"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.
Guerin G, Varewyck H, Bertaud M, Chasset P.A horse family in which a recombination occurred in the chromosome region coding for the serological specificities of the ELA complex and those of the A blood group system of a mare was further analysed by mixed lymphocyte reaction (MLR) and Southern blot hybridization. This family consisted of a stallion, a mare and five full sibs. The stallion and the mare were heterozygous for internationally recognized ELA specificities while only the mare was heterozygous for the A blood group system. MLR between all members of the family confirmed that the stallion possessed two different ELA haplotypes ...
Allen D, White NA, Tyler DE.The morphologic effects of induced intraluminal hydrostatic pressures (IHPs) of 0, 9, and 18 cm H2O were evaluated in 33 isolated equine jejunal segments. Fifteen segments were distended with Tyrode's solution for 1 hour and nine segments for 4 hours. Tyrode's solution was added as needed to maintain the prescribed pressures. Nine other segments were left undisturbed for 4 hours after the initial distention period. On decompression of the intestinal segments, progressive peristaltic contractions resumed in all segments. Evaluation of intestinal sections by light microscopy and transmission ele...
Hartmann E, Baumgärtner W, Hungerland C.The present report describes the clinical and pathological findings of a one year old foal presented with paralysis of the hind legs. Macroscopically and histologically, a lymphosarcoma in the vertebral body and the adjacent epidural space of T 16, in the spleen and the mesenterial lymph nodes was observed. The adjacent spinal cord showed focal degenerative changes characterized by dilatation of myelin sheaths, swollen axons and few macrophages.
Littlejohn A, Snow DH.These studies investigated circulatory, respiratory and metabolic responses in four Thoroughbred geldings during the first 400 metres of galloping (mean speed 14.4 +/- 0.38 m.s-1), cantering (mean speed 10.0 +/- 0.61 m.s-1) and walking (mean speed 1.58 +/- 0.05 m.s-1) from a standing start. A radio-controlled device which collected blood samples anaerobically during each 100 m section of the exercise track allowed analyses of changes in and functional relationships of the variables measured. During the 400 m gallop, the mean heart rate (HR) increased from 125 to 201 beats.min-1 and the haemato...
Geerken C, Doreau M, Boulot S.Urea, compared with deuterium oxide (D2O) as a reference, was used as a body marker to estimate body water volume in ten 2-month old nursing foals. Plasma urea clearance was regular over 10 h and the R2 of the disappearance curve was between 0.93 and 0.98. Mean urea space was about 4% lower than D2O space, but the standard deviation of the proportion of water in body weight was higher with urea (3.8%) than with D2O (1.6%). Calculated urea entry rate was 49 mg/h/kg LW0.75.
White KL, Thomson DL, Wood TC.An indirect immunofluorescence assay was used to detect the presence of H-Y antigen on equine blastocysts. A total of 33 blastocyst stage horse embryos were collected 6 to 7 days post-ovulation by trans-cervical flush and were immediately evaluated for the presence of H-Y antigen. Additionally, 17 embryos, were collected and cultured for 72 h to the expanded blastocyst stage and similarly evaluated. Embryos were placed in medium containing monoclonal antibodies to H-Y antigen followed by incubation in medium containing 1/10 (v/v) fluorescein isothiocyanate conjugated goat anti-mouse IgM Fc spe...
Clem MF, DeBowes RM, Yovich JV, Douglass JP, Bennett SM.Sixty-eight cases of cortical bone sequestration in 67 equine patients were reviewed with regard to the clinical presentation, method of treatment, and outcome. All lesions were located in skeletal areas with minimal soft tissue coverage, with 53% of them in the metatarsal and metacarpal bones. At the time of admission, 60% of the patients with limb lesions were lame; the majority improved with therapy. After sequestrectomy, there was a trend for surgical wounds which could be managed by primary closure to heal more rapidly (3.8 weeks) than wounds which required second intention healing (6.4 w...
Jaeschke G, Wintzer HJ.This is a review on Morbus maculosus equorum (purpura haemorrhagica) on the base of literature data and of a case report on 13 own patients. It is shown, that the clinical picture of this disease has not changed within the last 150 years. Clinical main symptoms are haemorrhagic diathesis (petechiae, ecchymosis, suggillations) as well as peripheral edema and fever. The main haematological findings are neutrophilia, mostly going along with shift to the left and lymphopenia. In the last few years thrombocytopenia was also described in some cases. Basic therapeutics are glucocorticoids and penicil...
