"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.
Eysker M, Mirck MH.The distribution of inhibited early third stage Cyathostominae larvae in different parts of the large intestine of the horse was studied in 20 Shetland ponies necropsied in autumn 1982, 1983 and 1984. The location of the larvae in the large intestinal wall was studied by histological examination of the intestines of the eight ponies from 1984. Inhibited larvae were located predominantly and more or less equally in the caecum and the ventral colon. Generally fewer early L3 were in the dorsal colon. In 1984 a considerable proportion (mean 17%, range 9.7-36.9%) of the inhibited larvae was found i...
Palmieri G, Panu R, Asole A, Farina V, Sanna L, Gabbi C.The most developed and organized lamina running trough the biceps brachii muscle belly forms a well-marked tendinous intersection connecting the proximal tendon with the distal one. Moreover, the lacertus fibrosus arises from this lamina close to the distal tendon and blends with the fascia of the forearm and joins the extensor carpi radialis muscle. The nerve supply for the biceps tendinous intersection arises from the intramuscular rami of the musculo-cutaneous nerve, whereas the lacertus fibrosus is provided with some cutaneous rami of the same nerve. The biceps brachii tendinous intersecti...
Köhler H, Oberlojer HG, Schönbauer M.In the ampulla roof of the wave-like extending horse rectum the muscular coat is only weakly developed as a deltoid-shaped tuna muscularis area, thus forming a place of minor resistance. With regard to the degree of development of the muscular coat a rectal ampulla with a stable form and strong muscles can be distinguished from an ampulla with a labile form and weak muscles. The rupture of the intestinal wall in this region in the case of rupture-experiments as well as the frequent occurrence of diverticula reveals this area as being a place of minor resistance which requires extreme caution d...
Kamerling SG, Dequick DJ, Weckman TJ, Tobin T.Sensitive methods for measuring the analgesic, physiological and behavioural effects of opioids in the horse have recently been developed. Fentanyl, a prototypic mu-opiate receptor agonist, has been previously shown to produce a syndrome characterized by marked analgesia and locomotor stimulation as well as tachycardia, tachypnoea and behavioural arousal. To determine whether other opiate receptors mediate some of the actions of the narcotic analgesics in the horse, an agent with activity at kappa- and to lesser extent mu-receptors was studied using a vigorous experimental protocol. Like fenta...
Todhunter RJ, Stick JA, Slocombe RF.The effects of 3 feeding techniques on healing of a cervical esophageal mucosal resection and anastomosis were investigated in 16 horses. Horses were fed a moistened pelleted diet 1 of 3 ways: 1) per os (n = 5), 2) by nasogastric (n = 5) or 3) by esophagostomy tube (n = 6) until the 14th postoperative day. The pelleted diet was then fed orally in all horses until euthanasia on the 60th postoperative day. Immediate postoperative feeding per os was unsatisfactory, as only 2 of 5 horses survived in this group. Endoscopic evaluation revealed that mucosal dehiscence of varying degrees occurred, wit...
McDonough PL, Shin SJ, Timoney JF.The salmonella serotypes isolated during 1978 to 1983 at the diagnostic and clinical laboratories of the New York State College of Veterinary Medicine from animal sources in New York state were reviewed and compared to earlier data from New York state animals and to national data for both human and animal sources. A total of 255 salmonella strains were studied from the six year period and included 33 serotypes. Salmonella enteritidis ser Typhimurium continued to be the most commonly reported serotype followed by serotype Anatum. Generally serotypes from New York state animals reflected nationa...
Dubin A, Potempa J, Schnebli HP, Koj A.Highly purified horse leucocyte proteinases 1, 2A and 2B hydrolyze synthetic substrates which are decomposed also by human leucocyte elastase but they are unable to hydrolyze typical substrates of cathepsin G. Thus in distinction to other mammalian species horse leucocytes are devoid of cathepsin G and contain only elastases.
Bos H, van der Meij GJ, Dik KJ.Bone structure, nutrient canals, form and definition, and a total evaluation of both fore navicular bones were radiologically evaluated in 169 three- and four-year-old Dutch warmblood mares divided into eleven daughter (half sister) groups. On the basis of the 'total evaluation', differences between the three- and four-year-old horses were detectable. Using the 'total evaluation', significant differences were found between daughter groups consisting of three-year-old mares. These differences support the theory that podotrochleosis may be (partly) due to the presence of genetic factors. The pos...
