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.
Lesser FR, Cowles RR.In this article, the author discusses the design of an equine ambulatory practice. He suggests a more systematic approach to the design of an ambulatory practice that should answer the needs of group and solo practices. Today's practitioners must actively manage their practices so that their resources can be leveraged in such a fashion that a return can be realized on their capital investment and the hours spent in practice.
Ionita M, Howe DK, Lyons ET, Tolliver SC, Kaplan RM, Mitrea IL, Yeargan M.A sensitive and specific PCR hybridization assay was applied for species-specific monitoring of the small strongyle (Strongylida: Cyathostominae) populations in horses in a herd before and after treatment with the anthelmintic drug ivermectin. Fecal samples were collected pre- and post-treatment weekly from eight individual horses (four foals and four yearlings) for 6 weeks to determine counts of strongyle eggs per gram of feces (EPGs). Additionally, one foal and one yearling were nontreated controls. Also, one horse, from another herd known to be infected with Strongylus spp., was a positive ...
Sairanen J, Nivola K, Katila T, Virtala AM, Ojala M.The Finnish mating records of Standardbred trotters (SB; n = 33 679) and Finnhorses (FH; n = 32 731) were analysed to study the effect of the level of inbreeding on foaling rates and to estimate the heritability of foaling rate. A linear mixed model was assumed, with the outcome of the foaling (foal or no foal) as the trait of the study. A restricted maximum likelihood-based method was used to calculate the estimates of the variance components. Predictions of breeding values and estimates of fixed effects were also calculated. The average level of inbreeding was 9.9% in the SB and 3.6% in the ...
Covaleda L, Fuller FJ, Payne SL.Equine infectious anemia virus (EIAV) infection is distinctive in that it causes a rapid onset of clinical disease relative to other retroviruses. In order to understand the interaction dynamics between EIAV and the host immune response, we explored the effects of EIAV and its S2 protein in the regulation of the cytokine and chemokine response in macrophages. EIAV infection markedly altered the expression pattern of a variety of pro-inflammatory cytokines and chemokines monitored in the study. Comparative studies in the cytokine response between EIAV(17) and EIAV(17DeltaS2) infection revealed ...
Rios LM, Sheu JJ, Day JF, Maruniak JE, Seino K, Zaretsky H, Long MT.The objective of this study was to examine the extrinsic risk factors of West Nile virus (WNV) clinical disease in Florida horses as established from confirmed and negative horses tested within the state from 2001 to 2003. An Arboviral Case Information Form (ACF) was submitted by a referring veterinarian at the time of testing to the Florida Department of Agriculture and Consumer Services on every horse suspected of a viral encephalitis in Florida. A follow-up survey that focused on arbovirus prevention and farm ecology was created and mailed to the owner of each tested horse. Data from the fo...
Moe KK, Yano T, Kuwano A, Sasaki S, Misawa N.Equine canker is a chronic pododermatitis of the hoof in horses. Although spirochetes are detectable histopathologically in the lesions, the precise etiology remains unclear. This study reports the 16S rRNA gene sequencing of randomly selected clones based on PCR with Treponema-specific primers, using the canker lesions from two horses and healthy frog and sole from a horse. A total of 114 clones were obtained from the lesions, but no clones were detected in the healthy hoof tissues. The clones from the canker lesions examined were grouped into 19 operational taxonomic units, such as treponema...
Nourian AR, Asplin KE, McGowan CM, Sillence MN, Pollitt CC.Anatomical changes in the hoof lamellar tissue induced by prolonged hyperinsulinaemia have not been described previously. Analysis of the induced lesions may promote understanding of hyperinsulinaemic laminitis pathogenesis and produce clinical benefit. Objective: To use light and transmission electron microscopy (TEM) to document hoof lamellar lesions in ponies clinically lame after prolonged hyperinsulinaemia. Methods: Nine clinically normal, mature ponies were allocated randomly to either a treatment group (n = 5) or control group (n = 4). The treatment group received insulin via a modified...
Pearson W, Lindinger M.Nutraceuticals are increasingly applied to the management of equine arthritis and joint disease, particularly those based upon glucosamine and chondroitin sulphate. While the first report of using glucosamine in horses appeared more than 25 years ago, it was not until 1992 that isolated studies began to be reported. Since that time, 15 in vivo papers have been published in the equine literature, usually on products already commercially available and often seeking evidence for efficacy. These studies demonstrate an encouraging trend to manufacturers of these products investing in research, but ...