Thein P, Brown K.Infections with EHV1 can lead to manifestation at the CNS of horses followed by encephalomyelitis and "equine stroke". Horse experiments could confirm the clinical picture and gave links to the potential pathogenesis of the disease. We also have been in the position to isolate and characterize an EHV4 virus out of the brain of a horse with CNS disorders. The two viruses carry different biological properties which obviously dominate the pathogenesis. These properties as well as experimental and field cases are described and different diagnostic tests are discussed.
Rapp HJ.During the combination of oral and intravenous application of saline solution for treatment of the COPD of horses the level of hydraemia basing on the total protein concentration in the serum, the urine production and the specific weight of urine was determined. Additionally the development of serum concentration and of renal excretion rates of potassium, calcium and magnesium were ascertained. The level of hydraemia resulting from the combined method is almost identical with the solely intravenous performed hyperinfusion therapy. Due to the excessive application of fluid an extremely high lev...
MacHarg MA, Foerner JJ, Phillips TN, Barclay WP.The medical management of three horses with simple and strangulating small intestinal obstructions was unsuccessful and was therefore supported by surgical bypasses. Jejunocecostomies were used to treat horses with postoperative paralytic ileus that was unresponsive to medical management. These horses had abdominal pain, gastric distention, heart rate elevations greater than 60/minute, and small intestinal distention on rectal palpation. Two horses experienced weight loss which responded to bypass removal. The bypass effectively decreased the need for intravenous fluid administration and repea...
Bowling AT, Clark RS.Data from 5934 matings of American Standardbred horses provided evidence for an excess of heterozygotes at the albumin locus, statistically significant (P less than 0.01) in one mating class (A1-AB stallions x Al-A dams), primarily attributed to an excess of heterozygotes among male offspring.
Kline KH, Bechtel PJ.1. Cross sections from the middle of the gluteus medius were removed from 10 adult horses and used to evaluate changes in histochemically determined muscle fiber type and biochemically determined metabolic enzyme activities as a function of sample depth. 2. Muscle fiber types determined using histochemical methods for myosin ATPase (pH 9.4) and succinic dehydrogenase (SDH) activity indicated percent fast-twitch glycolytic (FG) muscle fibers decreased and slow-twitch oxidative (SO) fibers increased as a function of increasing sampling depth. 3. Percent histochemically determined fast-twitch oxi...
Brethes B, Puech PL, Fraisse A, Dubois P, Domenech J, Bourdin P, Moreau JP, Capdevielle P, Desoutter D, Lechapt M.This epidemiological survey includes the study of human and animal leptospirosis in New Caledonia from clinical cases as well as a systematic serological study about exposed human and animal populations. The results show that this disease is endemic on the whole territory with a few important focuses in agricultural area, especially on the Western coast. Leptospira icterohemorrhagiae is the main serotype and is responsible for serious human leptospirosis. The male farmers constitute the most exposed population, especially from March to May, end of the host season. In order to reduce the import...
van den Hoven P, Meijer AE, Breukink HJ, Wensing T.Muscle biopsies from six horses with clinical histories of muscle atrophy, muscle tremors, myopathic symptoms, unsteadiness of pelvic limbs and progressive ataxia were examined. Muscle biopsies were studied with enzyme histochemical techniques to evaluate the diagnostic values of these methods in cases suspected of suffering from neuromuscular disorders. Hypertrophy, atrophy, fibre splitting, waxy degeneration, phagocytosis and necrosis were seen in haematoxylin eosin stained sections of the different cases. Fibre type predominance and fibre type grouping were seen in the calcium ion stimulate...
Lazary S, Antczak DF, Bailey E, Bell TK, Bernoco D, Byrns G, McClure JJ.Six laboratories participated in the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, testing 132 alloantisera against lymphocytes of 880 horses chosen to represent different families and breeds. Most of the alloantisera were produced by lymphocyte immunization between horses matched at the ELA-A locus. All horses were also tested with antisera contributed to the workshop by participating laboratories which identified ELA specificities A1-A10 and W12-W21. Previously identified workshop specificities ELA-W14, W15 and W19 were accepted as products of the ELA-A locus based on...
