"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.
The Journal of hygieneAugust 1, 1981
Volume 87, Issue 1 93-100 doi: 10.1017/s0022172400069278
Lemcke RM, Ernø H, Gupta U.Two unidentified mycoplasmas, N3 and N11, isolated from the respiratory tract of horses, were found to cross-react with strains of M. mycoides subsp. mycoides in indirect immunofluorescence tests, growth-inhibition tests carried out by the running drop/agar-well method, and in complement-fixation and double immunodiffusion tests. Serologically, the equine mycoplasmas were not completely identical with any of the reference strains of M. mycoides with which they were compared. Their cultural characteristics, ability to digest coagulated serum and casein, and survival at 45 degrees C, however, su...
Monath TP, McLean RG, Cropp CB, Parham GL, Lazuick JS, Calisher CH.Brain tissues were obtained from 5 horses with clinical encephalomyelitis during an epizootic in southwestern Michigan in August-September 1980. These tissues were tested for virus by intracerebral inoculation of suckling mice and by examination of frozen sections and impression smears by the indirect fluorescent antibody (FA) technique. Eastern equine encephalomyelitis virus was isolated and detected by FA technique in brains of 3 horses which died or were euthanatized within approximately 24 hours of onset of the disease but not from 2 horses at 2 and 3 days after onset. The latter 2 animals...
Miller RI.Treatment of equine phycomycosis with a vaccine derived from ultrasonicated hyphae of Hyphomyces destruens was attempted in 30 cases of clinical hyphomycosis, 10 cases of hyphomycosis following unsuccessful surgery and 5 cases of basidiobolomycosis. Approximately 53% of animals with clinical hyphomycosis were cured after vaccination, while a further 33% clinically improved. All horses with hyphomycosis treated within 2 weeks of unsuccessful surgery were cured. There was no response to vaccination with a Hyphomyces preparation in horses with basidiobolomyucosis, while surgery alone resulted in ...
Chen CL, Riley AM.Serum thyroxine (T-4) and triiodothyronine (T-3) concentrations were assayed in neonatal foals (1.5 to 4 months) and mature horses (2 to 25 years old) by a modified radioimmunoassay procedure. Blood was collected from 52 clinically healthy foals and horses of various breeds (Thoroughbreds, Quarter Horses, American Saddle Horses, and a single cross-bred horse). Neonatal foals had high serum concentrations of T-4 (mean, 4.02 microgram/dl) and T-3 (192.9 ng/dl) as compared with the values in mature horses (T-4, mean of 1.76 microgram/dl; T-3, mean of 98.69 ng/dl). Stallions had slightly higher T-...
Pedersoli WM, Ravis WR, Belmonte AA, McCullers RM.Digoxin (elixir, 0.022 mg/kg) was administered via stomach tube to healthy horses of mixed breeding and sexes. Serum digoxin concentrations reached a peak (2.21 +/- 0.6 ng/ml) at approximately 1 hour after dosing and had a half-life of 28.8 +/- 10.7 hours. Digoxin kinetics followed a triexponential curve, indicating that at least a 2 compartmental model is required to characterize the serum concentration-time curve after this route of administration. It was calculated that to achieve average serum concentrations of 1.1 ng/ml, an oral dose of 17.4 microgram of digoxin elixir/kg/day and an IV do...
Trout DR, Lohse CL.A foal with a congenital flexure deformity of the right hock was unable to walk because of an abnormally short peroneus tertius (PT) muscle. Tension on the muscle origin and insertions limited the dorsal angle of hock extension to a 70-degrees arc. The intrauterine position of the fetus probably caused the defect. All the PT attachments were dissected in several other limbs, and illustrations made from these dissections were used to study the anatomy and surgical approach. Immediately after resection of the PT muscle, the foal's right hock extended an additional 30 degrees. Two months later, t...
van der Gaag I, van Bruinessen-Kapsenberg EG, Dik KJ, Kroneman J.A two-month-old female foal with duodenal stenosis is described. The foal was in poor condition and showed an abnormal stable behaviour. She stood preferably with her head stretched out and reposing on the mare's back or on the stable ridge. Salivation was an important symptom. Clinical and radiological examination of the oral cavity, the pharynx, and the oesophagus showed no abnormalities, except for the antiperistaltic wave along the oesophagus. Because of her bad condition the filly was euthanized. At post mortem examination, apart from leukoplakia, an erosive ulcerative inflammation was fo...
