"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.
Wilbur DJ, Allerhand A.The titration behavior of individual tyrosine residues of myoglobins has been studied by observing the pH dependence of the chemical shifts of Czeta and Cgamma of these residues in natural abundance of 13C Fourier transform NMR spectra (at 15.18 MHz, in 20-mm sample tubes, at 37 degrees) of cyanoferrimyoglobins from sperm whale, horse, and red kangaroo. A comparison of the pH dependence of the spectra of the three proteins yielded specific assignments for the resonance of Tyr-151 (sperm whale) and Tyr-103 (sperm whale and horse). Selective proton decoupling yielded specific assignments for Cze...
Ogbourne CP.A total of 21 species of Cyathostominae was found in the lumen of the large intestine of 86 mature horses of various ages and breeds killed in south-west England during 1972-1974. Cylicostephanus longibursatus, C. goldi, C. calicatus, Cyathostomum catinatum, C. coronatum and Cylicocyclus nassatus were found in over 80% of the horses, while 12 of the remaining species were detected in less than 30%. Quantitative studies on 55 horses showed the adult cyathostome burdens to rise to a sharp peak (average over 400,000/horse) in April-June and a lower one in November-December. Parallel fluctuations ...
Breaud TP, Steelman CD, Roth EE, Adams WV.A tissue culture of Culex pipiens quinquefasciatus Say ovarian cells appeared to support the growth of equine infectious anemia (EIA) virus. Shetland ponies inoculated with 2nd, 7th, 9th, and 11th passages of mediums harvested from infected tissue culture had clinical signs of the disease and became EIA positive on 11, 19, 23, and 43 days after inoculation, respectively.
Tobin T, Blake JW, Tai CY, Arnett S.Rapid intravenous injection of 1 g of procaine hydrochloride in Thoroughbred mares produced variable signs of central nervous system excitation for as long as 4 minutes. Plasma concentrations of procaine were similarly variable and transient, decreasing with a half-life of approximately 25 minutes. In vitro, plasma from freshly collected equine blood hydrolyzed procaine with a half-life of approximately 7.5 minutes. This hydrolysis was apparently due to plasma esterases. Penicillin, when added free or complexed as procaine-penicillin, did not protect procaine against hydrolysis by these plasma...
Pfaff G.In South Africa 2,41% of horses bleed in a race. If all raced until they were 7 years old probably another 2,12% would bleed. Many others bleed after the race or during exercise or at rest. The incidence of epistaxis is significantly greater in geldings than in females and uncastrated males (P less than 0,001). There is an age distribution of bleeding which is highest at 4 years and lowest at 2 years of age (P less than 0,001).
Pascoe RR.A survey of 568 horses in training and 2,535 horses on breeding farms has shown 32 percent of the horses in training to be clinically affected while only 1.1 percent of breeding horses were affected with pathogenic dermatophytes. The majority of lesions on racing horses were located on the girth areas. Trichophyton equinum var. autotrophicum, M. canis and M. equinum were found to be restricted to racing horses only. M. gypseum occurred in racing, riding and breeding horses.
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...
Marasas WF, Kellerman TS, Pienaar JG, Naudé TW.When 2 horses were dosed with cultures of a Fusarium moniliforme isolate that had previously caused only hepatosis, 1 developed brain oedema and hepatosis, and the other only leukoencephalomalacia. A 3rd horse developed both leukoencephalomalacia and hepatosis after being dosed with another isolate obtained from maize which was associated with a natural outbreak of the nervous form of the disease. Since leukoencephalomalacia and hepatosis could be induced by the same culture material, it was concluded that both syndromes were manifestations of the same toxicosis. There was also some evidence t...
Rance TA, Park BK, Rowe PH, Dean PD.A radioimmunoassay procedure was developed for the measurement of dehydroepiandrosterone (DHA) in peripheral serum in nonpregnant mares. The synthesis and conjugation of 3beta-hydroxy-5-androsten-19-al-17-one 19(0-carboxymethyl) oxime is described. Antisera were developed against this antigen and characterized. The most specific antiserum was used to measure DHA. Concentrations of DHA were greatest immediately before ovulation.
Shoho C.1) Setaria equina (Abildgaard, 1789) is from the Horse and Donkey of Eurasia (and of America and the coastal stripe of North Africa). 2) Setaria equina theilerae n.sub.sp. is from the Zebra of Africa. 3) Setaria equina defaallai n.sub. sp. is from the Horse and the Donkey of southern Sahara area of the Ethiopean Region of Africa, from the Nile valley till to the western coast. 4) Crossing between S. equina and S. e. theilerae may be possible, as their host spp. does with the resultant bastard offspring experimentally.
Sampaio CA, Prado ES.Ala-Phe-Lys-CH2-Cl is a chloromethylketone derivative which is able to promote the inhibition of several proteolytic enzymes. In this paper the inhibition of horse urinary and plasmatic kallikreins is described and this inhibition is compared to that produced in human plasma kallikrein. This compound was designed based upon the structure of bradykinin. This enzyme substrate system can provide a model for the study of the interactions between bradykinin and its receptor. The inhibition of the enzymes was achieved both for its esterase and kinin-releasing activities.
