Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
Nilsson O, Ljungström BL, Höglund J, Lundquist H, Uggla A.Distal ileum, caecum and proximal colon of 470 horses were examined for helminths during 1 year at an abattoir in central Sweden. The infection levels of the horse tapeworm Anoplocephala perfoliata, their stage of development, site of attachment and gross pathological lesions caused by the worm were recorded. Faecal samples from 395 of the horses were examined specifically for tapeworm segments and eggs in order to correlate these findings with the numbers in the alimentary canal. In total 65% of the horses were infected with A. perfoliata and the mean intensity of infection was 79 worms per i...
Barlet JP, Davicco MJ, Coxam V.Intestinal absorption of inorganic phosphorus. In most mammalian species inorganic phosphorus (P) is absorbed at the duodenal and jejunal level. However in horses some P is absorbed from the large intestine, whereas in ruminant animals some absorption also takes place in the forestomachs. The structure of the putative phosphate-sodium carrier of the brush border from enterocytes still awaits identification. P absorption is modulated both by endocrine (calcitriol, triiodothyronine) and nutritional factors (minerals of the diet, chemical form of phosphorus). Regulation of salivary P secretion, i...
Mahmoud AL.From 60 horses showing skin lesions, 42% were positive for fungal infection. Horses less than 2-year old were more susceptible to this infection. Fourteen species belonging to nine genera of keratinophilic and cycloheximide-resistant fungi were recovered from collected specimens. Trichophyton was the dominant genus of which T. equinum was the most common. This species proved to be the main causative agent of ringworm in horses. In addition to dermatophytes, many species of the isolated fungi were keratinophilic. The presence of such fungi on hairs and skin of horses may create an opportunity f...
Lakritz J, Wisner ER, Finucane T, O'Brien TR, Tyler WS, Pascoe JR, Plopper CG.Interstitial and bronchointerstitial pulmonary patterns are commonly observed in thoracic radiographs of Thoroughbreds. Prominent interstitial and bronchointerstitial pulmonary patterns are observed in clinically normal horses, and in horses with respiratory tract disease. Until recently, the relevance of these pulmonary patterns was not known. Previous studies indicated that bronchiolitis, bronchiolar epithelial hyperplasia, epithelial metaplasia, and bronchial arteriolar recruitment correlated strongly with the prominence of the interstitial and bronchointerstitial pulmonary patterns observe...
Yeruham I, Braverman Y.Specific skin lesions caused by Stomoxys calcitrans on the feeding sites of different species are described. Skin lesions appeared on dogs, horses and calves following bites of stable flies. Necrotic dermatitis was observed in 32 dogs of various breeds at the tip of the ears. Exudative dermatitis appeared on the legs of 45 adult horses and dermatitis was diagnosed in the "hair whirlpools" on the backs of 18 white calves.
Madsen M, Christensen P.Semen samples were collected from 21 Danish Warmblood stallions by the Colorado artificial vagina (Colorado AV, 14 samples) or by the Missouri artificial vagina (Missouri AV, 7 samples). The semen was examined bacteriologically by direct plating (DP) on blood agar plates, and by plating of semen swabs stored in Stuart's transport media (TM) at 4 degrees C for 1-4 days. No significant differences were observed between results obtained by DP and cultures of identical TM samples. Of the 21 samples examined, only 1 TM (4.8%) and 2 DP samples (9.5%) were sterile, while the rest yielded a predominan...
Broström H.Associations between clinical parameters of sarcoids and the equine leucocyte antigen system (ELA) were analysed for 120 Swedish horses. Median age of affected horses was 5.2 years, and the majority presented with solitary tumors between 2 and 5 cm in diameter and ventral abdomen was a predilection site. Clinical signs first appeared at a median age of 3.5 years, and sarcoids at different locations first appeared at different ages. Lesions at different sites differed in size, and multiple tumors, early onset, long duration, and older age all had an association with large size. Clinical manifes...
