Equine diseases encompass a wide range of health conditions that can affect horses, including infectious diseases, metabolic disorders, and genetic conditions. These diseases can impact the overall health, performance, and well-being of horses. Common equine diseases include equine influenza, equine herpesvirus, laminitis, and equine metabolic syndrome. Diagnosis and management of these diseases often require a combination of clinical evaluation, laboratory testing, and appropriate treatment strategies. This page gathers peer-reviewed research studies and scholarly articles that explore the etiology, pathophysiology, diagnosis, and treatment options for various equine diseases, providing valuable insights for veterinarians and researchers in the field.
Delesalle C, Deprez P, Schuurkes JA, Lefebvre RA.The use of human prokinetic drugs in colic horses leads to inconsistent results. This might be related to differences in gastrointestinal receptor populations. The motor effects of 5-hydroxytryptamine (5-HT; serotonin) on the equine mid-jejunum were therefore studied. Longitudinal muscle preparations were set up for isotonic measurement. 5-HT induced tonic contractions with superimposed phasic activity; these responses were not influenced by tetrodotoxin and atropine, suggesting a non-neurogenic, non-cholinergic pathway. The 5-HT receptor antagonists GR 127935 (5-HT(1B,D)), ketanserin (5-HT(2A...
Silva LA, Ginther OJ.The spherical equine embryonic vesicle is mobile throughout the uterine lumen for several days before becoming fixed in the caudal segment of a uterine horn on Day 16 (ovulation = Day 0). Orientation refers to the position of the embryo proper at the periphery of the vesicle relative to the position of the mesometrial attachment. In mares, the embryonic pole of the vesicle is antimesometrial after completion of orientation. Day of vesicle fixation, differential thickening of the endometrium near the mesometrial attachment, and orientation of the embryonic vesicle were studied in 30 ponies, usi...
Busoni V, Heimann M, Trenteseaux J, Snaps F, Dondelinger RF.We describe the abnormal magnetic resonance (MR) imaging findings in the deep digital flexor tendon (DDFT) and distal sesamoid bone in horses with radiographic changes compatible with navicular syndrome. Thirteen postmortem specimens were examined using a 1.5-T magnetic field, with spin echo (SE) T1-weighted, turbo SE (TSE) proton density-weighted (with and without fat saturation), and fat saturation TSE T2-weighted sequences. The limbs were then dissected to compare the MR findings with the gross assessment and histologic examination of the DDFT and distal sesamoid bones. Tendonous abnormalit...
Puppione DL, Whitelegge JP, Yam LM, Bassilian S, Schumaker VN, MacDonald MH.In pigs, humans, chimpanzees and probably other great apes, a cysteine at residue 6 enables apolipoprotein A-II to form a homodimer. However, the apoA-IIs of other primates, lacking a cysteine residue, are monomeric. We have already reported that horse apoA-IIs form homodimers due also to a cysteine at residue 6. In this study, we wanted to determine whether other equine apoA-IIs might be monomeric. The high density lipoproteins were ultracentrifugally isolated from the plasmas of a horse (Equus caballus), a donkey (Equus asinus) and five wild equines: two types of zebras (Equus zebra hartmann...
Phumoonna T, Barton MD, Heuzenroeder MW.The aim of this study was to evaluate the usefulness of the previously identified B-cell epitope TSLNLQKDEPNGRASDTAGQ of the VapA protein of Rhodococcus equi and its association with R. equi pneumonia. A modified peptide designated PN11-14 corresponding to the epitope was recognized by all sera from experimentally infected foals with virulent R. equi ATCC103+ containing the virulence plasmid but not by its plasmid-cured derivative ATCC103- strain. Marked levels of VapA-specific immunoglobulin (Ig)G were detected in all sera from the ATCC103+ infected foals at 2 weeks after the infection. One c...
Kraus BM, Richardson DW, Sheridan G, Wilkins PA.To report rib fracture repair using the Securos Cranial Cruciate Ligament Repair System (SCCLRS; Securos Veterinary Orthopedics, Charlton, MA) in a neonatal foal. Methods: Case report. Methods: A 1-day-old Standardbred foal with fracture of left ribs 2-9. Methods: Four days after admission the foal was anesthetized and rib fractures were repaired using open reduction and the SCCLRS. Results: Rib fractures were successfully stabilized and the foal was discharged 7 days postoperatively without further complications. Conclusions: The SCCLRS provided a straightforward, effective method of rib frac...
