"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.
Parks AH, Scott EA, Cox JE, Stick JA.Six horses with monorchidism, identified at surgery for cryptorchidectomy, are reported. All six presented with a single scrotal testis. Following surgical removal of one testis, they were either hormonally, anatomically or behaviourally determined to be geldings. Three other horses reported in the literature are reviewed. Of these nine cases of monorchidism, eight were thought to be caused by testicular degeneration and one by testicular agenesis. The vaginal process was present in all of the former and absent in the latter. The left side was involved in five of these eight horses. In seven, ...
Nation PN.Trifolium hybridum (alsike clover) has been implicated as the cause of two diseases of the horse. One of these is photosensitivity, of which alsike clover is only one of a number of presumed causal agents. The other is a fatal syndrome which is known as "alsike clover poisoning" and which is manifest by progressive loss of condition, signs of hepatic failure, and varying degrees of neurological impairment. The underlying lesion of alsike clover poisoning is fibrosis and proliferation of the biliary tree. The experimental evidence implicating alsike clover as the cause of this syndrome comes en...
Eysker M, Boersema JH, Kooyman FN.Overwintering of horse cyathostomes as inhibited third stage larvae (L3) and the effect of repeated oxfendazole (OFZ) treatment on strongyle infections were studied in an experiment with two groups of three Shetland ponies. Both groups were grazed together from May 28 to November 11, 1986 and subsequently housed. Treatments with 10 mg OFZ kg-1 were given on May 26, July 1 and July 28 and again one week before each group was necropsied in December and April, respectively. Worm populations of both groups were dominated by inhibited early L3. The proportion of fourth stage larvae (L4) was signifi...
Clayton HM, Townsend HG.A photographic method was used to measure axial rotation, dorsoventral flexion and extension and lateral bending at each intervertebral joint complex from the occiput to the first thoracic vertebra in spinal segments from 19 foals under 12 months of age and 14 horses over three years of age. Comparisons between the two groups showed that there was a general reduction in cervical spinal mobility with age. For the three types of movement at the eight joints tested, adults' mobility exceeded that of foals in only three cases (axial rotation and lateral bending at the A-O joint, and lateral bendin...
Vesonder R, Haliburton J, Golinski P.Feed samples of corn, pelleted feed, and oats associated with equine leucoencephalomalacia (ELEM) were obtained from North Carolina, Illinois, Indiana, and Oklahoma. These samples contained a high colony density of Fusarium moniliforme Sheldon which ranged from 64 to 87% of the total fungi. Fifty-nine F. moniliforme strains were isolated. Isolates of F. moniliforme in feed samples from Illinois, Indiana, and Oklahoma were cultured on corn. The fermented corn, mixed with regular feed and fed to one-day-old ducklings, effected a high mortality coefficient (average 55%). Methanol extracts of corn...
Zaugg JL, Lane VM.We evaluated the efficacy of buparvaquone in eliminating Babesia equi of European origin in carrier horses and in experimentally infected splenectomized ponies. When administered at the rate of 2.5 mg/kg of body weight, IM, 4 times at 96-hour intervals, buparvaquone was effective in eliminating B equi carrier infection in 1 horse. Such results could not be repeated at the same dosage or at 3.5 or 5 mg/kg, IM. Buparvaquone given at the rate of 4 to 6 mg/kg IV and/or IM was therapeutically effective in 4 of 5 acute B equi infections in splenectomized ponies. The treated ponies became carriers.
Gallivan GJ, McDonell WN, Forrest JB.Pulmonary mechanics and lung volumes were measured in horses and cows to determine if differences in breathing pattern between the two species were due to differences in the mechanical properties of the lungs. Tidal volume (VT) was larger in the horses, while the respiratory rate (fR) and minute ventilation (VE) were higher in the cows. The horses often had a double peak in airflow during inspiration and, or, expiration, while the cows had a single peak during expiration. Measured lung volumes were larger in the horses and they had a higher dynamic lung compliance (Cdyn,L), although the static...