Tatarov G, Dilovski M.An avirulent immunogenic virus strain mutant of the causative agent of rhinopneumonia was found to cause abortions and respiratory diseases in horses. The mutant was obtained with the use of a virulent strain that induced strongly manifested clinical symptoms of the disease, and was cultured in cell media containing 5-iodine-2-desoxiuridine as an antimetabolite, following a definite pattern. It was found that the mutant completely lost its virulence, however, it retained its immunogenicity. It likewise retained these newly acquired biologic properties with regard to its being stable and irreve...
Elsner R.Examples of exercise performance and metabolic scope in non-human mammalian species are considered from the point of view of problems and questions which may provide insights into evolutionary processes influencing adaptations to muscular activity. Consideration of both aerobic and anaerobic performance is required. Some recent approaches, notably that concerned with the concept of symmorphosis, the integration of design for the accommodation of variations in activity, show promise of new ways for comparative investigations of the adjustments to exercise.
Whitton DL, Trim CM.Heart block is a relatively common arrhythmia in the adult horse. It may be a normal physiologic phenomenon or it may have pathologic implication. Four foals in which advanced heart block developed during anesthesia were unresponsive to atropine sulfate and supportive treatment alone. Resolution of the heart blocks was achieved after the addition of dopamine hydrochloride to the therapeutic regimen.
Uhlinger C, Johnstone C.A survey was conducted to determine the prevalence of benzimidazole (BZ)-resistant small strongyles in horses in a southeastern Pennsylvania practice. Resistant parasites were found in 291 of 342 horses surveyed. Anthelmintic practices and pasture management factors in use for 3 to 6 years did not correlate with the presence of resistant small strongyles. Benzimidazole-resistant small strongyles were recovered in horses that had been treated alternately with BZ and non-BZ products and in horses receiving BZ products as infrequently as twice a year. However, inasmuch as the horses may have been...
Markel MD, Orsini JA, Gentile DG, Freeman DE, Tulleners EP, Harrison IW.Four horses operated on for left dorsal displacement of the large colon (LDDLC) had major intraoperative or postoperative complications. One horse was euthanatized during surgery because of extensive necrosis of the large colon. Three horses that were discharged after surgical correction of LDDLC were readmitted with signs of abdominal pain between 5 weeks and 13 months after surgery. Two horses had recurrence of LDDLC, and the third horse had an omental adhesion attached to and obstructing the pelvic flexure. The displacements were corrected, the adhesion was broken down, and the horses were ...
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...
Wagner PC, Grant BD, Kaneps AJ, Watrous BJ.After desmotomy of the accessory ligament of the deep digital flexor tendon (distal check ligament) had been performed in 40 horses with flexural deformity of the distal interphalangeal joint (contracture of the deep digital flexor tendon), the horses' records were evaluated retrospectively. Information concerning soundness, return to intended purpose, and cosmetic appearance of the limb and hoof was obtained. The condition had been diagnosed and treated in 26 horses before they were one year old (group A, acute) and in 14 horses greater than one year of age (group B, chronic). Nine months to ...
Drudge JH, Lyons ET, Tolliver SC, Swerczek TW.Oxibendazole (OBZ; 10 mg/kg of body weight) was administered to ponies at 8-week intervals to control strongylosis in a breeding band of Shetland-type ponies (n = 29 to 50) from October 1978 through September 1984. A similar use of cambendazole (CBZ; 20 mg/kg of body weight) in this band of ponies during the preceding 4-year period resulted in the survival of a CBZ-resistant population (S) of small strongyles. Effectiveness of OBZ treatments was monitored by pre- and posttreatment counts of the number of strongyle eggs per gram of feces (epg) and of the number of strongyle larvae per gram of f...
Coyne CP, Hornof WJ, Kelly AB, O'Brien TR, DeNardo SJ.Equine fibrinogen was isolated and aliquots were stored frozen at -70 C before radiolabeling with 125I (half-life = 60.2 days; gamma = 35 keV, using monochloroiodine reagent. Radioiodination efficiencies were 49% to 53%, resulting in a labeled product with 98% protein-bound activity and 91% clottable radioactivity. In 6 equine in vivo investigations, plasma half-lives of 125I-labeled fibrinogen were from 4.1 to 5.2 days, corresponding to a mean daily plasma elimination rate of approximately 15%.
