The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
Ledbetter EC, Cutler TJ, Irby NL.The aim of this study was to describe the clinical, confocal microscopic, histologic, and virologic features of horses with macrodendritic ulcerative keratitis and conjunctival lymphoid hyperplasia associated with equine herpesvirus-2 and equine herpesvirus-5 infection. Methods: Four foals with bilateral ocular disease. Methods: Complete ophthalmic examination was performed for each horse, and corneal samples were collected for cytology and microbiologic evaluation, including virus isolation and molecular diagnostics for the equine herpesviruses. In vivo confocal microscopy examination of the...
Shi L, Hu J, Jin Z.Strangles is one of the most prevalent horse diseases globally. The infected horses may be asymptomatic and can still carry the infectious pathogen after it recovers, which are named asymptomatic infected horses and long-term subclinical carriers, respectively. Based on these horses, this paper establishes a dynamical model to screen, measure, and model the spread of strangles. The basic reproduction number $ mathcal{R}_0 $ is computed through a next generation matrix method. By constructing Lyapunov functions, we concluded that the disease-free equilibrium is globally asymptotically stable if...
Fortin-Trahan R, Sjolin E, Lack A, de Arbina CL, McFadden-Bennett A, Wang L, Baird JD, Rikihisa Y, Arroyo LG.Potomac horse fever (PHF) is characterized by fever, depression, anorexia, ileus, diarrhea, and occasionally, laminitis. The disease is caused by infection with and/or . Equids of all ages may be affected; however, the condition has not been well-characterized in foals. This report describes clinical signs, laboratory findings, and treatment of 2 foals diagnosed with PHF in southwestern Ontario. Feces submitted for an equine PCR panel tested positive for spp. and were subsequently confirmed to be (Case 1) and (Case 2). Both foals recovered following hospitalization and intensive care. Key ...
Thomas BA, Saylor RK, Taylor ZP, Rhodes DVL.Strangles is a highly contagious upper respiratory infection of equids that is globally distributed. The causative agent of strangles, subspecies , can be spread through indirect contact with infected fomites, and studies have shown this microbe to live well in varying environmental conditions. The purpose of this study was to analyze strangles case numbers across the United States of America from 2018 to 2022 to investigate potential temporal or weather patterns associated with outbreaks. Diagnosed case records were obtained from the Equine Disease Communication Center, university databases,...
Bardell D, Rocchigiani G, Ressel L, Milner P.Strangulating small intestinal disease (SSID) in horses carries a poor prognosis for survival, especially following resection of ischaemic tissue. The margins of a resection are principally based on visual appraisal of the intestine during surgery. We hypothesized that histological evaluation of resected tissue may identify occult changes indicative of prognosis. Small intestinal samples from 18 horses undergoing resection for SSID and 9 horses euthanised for reasons unrelated to gastrointestinal pathology were utilised. Histological appearance was used to generate a 'total damage score' (TDS)...
Risselada M, Worth DB.Tumors of various sizes and locations can create a treatment dilemma in achieving adequate surgical margins when sufficient free tissue is not available for closure. Extravascular local adjunctive chemotherapy has been investigated clinically to aid in achieving local tumor control in animals with naturally occurring neoplastic disease. Local chemotherapy can be an alternative primary or a local adjunctive treatment. This is a summary of relevant findings of in vitro and in vivo studies on local chemotherapeutic delivery through carrier media, together with a summary of outcomes of clinical us...
Adams AA, Siard-Altman MH, Reedy SE, Barker D, Elzinga S, Sanz MG, Urschel K, Ireland JL.Pituitary pars intermedia dysfunction (PPID) is an age-related neurodegenerative disorder, affecting >20 % of older horses. There is a need for improved endocrine tests for early disease detection, and the thyrotropin-releasing hormone (TRH) stimulation test has been recommended for diagnosis of early or mild cases. However, it is currently not recommended for year-round use due to marked seasonal variability. The aims of this cohort study were to evaluate effects of month and season on adrenocorticotropic hormone (ACTH) responses to TRH stimulation and to derive monthly cut-offs for PPID d...
Ward AB, Harris PA, Argo CM, Watson CA, Burns NM, Neacsu M, Russell WR, Grove-White D, Morrison PK.Native ponies are at increased risk of obesity and metabolic perturbations, such as insulin dysregulation (ID), a key risk factor for endocrinopathic laminitis. Management and feeding practices can be adapted to maintain healthy body condition and support metabolic health, but owners may inadvertently provide their ponies with inappropriate management leading to obesity and exacerbating risk of metabolic disease. Adoption of preventative weight management approaches (WMAs), including regular monitoring of body condition, providing appropriate preserved forage, promoting seasonal weight loss, a...