Watkins JP, Taylor TS, Schumacher J, Taylor JR, Gillis JP.The records of 35 horses with Grade 3 or 4 rectal tears, presented to the Veterinary Medical Center at Texas A & M University over a five year period, were reviewed. Grade 3 tears were sub-classified according to whether the remaining tissue was serosa (Grade 3a) or mesorectum (Grade 3b). Five horses were destroyed on presentation and 30 were treated by primary suture closure (8 horses), faecal diversion alone (9 horses) or in combination with suture closure (11 horses) and packing of the tear with medicated gauze sponges (two horses). Faecal diversion was achieved with a temporary indwell...
Kolmakova MV, Kuskova ZR, Ratner GM, Laptakova LM.Horse serum albumin has been shown to meet the requirements to protein preparations for microanalysis and thus to be suitable for use in kits of reagents for the radioimmunological determination of insulin and myoglobin, for the determination of tick-borne encephalitis virus antigen by the method of the enzyme immunoassay and for the stabilization of proteins in the hemagglutination test and the hemagglutination inhibition test.
Klein LV, Wilson DV.A mare with a thoracic laceration was anesthetized with halothane-O2 for surgical repair. Shortly after initiation of controlled ventilation, inspiratory plateau pressure began to increase. The increase in pressure continued despite decreasing the tidal volume. Tension pneumothorax was suspected, but because arterial PCO2 and PO2 were normal, the anesthetic apparatus was examined. Excess gas continued to exit through the bellows pop-off valve even when the fresh gas flow was turned off. It was determined that driving gas from the ventilator was entering the breathing circuit through a hole in ...
Principato M.Comparative data collected over 4 years show the most frequent species of Gasterophilus infesting free-ranging horses in Umbria (Central Italy) to be G. intestinalis (93.8%), G. nasalis (76.5%) and G. inermis (71%). G. pecorum and G. haemorrhoidalis were less frequent and appeared in 39.3 and 10.8% of the animals, respectively. For each of the 5 species, the duration of gastric and enteric lesions, the average numbers of larvae isolated throughout the year and the probable duration of oral lesions were discussed.
Baxter GM, Tackett RL, Moore JN.Palmar digital arteries and veins removed surgically from healthy horses under general anesthesia were cut into 4 mm vascular rings, suspended in tissue baths, and attached to force displacement transducers for continuous measurement of vascular tension. In vitro vascular responses were determined for acetylcholine, acepromazine, isoxsuprine hydrochloride (isoxsuprine), prostaglandin E2 (PGE2), and prostaglandin I2 (prostacyclin). After preconstriction with norepinephrine hydrochloride (norepinephrine), or prostaglandin F2 alpha (PGF2 alpha), the concentrations needed to produce 50% maximum re...
Hüthwohl H, Weiss R, Schmeer N, Schliesser T.Classification based on biochemical characteristics of 389 strains of plasma-coagulase-negative (plc-) staphylococci isolated from the genital tract of mares and stallions resulted in the following distribution of species: St. sciuri 130 (33.4%), St. equorum 42 (10.8%), St. xylosus 16 (4.1%), St. epidermidis 35 (9.0%), St. simulans 24 (6.2%), St. haemolyticus 33 (8.5%), St. warneri 18 (4.6%), St. lentus 12 (3.1%), St. hyicus 11 (2.8%). Strains of St. cohnii, St. capitis, St. gallinarum, St. saprophyticus and St. hominis have only been found sporadically (a. 1%). 48 (12.3%) strains could not be...
Sambraus HH, Radtke K.Studies were made on 27 horses which were known to weave. They were stallions, mares and geldings between the ages of 3 and 22 years. The horses were individually observed for several days in their habitual surroundings. A period, in which a horse makes pauses of not more than ten minutes, is considered a weaving phase. Shorter pauses subdivide the weaving phase into weaving series. The basic unit of weaving is the weaving displacement, i.e. the head movement between the turning points. The number of daily weaving displacements of the horses examined varied from less than 400 up to almost 18,0...
Buchwalder R, Schuster R.For the first time findings of Setaria equina (Abildgaard, 1789) in horses are reported from the German Democratic Republic. The nematodes, located in the peritoneum, were discovered in the course of autopsy. Based on a thorough analysis of the international literature, the paper discusses geographical distribution, morphology, cycle and diagnosis of this nematode as well as clinical symptoms mainly caused by the stages of the larvae.