Matthews A, Gilger BC.Equine immune mediated keratopathies are common in both Europe and the USA. This review article will compare the clinical differences in horses with this disease and also review the current theories on pathogenesis and treatment of equine IMMK.
Rodrigues NL, Doré M, Doucet MY.In order to study the evolution of histopathological and immunohistochemical changes in the gastric mucosa of horses with EGUS (equine gastric ulcer syndrome), a feasible, useful, valid and safe in vivo gastric biopsy technique is required. Objective: To determine the average gastric mucosal healing time following endoscopic gastric biopsy sampling, and evaluate the feasibility, safety and usefulness of samples obtained by this method for histopathological analysis. Methods: Six mature mares from the Faculté de Médecine Vétérinaire research herd were used. Transendoscopic gastric biopsy wa...
Bourke CA, Hunt E, Watson R.A new form of toxicity called equine fescue oedema is described. The clinical signs included inappetence, depression, and subcutaneous oedema of the head, neck, chest and abdomen. Affected horses had very low plasma albumin values. The toxicity affected 48 of 56 horses on six farms in different states of Australia, and 4 horses have died. All horses were grazing pastures that had been sown with varieties of Mediterranean tall fescue (Festuca arundinacea) that carry the endophyte known as Max P or Max Q. It is proposed that a pyrrolizidine alkaloid, N-acetyl norloline, which is produced by the ...
Wilsher S, Lefranc AC, Allen WR.Fillies completely devoid of endometrial glands (uterine gland knockout; UGKO) would make ideal experimental models in which to study the role of endometrial histotroph in embryogenesis and early fetal development in the mare. Objective: Administration of a synthetic progestagen plus oestrogen to newborn filly foals and, thereafter, at regular intervals to age 6 months, would permanently suppress endometrial gland development. Methods: Nine half-sister Thoroughbred filly foals were treated, in 3 groups, with: A) the weakly active progestagen, norgestomet, administered from birth to age 6 month...
Plummer CE, Ollivier F, Kallberg M, Brooks D, Barrie K, Utter M, Gelatt K.Amniotic membrane transplantation (AMT) is an effective clinical therapy for reconstruction of the ocular surface in human and veterinary patients. Amnion is avascular and strong, contains antiangiogenic and antiinflammatory properties and growth factors, and has properties that prevent or decrease fibrosis in healing tissue. Indications for its use are steadily growing and include grafting to replace diseased, missing or excised tissue, patching to support diseased tissue during the healing process and as a substrate for the expansion of epithelial cells for transplantation to the cornea. AMT...
Martineau H, Thompson H, Taylor D.Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach. Objective: To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem. Methods: Stomachs were removed from a mixed population of 21 horses at post ...
Bourzac C, Alexander K, Rossier Y, Laverty S.Osteochondritis dissecans (OCD) lesions of the femoropatellar (FP) joint are diagnosed routinely by radiography, but lesions located in the trochlear groove or without accompanying subchondral bone changes can be difficult to visualise. Ultrasonography allows evaluation of articular cartilage and subchondral bone in the FPjoint. Objective: To document the radiographic and ultrasonographic appearance of OCD lesions in the equine FP joint, grade ultrasonographic lesions and compare their accuracy in the diagnosis of these lesions. Methods: The medical records of all horses diagnosed with FP OCD ...
Luthersson N, Nielsen KH, Harris P, Parkin TD.The prevalence (up to 93% in Thoroughbred racehorses) and severity of equine gastric ulceration syndrome (EGUS) have been correlated with the type of training and associated management practices. However, there have been few reports to confirm these findings in nonracehorses in Europe. Objective: To describe the prevalence, anatomical distribution, severity and number of gastric ulceration lesions in a population of Danish pleasure horses; and to investigate differences for groups based on age, breed type and workload. Methods: A total of 201 horses not in active race-training, age 7 months-27...
