"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.
Rose RJ.Complications from neurectomy have been well known for many years. A 16-year-old mare suffered bilateral luxation of the coffin joints following palmar neurectomy and was destroyed. Autopsy showed complete rupture of the deep flexor tendons, and the supporting ligaments of the coffin joints. Arthritis of the coffin joints, with erosion of articular cartilage was evident.
McGavin MD, Knake R.A 35-kg Duroc pig died 3 days after eating a ration containing aflatoxin B1, B2, G1, and G2. It had hemorrhagic enteritis and extensive midzonal necrosis in the liver. A 13-year-old Quarterhorse that died 2 days after eating moldy hay had hemorrhagic enteritis, fatty degeneration of the myocardium and renal tubules, and extensive total midzonal necrosis of the liver.
Panitz E.Ethyl-6-ethoxybenzothiazole-2-carbamate (Sch 18099) was evaluated for efficacy against natural helminth infections in ponies, pigs, lambs and chickens. Sixteen critical trials were conducted in ponies at dosages of 15 to 150 mg/kg. At 15 mg/kg, efficacy against adult and larval Oxyuris equi was 100% and 91% and against small strongyles it was 98%. Efficacy levels were 95% against Strongylus vulgaris and S. edentatus at the 20 mg/kg dosage. In two trials at 100 mg/kg efficacy against Parascaris equorum was 77%. No efficacy was observed against Gastrophilus spp. or Anoplocephala spp. In swine si...
Steffey EP, Wheat JD, Meagher DM, Norrie RD, McKee J, Brown M, Arnold J.Effects of body position and type of ventilation were determined on arterial blood gases (PaO2, PaCO2) and pH during and immediately following clinical halothane anesthesia in 36 young, physically conditioned horses. Horses in dorsal recumbency had a lower PaO2 than did similarly breathing horses in a lateral position. Predictably controlled positive-pressure ventilation inproved arterial oxygenation and permitted maintenance of a normal PaCO2. Most horses, regardless of type of ventilation and operative body positioning, were hypoxemic in the immediate postanesthetic period.
Gaskin JM, Neal FC, Rubin HL.Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum pr...
Cimprich RE, Rooney JR.Corynebacterium equi is a pathogen associated with respiratory disease in the foal. This paper discusses two cases of Corynebacterium equi infection, one acute and one chronic, in which the major damage was intestinal. Necrosis of Peyer's patches was the only lesion seen in the small intestine of both foals. The foal with acute disease had distinct green-tan focal necrosis and thickened mucosa of the large intestine. In the foal with chronic disease, the mucosa of the large intestine was thickened, rugose, and mottled red-tan. Histologically, the predominant lesions were villous atrophy, mucos...
Mitchell KF, Karush F, Morgan DO.The heterogeneity of the IgM response has been studied with anti-lactose antibody purified from the sera of seven horses. The IgM antibody was induced with a bacterial vaccine and the sera were obtained during a one-year period of immunization. L and H chain preparations were derived from separate bleedings of each horse and examined by analytical isoelectric focusing. All of the L chain preparations were complex and similar and, under optimum conditions, exhibited about 45 bands. Their similarity included almost identical concentration distributions over the entire pH gradient. Isoelectric ba...
Sherman J, Thorsen J, Barnum DA, Mitchell WR, Ingram DG.Upper respiratory disease has been a serious problem in Standardbred horses on racetracks in Ontario, with outbreaks occurring once or twice annually in late winter and early spring seasons. To determine the causes of these epidemics, a 3-year investigation was carried out in which nasal swabs and serum samples were obtained at intervals from apparently healthy horses and from horses suffering from upper respiratory disease. The nasal swabs were used to isolate bacteria and viruses. The serum samples were examined for the presence and level of antibodies to equine influenza viruses and equine ...
Kimball FA, Wyngarden LJ.Preliminary studies indicate the presence of PGF2alpha specific binding sites in membrane fractions prepared from equine corpora lutea. The equilibrium binding data indicate an apparent dissociation constant of 3.2 X 10(-9)M and the concentration of binding sites of -0.1 pmoles/mg membrane protein. Competition of several natural prostaglandins for equine luteal PGF2alpha specific binding sites indicates specificity for the 9alpha-hydroxyl moiety and the 5,6-cis doublebond. Significant increases in relative binding affinities were demonstrated for PGF2alpha analogs with a phenyl ring introduced...