Sanders-Shamis M, Bramlage LR, Weisbrode SE, Gabel AA.The effect of electrical stimulation by means of selected electromagnetic field devices on healing of cannon bone osteotomies in horses was examined. The defects were created as 3 cm x 1 mm longitudinal osteotomies through the dorsal cortices of the mid-metacarpi/metatarsi of adult horses. This type of defect would asses bone healing in a situation similar to an acute, stable fracture of the cortex. Three electromagnetic devices of different design were tested in three different groups of horses. Healing was evaluated radiographically and histologically. Results showed that osteotomies treated...
Baird AN, True CK.Two horses were referred with fragments of nasogastric tubes as esophageal foreign bodies. Radiography and endoscopy were used to identify the location of the fragments. Portions of the tubes were retrieved by esophagotomy in 1 horse and by manual examination of the oral cavity in the other. Both tubes were friable in focal areas, but were quite pliable over most of the length of the tube.
Wilson DG.A 3-year-old Standardbred gelding was referred for evaluation of a fluctuant swelling that developed over the dorsum of the carpus subsequent to arthroscopic surgery on that carpus. A synovial hernia was diagnosed and surgically repaired. Although complications secondary to arthroscopy are rare, synovial herniation can develop after arthroscopic surgery. The condition must be differentiated from the more common true bursitis or false bursitis that is commonly referred to as a hygroma.
Park J, Shin YO, Choo HY.The propionylpromazine concentrations in plasma after intramuscular administration to horses were determined using gas chromatography with nitrogen-phosphorus detection. After hydrolysis by beta-glucuronidase/arylsulphatase, the parent drug and three metabolites were detected in urine. The metabolites were identified as 2-(1-hydroxypropyl)promazine, 2-(1-propenyl)promazine and 7-hydroxypropionylpromazine by gas chromatography-mass spectrometry. No N-demethylated or sulphoxidated metabolites of propionylpromazine were observed in the horse urine.
Ricci G, Del Boccio G, Pennelli A, Aceto A, Whitehead EP, Federici G.Glutathione transferase (EC 2.5.1.18) from horse erythrocytes has been purified and some molecular and kinetic properties have been investigated. It appears to be a dimeric protein composed of subunits of about 23 kDa, indistinguishable either in sodium dodecyl sulfate or in urea electrophoresis. Amino acid composition, substrate specificities, sensitivity to inhibitors, CD spectra, and immunological studies provide evidence that the horse enzyme is related to the pi class transferases. This enzyme has only two reactive thiol groups/dimer whose integrity appears to be essential for the activit...
Shirakawa T, Ide M, Taniyama H, Tobiwatari K, Senba H, Oishi H, Matsui T, Ono T.A 1-month-old male thoroughbred foal, which had difficulty in walking, was killed and examined by histological, histochemical and ultrastructural methods. The muscles of the trunk and upper hind limbs were chiefly affected, and changes in the affected muscles resembled those in muscular dystrophy in man. The type of muscular dystrophy present in this foal and the significance of this disease in thoroughbred horses are discussed. The dystrophy in this foal resembled the limb-girdle type or myotonic dystrophy of muscular dystrophy in man.
Moore JN, Allen D, Clark ES.This article reviews research findings relating to the pathophysiology of acute laminitis in horses. The data presently available suggest that the onset of the condition may be due to constriction of the postcapillary vessels in the digit, leading to increased capillary hydrostatic pressure and movement of fluid into the interstitial space.
Park RD.A complete radiographic examination of the equine foot consists of properly exposed, processed, and positioned radiographs. For radiographic interpretation, in addition to knowing radiographic signs of disease, a knowledge of normal radiographic anatomy and possible insignificant anatomic variations is necessary.
Liebler EM, Gerhards H, Denkhaus M, Pohlenz J.Infections with Micronema deletrix are described sporadically in humans and horses. This case report describes the infection with Micronema deletrix in a horse. The animal was sent to the clinic because of recurrent colic. On rectal palpation a mass was detected in the area of the right kidney and the horse was destroyed on its owners request. At slaughter a greatly enlarged right kidney interspersed with numerous white nodules was found. Histological examination revealed a granulomatous nephritis with numerous sections of nematodes. Based on their morphology and size, they were identified as ...
