having cystic ovaries. A large proportion of mares having a mature follicle responded within 48 hr, but others with atretic follicles failed to respond. The u...
Grøndahl AM, Jansen JH, Teige J.Fifty-six tarsocrural joints and 94 metatarsophalangeal joints were examined, at necropsy, from horses aged < or = 2 years. Osteochondral fragments at the cranial aspect of the intermediate ridge of the distal part of the tibia were seen in six horses, and at the proximoplantar aspect of the proximal phalanx in seven horses. Defects in the proximoplantar aspect of the proximal phalanx without osteochondral fragments were seen in a further two horses. Inflammatory and degenerative changes were not observed in any of the joints examined. From the incidence and natural course of these fragment...