Messer NT, Ganjam VK, Nachreiner RF, Krause GF.The effect that 5 consecutive days of treatment with dexamethasone (0.04 mg/kg of body weight, IM, q 24 h) would have on baseline concentrations of triiodothyronine (T3), thyroxine (T4), reverse T3 (rT3), free T3 (FT3), and free T4 (FT4), and on response to thyroid-stimulating hormone (TSH) administration was determined in 12 clinically normal horses. Results of TSH response tests indicated that the horses could be placed into 2 groups: in 6 horses (group A), T4 concentration after administration of TSH was more than twice the baseline concentration; in the other 6 horses (group B), T4 concent...
de la Rúa-Doménech R, Mohammed HO, Cummings JF, Divers TJ, de Lahunta A, Valentine B, Summers BA, Jackson CA.We have conducted an ambidirectional study to estimate the incidence of equine motor neuron disease (EMND) in the northeastern US. The clinical and pathological features of EMND are similar to those described in human motor neuron disease. We have also collected data on all EMND cases reported in the US and described the geographic distribution of the disease. To identify factors associated with the risk of EMND, the authors assembled 163 control horses from the population in which cases were identified. The significance of association between the hypothesized factors and the risk of EMND was ...
Wagner AE, Dunlop CI, Wertz EM, Chapman PL, Baxter GM, Klopp LS.Seven horses, which were part of an investigation of the effect of endotoxin administration on vascular reactivity, were anesthetized on two separate occasions for surgical excision of 4-cm sections of palmar digital artery and vein. On the first occasion, the horses were given an infusion of 1 L 0.9% NaCl solution intravenously (i.v.) just before induction of anesthesia (control); on the second occasion, the horses received an infusion of 1 L 0.9% NaCl containing Escherichia coli endotoxin, 0.1 microgram/kg (endotoxin). On both occasions, anesthesia was induced with xylazine, guaifenesin, and...
Rossdale PD, Ousey JC, McGladdery AJ, Prandi S, Holdstock N, Grainger L, Houghton E.Plasma progestagen concentrations were measured daily by radioimmunoassay (RIA) in 35 sick foals for the duration of their illness. The foals were divided into three groups on the basis of time to stand after birth. Foals were given intensive care treatment according to the severity of their illness. Plasma and urine concentrations of pregnenolone (P5) and pregnenediol (P5 beta beta) were measured by gas chromatography--mass spectrometry; plasma cortisol concentrations were measured by RIA and the foals' renal and respiratory status were assessed by creatinine clearance ratios and arterial oxy...
Back W, Schamhardt HC, Savelberg HH, van den Bogert AJ, Bruin G, Hartman W, Barneveld A.Kinematic data of the equine hind limb are presented graphically and related to functional aspects of the hind limb in locomotion. The trot of 24 two-year-old Dutch Warmblood horses was recorded at 4 m/s on a high-speed treadmill using kinematic analysis equipment. Joint angle-time, angle-angle, stick and marker diagrams were used to present graphically the data following standardised procedures. As the kinematic data were expressed with reference to the joint angles of the horse standing squarely and were time-standardised to the duration of the stride cycle, mean joint curves for the total g...
Foster AP, Lees P, Cunningham FM.Hypersensitivity responses to biting flies such as Culicoides are believed to be the cause of sweet itch, a seasonal intensely pruritic skin condition of horses. Little is known about the mediators released by antigen in the skin of affected horses. In the present study the cutaneous vascular and cellular responses to intradermally injected platelet activating factor (PAF) have been characterised in sweet itch cases during the active phase of the disease and compared with those of Culicoides antigen extract. Histamine was used as a positive control in vascular permeability studies. Responses w...