Tennant B, Dill SG, Glickman LT, Mirro EJ, King JM, Polak DM, Smith MC, Kradel DC.From June 1975 through June 1979, acute hemolytic anemia developed in 11 horses from 7 New York farms. Of the 7 horses that died, 6 had methemoglobinemia. In the 4 horses that recovered, methemoglobinemia was not observed. but Heinz body formation was seen in 3 of the 4. On 2 of the premises involved, frank methemoglobinemia was observed concurrently with Heinz body formation, suggesting a relationship between the pathogenesis of methemoglobinemia and Heinz body formation in the hemolytic process. In addition to the 11 cases described, 22 clinically similar cases were reported to us during the...
Sainsbury DW.The physiological requirements of the horse appear to be reasonably well established and should be adequately provided by ventilation based on straightforward principles, relying largely on natural air flow. On the other hand, there are few objective values for ventilation required to promote good health or alleviate equine respiratory disease. In the absence of such knowledge it is only possible to rely on a logical application of sound principles and experience. Both indicate the satisfactory nature of ventilation by stack effect, aspiration and perflation. Buildings should be well insulated...
Smith BP.The practical implications of equine salmonellosis in the light of present knowledge are reviewed. Emphasis is placed on the various clinical forms which the disease may take. These include asymptomatic infections, signs of fever, anorexia and depression, severe acute diarrhoea and the septicaemic form. Diagnosis depends on recovery of the organism from the blood or faeces or, at necropsy, from tissues. In asymptomatic infections, it may be necessary to make serial faecal cultures over several days before a negative diagnosis may be made with any degree of certainty. Isolation of salmonellae i...
Shull RM.Hemolytic or blood loss anemia was induce in six ponies and red blood cell concentrations of creatine, glucose-6-phosphate dehydrogenase (G-6-PD), lactate dehydrogenase (LDH), and aspartate transaminase (AST) were measured during the ensuing regenerative period. Creatine and G-6-PD levels correlated well and increased concentration of either was good indication of increased erythrogenesis. Erythrocyte LDH levels were of value in assessing the response to hemolytic anemia but not to blood loss anemia. The difference may be, at least in part, the result of differing degrees of regenerative effor...
Boucher JH, Ferguson EW, Wilhelmsen CL, Statham N, McMeekin RR.The erythrocytes of 14 conditioned horses participating in a 157-km endurance ride (requiring 14-21 h) were examined before the ride, immediately upon entering the 44-91-, and 130-km rest stops, and at the finish. At the first rest stop (44 km), the mean erythrocyte count increased 41% (P less than 0.001), the mean hematocrit (Hct) increased 30% (P less than 0.001) and the mean hemoglobin (Hb) increased 33% ( P less than 0.001). Although subsequent mean erythrocyte counts, Hct, and Hb values remained significantly elevated above controls, the values decreased 9-9% from the 4-km values later in...
Adams LG.Six groups of four adult horses were twice injected intramuscularly at a 24 hour interval with 0, 2, 4, 8, 16 or 32 mg/kg of imidocarb dipropionate (IMDP) and monitored for 21 days. The LD50 of IMDP for 21 days after injection was two doses of 15.99 +/- 1.49 mg/kg with mortalities occurring within six days following the first injection. Increasing levels of IMDP were correlated with increasing rates of morbidity, mortality, local and systemic reactions, increasing levels of blood urea nitrogen, serum aspartate amino transferase, serum sorbitol dehydrogenase, serum creatine phosphokinase, neutr...