Feist JD, McCullough DR.The social behavior of feral horses was studied in the western United States. Stable harem groups with a dominant stallion and bachelor hermaphrodite hermaphrodite groups occupied overlapping home ranges. Groups spacing, but not territoriality, was expressed. Harem group, stability resulted from strong dominance by dominant stallions, and fidelity of group members. Eliminations of group members were usually marked by urine of the dominant stallion. Hermaphrodite-hermaphrodite aggression involved spacing between harems and dominance in bachelor groups. Marking with feces was important in hermap...
Sampaio MU, Galembeck F, Paiva AC, Prado ES.The kinetic constants for horse urinary kallikrein and trypsin hydrolysis of BAEE, TAME, bradykinin methyl ester and bradykinyl-Ser-Val-Gin-Val-Ser were determined. The values of the ratio kcat/Km show that (1) kallikrein is catalytically less efficient than trypsin for all the substrates (2) the three esters are equally good substrates for trypsin while horse urinary kallikrein is 100-fold more effective on bradykinin methyl ester than on the other substrates (3) for both enzymes the ester of bradykinin is a better substrate than the tetradecapeptide.
Offord S, Tulloch LK, Franklin SH, Tremaine WH, Woodford NS, Allen KJ.The laryngeal tie-forward (LTF) procedure has been shown to move the larynx rostrally and dorsally whilst repositioning the basihyoid bone caudally and dorsally. Other studies have shown that the position of the hyoid bones influences the size of the nasopharynx. The effect of the LTF procedure on the size of the nasopharynx is unknown. It was hypothesised that the LTF procedure would result in a decrease in dorsoventral nasopharyngeal diameter. Twenty-five thoroughbred horses which underwent LTF with or without soft palate cautery (LTF±SPC) for treatment of dorsal displacement of the soft pa...
Anderson WI, De Lahunta A, Vesely KR, Tucker GW.Infarction of the pons and rostral medulla secondary to arteriolar thrombosis was documented histologically in a 17-year-old mixed-Arabian female horse. Clinically, the animal experienced a sudden onset of a head tilt and subsequent non-controllable seizures. There was no historical, clinical or histological evidence to suggest the presence of infection of Equine Herpesvirus-1 or the feeding of corn contaminated by Fusarium moniliforme.
McGlinchey L, Hanson RR, Boone LH, Rosanowski SM, Coleridge M, Souza C, Munsterman AS.To compare the bursting strength and failure mode of ventral midline celiotomy closed with a simple continuous suture pattern with 1 of 2 knot combinations, a novel self-locking knot combination of a forwarder start with an Aberdeen end knot (F-A) and a traditional combination of a surgeon's start with a surgeon's end knot (S-S). Methods: Ex vivo experimental. Methods: Equine cadavers (n = 14). Methods: A 20-cm ventral midline celiotomy was created in 14 equine cadavers. Horses were assigned to celiotomy closure with an F-A or S-S knot combination. Prior to closure, a 200-L inflatable blad...
Hébert L, Cauchard J, Doligez P, Quitard L, Laugier C, Petry S.There is great concern about the potential pathogen contamination of horse manure compost spread in the same fields horses graze in. To ensure that pathogen destruction occurs, temperatures need to be sufficiently high during composting. Here, we investigated the survival rate of two marker organisms, Rhodococcus equi and Parascaris equorum eggs, exposed to temperatures potentially encountered during horse manure composting. Our results show that the time required to achieve a 1 log10 reduction in R. equi population (D-value) are 17.1 h (+/-1.47) at 45 degrees C, 8.6 h (+/-0.28) at 50 degrees ...
Hyde KA, Altman A, Banasek R, Gastal MO, Gastal EL.Hay wastage when feeding round bales due to contamination, deterioration, and animal refusal can accrue large financial losses for farmers. The present study investigated the efficiency of the conventional Tombstone-style feeder system compared to the Hay Saver feeder system to reduce hay wastage in feeding round hay bales. Mares were distributed equally into two groups, Tombstone and Hay Saver, and fed six bales per group over 48 days. Hay wastage was collected daily, dried, and weighed, while the mares were weighed weekly. Overall, the Hay Saver feeder showed less hay wastage, higher mean ma...
Wulster KB.This article discusses the basis of image formation of radiography, scintigraphy, PET, computed tomography (fan beam and cone beam), and magnetic resonance as it relates to imaging of musculoskeletal injury in the sport horse. The benefits and drawbacks of each modality are discussed with particular emphasis on sensitivity, specificity, and accuracy of identification of subchondral bone injury. Examples of straightforward as well as confounding lesions are provided, emphasizing the need for appropriate clinical workup and diagnostic analgesia, where appropriate.
