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.
Mackey VS, Pool RR.Fracture of the lateral wing of the third phalanx with secondary infection of the distal interphalangeal joint occurred in a neurectomized mare. Puncture of the sole may have been the inciting cause, emphasizing the need for careful daily foot care in neurectomized horses.
Youngquist RS, Blanchard TL, Lapin D, Klein W.Four groups of five pony mares each were used to determine if the intrauterine infusion of EDTA-Tris solution caused adverse effects on the endometrium. The uteri of mares were infused with either saline or EDTA-Tris solution or biopsied or sham-biopsied without infusion. Acute endometritis developed in one (20%) to three (60%) mares in each group during the seven days following treatment, but there were no differences (P > 0.05) in the incidence of endometritis among the groups. Endometrial fibrosis was not evident in biopsies taken on days 14, 30 and 60 following infusion of saline or EDT...
Smit H, Gaastra W, Kamerling JP, Vliegenthart JF, de Graaf FK.The erythrocyte receptor for Escherichia coli K99 fimbrial adhesin was isolated from equine erythrocytes and characterized as Neu5Gc-alpha(2----3)-Galp-beta(1----4)-GLcp-beta(1----1)-Ceramide. This glycolipid acted as the receptor for K99 by four different experimental approaches: inhibition of equine erythrocyte hemagglutination by preincubation of K99-positive bacteria or purified K99 fimbriae with the isolated glycolipid; inhibition of attachment of K99-positive bacteria to porcine intestinal epithelial cells in the presence of the isolated glycolipid; induction of binding of K99-positive b...
Shawley RV, Rolf LL.Crystalline cantharidin in an alfalfa cake or in aqueous suspension was given to 8 horses at a dosage level of 450 to 489 micrograms/kg of body weight (group 1) and 2 horses at a dosage level of 720 micrograms/kg (group 2) via nasogastric tube. Both group 2 horses and 1 group 1 horse died. Horses were evaluated at 6-hour intervals for 36 hours and then again at postcantharidin hours 48. Data evaluation consisted of a comparison of the nonsurvival and survival data to one another and their respective base-line values at each sampling period, irrespective of the route of administration and dosag...
Allen WE, Goddard PJ.The uteri of 13 pony mares were examined daily by ultrasound during the first two months of gestation. The conceptus was first identified between 12 and 16 days after ovulation and the embryo was seen on the ventral surface of the conceptus after Day 21. The foetal heart could be visualised after Day 22 and spontaneous movement of the foetus occurred after Day 39. No consistent pattern was seen in the development of the foetal membranes, although attachment of the umbilical cord to the allantochorion was always on the dorsal aspect of the conceptus. Daily measurements were made of the diameter...
Muir WW, Sams RA, Ashcraft S.The hemodynamic, respiratory, and behavioral effects, as well as the pharmacokinetic properties of methocarbamol, were determined in horses. Heart rate, cardiac output, arterial and venous blood pressures, respiratory rate, and arterial blood gases did not change after IV methocarbamol (4.4, 8.8, 17.6 mg/kg) administration. There were no signs of behavior modification or ataxia observed. Analysis of plasma concentration time data indicated that the disposition of methocarbamol may be dose-dependent. Clearance and steady-state volume of distribution decreased as the dose increased. Plasma conce...
Kowalczyk DF, Beech J, Littlejohn D.The pharmacokinetics of theophylline were determined in 6 healthy horses after a single IV administration of 12 mg of aminophylline/kg of body weight (equivalent to 9.44 mg of theophylline/kg). Serum theophylline was measured after the IV dose at 0.25, 0.5, 1, 2, 4, 6, 8, 12, and 15 hours. Serum concentration plotted against time on semilogarithmic coordinates, indicated that theophylline in 5 horses was best described by a 2-compartment open model and in 1 horse by a 1-compartment open model. The following mean pharmacokinetic values were determined; elimination half-life = 11.9 hours, distri...
Hildebrand SV, Howitt GA.Cumulative vs single-bolus administration of pancuronium was studied in halothane-anesthetized ponies. Dosage levels were determined by giving small increments (0.01 to 0.04 mg/kg of body weight) until the desired relaxation occurred (0.125 +/- 0.038 mg/kg for 90% to 99% reduction of prerelaxant twitch height), then an additional 0.037 +/- 0.024 mg/kg for obliteration of twitch response. The dosage level defined by cumulative administration was then administered as a single bolus 2 more times, once on each of 2 days. Dosage requirements for the 2 methods correlated well. The difference in dura...