Zantingh AJ, Gaughan EM, Bain FT.A 14-year-old Hanoverian gelding was evaluated after a 10-week history of occasional straining during urination and dark red urine production after exercise. Physical examination findings were within normal limits. After 2 weeks of clinical signs, ultrasonography had found no abnormalities in the kidneys or bladder. A freely voided urine sample revealed an elevated protein concentration (500 mg/dL; reference range: <100 mg/dL) and few red blood cells. Vitamin C supplementation was suggested to acidify the urine, as was provision of a salt block to encourage water intake.
Moorthy AR, Spradbrow PB.
Summary:
During a survey in Queensland in 1974—77 four strains of rickettsia-like organisms were isolated from the respiratory tract of horses, of which two, NS7 and NS68 were isolated from nasal swabs of clinically normal horses and two, KSDH 91 and NSDH 100, from lung samples of slaughtered horses showing gross pathological lesions in the form of acute bronchiolitis and subacute interstitial pneumonia, respectively. The isolates are characterised as rickettsia-like organisms on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacteria...
Beadle RE, Short CR, Corstvet RE, Pawlusiow J, Nobles DD, McClure JR, Guthrie AJ, Clarke CR.A soft-tissue infection model was created in eight horses by infecting subcutaneous tissue chambers with Streptococcus zooepidemicus organisms. Responses of the horses to the infections were determined by monitoring changes in the complete blood count and body temperature and by following changes in the cytology and protein content of the tissue chambers. Systemic reactions to the infections included a mild neutrophilia, mild pyrexia and mild anemia. There was a marked influx of neutrophils and protein into the chambers after they were seeded with bacteria and chamber neutrophil viability decr...
Smith LH, Adams L, Derré M, Townsend WM.To describe the successful use of endoscopy to visualize and place a soft canine ureteral stent to relieve a chronic nasolacrimal duct (NLD) obstruction in a horse. Methods: A 7-year-old, Quarter horse gelding. Methods: Under general anesthesia, retrograde nasolacrimal endoscopy was performed using an 8.5 Fr Storz Flex XC ureteroscope through the nasal punctum (NP). An obstructive web of fibrous tissue was visualized approximately 20 cm proximal to the NP. A 0.035″/150 cm hydrophilic guidewire was passed normograde from the ventral lacrimal punctum and used to puncture the stenotic tissu...
Nyack B, Padmore CL, Dunn D, Kufuor-Mensan E, Mobini S.A 10-year-old Tennessee Walker gelding, with a history of progressive weight loss, intermittent colic and lethargy, had a slight fever, tachycardia, tachypnea, pallor, ascites and marked ventral edema. Blood analyses revealed anemia, leukocytosis, neutrophilia with a left shift, lymphopenia, monocytosis, hypoproteinemia and a slightly increased SDH level. Abdominocentesis produced red-orange fluid with many RBC and an increased fibrinogen content. Rectal palpation revealed a large mass in the left caudal abdominal quadrant. The animal died shortly after resection of the mass. The histopatholog...
Schubert B.Some chromatographic procedures, which can be used to detect and determine certain corticosteroids in samples from race horses, are described. These procedures include thin-layer, gas and high pressure liquid chromatography.
Losinger WC, Traub-Dargatz JL, Sampath RK, Morley PS.Of 7320 equine foals reported born alive during 1997 on 1043 operations that had equids on 1 January 1997, and that participated in the United States National Animal Health Monitoring System (NAHMS) Equine 1998 Study, 120 foals were reported to have died (by either euthanasia or natural causes) within the first 2 days of a live birth. The weighted estimate was 1.7% mortality (standard error=0.5) within the first 2 days of live birth for all foals born on operations in the 28 states included in the study.A multivariable logistic-regression model revealed that foals born in the southern region w...
Dumasia MC, Houghton E.The in vivo biotransformation of (1,2(n)-3H)1-dehydrotestosterone was studied in three equine male castrates and a number of neutral metabolites were identified in the urinary unconjugated and glucuronic acid conjugate fractions by gas chromatography/mass spectrometry. The metabolites were extracted from aliquots of the 0-24 h urine samples by Amberlite XAD-2 and separated into combined unconjugated plus glucuronic acid conjugated and sulphoconjugated fractions by Sephadex LH-20 column chromatography. After enzymatic hydrolysis of the glucuronides, the crude neutral unconjugated steroids plus ...
