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.
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...
Brommer H, Laasanen MS, Brama PA, van Weeren PR, Helminen HJ, Jurvelin JS.No quantitative data currently exist on the relationship of the occurrence of cartilage degeneration and changes in site-specific biomechanical properties in the metacarpophalangeal (MCP) joint in the horse. Objective: To gain insight into the biomechanical consequences of cartilage deterioration at 2 differently loaded sites on the proximal articular surface of the proximal phalanx (P1). Objective: Static and dynamic stiffness of articular cartilage decreases significantly in degenerated cartilage. Methods: Cartilage degeneration index (CDI) values were measured at the lateral dorsal margin (...
Vychodilova-Krenkova L, Matiasovic J, Horin P.The objective of this study was to identify single nucleotide polymorphisms (SNPs) within four functionally related immune response genes in the horse, and to develop genotyping techniques that could be useful for future genomic studies of horse infectious and allergic diseases. The genes analysed were: the lipopolysaccharide (LPS) receptor gene CD14, the toll-like receptor 4 gene TLR4, the gene Cepsilon encoding the IgE heavy chain molecule and the gene FcepsilonR1 alpha coding for the alpha subunit of the IgE receptor molecule. Horse-specific primers amplifying selected gene regions were des...
Branch MV, Murray RC, Dyson SJ, Goodship AE.Osteoarthritis (OA) is a common cause of distal tarsal pain, but disease development is poorly understood. Awareness of normal tarsal structure and function is important in order to understand the pathogenesis of OA. Thickening of the subchondral bone (SCB) plate has been related to the development of OA, but SCB plate patterns in the equine tarsus have not been documented. Objective: There is a repeatable pattern of SCB thickness across the distal tarsal joints, and specifically that thickness would be greatest dorsally and laterally. Methods: Twenty cadaver tarsi were collected from mature h...
Verheyen KL, Henley WE, Price JS, Wood JL.Dorsometacarpal disease (DMD) is common in young Thoroughbred (TB) racehorses, often interfering with their training programme. No reports exist on incidence rate or associated risk factors in the UK. Objective: To estimate the incidence rate of DMD in TB horses in training for flat racing in the UK and identify associated risk factors, particularly in relation to training regimens. Methods: Data were drawn from a large prospective study in which TB horses in 13 training yards were monitored for a period of up to 2 years, recording daily training information and details of musculoskeletal inju...
Mason BJ, Newton JR, Payne RJ, Pilsworth RC.Clinicians are often asked to guide owners and trainers over the relative advantages and disadvantages of equine castration performed in either the standing horse with an open unsutured scrotal wound with healing by second intention, or a recumbent horse under general anaesthesia in aseptic conditions, with sutured scrotal skin allowing primary wound closure. Objective: To identify types and frequency of complications following the 2 differing approaches, and to compare the financial cost associated with each procedure, based on practice charges. Methods: Veterinary expenses of 217 horses cast...
Woodie JB, Ducharme NG, Hackett RP, Erb HN, Mitchell LM, Soderholm LV.Dorsal displacement of the soft palate (DDSP) is a common condition in racehorses for which various surgical treatments are often performed. In light of recent findings that suggested the position of the larynx may influence the occurrence of DDSP, we investigated whether a noninvasive mean of affecting the position of the larynx could be effective in the management of DDSP. Objective: An external device (laryngohyoid support; LHS) positioning the larynx in a more rostral and dorsal location and preventing caudal displacement of the basihyoid bone would be effective in preventing DDSP during s...
Theurillat R, Knobloch M, Levionnois O, Larenza P, Mevissen M, Thormann W.A robust CE method for the simultaneous determination of the enantiomers of ketamine and norketamine in equine plasma is described. It is based upon liquid-liquid extraction of ketamine and norketamine at alkaline pH from 1 mL plasma followed by analysis of the reconstituted extract by CE in the presence of a pH 2.5 Tris-phosphate buffer containing 10 mg/mL highly sulfated beta-CD as chiral selector. Enantiomer plasma levels between 0.04 and 2.5 microg/mL are shown to provide linear calibration graphs. Intraday and interday precisions evaluated from peak area ratios (n = 5) at the lowest calib...
Simonen-Jokinen T, Pirie RS, McGorum BC, Maisi P.Airway matrix metalloproteinases (MMPs) increase following inhalation of organic dust. The relative contribution of dust components to this elevation is unknown. Objective: To identify components of organic dust responsible for elevated MMP levels in equine airways. Methods: Bronchoalveolar lavage (BALF) from 7 heaves-susceptible horses, collected 6 h following inhalation challenges with saline, 2 different hay dust suspensions (HDS-1 and -2) and soluble and particulate fractions of HDS-1, were analysed for MMP-2 and -9 using SDS-page gelatin zymography. Results: HDS-1 challenge increased BALF...