Magnuson NS, Perryman LE, Wyatt CR, Ishizaka T, Mason PH, Namen AE, Banks KL, Magnuson JA.Peripheral blood mononuclear cells (PBMC) from 14 foals with hereditary severe combined immunodeficiency (SCID) were studied to determine the extent of lymphocyte differentiation that occurs in this disorder. PBMC from all 14 horses had the morphologic characteristics of large granular lymphocytes (LGL). Cells from only one of 14 horses were responsive to phytolectin stimulation in a standard blastogenesis assay; however, PBMC from all 14 horses proliferated in continuous culture in the presence of partially purified interleukin 2. Furthermore, there were differences in the growth patterns of ...
Sabnis SG, Gunson DE, Antonovych TT.Seven horses ranging from three to 15 years of age had nephrotic syndrome; at necropsy, renal tissue of all seven horses had the morphologic lesions of mesangioproliferative glomerulonephritis (membranoproliferative glomerulonephritis). Homogeneous eosinophilic material which filled the glomerular capillary lumina was found in five horses. Ultrastructurally, this material primarily consisted of electron-dense deposits with a fibrillar pattern in five horses and in one horse, rhomboid crystalline deposits which resembled deposits seen in human cryoglobulinemia. The association of mesangioprolif...
Eysker M, Jansen J, Mirck MH.Inhibited early third stage larvae of Cyathostominae were found in the digested mucosa of the large intestine of 12 yearling, female Shetland ponies, which were used in two grazing experiments. The ponies were killed in late autumn. In some ponies the inhibited larvae were very abundant and in most animals the majority of the Cyathostominae populations consisted of these early third stage larvae, suggesting that the phenomenon has an epidemiological significance.
Ricketts SW, Greet TR, Glyn PJ, Ginnett CD, McAllister EP, McCaig J, Skinner PH, Webbon PM, Frape DL, Smith GR.An outbreak of pharyngeal and limb paresis involving four horses and nine ponies in the south east of England is described. Nine of the animals died or were destroyed on humane grounds. The clinical features suggested a diagnosis of botulism and mouse innoculation tests confirmed the presence of type B toxin in the serum of one case. All animals were fed big bale silage. It is describe how, in plastic wrapped silage manufacture, conditions of fermentation may be inadequate to prevent the growth of Clostridium botulism. Examination of a sample of silage fed to the affected horses suggested that...
Miller PJ, Holmes JR.Beat-to-beat variation in the amplitude of the QRS waveform from 13 horses with second degree partial atrioventricular block was examined using an orthogonal lead (X,Y,Z) system. The peak positive deflections (XR, YR and ZR) and peak negative deflections (XQS, YS and ZQ) were regressed against PR and RR intervals. XQS was used to indicate that the peak negative deflection in X could have been a Q or S wave. XR and YR were directly related to PR (P less than 0.001) and XQS and YS were inversely related to PR (P less than 0.001). YR was also directly related to RR (P less than 0.001) but not so ...
Ilgren EB, Teddy PJ, Vafadis J, Briggs M, Gardiner NG.We present a clinical and pathological study of brain injuries in horse-riding accidents. Among six fatal cases, all experienced riders varying in age and sex, two were not wearing helmets and four had inadequate protective headgear. Among five non-fatal cases, four wore adequate helmets and only one of these suffered permanent neurological damage. The fifth was not wearing a helmet and although he eventually returned to work, a CT scan following the fall showed a deep-seated perithalamic hematoma. These findings are consistent with those of virtually all other studies in that they suggest tha...
Hines MT.The continued study of immunology and its relationship to diseases of the eye will hopefully give some insight into the pathogenic mechanisms of certain ocular diseases of many species, including the horse. It may lead to a better understanding of equine recurrent uveitis, a disease that has remained an enigma for years and that now appears to be an immunologic hypersensitivity response to a number of varied antigens. The precise mechanism of the inflammation is still unclear, and the immunologic response may be variable or mixed depending upon the inciting antigen. Other ophthalmic diseases i...
Drudge JH, Lyons ET, Tolliver SC.Four controlled tests (experiments A, B, C, and D) were conducted in naturally infected yearling equids to evaluate activity of ivermectin (0.2 mg/kg IM) against migrating Strongylus vulgaris and S edentatus in mesenteric arteries and ventral abdominal wall, respectively. Data were also obtained on activity against other internal parasites of the gastrointestinal tract and eyeworms. The type and number of equids in the experiments were as follows: experiment A-3 ponies, 2 treated and 1 non-treated; experiment B-4 mixed-bred horses, 2 treated and 2 nontreated; experiment C-5 mixed-bred horses, ...