Rose RJ, Allen JR.Hematology has been widely used in attempts to provide information about disease states, performance problems, and fitness in performance horses. However, owing to factors such as the temperament of the horse and time of collection and feeding, considerable variation in the hemograms can be found. This article reviews some of the hematologic responses to exercise and training.
Christensen JM, Blythe LL, Craig AM.Phenylbutazone was administered to six Thoroughbred horses in a cross-over study in which the horses received cimetidine pretreatment or no cimetidine pretreatment. Blood samples were collected at various times for 48 h after phenylbutazone administration and the plasma was analysed for phenylbutazone. Cimetidine pretreatment elevated phenylbutazone plasma concentrations during the first 8 h after phenylbutazone administration. The absorption rate, maximum phenylbutazone plasma concentrations and AUC were significantly greater with cimetidine pretreatment. The half-life of phenylbutazone did n...
Soliman GA.The pharmacokinetic behaviour of gentamicin sulphate (3.4 mg/kg bwt) was studied following its intramuscular injection to a group of horses and to another group of horses premedicated with sodium methyl arsinate (2 mg/kg bwt) or imidocarb dipropionate (4.8 mg/kg bwt). Considerable differences were observed in the pharmacokinetics of gentamicin in pre-medicated horses and in horses which had received the antibiotic alone. Peak serum concentration of gentamicin (9.85 +/- 0.05 and 11.15 +/- 0.15 micrograms/ml) were attained within 1.45 +/- 0.05 and 0.92 +/- 0.04 h in arsinate and imidocarb-medica...
Chaffin MK, Cohen ND.To determine whether administration of commercially available Escherichia coli antiserum to neonatal foals would affect serum IgG concentration or morbidity and mortality rates during the first 60 days of life. Methods: Randomized controlled trial. Methods: 271 neonatal foals on 4 well-managed farms. Methods: Foals were randomly assigned to a treatment or control group. All foals were allowed to suckle colostrum normally. In addition, treatment-group foals were given E coli antiserum (10 micromilligrams) orally between 0 and 8 hours after birth. Serum samples were obtained between 18 and 36 ho...
Verschooten F, Picavet TM.Desmitis of the fetlock annular ligament was diagnosed in 30 horses during a period of eight years. Most of the horses had been lame for a prolonged period and had chronically distended digital flexor tendon sheaths. Air tendograms demonstrated thickened palmar or plantar annular ligaments. In 25 horses the ligament was cut longitudinally; of these, 16 horses returned to full work without any difficulty and one became sound after a second operation. Follow up time varied from three months to seven-and-a-half years. None of the five untreated horses returned to work.
Maia BT, Vendruscolo CDP, de Souza AF, Zoppa ALDV.The neurovascular bundle of the equine distal cannon can dynamically vary with limb position, and this can affect the performance of low 4- or 6-point block. This study aims to identify and describe the anatomical position and variations of the lateral and medial palmar/plantar nerve at the metacarpal/metatarsal distal level in horses by ultrasonography. Eight mares underwent ultrasound examination on the lateral and medial palmar/plantar sides of the metacarpus/metatarsus. Images were obtained for measurements of the cross-sectional area of the nerve, distances between the nerve and the skin ...
Rückert C, Emmerich I, Hertzsch R, Vervuert I.Pyrrolizidine alkaloids are secondary plant metabolites with hepatotoxic effect in humans and several animal species. In recent studies, foods such as herbal teas and honey have been found to be contaminated with pyrrolizidine alkaloids. Objective: The aim of this study was to identify and assess pyrrolizidine alkaloids in compound feeds manufactured for horses and containing either alfalfa or a blend of herbs. Methods: Forty-eight feed products for horses were included in the study. The feedstuffs were analysed for 28 selected pyrrolizidine alkaloids by liquid chromatography-mass spectrometry...
Booth TM, Butson RJ, Clegg PD, Schramme MC, Smith RK.Gentamicin-impregnated polymethylmethacrylate beads were used to treat infective arthritis in the small tarsal joints of 11 severely lame horses. Under general anaesthesia, between five and 10 beads were placed into a 7 to 8 mm tract drilled across the affected joint and, in all except one horse, they were left in place for 14 days. Two of the horses were euthanased for reasons other than persistent tarsal joint sepsis, but the other nine survived and seven of them returned to their previous level of athletic performance.