Kawanishi N, Kinoshita Y, Kambayashi Y, Bannai H, Tsujimura K, Yamanaka T, Cullinane A, Nemoto M.Equine influenza virus (EIV) infection is one of the most important respiratory diseases in the equine industry around the world. Rapid diagnosis, facilitated by point-of-care testing, is essential to implement movement restrictions and control disease outbreaks. This study evaluated a microfluidic immunofluorescence assay kit, which detects influenza virus and SARS-CoV-2 antigens in human specimens with a 12 min turnaround time, for its potential use in detecting EIV. The microfluidic immunofluorescence assay kit succeeded in detecting 11 EIV strains. Using the real-time reverse transcription...
Kinoshita Y, Niwa H, Uchida-Fujii E, Ueno T. is the predominant equine sp. isolated from clinically normal horses and is suspected to be associated with inflammatory airway disease in which cough is the primary sign. Quantitative evaluation of bacterial counts is useful in assessing the association between the bacteria in samples and observed clinical signs, but this evaluation has been difficult with conventional culture methods of given the need for pre-enrichment using liquid cultures. We established a quantitative real-time PCR (qPCR) assay for the quantification of , targeting the hypothetical protein FJM08_00025. We confirmed it...
Rakowska A, Czopowicz M, Bereznowski A, Witkowski L.Rhodococcus equi is a widely recognized bacterium responsible for pneumonia in preweaned foals. On endemic farms, foals with a subclinical course of the disease usually outnumber those presenting clinical signs. The disease is typically chronic and mainly manifests as fever and dyspnoea. Currently, field diagnosis is often based on lung ultrasound (LUS); however, both diagnostic and therapeutic approaches vary among practitioners and considerably change over time. This longitudinal, prospective study was designed to describe the appearance and progression of rhodococcal pulmonary lesions durin...
Jodzio D, DeNotta S, Plummer C, Sanchez C.Pain recognition in hospitalized horses is challenging, and the utility of pain scoring systems in horses with ocular disease has not been well-described. Objective: Evaluate the horse grimace scale (HGS) and behavior pain score (BPS) in hospitalized horses with ocular disease. We hypothesized that HGS and BPS would be associated with different clinical progressions. Methods: Privately owned horses hospitalized for ocular disease between September 2018 and September 2020. Methods: Retrospective observational study. The HGS and BPS were recorded daily throughout hospitalization. Clinical progre...
Drozdzewska K, Winter J, Barton AK, Merle R, Gehlen H.The basal (bACTH) and post-thyrotropin-releasing hormone stimulation concentration of adrenocorticotropin (pACTH) are recommended for diagnosis of pituitary pars intermedia dysfunction (PPID). Many factors influence bACTH (e.g., disease, age, month) and some affect the results only in autumn (e.g., breed, colour, sex). There are discrepancies about the impact of feeding on b/pACTH. Objective: To determine whether feeding, month, age, breed, colour, sex and body condition score affect b/pACTH. Methods: Prospective crossover. Methods: Sixty-one animals were divided into groups: healthy, PPID, tr...
Kashani-Carver A, O'Halloran C, Scurrell E, Featherstone H, de Freitas FF, Lowe R.Only 27 cases of equine conjunctival haemangiosarcoma have been reported in the literature over the past 37 years. Out of these, 22% of cases were lost to follow-up, 52% were euthanized, and 26% survived. A scarcity of cases and information is available for this rarely seen conjunctival tumour. Unassigned: To describe the clinical features, management, and outcome of conjunctival hemangiosarcoma in seven horses in the UK. Unassigned: Optivet medical records were reviewed for equine cases seen or advised on with a histopathological diagnosis of conjunctival haemangiosarcoma between January 2013...
Sant C, Lima DM, d'Abadie R, Pargass I, Georges KC.This study aimed to develop a sound database for the hematological reference intervals of thoroughbred foals in Trinidad, West Indies from birth to 1 month of age. Methods: 89 foals. Methods: Whole blood samples were taken from 89 foals throughout Trinidad at approximately 1 day, 1 week, and 1 month of age. These foals were examined to be classified as healthy or free from disease. Complete blood count (CBC), microscopic analysis of blood smears, and conventional PCR for Theileria equi and Babesia caballi were performed. Results: Of the 89 foals, 67 were deemed healthy and suitable for establi...