Gehlen H, Ohnesorge B.To describe removal of guttural pouch chondroids through a laser fenestrated mesial septum in a pony with an obstructed pharyngeal ostium of the left guttural pouch. Methods: Case report. Methods: Pony. Methods: Transendoscopic laser neodymium:yttrium aluminum garnet (Nd:YAG) fenestration of the mesial guttural pouch septum was made by contact method (bare fiber, 15-25 W, exposure time 4 seconds). Dissected tissue was removed by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and multiple chondroids of varying size were removed from the left guttural pouch through the ...
Watanabe T, Hosaka Y, Yamamoto E, Ueda H, Sugawara K, Takahashi H, Takehana K.The distribution pattern of collagen fibril diameter in the equine superficial digital flexor tendon (SDFT) is known to differ in central and peripheral areas of some regions. This study reports the essence of collagen fibril differences among different regions of the equine SDFT by transmission electron microscopic (TEM) and high-voltage electron microscopic observations and biochemical analysis. The distribution of large collagen fibrils increased but the density of collagen fibrils decreased from the proximal metacarpal region to the distal metacarpal region. Large collagen fibrils with an ...
McAleese SM, Brown JK, Macrae AI, Mackellar A, Huntley JF, Miller HR.The high-affinity receptor for IgE (FcepsilonRI) plays a central role in IgE-mediated allergic reactions. Cross-linking of FcepsilonRI by IgE-antigen complexes results in the activation of mast cells and basophils and is thought to contribute to the immunopathology of Heaves, a chronic obstructive pulmonary disease of horses. Recombinant protein corresponding to the extra-cellular portion of the FcepsilonRI alpha subunit, cloned and sequenced previously, was expressed using both mammalian cells and insect cells. The yield of expressed protein was considerably greater using insect cells and the...
Quinlivan M, Dempsey E, Ryan F, Arkins S, Cullinane A.Equine influenza is a cause of epizootic respiratory disease of the equine. The detection of equine influenza virus using real-time Light Cycler reverse transcription (RT)-PCR technology was evaluated over two influenza seasons with the analysis of 171 samples submitted for viral respiratory disease. Increased sensitivity was found in overall viral detection with this system compared to Directigen Flu A and virus isolation, which were 40% and 23%, respectively, that of the RT-PCR. The assay was also evaluated as a viable replacement for the more traditional methods of quantifying equine influe...
Biros DJ, Brooks DE, Brown MP, Merritt KA, Kubilis PS.To determine regional and zonal variation in sulfation patterns of chondroitin sulfate in normal equine corneal stroma. Methods: 22 normal eyes from 11 horses. Methods: Corneas were collected within 24 hours of death from equine necropsy specimens. After papain-chondroitinase digestion of corneal tissue, disaccharides deltaDi4S and deltaDi6S were quantified by use of capillary zone electrophoresis in the superficial, middle, and deep zones of central and peripheral regions of the cornea. Results: For the 2 regions combined, deltaDi6S/deltaDi4S values were significantly lower in the deep and mi...
Causey RC.Equine uterine infections inflict major losses on the equine industry. Persistent inflammation of the oviduct and uterus leads to loss of the conceptus and mares susceptible to infection have weakened uterine defences partly due to retention of inflammatory exudate. Bacteria may trigger inflammation, resist phagocytosis, or adhere to the endometrium and types of infection range from genital commensals in susceptible mares to reproductive pathogens in normal mares. Uterine infections are diagnosed by history, detection of uterine inflammation, and isolation of typical organisms and susceptible ...
Oki H, Miyake T, Hasegawa T, Sasaki Y.Tying-up is a condition that primarily affects the muscles of horses. In this study, the heritability of the Tying-up syndrome in the Thoroughbred racehorse was estimated by Bayesian analysis with Gibbs sampling based on the threshold model for binary traits. The data used were the clinical data in racehorses diagnosed by veterinarians of the Racehorse Clinics of Japan Racing Association from 2000 to 2003. The health status of the Tying-up was treated as a binary trait. In the genetic analysis, the effect of changing the amount of the pedigree or inbreeding information on the estimation of her...
