Veterinary medicine for horses encompasses the study and application of medical practices to diagnose, treat, and prevent diseases in equine species. This field involves a comprehensive understanding of equine anatomy, physiology, pathology, and pharmacology. Veterinary practitioners employ a range of diagnostic tools and therapeutic interventions to address health issues in horses, including lameness, gastrointestinal disorders, respiratory conditions, and infectious diseases. Preventative care, such as vaccination and deworming programs, is also a significant aspect of equine veterinary medicine. This page gathers peer-reviewed research studies and scholarly articles that explore various aspects of veterinary medicine as it pertains to horses, including advancements in diagnostic techniques, treatment protocols, and preventive health strategies.
There is a paucity of information regarding the association between common disorders and outcome over time in a large population of ill equine neonates. Objective: To describe the relative frequency of neonatal disorders in a large population of foals admitted to a neonatal intensive care unit, to determine the disorders and factors associated with nonsurvival and determine if the outcome of ill neonatal foals has improved over time. Methods: Retrospective study. Methods: Cases were selected from equine neonatal (≤14 days of age) admissions between 1982 and 2008. Multivariable logistic regre...
To compare ocular structures of Quarter Horses homozygous for hereditary equine regional dermal asthenia (HERDA) with those of Quarter Horses not affected by HERDA (control horses) and to determine the frequency of new corneal ulcers for horses with and without HERDA during a 4-year period. Methods: Cohort study of ocular structures and retrospective case series of horses with and without HERDA. Methods: The cohort portion of the study involved 10 Quarter Horses with HERDA and 10 Quarter Horses without HERDA; the retrospective case series involved 28 horses with HERDA and 291 horses without HE...
To document morphologic changes that occur in equine intestinal serosa after experimentally induced ischemia and subsequent reperfusion (jejunum, ascending colon) or after intraluminal distention and decompression (jejunum). Methods: Morphologic effects of ischemia-reperfusion or intraluminal distention-decompression determined on the serosal layer of the equine jejunum. The large colon serosa was evaluated after ischemia-reperfusion injury. Methods: Seven adult horses. Methods: After induction of general anesthesia and ventral median celiotomy, ischemia was created by arteriovenous (AVO) and ...
This Opinion piece is offered as a cursory overview of sperm development, function, and transport through the eyes of an equine veterinarian. My professional background is predominantly clinical in nature, but my fascination with sperm function and preservation has led to a fairly sizeable review of the scientific literature over the years in hopes of extracting laboratory findings that have application to my daily activities in the clinical arena. Spermatozoa are quite unique among cellular types with regard to both form and function, and represent the only endogenously derived cell type that...
This article provides an overview of initial assessment and management of common emergency presentations in donkeys and mules. The principles are similar to those in horses (and ponies), but clinicians must be aware of differences in recognition of signs of pain/disease, approach to handling, pharmacology of some drugs, and subtle differences in the physiology and local anatomy in donkeys and mules. The epidemiology of common disease presentations will vary between pet/companion or working/farmed donkeys and mules. Regular dental checks, deworming, vaccination, and monitoring of behavior and q...
To determine risk factors for Clostridium piliforme infection in neonatal foals on a Thoroughbred breeding farm in California. Methods: Case-control and retrospective cohort studies. Methods: 322 neonatal Thoroughbred foals either born on the study farm or born elsewhere but traveled to the farm with their dam during the 1998, 1999, and 2000 breeding seasons. Methods: Mare and foal records from 1998, 1999, and 2000 were examined, using case-control design methods to determine variables associated with increased risk of C. piliforme infection in foals. Important risk factors identified in the c...
The objective of this study was to compare effects of butorphanol (BUT) or buprenorphine (BUP), in combination with detomidine and diazepam, on the sedation quality, surgical conditions, and postoperative pain control after cheek tooth extraction in horses, randomly allocated to 2 treatment groups (BUT: = 20; BUP: = 20). A bolus of detomidine (15 μg/kg, IV) was followed by either BUP (7.5 μg/kg, IV) or BUT (0.05 mg/kg, IV). After 20 min, diazepam (0.01 mg/kg, IV) was administered and sedation was maintained with a detomidine IV infusion (20 μg/kg/h), with rate adjusted based on scores to ...