Moore JN, Mcilwraith CW.Two cases of osteochondrosis are presented. Lesions involving the lateral trochlear ridge of the femur are demonstrated on conventional radiographs and double-contrast arthrograms. A radiographic suggestion of osteochondrosis lesions in the patella is noted. Post mortem examination of one case confirmed the presence of partially free cartilaginous flaps. Reference is made to familial tendency to osteochondrosis in man, dog, pig and horse. The significance of rapid growth rate in the pathogenesis of the condition is also discussed.
Kang CH, Ferguson-Miller S, Margoliash E.1. The steady state kinetics for the oxidation of ferrocytochrome c by yeast cytochrome c peroxidase are biphasic under most conditions. The same biphasic kinetics were observed for yeast iso-1, yeast iso-2, horse, tuna, and cicada cytochromes c. On changing ionic strength, buffer anions, and pH, the apparent Km values for the initial phase (Km1) varied relatively little while the corresponding apparent maximal velocities varied over a much larger range. 2. The highest apparent Vmax1 for horse cytochrome c is attained at relatively low pH (congruent to 6.0) and low ionic strength (congruent to...
Walasek OF, Margoliash E.Donkey cytochrome c was shown to differ from horse cytochrome c by having a serine in position 47 rather than a threonine. The rest of the amino acid sequences are identical. Mules and hinnies, both males and females, carry equal amounts of horse and donkey cytochromes c. The same ratio is found in hinnies in preparations from heart tissue and from skeletal muscle. These results demonstrate that cytochrome c is transmitted in horse-donkey crosses as a simple Mendelian character which is neither sex-linked nor shows dominance. The cytochrome c gene is therefore located in the nuclear genome, as...
Froydenlund TJ, Dixon PM, Smith SH, Reardon RJ.The morphology of the dorsal (DCB) and ventral (VCB) nasal conchal bullae, including their cellulae, drainage and histology, are poorly described. The recent recognition that these bullae can become infected, causing chronic unilateral nasal discharge has stimulated interest in these structures. A more complete understanding of their anatomy would be useful in the diagnosis and treatment of their disorders. Objective: To document the structure, drainage and histology of the equine DCB and VCB. Methods: Descriptive. Methods: Fourteen fresh cadaveric horse heads, were transected sagittally midli...
Jaeschke G, Rudolph R.Clinicopathological aspects of equine leukosis are discussed in a review. Among various other findings, only hypercalcaemia accompanied by paraneoplastic syndrome in the course of equine leukosis, increased values of alkaline phosphatase as usual in tumorous diseases, and hypalbuminaemia and hypergammaglobulinaemia in mesentric and intestinal forms of equine leukosis seem to have some diagnostic and pathogenetic significance. Changed values of further parameters are more or less non-specific concomitant signs, indicating that other organs or organ systems have been affected. However, in case o...
Kimura R, Borankulova S, Maratbek SZ.This study aimed to evaluate the effect of differences in trainer skills on horse training during the early stages of riding habituation by measuring the levels of stress and changes in stress levels. Among nine untrained horses employed, five in Group A were trained by two low-skilled trainers, whereas the remaining four in Group B were trained by two high-skilled trainers using the traditional Kazakh method. Salivary α-amylase concentration was measured as a biomarker of stress immediately before and after each riding session during the training period. In the duration of riding and mooring...
León B, González G, Nicoli A, Rojas A, Pizio AD, Ramirez-Carvajal L, Jimenez C.Venezuelan Equine Encephalitis virus (VEEV) is an arboviral pathogen in tropical America that causes lethal encephalitis in horses and humans. VEEV is classified into six subtypes (I to VI). Subtype I viruses are divided into epizootic (IAB and IC) and endemic strains (ID and IE) that can produce outbreaks or sporadic diseases, respectively. The objective of this study was to reconstruct the phylogeny and the molecular clock of sequences of VEEV subtype I complex and identify mutations within sequences belonging to epizootic or enzootic subtypes focusing on a sequence isolated from a mare in C...
Erkert RS, Crowson CL, Moll HD, Bentz BG, Confer AW, Blaik MA.A 4-year-old Thoroughbred stallion was referred for signs of mild to moderate colic, anorexia, and decreased water intake of 3 weeks' duration. Ultrasonographic examination revealed an intussusception, the most common of which would be a cecal inversion or ileocecal intussusception. Surgical exploration identified an ileocecocolic intussusception with extension of the intussusceptum into the right ventral colon; however, the cause of the intussusception could not be identified. The intussusception could not be surgically corrected, and the horse was euthanatized. A side-to-side jejunocecostomy...