Ledbetter EC, Scarlett JM.To describe morphologic features, pachymetry and endothelial cell density of the normal equine cornea and limbus by in vivo confocal microscopy. Methods: Ten horses without ocular disease. Methods: The central and peripheral corneas were examined with a modified Heidelberg Retina Tomograph II and Rostock Cornea Module using a combination of automated and manual image acquisition modes. Thickness measurements of various corneal layers were performed and endothelial cell density determined. Results: Images of the constituent cellular and noncellular elements of the corneal epithelium, stroma, en...
de Grauw JC, van de Lest CH, Brama PA, Rambags BP, van Weeren PR.Meloxicam is a commonly used nonsteroidal anti-inflammatory drug in equine practice, but little is known about its in vivo effects on joint inflammation and cartilage turnover. Objective: To study the effects of meloxicam on biomarkers of inflammation, matrix metalloproteinase (MMP) activity, and cartilage biomarkers in joints with experimental synovitis. Methods: In a 2-period cross-over study, synovitis was induced at T = 0 h in the L or R intercarpal joint of 6 horses by intraarticular injection of 0.5 ng lipopolysaccharide (LPS). Horses received once daily meloxicam (0.6 mg/kg bwt per os) ...
Gläser KE, Sun Q, Wells MT, Nixon AJ.No large scale equine microarray is available commercially to allow genomic and transcriptional profiling of the majority of genes that would define the genetic basis of equine disease. Objective: To generate a whole transcript target labelled GeneChip to interrogate the equine transcriptome and validate chip performance using RNA samples derived from organs, articular cells and normal cartilage. Methods: Equine mRNA and selected equine gene sequences derived from perfect cross-hybridisation of equine RNA on human microarray GeneChips, were used to design a custom equine gene microarray. Seque...
Luthersson N, Nielsen KH, Harris P, Parkin TD.The prevalence (up to 93% in Thoroughbred racehorses) and severity of equine gastric ulceration syndrome (EGUS) has been associated with type of training and differing management practices. However, there have been few studies to confirm these findings in nonracehorses in Europe. Objective: To investigate the prevalence of EGUS in a population of Danish horses, during winter when the horses had been housed and fed for at least 8 weeks and to analyse the influence of feed, work level and environment on the risk of EGUS of > or = grade 2 in severity. Methods: A total of 201 horses, not in active...
Mathes RL, Dietrich UM, Krunkosky TM, Hurley DJ, Reber AJ.To establish a reproducible method for the culture of primary equine corneal epithelial cells, keratocytes, and endothelial cells and to describe each cell's morphologic characteristics, immunocytochemical staining properties and conditions required for cryopreservation. Methods: Corneas from eight horses recently euthanized for reasons unrelated to this study were collected aseptically and enzymatically separated into three individual layers for cell isolation. The cells were plated, grown in culture, and continued for several passages. Each cell type was characterized by morphology and immun...
Trope GD, Whitton RC.A 12-year-old show-jumping mare was presented for investigation of a chronic hindlimb lameness of 16 weeks duration. Perineural anaesthesia and ultrasonography localised the lesion to the medial collateral ligament of the distal interphalangeal joint of the left hindlimb. Treatment consisted of a heavily padded distal limb cast for 6 weeks, strict box rest and a strictly regulated hand walking program. Serial ultrasonographic examinations were performed throughout the rehabilitation period. Collateral ligament desmitis of the distal interphalangeal joint is a commonly diagnosed condition of th...
Sabaté D, Homedes J, Salichs M, Sust M, Monreal L.In horses, it has been demonstrated that suxibuzone (SBZ) has a lower gastric ulcerogenic effect than phenylbutazone (PBZ). However, no field trials have been reported comparing the efficacy of the drugs in alleviating lameness. Objective: To compare the therapeutic effect of SBZ to that of PBZ when administered orally in lame horses. Acceptability of both products was also compared. Methods: Lame horses (n = 155) were used in a multicentre, controlled, randomised and double-blinded clinical trial. Horses were treated orally with either SBZ or PBZ at equivalent therapeutic dosages. PBZ was giv...
Soboll G, Hussey SB, Minke JM, Landolt GA, Hunter JS, Jagannatha S, Lunn DP.Equine influenza virus remains an important problem in horses despite extensive use of vaccination. Efficacy of equine influenza vaccination depends on the onset and duration of protective immunity, and appropriate strain specificity of the immune response. This study was designed to test the protective immunity resulting from vaccination with the North American commercial ALVAC equine influenza vaccine (RECOMBITEK Influenza, Merial, USA)(1) against challenge with American lineage influenza viruses. In experiment 1, 12 ponies were vaccinated twice, at a 35 day interval, using the ALVAC-influen...