Equine recurrent uveitis serves as a spontaneous model for human autoimmune uveitis. Unpredictable relapses and ongoing inflammation in the eyes of diseased horses as well as in humans lead to destruction of the retina and finally result in blindness. However, the molecular mechanisms leading to inflammation and retinal degeneration are not well understood. An initial screening for differentially regulated proteins in sera of uveitic cases compared to healthy controls revealed an increase of the alternative pathway complement component factor B in ERU cases. To determine the activation status ...
This study was designed to investigate whether horses with clinical signs of back pain due to suspected soft tissue injuries were affected by polysaccharide storage myopathy (PSSM). Diagnosis of PSSM in muscle biopsies obtained from the M. longissimus lumborum of 5 showjumpers and 4 dressage horses with a history of back pain is reported. M. longissimus lumborum biopsies of these horses were characterised histopathologically and in 3/9 cases also by electron microscopy. Observations were compared with M. gluteus biopsies of the same horses, and with M. gluteus biopsies obtained from 6 Standard...
is one of the most pathogenic nematodes affecting equids. Larval migration through the cranial mesenteric artery (CMA) with attendant arteritis and thromboembolism can result in fatal non-strangulating intestinal infarction. Once considered a historical disease, recent studies have described the reemergence of this pathogen in several European countries; however, little is known of the current prevalence of in the Canadian horse population. Unassigned: To determine the prevalence of active cranial mesenteric arteritis in horses submitted for postmortem examination to the Diagnostic Services...
Vesicular stomatitis is an infrequent yet important vesicular disease of cattle, horses, and swine. Periodic outbreaks of this disease in the United States have caused economic losses in cattle herds because of decreased production, movement restrictions, and trade embargoes. Vesicular stomatitis causes clinical signs indistinguishable from those of foot-and-mouth disease. It is of utmost importance that appropriate samples are collected from clinical cases of vesicular disease in cattle and swine so a rapid laboratory diagnosis can be made.
Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 microgram/kg of body weight; and (3) injectable ivermectin at the rate of 300 microgram/kg. All treatments were given IM in the neck. All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decre...
Four horses were evaluated because of hind limb lameness. Two had a distinct gait abnormality at the walk characterized by lateral rotation of the point of the calcaneus and medial rotation of the toe during the stance phase. Nuclear scintigraphy revealed a focal area of intense radioisotope uptake in the caudodistal aspect of the femur in all 4 horses, and 3 of the horses had a corresponding proliferative reaction on the caudodistal cortex of the femur on radiographs. In all 4 horses, a diagnosis of injury to the origin of the gastrocnemius muscle was made. Three of the horses returned to ath...
A clinical evaluation of a new, purified, heat-treated equine rabies immunoglobulin (PHT-Erig), F(ab')2 preparation, was carried out in Thailand and in the Philippines-two countries where rabies is endemic. An initial prospective, randomised, controlled trial (Study 1), compared the safety and pharmacokinetics (serum concentrations of rabies antibodies) after administration either of PHT-Erig or of a commercially-available, equine rabies immune globulin (Erig PMC). A second trial (Study 2) simulated post-exposure rabies prophylaxis by using a reference cell culture vaccine, the purified Vero-c...
Two closed horse herds (Old Lot 4 and Field 24), infected since 1966 with Population B small strongyles resistant to thiabendazole (TBZ) and phenothiazine (PTZ), were terminated in February, March, and May, 2005. At necropsy, only the large endoparasites were identified and counted. The number of horses on pasture was 14 (239 days of age to 23 years old) for Old Lot 4 and two (3 to 20 years old) for Field 24. The time of the last antiparasitic treatment, relative to the year (2005) of necropsy, was 26 years for Old Lot 4 and 9 years for Field 24 horses. Gasterophilus intestinalis third instars...