Rosskopf U, Noeske K, Werner E.The bacterium Clostridium (C.) tetani is an ubiquitous pathogen. This anaerobic, gram-positive bacterium can form spores and can be found in the whole environment. It enters the body via injuries of the skin and wounds where it releases the neurotoxin "tetanospasmin" (= tetanus toxin). The animals most susceptible to tetanus infection are horses and sheep. Only active immunisation by tetanus vaccine provides effective protection against tetanus intoxication. The marketing authorisation requirements stipulate that efficacy of tetanus vaccines ad us. vet. must be demonstrated in all target anima...
Hodder AD, Coyne CP, Madigan JE.An 11-year-old American Buckskin mare gave birth to live triplets unattended at approximately 300 days gestation. All foals were small and dysmature, requiring intensive care. The smallest foal died 4 days after admission, the second was subjected to euthanasia 24 days after admission due to poor healing of a third metatarsal fracture. The remaining foal survived to discharge and was considered small but otherwise normal at age one year.
Sandh G.The author has modified a surgical technique, which was originally developed at the turn of the century, for the aseptic establishment of an intestinal anastomosis. The principle of this technique, known as the "cutting thread" principle, was that a loop of thread was introduced into the lumen of each of two approximated loops of intestine. After suturing the two loops of intestine together around the intraluminal parts of the thread, the latter was used as a "wire-saw" to create a stoma between the two intestinal loops. The author modified the method in such a way that the cutting could be pe...
Riddell LP, Yoshimura S, MacKay AV, Wilson DG.A 17-year-old Quarter horse mare was presented because of traumatic luxation of the fifth sacral and first coccygeal vertebrae resulting in loss of sensation, motor function, and perfusion of the tail. The case was complicated by an associated tail head hematoma. Due to the severity of the injury, tail amputation was performed at the level of the luxation. Tail amputations in horses at the sacrococcygeal junction following a suspected tail pull injury are infrequently reported in the literature. . Une jument Quarter horse âgée de 17 ans fut présentée pour cause de luxation traumatique de l...
Sangiah S, McAllister CC, Amouzadeh HR.The basal gastric pH, free and total acid contents from five adult horses were determined at two-hour intervals for six- to eight-hour periods. The basal gastric pH, free and total acid contents varied from 2.14 +/- 0.08 to 2.41 +/- 0.14, 28.63 +/- 8.27 to 17.89 +/- 2.86 mmol litre-1 and 41.38 +/- 9.72 to 37.38 +/- 3.70 mmol litre-1, respectively. Cimetidine (8.8 mg kg-1 orally) and ranitidine (2.2 mg kg-1 orally) increased the basal gastric pH to above 3.6 (P less than 0.05) with a concomitant reduction of 75 per cent and 75 to 100 per cent in the basal gastric free acid content, respectively...
Dabareiner RM, Chaffin MK, Quirham H, Carter GK.4 horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint were examined. Results: All 4 horses had a history of acute, severe, unilateral forelimb lameness and had signs of pain during manipulation of the affected upper forelimb; 2 also had swelling in the axillary region. There was no improvement in lameness after diagnostic local analgesia below the carpal region, and 1 of 4 horses had mild improvement after cubital joint analgesia. Radiography revealed enthesophyte formation on the radial tuberosity and linear mineralization of the medial collateral liga...
Labens R, Jermyn K.To assess suspensory ligament extensor branch location and fracture gap reduction with simulation of standing and recumbent cortical bone screw repair of experimental incomplete parasagittal proximal phalanx (P1) fractures. Methods: Controlled laboratory study. Methods: Twenty equine cadaver forelimbs. Methods: Simulated fractures were repaired twice in random order. A proximal cortical bone screw was placed in lag fashion with the limb unloaded (simulated recumbent repair) and loaded to 38% of body weight (range, 375-568 kg; simulated standing repair). Changes in fracture gap width were ass...
Holl HM, Armstrong C, Galantino-Homer H, Brooks SA.Laminitis results in impaired tissue integrity and Inflammation of the epidermal and dermal lamellae connecting the hoof capsule to the underlying distal phalanx and causes loss-of-use, poor quality of life and euthanasia in horses. Historically, studies to better understand the etiology of laminitis by documenting changes in gene expression were hampered by the paucity of gene annotation specific to hoof tissues. Next-generation sequencing enables improvements to annotation by incorporating equine- and hoof-specific transcripts. Here we characterize the hoof lamellar tissue transcriptome of n...
Busschers E, Richardson DW.A 16-year-old Thoroughbred gelding was examined because of chronic right forelimb lameness. Results: On radiographs of the right front foot, the distal interphalangeal (DIP) joint space was narrow, and osteophytes and periarticular bony proliferation indicative of severe osteoarthritis were seen. Arthrodesis of the right DIP joint was recommended to improve the horse's comfort on the limb. Results: The horse was anesthetized, and palmar and dorsal arthroscopic approaches were used to remove as much of the articular cartilage as was accessible. Holes were then drilled through the dorsal aspect ...