Gilger BC, Histed J, Pate DO, Clode AB, McMullen RJ.This case report describes the clinical, diagnostic, computed tomography findings, and surgical treatment of a 2-year-old Morgan filly with bilateral, proximal, and distal anomalous nasolacrimal duct openings.
Drews B, Milojevic V, Robles M, Wimel L, Dubois C, Rudolf Vegas A, Giller K, Chavatte-Palmer P, Daniel H, Giesbertz P, Bruckmaier RM, Ulbrich SE.Female mammalian reproductive functions are closely linked to body condition and metabolic status. Energy homeostasis is regulated by endocrine hormones such as insulin, IGF-I, leptin, and adiponectin via the hypothalamic-pituitary-adrenal axis. These metabolic hormones and their receptors are also expressed in reproductive tissues and the embryo. We investigated the relationship between circulating leptin and the fatty acid (FA) and amino acid (AA) composition of the equine uterine fluid (UF) and peripheral blood plasma (BP) by using a mass spectrometry-based approach. UF and BP were collecte...
Czernomysy-Furowicz D, Silecka A, Nawrotek P, Jankowiak D, Karakulska J, Furowicz A.The research was conducted on clinically healthy mares (n = 40) and foals (n = 78) during Y. pseudotuberculosis associated enzootics. The animals were divided into groups: I to IV--mares, IA to IVA--their offsprings, IB to IVB--foals which mothers were not treated with any medicaments. The animals in group I, IA and IB were injected with PBS; in group II, IIA and IIB--with Y. pseudotuberculosis strain-based vaccine, in group III, IIIA and IIIB--with P. acnes strain-based immunostimulator; in group IV, IVA and IVB--with P. acnes strain-based immunostimulator and (5 days after the immunostimulat...
Boyd JS.The deformities observed in 2 Clydesdale foals are described. Both had abnormal joint positions in the forelimbs and discrepancies in the symmetry of the vertebral column. The changes were only mild in one case but extreme in the other where it was accompanied by torticollis, scoliosis and vertebral fusion. A comparison is made with deformities described in the contracted foal syndrome and some of the developmental implications discussed.
Eichenberger EM, Dent A, Hayes T, Woc-Colburn L.Streptococcus equi is an opportunistic pathogen in horses that has rarely been transmitted to humans. Here we present a zoonotic S. equi meningitis case in a kidney transplant recipient with exposure to infected horses. We discuss the patient's risk factors, clinical presentation, and management in the context of the limited literature on S. equi meningitis.
Henneke DR, Kreider JL.Quarter Horse mares (n = 30) and their foals were used in a 2-year study. Objectives of the study were (i) to determine the effects of a treatment regimen, which permitted nursing for four 1-hour periods each day, on the postpartum reproductive performance of the dams, and (ii) to assess the effects of this procedure on the growth and development of foals. Mares in the restricted suckling treatment group showed estrus and ovulated sooner (P less than 0.01) after parturition than did control mares during the first year of the study, but not during the second year. Plasma progesterone concentrat...
Shortridge EH.Extract
Recent reviews of brucellosis in horses (Stableforth and Galloway, Citation1959; Mascaro and Hoffman, Citation1963: Ritscher, Citation1963) refer to Brucella abortus associated with fistulous withers, arthritis and debility and emphasize the rarity of abortion caused by this organism. One case of abortion in a mare caused by Br. abortus was reported as having occurred in Iowa, U.S.A. (McNutt and Murray, Citation1924).
Häsler S, Dängeli J.Saint Eligius became the saint patron of farriers and veterinarians in the 13th century. This was first mentioned by Jordanus Ruffus, emperor Frederic the 2nd's equerry, who refers to a gregorian hymnal dedicated to Eligius. The legend says that Eliguis amputated a horse's foot, shoed it and placed it back on the horse's leg. This legend might have replaced the Germanic cult described in the incantations of Merseburg. In Switzerland the veneration of Eligius is particularly spread in the canton of Lucerne. Der Heilige Eligius wurde im 13. Jahrhundert Schutzpatron der Hufschmiede und Tierärzte...