Treiber KH, Boston RC, Kronfeld DS, Staniar WB, Harris PA.Insulin resistance has been suggested to increase the risk of certain diseases, including osteochondrosis and laminitis. Our objective was to evaluate the effect of adaptation to high-glycemic meals on glucose-insulin regulation in healthy Thoroughbred weanlings. Twelve Thoroughbred foals were raised on pasture and supplemented twice daily with a feed high in either sugar and starch (SS; 49% nonstructural carbohydrates, 21% NDF, 3% crude fat on a DM basis) or fat and fiber (FF; 12% nonstructural carbohydrates, 44% NDF, 10% crude fat on a DM basis). As weanlings (age 199 +/- 5 d; BW 274 +/- 5 k...
Dumasia MC.The in vivo biotransformation of metoprolol tartrate in the thoroughbred racehorse was studied after administration of a single oral dose. Metoprolol and its basic and bifunctional phase I metabolites were isolated from urine and plasma using mixed mode solid phase extraction (SPE) cartridges. The isolates were derivatised as trimethylsilyl ethers and analysed by capillary column gas chromatography--positive ion electron ionisation and ammonia chemical ionisation mass spectrometry. Metabolism was primarily confined to the oxidative transformations of the p-(2-methoxy)ethyl substituent. Metopro...
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 ...
Craig AM, Blythe LL, Rowe KE, Lassen ED, Barrington R, Walker KC.Recent evidence concerning the pathogenesis of equine degenerative myeloencephalopathy indicated that low blood alpha-tocopherol values are a factor in the disease process. Variables that could be introduced by a veterinarian procuring, transporting, or storing samples were evaluated for effects on alpha-tocopherol concentration in equine blood. These variables included temperature; light; exposure to the rubber stopper of the evacuated blood collection tube; hemolysis; duration of freezing time, with and without nitrogen blanketing; and repeated freeze/thaw cycles. It was found that hemolysis...
Blackmore DJ, Elton D.This paper records the concentrations of aspartate amino transferase (A.A.T.), creatine kinase (C.P.K.), sorbitol dehydrogenase (S.D.H.), alpha-hydroxybuturate dehydrogenase (alpha-H.B.D.) and alkaline phosphatase (A.P.) activity observed in the sera of Thoroughbred horses in the United Kingdom, at rest and during training. The methods of analysis have been selected to achieve the optimum precision when used for horse serum. During training A.A.T., C.P.K. and alpha-H.B.D. are related and demonstrate intermittent periods of increasing activity. S.D.H. remains unchanged but demonstrates increase...
Ponthier J, Franck T, Parrilla-Hernandez S, Niesten A, de la Rebiere G, Serteyn D, Deleuze S.Myeloperoxidase (MPO) is a pro-oxidant enzyme associated with decreased motility in thawed equine semen. This study aimed to describe MPO concentration, activity and subunits in raw and thawed semen and to correlate these data with motilities in raw and thawed semen. Semen samples from five stallions were collected four times. Motilities were assessed in raw and thawed semen. MPO assays were performed in raw seminal plasma, raw sperm-rich pellet and thawed semen. Total and active MPO concentrations were, respectively, assayed by enzyme-linked immunosorbent assay and specific immunological extr...
Brown MP, MacCallum FJ.Tetracycline-labeled bones of 23 foals from 52 to 104 days old were sectioned and macroscopically examined to assess the extent of ossification or fusion of ossification centers. A grading system was devised with which to record information about the ossification centers and growth plates. The objective was to define anatomic standards which could contribute toward obtaining an accurate radiologic interpretation. Labeled limb bones of 3 neonatal foals were similarly treated, but grading of these was limited to the consideration of whether each site was still cartilaginous or had commenced to o...
Takasawa T, Fukushi K, Shiokawa H.A crystalline creatine kinase was obtained from equine skeletal muscle. The enzyme was homogeneous, as judged by ultracentrifugation and disc electrophoresis on polyacrylamide gel. The crystalline enzyme had a specific activity of 110 units per mg of protein, that is, 14-fold purification over the crude extract of equine skeletal muscle. The molecular weight of the enzyme was determined to be 84,600 by the conventional low-speed sedimentation equilibrium method, and s020,w was 5.32S. Eight cysteine residues were found on amino acid analysis, two of which were essential for the enzymatic activi...
Frank N.Equine athletes are affected by 2 major endocrine/metabolic disorders, insulin dysregulation (ID) and pituitary pars intermedia dysfunction. ID is a risk factor for laminitis in horses, which poses the greatest threat to performance because of the damage that it causes to hoof structures. This article includes an in-depth discussion of ID and other risk factors for laminitis that are grouped together as equine metabolic syndrome. As horses age, the risk of pituitary pars intermedia dysfunction increases, and this endocrine disorder may exacerbate preexisting ID and further increase the risk of...
Justines G, Sucre H, Alvarez O.Transplacental passage of Venezuelan equine encephalitis virus, epizootic strain P-676, occurred in four of nine fetuses studied. The mares were infected near term. Virus was recovered in high titer from fetal blood and organs, while no virus was detected in maternal blood but neutralizing antibodies were present. No evidence of in utero infection was found in two fetuses from mares infected with MF-8, another epizootic strain of Venezuelan equine encephalitis virus.