Leleu C, Couroucé A.Equine squamous gastric disease (ESGD), as part of the equine gastric ulcer syndrome (EGUS), are common in racing horses. The use of buffering feed supplements to treat and/or prevent gastric ulcers is an option to control this condition. Objective: The purpose of this study was to evaluate the effect of a 30-day supplementation with a blend of magnesium oxide (MgO) on ESGD scores in trotters under training. Methods: Forty-two young trotters were submitted to a gastroscopic evaluation to assess their ESGD score and were randomly assigned in a group supplemented with MgO or in a control group. ...
Emelogu U, Lewin AC, Balasuriya UBR, Liu CC, Wilkes RP, Zhang J, Mills EP, Carter RT.Equid alphaherpesvirus 1 (EHV-1) is a global viral pathogen of domestic equids which causes reproductive, respiratory and neurological disease. Few isolates acquired from naturally infected USA-based hosts have been fully sequenced and analyzed to date. An ORF 30 (DNA polymerase) variant (A2254G) has previously been associated with neurological disease in host animals. The purpose of this study was to perform phylogenomic analysis of EHV-1 isolates acquired from USA-based hosts and compare these isolates to previously sequenced global isolates. EHV-1 was isolated from 23 naturally infected USA...
Gruber N, Gesell-May S, Scholler D, Zablotski Y, May A.Equine colic is an important condition associated with acute abdominal pain and one of the leading causes of death in horses. As such, objectively evaluating pain is of interest for attending veterinarians. Pain scales for assessment are present, but no single pain-specific biomarker has been reported. The aim of this study was to determine if substance P (SP) could be a reliable biomarker to reflect pain and serve as a parameter to predict outcome in equine colic. The hypothesis was that horses displaying severe colic signs present with higher values of SP in contrast to those with mild colic...
Tinsley T, Fogle C, Means E, Robertston J.Dental disease is a common condition affecting horses. Its prevalence and characteristics among most of the common breeds of horses and donkeys have been investigated and described in the literature, but information about the prevalence and etiology of dental disease of miniature horses is sparse. Unassigned: To determine the prevalence and characteristics of dental disease of miniature horses, we performed oral and dental radiographic examinations on 100 miniature horses. The findings of these examinations were analyzed to determine the prevalence of dental disease and its correlation to age,...
Virtanen J, Hautala K, Utriainen M, Dutra L, Eskola K, Airas N, Uusitalo R, Ahvenainen E, Smura T, Sironen T, Vapalahti O, Kant R, Virtala AK....Parapoxviruses (PPV) cause skin and mucous membrane lesions in several animal species, and of the five recognized PPVs, at least three are zoonotic. Equine PPV (EqPPV) is the sixth one initially described in humans in the United States and later in a severely sick horse in Finland in 2013-2015. In 2021-2022, a large-scale pustulo-vesicular pastern dermatitis outbreak occurred in horses all over Finland. This study aimed at analysing the outbreak, identifying and describing the causative agent, describing clinical signs, and searching for risk factors. EqPPV was identified as a probable causati...
van Spijk JN, Lo HC, Merle R, Richter IG, Diemar A, Stoeckle SD, Gehlen H.Matrix metalloproteinase-9 is increased in renal tissue in human kidney disease, but its role as a biomarker for kidney disease has not been fully evaluated yet. The aim of this study was to evaluate serum MMP-9 (sMMP-9) and urinary MMP-9 (uMMP-9) concentrations in dehydrated horses. Dehydrated horses were prospectively included. Blood and urinary samples were taken at admission, and after 12, 24, and 48 h (t0, t12, t24, t48), an anti-equine MMP-9 sandwich ELISA was used. Four healthy horses served as the controls. Serum creatinine, urea, symmetric dimethylarginine (SDMA), urine-specific gravi...
Wood MK, Mason RM, Burk SV, Birmingham SSW.The goal of this study was to determine whether oral administration of α-casozepine (Zylkene) supplementation decreases the risk of disease in foals, as measured through salivary cortisol levels, temperature, clinical signs of disease, and body weight before and after weaning. Methods: 20 Thoroughbred foals were observed over 10 weeks, beginning 14 days prior to the time of weaning. Methods: Experimental foals were randomly selected and given α-casozepine daily for 10 weeks, while the controls received a placebo with the same frequency as the experimental group. The average daily height and ...