Gilbert RO.Luteolysis with subsequent shortening of diestrus has been reported to follow equine endometrial biopsy performed early in the luteal phase of the estrous cycle, but a comprehensive study of the effect of endometrial biopsy on cycle length at different times of the cycle has not been reported. In this study, endometrial biopsies were obtained from four different pony mares on each of Days 0, 4, 8, 12, 16 and 20 after ovulation as determined by serial palpation per rectum. Compared with control cycles in the same mares, the ovulatory interval was shortened in mares from which biopsies were obta...
Chopin JB, Wright JD, Melville L, Robinson WF.This report describes traumatic avulsion of the lateral collateral ligament of the humeroradial joint in a horse. The history and diagnostic procedures are included with relevant radiographs and ultrasonographs. The poor prognosis associated with this injury is due to degenerative joint disease.
Ketelaars HC, Peters JG, Anzion RB, Van Ginneken CA.The isolation, partial identification and quantitative determination of four guaiphenesin glucuronides in plasma and urine of the horse is described. The identity of the glucuronides was checked by UV and fluorescence spectrophotometry, by NMR spectrometry and by mass spectrometry after permethylation. The applicability of the procedure to pharmacokinetic studies is demonstrated.
Guay KA, Brady HA, Allen VG, Pond KR, Wester DB, Janecka LA, Heninger NL.Matua bromegrass hay (Bromus willdenowii Kunth) is a high quality forage, but its value for mares during gestation and lactation is not well known. Intake, rate of passage, performance, and reproduction by gestating and lactating Quarter Horse mares fed the hay was investigated. In this experiment, 12, 2- to 12-yr-old gravid mares (mean BW = 553 kg, SD = 36) were fed Matua hay (CP = 11.5%) or alfalfa hay (Medicago sativa L.) (CP = 15.4%) for variable days prepartum (mean 59.9 d; SD = 23.5) and for 70 d postpartum. Matua and alfalfa hay were fed as the roughage portion of the diet with a grain ...
Linhares Boakari Y, El-Sheikh Ali H, Dini P, Loux S, Barbosa Fernandes C, Esteller-Vico A, Scoggin K, Lawrence L, Ball B.An intravenous large dose of protein led to an increased blood urea nitrogen (BUN), resulting in a lesser uterine pH and altered uterine gene expression in mares. The objective of the present study was to evaluate effects of a more physiological methodology to increase BUN on the endometrium of mares. Mares were fed hay and a treatment or control diet (n = 11 mares/treatment) in a crossover design starting at time of ovulation detection (D0) and continuing until D7. Mares of the treated group were fed urea (0.4 g/kg BW) with sweet feed and molasses, and those of the control group were fe...
Stanley SD, Moffitt K, Wiebe V.Equine practitioners should follow these recommendations when using compounded medications: (1) the decision must be veterinary driven, based on a valid veterinarian-client-patient relationship and on evidence-based medicine; (2) compliance with the Animal Medicinal Drug Use Clarification Act of 1994; and (3) use limited to (a) horses for which no other method or route of drug delivery is practical; (b) those drugs for which safety, efficacy, and stability have been demonstrated; or (c) disease conditions for which a quantifiable response to therapy or drug concentration can be monitored.
Meier HP.The genetic predisposition to navicular disease is proven nowadays, but otherwise, etiology and pathogenesis are still unclear. Causal therapy isn't possible and because of the poor prognosis, neurectomy is still of bearing. This operation was performed already 200 years ago, but in the middle of the last century, critical voices have been raised in regard to the surgical procedure and its indication both for medical reasons and breeding. Clear instructions for exclusion of diseased animals from breeding are also older than one hundred years. These facts call for ethic considerations which con...
Wong JK, Tang FP, Wan TS.The study of the metabolism of drugs, in particular steroids, by both in vitro and in vivo methods has been carried out in the authors' laboratory for many years. For in vitro metabolic studies, the microsomal fraction isolated from horse liver is often used. However, the process of isolating liver microsomes is cumbersome and tedious. In addition, centrifugation at high speeds (over 100 000 g) may lead to loss of enzymes involved in phase I metabolism, which may account for the difference often observed between in vivo and in vitro results. We have therefore investigated the feasibility of us...