Desrochers AM, Dolente BA, Roy MF, Boston R, Carlisle S.To evaluate the viability of Saccharomyces boulardii after PO administration in clinically normal horses and its efficacy as a treatment for horses with acute enterocolitis. Methods: Prospective study. Methods: 5 clinically normal horses and 14 horses with acute enterocolitis. Methods: Feces were collected from 5 clinically normal horses and submitted for microbial culture for 2 days prior to administration of a lyophilized form of S. boulardii (25 or 50 g, PO, q 12 h) for 10 days. Feces were collected for microbial culture 5 and 10 days after treament initiation and 10 days after treatment wa...
Meier A, Hertzberg H.Small strongyles (cyathostomes) that are resistant against anthelmintics have become a major problem in equine medicine in the recent years. In many European countries benzimidazole-resistant cyathostomes are widespread and are now present in well over 50% of equine populations investigated. In contrast, resistance against ivermectin has not been reported despite its widespread use in the recent years. Optimising the frequency of treatments based on quantitative faecal monitoring is of great importance to preserve remaining anthelmintic efficacy.
Meier A, Hertzberg H.The occurrence of anthelmintic resistance in strongyles was investigated in 440 horses on 90 farms in Switzerland. The egg hatch assay suggested that benzimidazole (BZ)-resistance was present in 40 of 82 farms (49%). Faecal egg count reduction after pyrantel-treatment was above 96% in 14 of 15 farms. In the remaining farm the efficacy was only 80%. Ivermectin efficacy was investigated on 5 farms and the efficacy was recorded at 98-100%. Faecal cultures undertaken after treatment revealed almost exclusively larvae of the family Cyathostominae. Data about management practices, pasture hygiene an...
Lassaline ME, Brooks DE, Ollivier FJ, Komaromy AM, Kallberg ME, Gelatt KN.Amniotic membrane has antifibrotic, anti-angiogenic and antiprotease properties. This retrospective study was designed to investigate the use of equine amniotic membrane transplants (AMT) at preserving vision, maintaining the structural integrity of the globe and maximizing cosmesis in equine eyes with corneal ulceration and severe keratomalacia. Methods: Equine amnion had previously been aseptically harvested from a 12-year-old Thoroughbred mare during an elective Cesarean section. Sections of amnion were stored at -80 degrees C and thawed as needed. Records of equine cases at the University ...
Gilmour MA, Clarke CR, Macallister CG, Dedeo JM, Caudell DL, Morton RJ, Pugh M.To investigate intraocular penetration of orally administered doxycycline in the normal equine eye and to compare intraocular and serum doxycycline concentrations. Procedures Six mares were administered doxycycline at 10 mg/kg every 12 h by nasogastric tube for 5 days. Blood, aqueous, and vitreous samples were collected on days 1 and 5. All samples were assayed for doxycycline concentrations. Aqueous and vitreous samples were also assayed for protein quantitation. Results: Doxycycline was rapidly absorbed after the first dose (T(max) value of 1.42 +/- 1.28 h); and elimination of doxycycline oc...
Lepault E, Céleste C, Doré M, Martineau D, Theoret CL.Wound repair in horse limbs is often complicated by exuberant granulation tissue, a condition characterized by excessive fibroplasia and scarring and that resembles hypertrophic scars and keloids in man. The aim of this study was to compare microvascular occlusion and apoptosis in wounds of the limb with those of the body, which heal normally. Five 6.25 cm(2) wounds were created on both forelimbs and on the body of six horses. One limb was bandaged to stimulate excessive fibroplasia. Weekly biopsies were evaluated histologically and immunohistochemically for mutant p53 protein by terminal deox...