Mitten LA, Hinchcliff KW, Pate JL, Kohn CW, McKeever KH.Exertion has an effect on plasma, serum, and/or urine prostanoid concentrations in many species. We investigated the effect of exercise intensity on plasma prostaglandin concentrations during and after exercise in horses. Six Thoroughbreds completed 4 trials: 3 exercise trials (low-, medium-, and high-speed) and 1 nonexercise (control) trial on a high-speed treadmill. Blood samples were collected from a jugular catheter before, during, and after exercise. The PCV and blood lactate, plasma protein, plasma prostacyclin (6-keto-PGF1 alpha), thromboxane B2 (TXB2), and prostaglandin E2 (PGE2) conce...
Ehrlich PJ, Seeherman HJ, Morris E, Kolias C, Cook WR.The effect of left recurrent laryngeal neuropathy (LRLN) on the metabolic cost of locomotion (MCL) and peak aerobic power (VO2peak) was evaluated in four trained Thoroughbred racehorses. Oxygen consumption (VO2), carbon dioxide production (VCO2), venous lactate concentrations (LAC), and heart rate (HR) were measured during a treadmill exercise test (TET). Each horse performed the exercise test four times, alternating between normal upper airway function and reversibly induced LRLN. Subcutaneous infusion of 2% mepivicaine, a local anesthetic, into the region were the left recurrent laryngeal ne...
Donahue JM, Smith BJ, Poonacha KB, Donahoe JK, Rigsby CL.In this study, the prevalence of leptospira-induced abortions/stillbirths for the past 3 foaling seasons (1991-1993) was determined, and fetal tissues and/or the mare's urine from positive cases were cultured in an attempt to isolate and identify the leptospira serovars responsible for the abortions. The sensitivity and specificity of the primary diagnostic tests, the fluorescent antibody test (FAT) and the microscopic agglutination test (MAT), used for the diagnosis of leptospirosis were also determined. For the 3 years, 74 (3.3%) of 2,264 abortion/stillborn submissions were diagnosed as lept...
Andrews RK, Booth WJ, Bendall LJ, Berndt MC.von Willebrand Factor (vWF) is a multifunctional glycoprotein in plasma and vascular subendothelial matrix which plays a major role in cellular adhesion. vWFdependent adhesion of platelets to the subendothelium at high shear rates involves a specific platelet membrane receptor, the glycoprotein (GP) Ib-IX complex. We have previously purified a 39/34-kiloDalton (kDa) dispase fragment of vWF (Leu-480/Val-481 to Gly-718) and demonstrated that this fragment contains the binding site for the GP Ib-IX complex [Andrews R K, et al. Biochemistry 1989; 28: 8326-83361. vWF also mediates agglutination of ...
Ratajczak K, Kiełbowicz Z.Prolonged operation or a current need to improve intraoperative conditions, while anaesthesia is still on, may require applying controlled ventilation (CV). The purpose of this study was to evaluate cardiovascular effects of such a decision. Seven halothane-anaesthetized horses were the subject of our investigation, at first kept spontaneous ventilation (SV), then they were connected to respirator. After 30' CV, SV was restored and anaesthesia was continued. In those three stages of experiment haemodynamic parameters and gasometry were measured. It was found that during CV period both optimal ...
Collatos C, Barton MH, Moore JN.Plasma fibrinolytic activity was evaluated over 5 consecutive days in 59 horses admitted to the Large Animal Teaching Hospital with acute gastrointestinal diseases. Only horses hospitalized for at least 5 days were included in the study. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor type-1 (PAI-1) were quantitated using standard chromogenic activity assays. Statistical analyses were performed using analysis of variance; differences were considered significant when P < or = .05. Activity of PAI-1, the primary endogenous inhibitor of fibrinolysis, was significantly incre...
Roethlisberger-Holm K, Roepstorff L, Obel N.After giving an account of the principles of pressure measurement in flowing air and a review of the literature on tracheal catheters, the authors describe the construction, the introduction and the function of their own transtracheal catheter. This is a teflon catheter with several side-ports which is introduced into the cervical trachea by a guide technique. After introduction, the catheter is stiffened by the insertion of 2 steel wires. The catheter was studied in model experiments concerning: a) the ability to measure the static pressure in flowing air, and b) the dynamic accuracy of a rec...