A 4-month-old Thoroughbred filly presented for abdominal pain was diagnosed with a T-shaped malformation of the ventral colon at exploratory laparotomy. Following resection and anastomosis of the large colon, no further episodes of abdominal pain occurred during a 12-month follow-up. Acute dehiscence of the linea alba occurred as a complication of the initial laparotomy, but was successfully managed following additional surgical repair. T-shaped malformation of the ventral colon has not previously been reported and is considered a congenital malformation of mesocolon formation.
To determine the causes of horse-related injuries in a rural western community. Methods: Prospective identification of persons with horse-related injuries and retrospective interviews with patients or witnesses to determine causes. Methods: A small rural community in Alberta where the western style of riding predominates. Methods: All patients presenting to two family medicine clinics or to the Sundre General Hospital emergency department. Methods: Factors contributing to the injury as recalled by patients or witnesses, and characteristics of the persons, horses, and injuries. Results: Two thi...
Exertional rhabdomyolysis (ER) and its familial basis in Warmblood horses is incompletely understood. Objective: To describe the case details, clinical signs and management of ER-affected Warmblood horses from a family with a high prevalence of ER, to determine if histopathological signs of polysaccharide storage myopathy (PSSM) and the glycogen synthase (GYS1) mutation are associated with ER in this family, and to investigate potential risk factors for development of ER. Methods: A family consisting of a sire with ER and 71 of his descendants was investigated. History of episodes of ER, husba...
The upper respiratory tract is a frequent cause of exercise intolerance in horses, particularly in racing horses. There are a myriad of laryngeal abnormalities that may restrict airflow at the rima glottidis. Careful endoscopic examination is a crucial part of the examination of any racing horse suffering from poor performance. There has recently been interest in spectrum analysis of respiratory sounds. It has been determined that laryngeal hemiplegia and dorsal displacement of the soft palate have unique sound patterns. Therefore, spectrum analysis of respiratory sounds may prove to be useful...
Serum anti-Müllerian hormone (AMH), a marker of equine cryptorchidism, is detectable in intact and cryptorchid stallions but not in geldings because it is secreted from Sertoli cells. A 4-year-old uncastrated Thoroughbred racehorse had no visible testes; therefore, the horse was considered a bilateral cryptorchidism. However, the serum AMH was undetectable (<0.08 ng/ml). Human chorionic gonadotrophin (hCG) stimulating test result indicated that the horse was a gelding. The results of sex chromosomal analysis and sequence analysis of SRY gene suggested that the horse was a genetically-intac...
Equine chronic degenerative endometritis (CDE) is a progressive process characterized by endometrial fibrosis that could be responsible for alterations of uterine environment and foetal-maternal communication. Objective: The aim of this study was to try to restore this communication by intrauterine administrations of amniotic cell-derived extracellular vesicles (AMC-EVs) in a case series. Methods: Twelve mares were selected on the basis of their reproductive history of early embryonic loss or abortion and clinical suspicion of CDE subsequently verified with histopathological examination of end...
Rissi DR, Mendes RE.Squamous cell carcinoma (SCC) is the most common ocular and periocular neoplasm of horses, typically arising from the limbus, third eyelid mucosa or mucocutaneous junctions of the upper and lower eyelids. Tumours are locally invasive, prone to recurrence and may rarely metastasize. Histological evaluation is required for definitive diagnosis and atypical SCC subtypes may be diagnostically challenging. Here we describe a clear cell SCC in the third eyelid of a 16-year-old female Quarter Horse. The red and invasive mass was surgically excised for histological evaluation. The lesion consisted of ...
Whitelock A, Goodwin W, Dryburgh L, Mshelbwala PP, Rae L, Marwedel L, Lok T, Kemp K, Stewart AJ.To describe Australian practices and attitudes regarding equine analgesia. Methods: Cross-sectional anonymous, voluntary survey of Australian veterinarians treating equine patients. Methods: Australian veterinarians in equine or mixed practices completed a six-section, 60-question survey between November 2019 to August 2020. Information was gathered on demographics, analgesia prescription, pain assessment and attitudes surrounding specific analgesics. Respondents assigned a pain score ranging from 0 to 10 for various conditions; these were averaged to give each respondent an "average pain scor...