Dranchak PK, Valberg SJ, Onan GW, Gallant EM, MacLeay JM, McKenzie EC, De La Corte FD, Ekenstedt K, Mickelson JR.To develop a diagnostic test for recurrent exertional rhabdomyolysis (RER) in Thoroughbreds that relied on in vitro contracture of muscle biopsy specimens and determine whether the inheritance pattern of RER diagnosed on the basis of this contracture test was consistent with an autosomal dominant trait. Methods: Clinical trial. Methods: 8 adult horses with RER and 16 control adult horses for development of the contracture test; 23 foals for inheritance of RER. Methods: External intercostal muscle biopsy specimens from the 24 adult horses were tested for contracture in response to halothane and...
McClure SR, Carithers DS, Gross SJ, Murray MJ.To determine whether conditions representing activities that are typical in the recreational use of horses, including transport to and from show grounds, stall confinement in unfamiliar surroundings, and light exercise, are associated with increased incidence of gastric ulcers in horses. Methods: Randomized controlled study. Methods: 20 client-owned horses. Methods: Horses had no gastric ulcers as determined by endoscopic examination on study day -1. Ten control horses were maintained on-site with no changes in management variables. Ten horses were transported via trailer for 4 hours on day 0 ...
Herrera M, León G, Segura A, Meneses F, Lomonte B, Chippaux JP, Gutiérrez JM.Caprylic acid purification of IgG, currently used in the manufacture of horse-derived antivenoms, was successfully adapted for the preparation of sheep and camel IgG. Sheep IgG had a molecular mass of approximately 150 kDa, whereas camel IgG presented two bands of molecular masses of approximately 160 and 100 kDa, the latter corresponding to heavy-chain IgG, which is devoid of light chains. Horse, sheep and camel IgGs were compared by several parameters aiming at predicting their potential for induction of early and late adverse reactions. Horse and sheep IgGs showed a higher anticomplementary...
Pielberg G, Mikko S, Sandberg K, Andersson L.Grey horses are born coloured, turn progressively grey and often develop melanomas late in life. Grey shows an autosomal dominant inheritance and the locus has previously been mapped to horse chromosome 25 (ECA25), around the TXN gene. We have now developed eight new single nucleotide polymorphisms (SNPs) associated with genes on ECA25 using information on the linear order of genes on human chromosome 9q, as well as the human and mouse coding sequences. These SNPs were mapped in relation to the Grey locus using more than 300 progeny from matings between two Swedish Warmblood grey stallions and...
Barakzai SZ, Dixon PM.Race records were obtained for 31 thoroughbred racehorses that were treated conservatively (rest, improvement of fitness and/or use of a tongue tie) for dorsal displacement of the soft palate, and for 62 matched control horses. Their racing performance, based on prize money won, was compared for three races run before and after the disorder was diagnosed. Nineteen (61 per cent) of the conservatively treated horses had higher earnings after conservative treatment than before treatment, compared with 27 (43.5 per cent) of the controls. There was a significant (P=0.049) increase in the earnings o...
Black SJ, Lunn DP, Yin C, Hwang M, Lenz SD, Belknap JK.The mechanisms that initiate the pathophysiologic changes in the digital laminae in equine laminitis are poorly understood. Due to the fact that (1) the horse at risk of laminitis has many similarities clinically to the human sepsis patient and (2) our recent finding of marked laminar proinflammatory cytokine expression at the developmental time point of the black walnut extract (BWE) model of laminitis, we tested the possibility that, similar to organ damage in human sepsis, leukocyte emigration is an early event in laminitis. Using immunoperoxidase methods with an anti-equine CD13 monoclonal...
Southwood LL, Cohen J, Busschers E, Habecker P.To report a case of multiple acquired jejunal pseudodiverticula managed successfully by resection and jejunojejunostomy. Methods: Clinical report. Methods: Arabian filly. Methods: The filly was referred for signs of acute colic of several hours duration and had a 2-week history of inappetence and weight loss. Three meters of thickened, edematous, and dilated jejunum removed during exploratory celiotomy had an intussusception and numerous diverticula; jejunojejunostomy performed. The pathoanatomic diagnosis was proliferative enteropathy with pseudodiverticula formation and jejunal muscular hype...