Crabill MR, Chaffin MK, Schmitz DG.The bicipital tendons and bursae of 25 healthy adult Quarter Horses were ultrasonographically examined. Cross-sectional images of the right and left bicipital tendons were obtained from each horse, using a 7.5-MHz transducer held in the frontal plane at the point of the shoulder. The bicipital tendon at the point of the shoulder appeared as a bilobate structure overlying the echogenic surface of the humerus. Median distance from the skin surface to the cranial surface of the tendon on the medial sagittal plane of the tendon was 23 mm (range, 16.5 to 30 mm); median distance on the lateral sagit...
Doxey DL, Milne EM, Woodman MP, Gilmour JS, Chisholm HK.The number of neurons in the coeliacomesenteric ganglia and the myenteric and submucosal plexuses of the jejunum, ileum and small colon, and the pathological changes induced in them, were studied in various types of equine dysautonomia. In all forms of dysautonomia, severe and extensive neuron loss and damage occurred in the ileum. In acute and subacute dysautonomia, jejunal neuron loss and damage were severe, but in chronic cases significantly less loss or damage occurred. The damage followed the same pattern in the small colon but it was always less obvious than in the jejunum. The distribut...
Fortier LA, Foerner JJ, Nixon AJ.Medical records from 119 horses that had undergone arthroscopic surgery for removal of axial osteochondral fragments of the palmar/plantar proximal aspect of the proximal phalanx were reviewed. Standardbred racehorses represented 109 (92%) of those affected. Ninety-three (78%) of the horses were < 3 years old. Gender distribution was consistent with that of the equine hospital population. Fragments most commonly were observed in the hind limbs (155/164; 95%), specifically, on the medial aspect of the left hind limb (72/164; 44%). Bilateral fragmentation occurred in 21 of 119 (18%) horses, a...
Sheoran AS, Timoney JF, Tinge SA, Sundaram P, Curtiss R.The aim of this study was to investigate the intranasal immunogenicity for the horse of a Deltacya Deltacrp-pabA mutant (MGN-707) of Salmonella enterica serotype Typhimurium (S. typhimurium). MGN-707 caused no sign of disease, was not detected in feces and a single administration induced strong Salmonella-specific serum and nasal mucosal antibody responses. All ponies had made strong salmonella specific serum IgGa, IgGb, IgA and IgM antibody responses by day 25 after the first immunization. IgM responses to salmonella lipopolysaccharide (LPS) were short lived whereas salmonella specific serum ...
Hardeman LC, van der Meij BR, Back W, van der Kolk JH, Wijnberg ID.In equine laminitis, the deep digital flexor muscle (DDFM) appears to have increased muscle force, but evidence-based confirmation is lacking. Objective: The purpose of this study was to test if the DDFM of laminitic equines has an increased muscle force detectable by needle electromyography interference pattern analysis (IPA). Methods: The control group included six Royal Dutch Sport horses, three Shetland ponies and one Welsh pony [10 healthy, sound adults weighing 411 ± 217 kg (mean ± SD) and aged 10 ± 5 years]. The laminitic group included three Royal Dutch Sport horses, one Friesian, o...
Grosenbaugh DA, Amoss MS, Hood DM, Williams JD.A heterologous radioreceptor binding assay (RRA) has been developed capable of detecting nanogram amounts of epidermal growth factor (EGF) receptor-binding activity in equine urine. The binding parameters of [125I]mEGF (murine EGF) to EGF receptors on equine plasma membranes are in good agreement with values from other EGF-RRA systems. The dissociation constant estimated from equilibrium methods (KD = 4 X 10(-10) M) is in reasonable agreement with that determined from the rate constants (KD = 6 X 10(-10) M) and is in good agreement with values determined in other species. The assay is specific...