Davies JV, Gerring EL.Small intestinal ischaemia is a cause of pain in man and horses. Occlusion of the vascular supply to Thiry loops in experimental ponies caused severe discomfort and loss of motility within a few minutes but these effects could not be reproduced by a similar procedure in intact gut preparations. However, embolisation of the mural vascular network produced ischaemia of the small intestine of anaesthetised ponies which led to a cessation of motility in the affected segments, though unaffected segments became hypermotile with a characteristic motility pattern. These results suggest the need for re...
Sloet van Oldruitenborgh-Oosterbaan MM, Grinwis GC.Equine sarcoidosis seems to be an emerging problem. As more horses are referred for dermatologic disease, equine sarcoidosis should be considered in any case of exfoliative and/or nodular skin disease with or without systemic involvement, including generalized granulomatous disease affecting most internal organs. Multiple breeds are affected with mares being predisposed. Affected horses are typically 3 years or older. The prognosis for generalized granulomatous disease is generally poor, whereas the prognosis for the localized cutaneous form is favorable but may require lifelong treatment.
Rubio-Martínez LM, Redding WR, Bladon B, Wilderjans H, Payne RJ, Tessier C, Geffroy O, Parker R, Bell C, Collingwood FA.Fractures of the medial intercondylar eminence of the tibia (MICET) are scarcely reported in horses. Objective: To report the clinical and diagnostic findings, surgical treatment and outcome in a series of horses presented with MICET fracture and treated with arthroscopic fragment removal. Methods: Multicentre retrospective case series. Methods: Case records of horses diagnosed with MICET fractures that had undergone surgical treatment were reviewed. Follow-up information was obtained from re-examination visits and/or owners. Results: Twenty-one cases were identified at 9 equine hospitals betw...
Fey K, Weiss R, Sasse HH.Both, the oral and intravenous application of two trimethoprim-potentiated sulfonamides induced measurable antibacterial activities in the feces of horses. With regard to the risk of antibiotic-induced alterations of the gastrointestinal flora, the route of application of potentiated sulfonamides seems to be of minor importance. The antibiotics used were Sulfadimethoxine/Trimethoprim (Trafigal 30% ad us. vet.) for oral and Sulfadoxine/Trimethoprim (Borgal 24% ad us. vet., both Hoechst AG, Frankfurt) for intravenous application. As recommended, both drugs were given in a dose of 20 mg per kg bo...
Jaussaud P, Courtot D, Doron P, Guyot JL.Chronopharmacokinetics of intravenous phenylbutazone in the horse was studied with the aim of antidoping control. Among parameters studied, the single one which seemed to depend on circadian rhythm was the elapsed time between the injection and the plasmatic peak. There was no relationship between the injection time and the both parameters: half-life and time required to reach the forensic level of 4 micrograms/ml. This later, and oxyphenbutazone/phenylbutazone ratio, should depend on individual factors. Therefore, the injection time should not be a main parameter for the phenylbutazone evalua...
Hoque S, Senba H, Tsunoda N, Derar RI, Watanabe G, Taya K, Osawa T, Miyake Y.To clarify the endocrinological characteristics of the mares with granulosa theca cell tumor (GTCT), peripheral plasma samples from the 6 mares affected with GTCT were collected before and after the surgical removal of the affected ovary. Concentrations of testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH), immunoreactive-inhibin (ir-INH), progesterone (P) and estradiol-17beta (E(2)) in the plasma samples were measured by radioimmunoassay. Before removal of GTCT in all cases, the concentrations of T were significantly higher than those of normal mares at the breedin...
Southwood LL, Trotter GW, McIlwraith CW.To determine the outcome of horses after arthroscopic removal of abaxial fracture fragments of the proximal sesamoid bone and association of fracture grade with outcome. Methods: Retrospective study. Methods: 47 horses. Methods: Information obtained from dorsopalmar and dorsoplantar radiographic views of metacarpophalangeal and metatarsophalangeal joints was used to classify fractures as grade 1 ( 25 mm long) and type 1 (abaxial) and type 2 (apical-abaxial). Outcome was determined by whether the horse returned to its intended use, raced in the same class or higher (racehorses), or performed sa...