Pihl TH, Jacobsen S, Olsen DT, Højrup P, Grosche A, Freeman DE, Andersen PH, Houen G.OBJECTIVE To purify and characterize equine vitamin D-binding protein (VDBP) from equine serum and to evaluate plasma concentrations of VDBP in healthy horses and horses with gastrointestinal injury or disease. ANIMALS 13 healthy laboratory animals (8 mice and 5 rabbits), 61 healthy horses, 12 horses with experimentally induced intestinal ischemia and reperfusion (IR), and 59 horses with acute gastrointestinal diseases. PROCEDURES VDBP was purified from serum of 2 healthy horses, and recombinant equine VDBP was obtained through a commercial service. Equine VDBP was characterized by mass spectr...
Suarez-Fuentes DG, Caston SS, Tatarniuk DM, Kersh KD, Ferrero NR.Contaminated or septic navicular bursitis has been reported to have a guarded prognosis after surgical treatment with navicular bursotomy only. In our experience, the use of navicular bursotomy for the treatment of this disease in combination with systemic and local delivery of antimicrobials can provide a good prognosis, even in horses with chronic disease. Objective: To report the outcome of horses undergoing navicular bursotomy for the treatment of contaminated or septic navicular bursitis. Methods: Descriptive case series. Methods: Navicular bursotomy was performed in combination with syst...
Liggett AD, Weiss R, Blue JL.Myospherulosis was diagnosed in a mature pony. Several parent bodies containing many spherules were observed microscopically in biopsy material from an area of cellulitis. The spherules are altered red blood cells that form as the result of prolonged contact with necrotic fat or petrolatum-based ointments. These structures must be differentiated from fungal elements. The recommended treatment is surgical excision.
Vermedal H, Strand E.To report dynamic laryngeal collapse (DLC) associated with poll flexion as a potential complication of the laryngeal tie-forward procedure (LTFP) in harness racehorses. Methods: Short case series. Methods: Three harness racehorses. Methods: Preoperative and postoperative medical records of all harness racehorses that underwent the LTFP were reviewed, as were high-speed treadmill videoendoscopy recordings of 35 horses that returned for upper airway evaluation postoperatively. Results: One standardbred and two Norwegian coldblooded trotters in which dorsal displacement of the soft palate had bee...
Martin GS, Strand E, Kearney MT.To determine the relationship between prediction errors of a regression model of racing finish times and earnings or finish position; the relationship between standardized finish times, determined by use of this model, and earnings or finish position; and whether this model was valid when applied to data for horses that underwent surgical treatment. Methods: Survey. Methods: Records of 6,700 healthy Thoroughbreds racing in Louisiana and of 31 Thoroughbreds with idiopathic left laryngeal hemiplegia that underwent surgical treatment. Methods: Predicted and standardized finish times were calculat...
Barber SM, Panizzi L, Lang HM.To evaluate arthrodesis as a treatment for carpometacarpal joint osteoarthritis (CMC-OA). Methods: Case series. Methods: Horses (n=12) with CMC-OA. Methods: Arthrodesis was facilitated by insertion and fanning of a drill bit into the CMC joint at several (3-5) locations in 15 limbs. Follow-up radiographs were obtained for 7 horses (9 limbs). Outcome was determined by telephone survey of owners based on postoperative pain, return to use, appearance of the limb, and success of treatment. Results: Postoperative pain was slight or moderate in 10 of 12 (83%) horses during the first 30 days, and 11 ...
Timoney PJ.The usefulness of the double immunodiffusion test for the diagnosis of louping ill infection was investigated. Whereas louping ill viral antigen was not detected in brain material from field cases of the infection, its presence was readily confirmed in suckling mouse brain isolates of the virus. The double immunodiffusion test was found to be unreliable as a serological test for the retrospective diagnosis of louping ill infection in the horse.
Miller JR, Blake JW, Tobin T.An electron capturing derivative of apomorphine was prepared by incubating the drug with heptafluorobutyric anhydride (HFBA), triethylamine and heat. Mass spectral analysis suggests that HFBA reacts with both phenolic hydroxyl groups on apomorphine to give a derivative detectable at low picogram levels. This method is sufficiently sensitive for pharmacokinetic studies in the horse and is likely applicable to other dopaminergic analogues of apomorphine.