López ML, de Souza W.The presence and distribution of cholesterol in mature and immature epididymal spermatozoa was analyzed using filipin as a cytochemical tool in freeze-fracture replicas and thin section preparations. The polyenic-antibiotic filipin formed complexes with 3, beta -OH sterols, producing characteristic protrusions, or pits, that were heterogeneously distributed in the plasma membrane of stallion spermatozoa, revealing a specific organization in a functionally specialized area of the gamete. The acrosomal region of the sperm head presented a significantly higher density of filipin sterol complexes ...
Morrissey NK, Bellenger CR, Ryan MT, Baird AW.To measure the expression of cyclooxygenase-2 (COX-2) mRNA in gastric biopsy specimens serially obtained from horses before, during, and after an 8-day intermittent feed-deprivation trial and to investigate the mucosal location of COX-2. Methods: 9 mixed-breed horses for retrieval of gastric biopsy specimens and 16 additional horses for immunohistochemical analysis. Methods: Gastric biopsy specimens were obtained from 6 horses; 3 of these horses and 3 more participated in an intermittent feed-deprivation trial 9 weeks later. A quantitative PCR assay was used to determine the amount of COX-2 mR...
Berzina I, Trumble NS, Novicki T, Sharkey LC.An 11-year-old American Saddlebred gelding was presented for evaluation of a nonpainful subconjunctival mass involving the lateral canthus of the left eye. Other findings included a central corneal scar and a small central cataract of the lens in the left eye. Fine-needle aspiration of the mass was performed and cytologic examination revealed marked pyogranulomatous inflammation with intralesional fungal hyphae, consistent with mycetoma. The fungal structures were elongated and characterized by nonstaining walls; several bulbous yeast-like structures were also observed. The mycetoma was surgic...
Rossignol F, Vitte A, Boening J.To (1) report a modified transfixation pin cast technique, using dorsal recumbency for fracture reduction, distal positioning of the pins in the epiphysis and distal metaphysis, and a hybrid cast, combining plaster of Paris (POP) and fiberglass casting, and (2) report outcome in 11 adult horses. Methods: Case series. Methods: Adult horses (n = 11) with comminuted phalangeal fractures. Methods: Horses were anesthetized and positioned in dorsal recumbency. The phalangeal fracture was reduced by limb traction using a cable attached to the hoof. Screw fixation in lag fashion of fracture fragments ...
Barrey E, Valette JP, Jouglin M, Picard B, Geay Y, Robelin J.The content in slow and fast myosin heavy chains (MHC 1 and MHC 2) of 5 equine muscles was determined using an enzyme-linked immunosorbent assay. The results obtained with this immunoenzymatic method were compared with complementary techniques: electrophoresis and immunohistochemistry. Slices of masseter, diaphragm, tensor faciae latae, semitendinosus and cutaneus trunci were obtained from a 12-year-old saddle horse after slaughter. Muscular proteins were specifically extracted to be analysed by ELISA. The technique used 2 complimentary monoclonal antibodies (MAb). MAb 1 was prepared from a hu...
Figueras F, Castelo-Branco C, Pons F, Sanjuán A, Vanrell JA.The aim of the present study was to determine whether assignment to continuous estrogen-progestin therapy is more effective in protecting against bone loss than assignment to a sequential regimen. Methods: A total of 104 postmenopausal women were randomly assigned to one of two groups of treatment, Conjugated Equine Estrogens and Medroxyprogestin without interruption (continuous group) and Conjugated Equine Estrogens over 25 days with Medroxyprogestin beyond the 14th day (sequential group). Bone mineral density (BMD) was measured at inclusion, 12 and 24 months later by dual energy X-ray absorp...