Schvartz G, Epp T, Burgess HJ, Chilton NB, Armstrong JS, Lohmann KL.Passive surveillance of ticks on horses in Saskatchewan revealed that the horses were parasitized by 3 species, Dermacentor albipictus, D. andersoni, and D. variabilis. The nymphs and adults of D. albipictus occurred on horses earlier in the year than did adults of the 2 other species. Une surveillance passive des tiques chez des chevaux de la Saskatchewan a révélé que les chevaux étaient affectés par des parasites de trois espèces: et Les nymphes et les adultes de se présentaient chez les chevaux plus tôt dans l’année que les adultes des deux autres espèces.(Traduit par Isabel...
Fulton IC, Stick JA, Derksen FJ.Left laryngeal hemiplegia is a frustrating condition for the equine athlete and equine veterinarian. Treatment for the past 30 years has centered on the prosthetic laryngoplasty ("tie-back") with or without ventriculectomy. Laryngeal reinnervation has been used successfully in people and has been shown experimentally to benefit affected horses. This article reviews equine laryngeal reinnervation using the nerve muscle pedicle graft and describes the surgical technique, its complications, and the follow-up in 146 cases treated over the past 10 years. Also discussed is ongoing research into stim...
Valentine BA, Habecker PL, Patterson JS, Njaa BL, Shapiro J, Holshuh HJ, Bildfell RJ, Bird KE.Skeletal muscle samples from 38 draft horse-related animals 1-23 years of age were evaluated for evidence of aggregates of glycogen and complex polysaccharide characteristic of equine polysaccharide storage myopathy (EPSSM). Cardiac muscle from 12 of these horses was also examined. Antemortem serum levels of creatine kinase (CK) and aspartate aminotransferase (AST) from 9 horses with EPSSM and 5 horses without EPSSM were compared. Skeletal muscle from 17 horses contained inclusions of periodic acid-Schiff (PAS)-positive, amylase-resistant complex polysaccharide. Similar inclusions were also pr...
Vasey JR.In 15 horses with acute abdominal disease, a diagnosis of incarceration of small intestine through the epiploic foramen was made, either at the time of exploratory celiotomy or at necropsy.The horses exhibited signs of moderate to severe abdominal pain and were suffering from hypovolaemic and/or endotoxic shock. Nasogastric intubation produced either gas or fluid, the pH of which was in the range of 5 to 7.2, indicating reflux of small intestinal content into the stomach. Consistent physical findings included absence of gut sounds on auscultation, dilated small intestine palpable on rectal exa...
Schuh JC, Valentine BA.Basal cell tumors from 11 horses were examined histologically. Distinct patterns identified in the order of frequency are adenoid (six), solid (three), and medusoid (two). A minor component of most of these neoplasms was a ribbon pattern and cystic spaces. Hyalinized connective tissue and clear cells reminiscent of hair follicle glassy membranes and outer root sheath were present in a solid and the medusoid tumors. Heavy melanin pigmentation was present in one solid basal cell tumor. In eight cases for which information was available, the tumors had not recurred 3 to 8 years after excision.
Hildebrand SV, Holland M, Copland VS, Daunt D, Brock N.Neuromuscular blocking agents (muscle relaxants) are useful and common adjuncts to general anesthesia for human beings, but have not been used extensively during anesthesia of large animal species. Over a 3-year period, atracurium or pancuronium were used as adjuncts to general anesthesia for 89 anesthetic procedures in 88 equids (of 18 breeds and age ranging in age from 5 weeks to 25 years) at the teaching hospital. Forty-one of the anesthetic procedures were for abdominal surgery, and orthopedic (n = 19), ophthalmologic (n = 17), thoracotomy (n = 1), and soft tissue (n = 14) procedures compo...
Marcus LC, Ross JN.The hearts of 23 aged equids (18 horses and 5 mules) were examined histologically. Major findings included arteriolosclerosis and intimal bodies in small muscular arteries, myocarditis, myocardial fibrosis, fatty metamorphosis of myocardial and Purkinje fibers, myocytolysis, and basophilic (mucinous) degeneration of myocardium. Lesions less frequently seen included chronic fibrotic valvulitis, acute myocardial necrosis, sarcosporidiosis, and hemosiderosis. Single cases of malignant melanoma, cartilaginous metaplasia of the I-V septum, mineralization of connective tissue in the I-V septum, and ...