Santschi EM, Grindem CB, Tate LP, Corbett WT.Ten student surgery ponies were subjected to exploratory laparotomy. Abdominal paracentesis was performed preoperatively and daily postoperatively for 6 days, then the ponies were euthanatized and necropsied. Initial baseline peritoneal fluid parameters were within established reference limits. Postoperatively, the total leukocyte count and total protein in the peritoneal fluid rose and remained elevated for the 6 days of the study. Complete blood counts (CBCs) were performed preoperatively and on days 1 and 4 postoperatively. On day 1, a stress leukogram with a mild inflammatory component dev...
Merkens HW, Schamhardt HC, Hartman W, Kersjes AW.The amplitudes, impulses and times of occurrence of a number of selected peaks in the ground reaction force tracings of 17 horses with various clinical histories were compared with those of 20 horses used to establish values for the 'standard' Dutch Warmblood horse. The resulting factors were combined, using different weighting factors, into indices characterising each limb. The symmetry between the loading of the forelimbs and the hindlimbs was used to calculate amplitude and peak-time symmetry indices. Limb and symmetry indices were combined in one H(orse) INDEX. This method of quantifying t...
Hansen TO, White NA, Kemp DT.Total parenteral nutrition was accomplished in 4 healthy adult horses. During the 10-day study, the horses were not permitted to ingest food or water. Body weight was maintained at 94% of initial values without clinical evidence of dehydration. Serum urea nitrogen and triacylglycerol concentrations decreased during the study, without other significant hematologic or biochemical changes. Horses adapted without problems to the routine of IV feeding and confinement. All horses were healthy at the conclusion of the study. It was concluded that intravenous feeding with a lipid-glucose-amino acid-el...
Bosler EM, Cohen DP, Schulze TL, Olsen C, Bernard W, Lissman B.By using paired sera the IgM and IgG host responses were analyzed in dogs with ELISA and Western blot techniques. Antibodies in clinical seropositive dogs bound to 4-25 IgM and up to 40 or more IgG antigenic determinants. Early IgM response to the 41-kDa flagellin persisted for at least 9 months and involved as many as seven other peptides. IgG response expanded later in the disease and involved more immunogens than are currently recognized in late human disease. A percentage of asymptomatic dogs that later developed clinical symptoms were seropositive. Immunoblot studies suggested that B. bur...
Kuttler KL, Goff WL, Gipson CA, Blackburn BO.Both the complement-fixation test (CFT) and the indirect fluorescent antibody test (IFAT) were conducted on weekly serum samples from nine Arab geldings for 28 days before and 256 days after their exposure to Babesia equi of European origin. On an average the IFAT became positive 8 days before the CFT and showed higher relative serum titer increases. Both test procedures successfully detected infection and neither showed an appreciable drop in titer during this time frame, with the exception of the CFT, which showed a transient drop immediately following treatment with imidocarb. A test conduc...
Cozzi B, Pellegrini M, Droghi A.The structure and histochemical properties of neuromelanin in the Substantia nigra of the horse were studied by light and electron microscopy. Morphological, histochemical and cytochemical evidences showed the presence of a melanin component in some pigment granules, even if a large quantity of granules displayed only the properties of lipofuscins. Pigment formation in the neurons of the Substantia nigra of the horse may take place through the tyrosine-tyrosinase enzymatic pathway, as shown by positive Dopa-reaction. The results obtained were discussed in reference to the possible use of melan...
Belknap JK, Derksen FJ, Nickels FA, Stick JA, Robinson NE.Upper airway flow mechanics and arterial blood gas measurements were used to assess the efficacy of subtotal arytenoidectomy for treatment of induced left laryngeal hemiplegia in horses. Measurements were collected with the horses at rest, and trotting or pacing on a treadmill (6.38 degrees incline) at speeds of 4.2 and 7.0 m/s. Experimental protocols were performed after right common carotid artery exteriorization (baseline), after left recurrent laryngeal neurectomy (LRLN), and after left subtotal arytenoidectomy. At baseline, increasing treadmill speed progressively increased peak inspirato...