Kvigstad EF, Øverland IK, Skedsmo FS, Jäderlund KH, Gröndahl G, Hanche-Olsen S, Gunnes G.Over the past 25 years, acquired equine polyneuropathy (AEP) has emerged as a neurological disease in Scandinavian horses. This condition is characterized by histopathological features including the presence of Schwann cell (SC) inclusions. Cultivated equine SCs would serve as a valuable resource for investigations of factors triggering this Schwannopathy. Ideally, cells should be sampled for cultivation from fresh nerves immediately after death of the animal, however the availability of fresh material is limited, due to the inconsistent case load and the inherent technical and practical chall...
Ruff JH, Tufts S, Robertson J, Horne C, Schnabel LV, Jacobs C.To compare palpation and ultrasound scores of effusion of the medial femorotibial and femoropatellar joints of horses. Methods: 40 horses (80 stifles) were evaluated over a 12-week period. Methods: Horses > 1 year of age without history of stifle disease were enrolled from September to December 2022. Palpation of right and left medial femorotibial and femoropatellar joint compartments was performed. Amount of effusion was scored by a board-certified large animal surgeon, a third-year large animal surgery resident, and an equine sports medicine intern. Effusion of right and left medial femoroti...
Sauer FJ, Hellige M, Beineke A, Geburek F.Few case reports describe equine coxofemoral joint osteoarthritis (CFJOA). Objective: To evaluate diagnostic findings and outcome of horses with CFJOA and to provide a score facilitating radiographic assessment. Methods: Retrospective case series. Methods: History, clinical signs, ultrasonographic, radiographic and intra-articular anaesthesia findings, treatments, outcome, and necropsy results of horses with CFJOA presented between 2002 and 2023 were collated. Radiographic findings were categorised to develop a radiographic score which was applied by two masked examiners. Intra- and inter-obse...
Ferlini Agne G, Kapusniak AE, Wooldridge AA, Jung SW.In this case report, a high dose of torsemide (6mg/kg, every 12 hours for 3 days followed by 12mg/kg, every 12 hours for 4 days) was administered orally to a horse with congestive heart failure (CHF) and atrial fibrillation. Blood samples for measurement of plasma torsemide concentrations were obtained one hour after each drug administration. Pharmacodynamic effects of oral torsemide were evaluated by daily physical examination, electrocardiography, and serum biochemistry. The horse tolerated administration of torsemide. A decrease in ventral oedema and venous congestion was subjectively noted...
Cattaneo A, Guandalini A, Peruccio C.This retrospective study evaluated tear film (TF) interferometry on horses examined in Northern Italy in 2019-2021. The objectives were to evaluate horses affected by keratitis, and to describe TF values in horses with no evidence of ocular disease. All horses received a complete ophthalmic examination and were examined with the Ocular Surface Analyser, Veterinary-setting, prior to eye manipulation, staining and sample collection. Eighteen horses with no evidence of ocular disease were included in the comparison group. Additionally, 46 horses displaying signs of keratitis (neovascularization, ...
Fuss FK.The horse's navicular bone is located inside the hoof between the deep flexor tendon (DDFT) and the middle and end phalanges. The aim of this study was to calculate the stress distribution across the articular surface of the navicular bone and to investigate how morphological variations of the navicular bone affect the joint forces and stress distribution. Joint forces normalised to the DDFT force were calculated from force and moment equilibria from morphological parameters determined on mediolateral radiographs. The stress distribution on the articular surface was determined from the moment ...
Menzies-Gow NJ, Shurlock T.Feedstuffs are often recommended to mitigate potential damage from acid associated with equine squamous gastric disease (ESGD). In acidic conditions, pectin alters its structure to one like mucus and binds the stomach mucosa, whilst alfalfa has a strong intrinsic acid buffering capacity. The study aimed to determine whether feeding a commercial beet pulp/alfalfa/oat fibre mix aids ESGD healing and/or prevention of recurrence. Ten adult horses with naturally occurring ESGD were included. All animals were treated with omeprazole as per the attending veterinarian's recommendation and randomly all...
Larsen EA, Williams MR, Schoonover MJ, Jurek KA, Young JM, Duddy HR.Navicular syndrome is a common cause of forelimb lameness in horses. Beyond changes to the navicular bone itself, horses with a clinical diagnosis of navicular syndrome often have pathology associated with other components of the navicular apparatus, including the navicular bursa, deep digital flexor (DDF) tendon, collateral sesamoidean ligaments, and impar ligament. Palmar digital neurectomy (PDN) is often used as a salvage procedure for horses diagnosed with navicular syndrome that become unresponsive to medical management. There are many potential complications associated with PDN, some of ...