Miyamoto C, Takashima I, Karaiwa H, Sugiura T, Kamada M, Hashimoto N.To investigate the overall prevalence of chlamydial infections in light (i.e. non-draught) horses in Japan, 599 sera obtained from 12 localities in 1991 were tested for complement fixation antibodies. The mean antibody positive rates of the all sera were 15.2% (91/599) and the regional positive rates were higher in Honshu (19.1%, 48/251) and Kyushu (20.0%, 20/100) than in Hokkaido (9.3%, 23/248). In Honshu, the highest rate (56.0%, 28/50) was observed in Utsunomiya. Analysis of the positive rate in different age groups showed that the 2-5 years age-group had the highest prevalence of chlamydia...
Valeri CR, Valeri DA, Gray A, Contreras TJ, Lindberg JR.When equine RBC were frozen with 20% (w/v) glycerol and stored at -150 C for as long as 5 years, there were no adverse effects on freeze-thaw or freeze-thaw-wash recovery or oxygen transport function. The manner in which the glycerol was added to, and removed from, the equine RBC was shown to be an important consideration in ensuring optimal freeze-thaw-wash recovery values.
Lisowski ZM, Lefevre L, Mair TS, Clark EL, Hudson NPH, Hume DA, Pirie RS.Studies in rodents and humans have demonstrated that intestinal manipulation or surgical trauma initiates an inflammatory response in the intestine which results in leucocyte recruitment to the muscularis externa causing smooth muscle dysfunction. Objective: To examine the intestinal inflammatory response in horses undergoing colic surgery by measuring relative differential gene expression in intestinal tissues harvested from surgical colic cases and control horses. Methods: Prospective case-control study. Methods: Mucosa and muscularis externa were harvested from healthy margins of resected s...
Ortved KF, Goodale MB, Ober C, Maylin GA, Fortier LA.Orthobiologics such as autologous conditioned serum (ACS) are often used to treat joint disease in horses. Because ACS is generated from the horse's own blood, any medication administered at the time of preparation would likely be present in stored ACS, which could lead to an inadvertent positive drug test following intra-articular (IA) injection. The main objective of this study was to determine if ACS prepared from firocoxib positive horses could result in detectable plasma concentrations of the drug following IA injection. Firocoxib was administered to six horses at 0.1mg/kg PO twice at a 2...
Chvátal O, Hanák J.Surface electric potentials of the heart of four horses were measured by use of unipolar leak with the so called central Wilson's clip; the measurements were performed on 95 precisely fixed places of the equine body. Potentials found out in this way were re-measured with bipolar leaks: the negative electrode was fixed in the place of the highest negative potentials, the positive electrode was gradually attached to places with the highest values of positive potentials. The largest potential differences when the negative electrode was placed in the region of the heart were obtained from the regi...
Evans PM, Armour MD, Dubielzig RR. To describe the gross and histopathological ocular findings in a horse following suspected lightning injury. Methods: The eyes of a 2-year-old thoroughbred gelding were clinically and histopathologically evaluated following a severe lightning storm following euthanasia because of visual impairment. Results: Severe corneal edema and hydrops were noted clinically oculus dexter. Indirect ophthalmoscopy revealed bilateral symmetrical raised hyporeflective peripapillary geographic lesions. Histopathologic evaluation revealed corneal edema in the right eye with normal corneal endothelium...
Lang HM, Panizzi L, Smyth TT, Plaxton AE, Lohmann KL, Barber SM.Records were reviewed for 2 horses with partial glossectomy, 1 traumatic and 1 elective. According to long-term follow-up by telephone, both horses had recovered well, experiencing only temporary difficulty while eating, and went on to be ridden successfully using mouth bits. Partial glossectomy, therefore, had a favorable prognosis in 2 performance horses. Les dossiers ont été examinés pour 2 chevaux ayant subi une glossectomie partielle, 1 étant une glossectomie traumatique et 1 étant une glossectomie non urgente. Selon le suivi à long terme par téléphone, les deux chevaux se sont b...
Asmundsson T, Gunnarsson E, Johannesson T.Blood samples were taken from 18 healthy horses (Group A), 15 horses clinically diagnosed to have "haysickness" ("farmer's lung") (Group B), 10 closely related horses (Group C) and 14 inbred horses (Group D). Precipitins in sera were measured by double gel diffusion test against Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Alternaria, Penicillium and Rhizopus species. In Group A, all the horses were precipitin negative except one with a faint reaction to Rhizopus species. In Group B all had precipitin against M faeni. One horse also had precipitins against Rhizopus ...