Brusie RW, Sullins KE, Silverman DG, Rosenberger JL.Arteriovenous (ischaemic strangulating obstruction, ISO) and venous obstructions (haemorrhagic strangulating obstruction, HSO) were created for 70 min in the small intestine of eight anaesthetised horses, and ISO was created in four horses for 2 h and four horses for 3 h at the sternal and diaphragmatic flexures of the large colon. Five minutes following release of the occlusions, sodium fluorescein 20 per cent (0.5 mg/kg bodyweight intravenously) was administered. Serial quantitative measurements of serosal surface fluorescence of the injured segments and a control segment were made at 2, 10,...
Walthall JC, McKenzie RA.Horses grazing manily Cenchrus ciliaris and/or Panicum maximum var. trichoglume pastures on over 30 properties in southern central Queensland developed lesions of osteodystrophia fibrosa. Horses on individual properties in coastal Queensland grazing Setaria anceps, Brachiaria mutica or Pennisetum clandestinum also developed the disease. Ill-thrift, lameness, and fibrous swellings of nasal bones, maxillae and mandibles were observed. Calcium and phosphorus levels of pasture were normal but all the above pasture species contained oxalates which were suspected of causing the disease.
Proietto L, Beatty SS, Plummer CE.To compare corneal cytology samples from three common sampling techniques: cytobrush (CB), Kimura platinum spatula (KS), and the handle edge of a scalpel blade (SB). Methods: Equine patients presenting to the University of Florida College of Veterinary Medicine with ulcerative keratitis were included. Following diagnosis of corneal ulcer and sampling for microbial culture, two cytology samples per technique were collected with sterile CB, KS, and SB in a randomized order. Cytologic evaluation was performed by two observers masked to collection method. Objective measures of sample cellularity, ...
McDonnell SM, Kenney RM, Meckley PE, Garcia MC.Sexual behavior dysfunction unaccompanied by detectable physical or endocrine abnormality is an important cause of reproductive failure among domestic stallions. Several authors have suggested that such dysfunction may be psychogenic, related to negative experience associated with intense handling and training. An experimental model of experience-related dysfunction was developed by exposing pony stallions to erection-contingent aversive conditioning. This resulted in rapid, specific suppression of sexual arousal and response similar to spontaneously occurring dysfunction. Subsequently, treatm...
Laing JA, Leech FB.In a group of 852 Thoroughbred mares, 69-7% had foals which survived beyond 6 weeks, 7-1% had dead, premature or full-term foals and 1-1% had foals which died within 6 weeks after birth. Possible factors which may have influenced these data are mentioned.
Davies Morel MC, Newcombe JR.Despite the widespread use of hCG to advance ovulation in the mare there is little information on efficacy of dose rates and any contraindications of its use. This study aims to investigate the effect of dose of hCG on ovulation within 48h and the effect of hCG on: ovulation, multiple ovulation (MO), pregnancy, multiple pregnancy (MP) rates and synchrony of MO; additionally whether any seasonal effect is evident. Sequential ultrasonic scanning was used to monitor the occurrence of ovulation, within 48h of treatment, in 1291 Thoroughbred mares treated with either 750iu hCG or 1500iu hCG s.c. Ov...
Hillyer MH, Mair TS.Equine multisystemic eosinophilic epitheliotropic disease is rare in horses. The clinical signs vary according to the organs affected, the skin and gastrointestinal tract being most commonly involved. This paper gives the first reported description of a horse with multisystemic eosinophilic epitheliotropic disease in the United Kingdom and the attempts to treat it. The horse showed dermatological, gastrointestinal, hepatic, pulmonary and pancreatic involvement. Some improvement was seen when the horse was treated with corticosteroid and hydroxyurea.
Fredricson I, Drevemo S, Dalin G, Hjertën G, Björne K.Locomotive disorders constitute a serious problem in horse racing which will only be rectified by a better understanding of the causative factors associated with disturbances of gait. This study describes a system for the quantitative analysis of the locomotion of horses at speed. The method is based on high-speed cinematography with a semi-automatic system of analysis of the films. The recordings are made with a 16 mm high-speed camera run at 500 frames per second (fps) and the films are analysed by special film-reading equipment and a mini-computer. The time and linear gait variables are pre...
Zdovc I, Ocepek M, Gruntar I, Pate M, Klobucar I, Krt B.The prevalence of Taylorella equigenitalis infection in Slovenia is unknown and methods used to refine identification in these stallions are required. Objective: In diagnosis of T. equigenitalis, polymerase chain reaction (PCR) would have advantages over culture methods, especially in cases where small numbers of causal agent or intensive contamination of genital swabs are involved. Methods: Culture method and PCR were used to examine a total of 980 genital swabs from the urethra and fossa urethralis of 245 stallions for the presence of the contagious equine metritis organism. Results: Among 2...