van der Kolk JH, Wensing T, Kalsbeek HC, Breukink HJ.Lipid metabolism was studied in 21 horses with hyperadrenocorticism. To be included in the study, horses had to have histologic evidence of a pars intermedia adenoma found at necropsy (n = 9), a baseline ACTH concentration greater than 400 pg/ml (n = 6), or a plasma cortisol concentration 2 hours after i.v. administration of 25 IU of ACTH greater than 413 nmol/L (n = 16). Mean +/- SD baseline plasma cortisol concentration was 338 +/- 261 nmol/L (n = 20), mean +/- SD plasma insulin concentration was 97 +/- 54 microU/ml (n = 15), mean +/- SD plasma beta-hydroxybutyrate concentration was 1.8 +/- ...
Carmalt JL, Johanssen B, Waldner C.To compare the performance of horses with intermittent dorsal displacement of the soft palate (IDDSP) treated surgically with a control group and to determine whether there was a difference in postoperative performance between horses treated with a staphylectomy or a tie-forward procedure. Methods: A retrospective observational study. Methods: Swedish Warmblood trotting horses (Standardbreds) with endoscopically confirmed IDDSP (n=56) and control horses (n=48) with endoscopically normal upper airways tested using overground endoscopy identified from medical records. Methods: Generalized estima...
Wilkins CA, Bergh N.An examination of the sera of 329 horses for L. pneumophila antibodies revealed a much lower exposure rate than that reported in the United States of America. Further serological investigations of persons closely associated with a sero-positive horse indicated that the horse could not be considered to be a source of infection but that both humans and animals were probably exposed to a common source of infection. The results showed that 192/329 (58.4%) of the sera tested negative, 114/329 (34.7%) had end-point titres of 1/2, 22/329 (6.7%) end-points of 1/16 and one an end point of 1/256 (0.3%)....
Hanák J, Jagos P.In 246 horses of the English Thoroughbred breed of several age categories, divided into four test populations, the influence was studied of age and training on the pulse rate and time intervals of ECG (PQ, QRS, QT and QTc). It was found that with the increasing age and training action slowed down gradually. Duration of the atrioventricular path (PQ) is prolonged, time of ventricular activation (QRS) and time of the electrical systole (QT) including its value corrected according to the actual pulse rate (QTC). In this way the origin of the so called sports electrocardiogram in trained race hors...
Dart AJ, Pascoe RR.A 12-year-old Quarterhorse stallion was presented with a severe lameness in the left forefoot. There was a 3 cm diameter cavity in the sole that extended to the solar surface of the distal phalanx. Radiographs revealed an osteomyelitis and a sequestrum which probably developed following the prolonged topical application of 10 percent formalin. The sequestrum was removed and the infected bone curetted under general anaesthesia. The horse was shod with heart bar shoes on both front feet 7 days after the surgery. Eight months later, radiographs showed marked rotation of the distal phalanx despite...
Peyton LC, Connelly MB.Bacterial quantification was evaluated in 15 cases as a means of wound assessment. This study suggests that bacterial quantification may be used as an aid in the evaluation of treatment procedures and wound preparation in veterinary surgery.
Costa MF, Davies HM, Anderson GA, Slocombe RF.Studies in man have shown a correlation between Angiotensin I-converting enzyme (ACE) genetic polymorphisms, ACE activity in the blood and superior athletic performance in sports requiring endurance. It has been hypothesised that the same correlation occurs in horses. There is no information in the literature concerning the effects of training on ACE activity in equine plasma. Objective: Exercise training influences the activity of circulating ACE and the response observed is dependent on the exercise protocol. Methods: Thirteen horses of mixed breeds were randomly allocated 2 different traini...
Bertone AL, van Soest PJ, Stashak TS.Nutritional alterations were evaluated in 9 horses before surgery and 3 weeks, 3 months, and 6 months (4 total trials) after sham operation (group 1; n = 3) or extensive large colon resection (group 2; n = 6). Feed and fecal analyses were performed to determine apparent digestion of dry matter, organic matter, crude protein, calcium, phosphorus, magnesium, potassium, manganese, zinc, copper, and iron, and true digestion of dry matter, organic matter, crude protein, total plant cell wall, hemicellulose, cellulose, and lignin. Additional fecal and metabolic variables included the percentage of f...