Soboll G, Breathnach CC, Kydd JH, Hussey SB, Mealey RM, Lunn DP.The control of EHV-1 infection by cytotoxic T-cell responses (CTL) via a reduction in cell associated viremia remains an important goal in horses. Unfortunately, current vaccines are inefficient at inducing these responses. We have identified the immediate early (IE) gene of EHV-1 as a potent stimulator of virus-specific CTL responses in ponies expressing a specific MHC class I serological haplotype (A3/B2). This study was designed to determine if vaccination of A3/B2 MHC I positive ponies with the IE gene could induce protection and immune responses associated with cell mediated immunity. Pon...
Traversa D, Otranto D.The myiasis caused by larvae of Rhinoestrus purpureus and Rhinoestrus usbekistanicus (Diptera, Oestridae) are of importance in the horse medicine since it causes severe respiratory diseases. Therefore an accurate diagnosis of rhinoestrosis is central to its epidemiology and control. This paper describes concisely a molecular diagnostic tool that overcomes the current inherent diagnostic constraints and, therefore, is of importance to understand the actual incidence and epidemiology of this myiasis in live horses.
Romagnoli SE, Momont HW, Hilbert BJ, Metz A.Two yearling, paternal half-sibling Appaloosa fillies were ovariohysterectomized for treatment of multiple uterocervical leiomyomas. The tumors recurred in both fillies, originating from cervical tissue that could not be removed at surgery. Previously reported cases of uterine leiomyoma in the mare have been of solitary tumors in older mares that were treated successfully by surgical removal.
Gleeson LJ, Sullivan ND, Studdert MJ.The inoculation of equine herpesvirus type 3 (EHV3) strain 65/61 into the amniotic cavity of a mare 6-7 months pregnant resulted in abortion 11 days later. Following abortion typical lesions of coital exanthema were not observed in the genital tract of the mare, nor was EHV3 isolated from her. Serological evidence, however, indicated that the mare was infected with EHV3 following inoculation. Grossly the foetal disease was characterised by placentitis, focal ulcerative dermatitis, focal necrosis of the lungs and a striking diptheritic gastritis. Histological findings were interstitial pneumoni...
Heymering HW.The causes of laminitis are many-often interrelated, sometimes direct opposites. The history of laminitis has been a search for the cause or causes of laminitis and for effective treatment. Going in and out of fashion, many treatments have lasted for centuries, some for millennia, but very few have been proven.
Blott S, Cunningham H, Malkowski L, Brown A, Rauch C.Exercise-induced pulmonary haemorrhage (EIPH) occurs in horses performing high-intensity athletic activity. The application of physics principles to derive a 'physical model', which is coherent with existing physiology and cell biology data, shows that critical parameters for capillary rupture are cell-cell adhesion and cell stiffness (cytoskeleton organisation). Specifically, length of fracture in the capillary is a ratio between the energy involved in cell-cell adhesion and the stiffness of cells suggesting that if the adhesion diminishes and/or that the stiffness of cells increases EIPH is ...
McLaughlin BG, Doige CE, Fretz PB, Pharr JW.Six foals with angular limb deformities present at birth or shortly after were examined. The limb deformities were caused by abnormalities of the carpal bones and included hypoplasia and osteochondritis dissecans. The 3rd carpal bone was affected most frequently.
Dupuis-Dowd F, Lavoie JP.Airway smooth muscle remodelling in severe equine asthma includes both thickening of airway smooth muscle, resulting from hyperplasia and hypertrophy, and changes in contractility. However, airway smooth muscle changes have not been studied in milder forms of the disease. Objective: To investigate bronchial smooth muscle remodelling in horses with mild and moderate asthma (MEA). Methods: Retrospective case-control study. Methods: The endobronchial biopsies from 18 horses with MEA referred to the Equine Hospital of the Université de Montréal and from seven healthy age-matched control horses w...
Gibson JA, Eaves LE, O'Sullivan BM.During a 20 month period Enterobacter agglomerans was
isolated from 17 cases of equine abortion. In 8 cases E
agglomerans was isolated in pure culture and in 9 cases it was
isolated in mixed culture from the foetus and/or foetal
membranes. Fifteen cases had histological evidence of foetal
infection and/or placentitis.
The occurrence of E agglomerans in pure culture, associated
with inflammatory lesions in the foetus and foetal membranes,
suggests it to be a cause of abortion in mares.