Leach DH, Zoerb GC.The mechanical properties of pigmented equine hoof wall tissue were determined for samples taken from the inner and outer portions of the stratum medium of the toe. Two properties, the modulus of elasticity and proportional limit, which are measures of the rigidity and yield point, respectively, of the tissue, were studied for samples compressed in 3 orthogonal directions. All samples tested were anisotropic. Inner wall samples were less rigid and had a lower yield point than outer wall samples.
de Pinho FA, Mendes MO, de Magalhães VLP, Tinôco AAC, Seoane JHL, Rêgo FD, Soares RP, Barrouin-Melo SM.Leishmania infantum infections have long been described in humans and dogs worldwide, but characterization of equine cases remains scarce. We describe the clinical evolution of a natural L. infantum infection to contribute to the diagnostic knowledge and epidemiology of equine leishmaniasis (EL). An auction-acquired four-year-old Mangalarga Marchador mare from Pernambuco state, presented a few subcutaneous nodules on the head and neck upon arrival at the purchaser's stud at Bahia state, in November of 2019. They progressed to multiple ulcerated and non-ulcerated nodules and spread to both righ...
Keay G, Doxey DL.Samples of serum from both young and adult normal cattle, sheep and horses were subjected to protein electrophoresis on agarose gel films. After processing, the stained electrophoretic patterns and densitometric traces of each species exhibited certain specific characteristics. The separations also revealed differences between young and adult animals of the same species. These age-related differences are described here.
Art T, Lekeux P.In order to study the in vitro mechanical properties of the equine trachea submitted to the compressive pressures observed in vivo, the pressure-volume relationship was determined in intra- and extra-thoracic tracheal segments taken post mortem from 29 healthy horses (one to 15 years old; 352 to 651 kg). At the same time, the cross-sectional lumen area (X-SA) at the mid-point of the segment was measured using a slit-lamp transillumination and photographic measurement by endoscopy. The tracheal specific compliance (Cs) as well as the relative changes in X-SA and in the sagittal and transverse d...
Jarvis GE, Evans RJ.Endotoxin has previously been shown to induce platelet aggregation in equine heparinised whole blood. This study aimed to determine whether platelet-activating factor or products of cyclo-oxygenase metabolism (thromboxane A2 or prostaglandins) were important in mediating the response of platelets to endotoxin. The effects of the following drugs on endotoxin-induced aggregation were investigated: aspirin, flunixin meglumine and carprofen (non-steroidal anti-inflammatory drugs); CV-3988 and WEB2086 (platelet-activating factor receptor antagonists); quinacrine (phospholipase A2 inhibitor). The ef...
Arias MS, Piñeiro P, Hillyer GV, Francisco I, Cazapal-Monteiro CF, Suárez JL, Morrondo P, Sánchez-Andrade R, Paz-Silva A.The utility of an enzyme-linked immunosorbent assay to determine the sensitization against the trematode Fasciola hepatica in horses from an endemic area (NW Spain) was assessed. Blood samples were collected from 536 horses and tested against a 2.9-kDa recombinant surface protein (FhrAPS) to estimate the presence of IgG antibodies. Data were analysed regarding several intrinsic (age, gender and breed) and extrinsic factors (aptitude and housing). The farm size (number of horses/farm) was also considered. Sixty percent (95% CI 56, 64) of the horses were positive to the FhrAPS-ELISA, with a sign...
Saulez MN, Dzikiti B, Voigt A.Two of 348 horses that underwent gastrointestinal surgery under general anaesthesia developed perforations in their tracheas caused by the endotracheal tube. In one case the damage was probably caused when the horse was being moved from the induction room for surgery and excessive traction was exerted on the tube when the anaesthetic machine was moved too far ahead of the horse. The trachea of the other horse may have been damaged when it was intubated.
Moudgal NR, Papkoff H.The ability of equine luteinizing hormone (eLH) to promote follicular growth and maturation in hypophysectomized rats has been assessed. A single injection of equine LH has been shown to promote the growth of a large number of antral and preovulatory follicles. In addition, equine LH markedly increased serum estrogen levels and uterine weight. Furthermore, equine LH, like equine chorionic gonadotropin (eCG; PMSG) was able to significantly enhance the incorporation of [3H]thymidine into ovarian DNA, an activity shown to be specific to hormones having follicle-stimulating hormone (FSH) activity....