Ross WA, Kaneene JB, Caron JP, Gallagher KF, Gardiner JC.The objective of this study was to identify factors that may affect recovery from and duration of a case of lameness in a stratified random sample of Michigan horses. This was done using data from Phase-II of the Michigan equine monitoring system (MEMS Phase-II), the equine health-monitoring study [Kaneene et al., Prev. Vet. Med. 29 (1997b) 277-292; Ross and Kaneene, Prev. Vet. Med. 28 (1996a) 209-224; Ross and Kaneene, Prev. Vet. Med. 29 (1996b) 59-75; Ross et al., Am. J. Vet. Res. 59 (1997) 23-29]. In this study, statistical modelling was conducted to evaluate risk factors affecting recovery...
Benbarek H, Deby-Dupont G, Caudron I, Deby C, Lamy M, Serteyn D.Divergent results have been reported on the effects of lipopolysaccharides (LPS) on the activation of equine polymorphonuclear leukocytes (PMN). We therefore attempted to determine whether LPS alone can stimulate equine PMN or whether plasma factors are necessary. PMN were isolated from citrated blood on a discontinuous density gradient of Percoll. The luminol (10(-3) mol/L)-enhanced chemiluminescence (CL) of 1.25 x 10(6) cells was measured after addition of Escherichia coli LPS (0.001-10 micrograms/ml) alone or after incubation in autologous plasma (1 h, 37 degrees C). After direct stimulatio...
Kamalov AA, Gukhikh GT, Kirpatovskiĭ VI, Zaraĭskiĭ EI, Poltavtseva RA, Plotnikov EIu, Kudriavtsev IuV, Efremov EA, Obokhotov DA.The study of cell cultures enriched with stem and progenitor cells in the treatment of experimental hypergonadotropic hypogonadism was made on 30 white non-inbred rats with experimental cryptorchism who have undergone xenotransplantation of human fetal enriched cell cultures. Spermatogenic epithelium on histological sections was studied on day 14 and 28 after xenotransplantation with calculation of the spermatogenesis index. The fertility index was estimated for each of the groups. Transplantation of enriched cell cultures enhances efficacy of restoration of adequate germinogenic and spermatog...
Little D, Keene BW, Bruton C, Smith LJ, Powell S, Jones SL.A 49-kg (107.8-lb) sexually intact male Arabian foal was evaluated at 3 days of age because of profuse watery diarrhea, anorexia, and signs of abdominal pain. Physical examination findings were unremarkable except for evidence of diarrhea. A catheter was placed in the right jugular vein for administration of antimicrobials and lactated Ringer's solution. The foal was discharged with instructions to the owner to continue antimicrobial administration and fluid therapy; at home, the owner inadvertently cut the catheter at the level of the hub during attempted removal, and the catheter fragment mi...
Brokken MT, Schneider RK, Tucker RL.To describe a surgical approach for the removal of nonarticular base sesamoid fragments in performance horses and to report the outcome. Methods: Retrospective study. Methods: Horses (n=11), 7 months to 10 years of age, with lameness because of nonarticular base sesamoid fragments. Methods: Lameness was localized to the metacarpophalangeal/metatarsophalangeal region by clinical examination or response to diagnostic local anesthesia. Radiographs confirmed the diagnosis of a nonarticular base sesamoid fragment. Surgical removal was performed with an incision over the base of the affected sesamoi...
Tornquist SJ, Crawford TB.Foals infected with equine infectious anemia virus become thrombocytopenic 7 to 20 days after virus inoculation, and within a few days following the onset of detectable viremia. The thrombocytopenia is associated with suppression of platelet production. Possible mediators of suppression of thrombopoiesis include tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta), cytokines that are released during inflammation. To assess effects of plasma or serum from infected foals on megakaryocyte (MK) growth and maturation in vitro, equine low-density bone marrow cells w...
Kaspar B, Kähn W, Laging C, Leidl W.During macroscopic post-mortem examinations of the genital tract in 104 mares endometrial cysts occurred in 14 (13%) cases. Whereas in mares up to the age of 10 years cystic changes were absent, endometrial cysts occurred in 19% of the animals above the age of 10 years. In 6 mares only 1-2 cysts per uterus were found, and in 8 animals there were between 5 and 18 cystic changes per organ. The cysts were equally distributed in the uterus body and horns. Sporadically occurring cysts were about 11 mm in diameter with a decreasing size to a mean value of 5 mm in multiple cysts. Predominantly in the...