Johnston KG, Henderson AW.Under the title “Equine Granuloma in the
Northern Territory of Australia” Lewis (1914)
gave an account of a disease of horses otherwise
known as “swamp cancer”. A variety of superficial sites are affected but these are rarely above
the level of the shoulder joint and principally
involve the lower legs and the ventral aspect of the
thoracoabdominal wall. The lesions on the legs are
granulating ulcers, those on the body are subcutaneous swellings and both are characterised by
the presence of conspicuous necrotic cores or
“kunkers” in the inflammatory tissue.
Johnston (1971)...
Kirkpatrick CE, Saik JE.Ciliated protozoa of several morphological types were found in the colonic tissue of 8 horses, mostly immature Standardbreds. Most of the protozoa observed appeared similar to those normally found as commensals in the equine large intestinal lumen. In all cases, organisms were located in the lamina propria; organisms were also found in the submucosa of 2 horses. The association of colonic disease with the presence of intramural ciliates was unclear.
Gough MR, Munroe GA, Mayhew G.This paper tests the hypothesis that serum and synovial urea concentrations are similar and that urea concentration can be used as an accurate marker for synovial fluid dilution in normal equine joints. Serum and synovial fluid urea concentrations were compared in 42 horses and were equivalent for individual horses (P<0.0001). Mean +/- s.e. serum concentration was 6.1+/-0.552 mmol/l and synovial concentration 6.0+/-0.459 mmol/l. The normal range for synovial urea concentration was determined as 2.5-7.7 mmol/l. The synovial urea concentration from different synovial structures in individual hor...
Blach EL.This article explores customer service in equine veterinary medicine. It begins with a discussion about the differences between customers and clients in veterinary medicine. An overview of the nature of the veterinary-client-patient relationship and its effects on the veterinarian's services sheds light on how to evaluate your customer service. The author reviews a study performed in 2007 that evaluated 24 attributes of customer service and their importance to clients of equine veterinarians in their decision to select a specific veterinarian or hospital. The article concludes with an overview...
García-López JM.Angular limb deformities are seen in young foals and are defined as lateral or medial deviations of the limb in the frontal plane distal to a particular joint. Several factors can contribute to the development of an angular limb deformity. Early assessment of the level of ossification of the cuboidal bones is critical to avoid complications long term. Although most deviations self-correct with minimal intervention other than modifications in exercise and hoof trimming, some require surgical intervention in the form of growth acceleration or retardation. This article focuses on growth augmentat...
Greiner EC, Mays MB, Smart GC, Weisbrode SE.Verminous mastitis was the reason for euthanasia of a 22-yr-old Paso Fino mare from Miami, Florida. The etiologic agent was a species of Cephalobus (Rhabditida: Cephalobidae), a genus of soil-inhabiting nematodes that were obviously multiplying in the mammary gland. Only females and larvae were detected in the tissues by histologic section or by teasing the tissue to liberate the worms. At least 12,900 individuals were present per gram of tissue. This is the first case of Cephalobus infecting horses and it indicates that not all histiotropic infections of horses by rhabditoid nematodes are by ...
Pascoe RR.The effect on the fertility of mares during two outbreaks of equine coital exanthema have been described. Conception was not prevented, nor was pregnancy terminated in mares showing active lesions of coital exanthema. Normal pregnancy rates occurred in mares served during active infection of the stallions. Origin of the disease was not determined.
Caivano D, Corda A, Rishniw M, Giorgi ME, Parpaglia MLP, Conti MB, Porciello F, Birettoni F.Equine cardiovascular structures and function are routinely assessed by transthoracic echocardiography. Recently, investigators have described the echocardiographic visualization of equine pulmonary vein ostia. In companion animals, the right pulmonary vein (RPV) to right pulmonary artery (RPA) ratio has been used as an index to estimate the severity of cardiac diseases resulting in left ventricular volume overload. We sought to assess the feasibility of measuring RPV and RPA dimensions, and sought to provide various previously examined RPV and RPA variables in clinically healthy horses that c...
Leisinger CA, Medina V, Markle ML, Paccamonti DL, Pinto CRF.A novel in vivo model utilizing serial administrations of PGF2α to induce aluteal cycles in the mare was used to evaluate the effects of progesterone-deprivation on the morphology of in vivo preimplantation embryos. We hypothesized that equine embryos produced during induced aluteal cycles (AL) would be developmentally affected, characterized by earlier embryo stage at collection, smaller embryo diameter, and lower quality grade, compared with those collected on the same day post-ovulation from control cycles during diestrus (high progesterone; > 4 ng/mL). Seven cyclic mares with a median ...