Teuscher C, Kenney RM, Cummings MR, Catten M.In this study, 2 stallions were immunised with their own spermatozoa to ascertain whether an antisperm autoantibody response could be mounted. The results demonstrated that the stallion can recognise and respond to sperm autoantigens by producing circulating antisperm antibodies, primarily of the IgG class. Such autoantibodies appeared 2-4 weeks after inoculation and persisted for 6-20 weeks. Immunochemical characterisation by western blot identified two major sperm autoantigens, with molecular weights of 70 kD and 62 kD. Control pony stallions immunised with adjuvants alone failed to exhibit ...
Stephen J, Harty M, Hollis A, Yeomans J, Corley K.An 11-year-old mare presented 36 hours after foaling with a ruptured bladder. Uroperitoneum was diagnosed on ultrasound and from the creatinine concentration of the peritoneal fluid. Bladder endoscopy demonstrated tissue necrosis and a rent in the dorsocranial aspect of the bladder. Following stabilisation, including abdominal drainage and lavage, the mare was taken to standing surgery. Under continuous sedation and epidural anaesthesia, and after surgical preparation, a Balfour retractor was placed in the vagina. Using sterile lubricant and moderate force, it was possible to insert a hand int...
Schoonover MJ, Whitfield CT, Young JM, Sippel KM, Payton ME.OBJECTIVE To determine effects for 2 IV regional limb perfusion (IVRLP) protocols involving tiludronate on lameness of horses with navicular syndrome. ANIMALS 15 horses with bilateral forelimb navicular syndrome. PROCEDURES Shoeing and anti-inflammatory injection into the distal interphalangeal joint (DIPJ) of both forelimbs (day 0) were performed on all horses. On day 14, horses received 1 of 3 IVRLPs consisting of 0.1 mg of tiludronate/kg (low-dose tiludronate [LDT]; n = 5), 0.2 mg of tiludronate/kg (high-dose tiludronate [HDT]; 5), or saline (0.9% NaCl) solution (placebo; 5); treatments wer...
Kraus BL, Kirker-Head CA, Kraus KH, Jakowski RM, Steckel RR.The vascular and microvascular anatomy of the equine deep digital flexor tendon (DDFT) within the digital sheath was studied by injecting the vasculature with either colored latex or barium sulphate for radiographic, microangiographic, histologic, and computed tomographic (CT) evaluation. Consecutive 4-mm thick two-dimensional CT slice data were reconstructed to 3-dimensional volumetric images to enhance spatial evaluation of the blood supply. Gross dissection and angiographic studies identified three major vascular sources. Above the fetlock, the DDFT was supplied by either a branch of the me...
Tryland M.In December 1801, the first vaccination against smallpox in Norway took place. Vaccine material came from Denmark, England, Ireland, and other countries; it was also obtained from a few local cowpox cases. What mattered was the effect, not the origin. Several reports indicate that variola virus itself, the cause of smallpox, was also used for human vaccination after passages through cows and horses. A vaccine institute for production of vaccine in calves was established in Kristiania in 1891. Cowpox was once a rare disease in cattle, but a total of 70,985 bovine cases were reported between 188...
Rapisarda G, Marino F, Ferrara G, Gioffrè F, Galofaro V.Here we present a case of preputial benign fibrous histiocytoma in a 7-year-old mule. This case was treated surgically. Pathologic analysis and diagnosis of these lesions were based on a combination of light microscopy and immunohistochemistry. Histologically, the tumour was composed primarily of a storiform pattern of fibroblastic and poligonal cells. In immunohistochemistry, except for consistent immunoreactivity for vimentin, nearly all tumour cells were positive for CD68, S-100 protein, pan-cytokeratin, alpha-smooth muscle actin, and desmin. Benign fibrous histiocytoma of the prepuce in mu...
Dória RGS, Freitas SH, Laskoski LM, Arruda LP, Shimano AC.Surgical site infection of abdominal incisions is an important complication after laparotomy with increased risk of incisional hernia formation in horses. This study aims to evaluate the healing process of abdominal incisions and correlate peritonitis with the occurrence of surgical site infection and incisional hernias. Nine horses underwent standardized laparotomy, intestinal exploration, and induced septic peritonitis. Standardized relaparotomy was performed two (n = 3), four (n = 3), and six (n = 3) months later to evaluate the abdominal cavity for adhesions and to collect the sutured v...