Bossut DF, Leshin LS, Malven PV.Radioimmunoassay procedures were developed and validated for the quantification of beta-endorphin (beta-EP)-like immunoreactivity in equine plasma. beta-EP could be quantitatively extracted from plasma with silicic acid powder and subsequently assayed, however, valid estimates of this hormone could also be obtained on unextracted plasma. Although beta-lipotropin (beta-LPH) cross-reacted in the assay, it was not necessary to correct for beta-LPH activity when assaying unextracted plasma because chromatographic analyses showed that 92% of the immunoreactivity in plasma extracts was similar in mo...
Pye J, Spriet M, Dow P, Katzman S, Murphy BG.To describe clinical, imaging, gross, and histopathological abnormalities associated with osteochondral necrosis of the femoral condyles in foals and identify features suggestive of a common pathogenesis. 8 Thoroughbred foals euthanized with a presumptive diagnosis of necrosis of the femoral condyles. Postmortem CT was performed on all distal femoral epiphyseal samples. The articular epiphyseal cartilage complex (AECC) of affected distal femurs was examined grossly and histologically, focusing on lesions of interest identified on CT images. 7 foals were between 9 and 23 days old at the time of...
Ghaeli T, Karimi B, Kojouri GA, Dehkordi RR, Ahadi AM.One of the initial responses of the host's innate immunity of newborns against pathogens is the use of oxidative enzymes. This study aimed to evaluate changes in serum xanthine oxidoreductase (XOR) activity, the leukocyte myeloperoxidase (MPO) and XOR genes expression, and some biochemical parameters in healthy Darehshuri newborn foals up to 60 days of life. Blood samples were collected from 16 foals at 1, 7, 15, 30, and 60 days and used for detecting XOR activity, biochemical parameters, and also gene expression by real-time RT-PCR. High activity of XOR was observed at birth, explained by phy...
Lawson JS, Bolt DM, May S, Smith AJ, Felstead CW, Weller R.Joint effusion is one of the classic radiographic signs of osteoarthritis, but no information is available regarding clinicians' ability to detect joint effusion radiographically. This study determined the accuracy and precision of experienced and inexperienced observers in detecting joint effusion of the distal interphalangeal (DIP), metacarpophalangeal (MCP) and midcarpal joints on radiographs. Fresh cadaverous forelimbs were loaded in a material testing machine to mimic a standing horse. The joints were gradually distended and lateromedial and dorsopalmar radiographs were acquired. The imag...
Goldkuhl JEC, Zablotski Y, Sill V, Jahn W, Lorenz I, Brunk J, Gerlach K, Troillet A.Osteochondral fragment removal is commonly performed but there are little scientific data supporting this procedure in the absence of clinical signs. More information is needed to facilitate clinical decision-making regarding fragment removal of the metacarpo-/metatarsophalangeal joint. Objective: To assess prevalence of cartilage injury in the equine metacarpo-/metatarsophalangeal joint and its association to fragment size, location, age and lameness. Methods: Retrospective observational study. Methods: Clinical records, including radiographs of 823 metacarpo-/metatarsophalangeal joints (640 ...
Paulussen E, Decloedt A, Vera L, Lefere L, van Loon G.Venous stenosis, a possible cause of jugular dilatation and congestion, is well known in human medicine but has poorly been described in horses. Objective: To report unilateral jugular vein stenosis as a cause of jugular vein dilatation in horses and describe treatment by percutaneous transluminal angioplasty (PTA). Methods: Case report. Methods: Details of horses diagnosed with unilateral jugular stenosis were retrieved from medical records. Results: Five horses were presented with a non-painful, unilateral dilatation of the jugular vein of which two horses showed headshaking during exercise....
Becker CK, Savelberg HH, Buchner HH, Barneveld A.To evaluate posttrauma biomechanical behavior of the scar attributable to desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT), compared with the histomorphologic and ultrasonographic appearance. Methods: 5 Standardbred trotters. Methods: Gross appearance, length, cross-sectional area (CSA), in vitro material properties, and ultrasonographic and histomorphologic features were studied 6 months after desmotomy. Tensile tests were conducted, with forces and elongation simultaneously recorded. Surgically treated limbs were compared with nontreated contralateral limbs. Re...