Dart AJ, Snyder JR, Pascoe JR, Meagher DM, Wilson WD.To quantify some components of prepurchase evaluations in horses, records from 134 evaluations performed during a 2-year period were reviewed and the outcome was determined via telephone follow-up interview. Sixty-two percent of the prepurchase evaluations had been performed at the clinic and 38% had been performed in the field by the ambulatory service. All evaluations included physical and lameness examinations, whereas radiography (49%), endoscopy (15%), nerve blocking (5%), transrectal palpation (3%), hematologic analysis (2%), electrocardiography (2%), drug testing for analgesic agents (2...
Song L, Porter DG, Coomber BL.Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) play very important roles in extracellular matrix (ECM) remodeling in ovarian follicle growth and ovulation. Equine follicles are embedded in cortex that is at the center of the ovary, and they must expand/emigrate to the fossa, the only site in the ovary for ovulation. Therefore, equine ovarian stromal cells (EOSC) are probably involved in ECM remodeling during follicle growth. This study examined whether cultured EOSC synthesize gelatinases and TIMPs, molecules essential for ECM remodeling in other systems. Results showed...
Watts K.The sugar, starch, and fructan content (collectively referred to as nonstructural carbohydrates [NSC]) of pasture plants is dependent on the environmental conditions under which they have grown. Pasture that is stressed by cold, drought, or lack of nutrients can be 2 to 3 times higher in NSC than pasture that grows quickly in warm weather and is adequately watered and fertilized. Horses at risk for laminitis should have access to pasture limited or be removed completely when environmental conditions are conducive to high levels of NSC accumulation.
Cleale RM, Edmonds JD, Paul AJ, Reinemeyer CR, Chapman MR, Clem R, Meccoli RA, Tolliver SC, Amodie DM.Controlled trials with a common protocol were conducted in Idaho, Illinois and Tennessee to evaluate anthelmintic effectiveness of Quest Gel (QG; 2% moxidectin) against lumenal parasites in horses. Candidate horses were required to have naturally acquired nematode infections, as confirmed by presence of strongylid eggs in feces. At each site, 24 equids were blocked on the basis of pretreatment strongyle fecal egg counts (EPG) and randomly assigned to treatments within blocks. Within each block of two animals, one received QG on Day 0 at a dosage of 0.4 mg moxidectin/kg b.w. and one was an untr...
Kates KC, Colglazier ML, Enzie FD.The efficacy of oxibendazole against gastrointestinal parasites of horses was evaluated by the critical test method. Naturally infected ponies of various ages were given single oral doses of 5, 10, or 15 mg-kg of bodyweight. The drug was highly effective against adult large strongylids (Strongylus vulgaris, S edentatus, S equins), adult small strongylids (especially species of the genera Cylicostephanus, Cylicocyclus, Cyaathostomum, and Triodontophorus), and adult and larval stages of the large pinworm, Oxyuris equi. There was no apparent dose-related differences in efficacy. Oxibendazole was ...
Nollet H, Vercauteren G, Martens A, Vanschandevijl K, Schauvliege S, Gasthuys F, Ducatelle R, Deprez P.In Belgium and even in northern Europe Rhinosporidium seeberi has not been reported in autochtonous people or animals. In this paper, the authors report the first observation of laryngeal masses, caused by Rhinosporidium seeberi, in a Belgian Warmblood horse. Moreover, laryngeal rhinosporidiosis is extremely rare since this localisation is only described in four human cases.
Ball BA, Hillman RB, Woods GL.To test the hypothesis that an abnormal uterine environment was a cause of early embryonic loss in subfertile mares, morphologically normal embryos were transferred to normal mares (n = 20) and subfertile mares (n = 20), and embryo survival rates were compared. Embryos were recovered nonsurgically at Days 7 to 8 postovulation and transferred surgically to normal and subfertile mares that had ovulated on the same day or within 2 d after a donor. Survival of transferred embryos was monitored by ultrasonography of the recipient mare's uterus from Day 9 through Day 28 postovulation. There were no ...