Dao TTH, Szűts T, Duong NN, Troung DTQ, Solymosi N, Takács N, Hornok S, Farkas R.Equine piroplasmosis, caused by , and , significantly impacts on the veterinary and economic aspects of the global horse industry. However, many countries, including Vietnam, have not yet conducted epidemiological surveys to determine the prevalence of these haemoparasites. This study aimed to detect and/or infections in horses and to identify their genotypes. Blood samples were collected from 154 apparently healthy horses in eight districts of Hanoi, Thai Nguyen, and Son La provinces located in the northern part of the country. Twenty-four horses (15.58%, 95%CI: 10.70–22.14%) were found ...
Motta D, Aymée L, Roussouliéres I, Di Azevedo MIN, Jacob JCF, Lilenbaum W.Leptospirosis is a zoonotic disease caused by spirochetes of the genus Leptospira. Equine genital leptospirosis (EGL) has been described as a chronic and silent syndrome, presenting reproductive alterations such as abortion, stillbirth, placentitis, embryonic loss, repeat breeding syndrome, and subfertility. This study aimed to investigate the genital Leptospira infection in naturally infected mares with poor reproductive performance, as well as to genetically characterize the agents. A total of 41 mares with a history of poor reproductive performance were selected. Sera were collected for ser...
Dos Santos TS, Dillmann JB, Giovelli M, Elias GO, Lima RK, Cescon S, Stainki DR, Dos Santos RC, Corrêa C, Monteiro SG.This study reports the successful use of maggot therapy in four horses with traumatic wounds caused by wire fences, treated in veterinary clinics and under field conditions in southern Brazil. All lesions showed tissue necrosis, purulent discharge, and foul odor, indicating infection and delayed healing. Sterile Lucilia cuprina larvae (L1 stage) were applied directly to the wounds for 48 hours. Rapid improvement was observed, with marked reduction of necrotic tissue, exudate, and odor, and stimulation of granulation tissue in three cases. Complete wound closure occurred between 10 and 60 days ...
Hoogelander B, Frippiat T, Bergman HJ, Vanderperren K, van Veggel ECS.Thoracolumbar congenital abnormalities are considered rare in mature, performing horses. This case report describes a 14-year-old Welsh pony presented with marked epaxial muscle atrophy, mid-thoracic spinal pain, and stiffness, most pronounced during canter. The thoracic spine exhibited scoliosis, centered at T9-T10, and kyphosis. Radiography and postmortem computed tomography revealed complex congenital malformations of the thoracic vertebral column, including abnormal morphology of the T10-T12 vertebral bodies, partial vertebral fusion, a malformed spinous process, a malformed rib with assoc...
Böckmann S, Trzebiatowski L, Georgiev P, Büttner K, Wehrend A.Immunoglobulins ingested via colostrum must remain intact to be absorbed by the neonate. Equine colostrum contains antitrypsin activity, which likely protects these proteins from proteolysis in the gastrointestinal tract. Objective: To quantify antitrypsin activity in equine colostrum and milk, describe its temporal changes during the first five days after parturition, compare actitvity between left and right mammary glands, evaluate differences between nulliparous and pluriparous mares, and examine associations with immunoglobulin G (IgG) concentrations and mare age. Methods: This retrospecti...
Sullivan J, Blea J, McKemie DS, Kass PH, Knych HK.The pharmacokinetics and pharmacodynamics of betamethasone following intra-articular administration to horses have been described; however, studies characterizing intramuscular administration are lacking. Twenty-four horses received an intramuscular dose of 12 mg betamethasone sodium phosphate/betamethasone acetate. Blood and urine were collected at post administration for up to 408 h. Concentrations of betamethasone were determined using LC-MS/MS and pharmacokinetic parameters determined using a Population PK three-compartment model. The duration of pharmacodynamic effects was assessed by...
Kim T, Lee S, Seo JP.Foot diseases are common causes of lameness in horses. Computed tomography (CT) is a valuable tool for diagnosing musculoskeletal lesions in horses and providing a detailed evaluation of foot diseases. Objective: The objective of this study was to establish reference ranges related to the feet of normal Jeju horses by measuring the angles and length of the hoof, and the Hounsfield Unit (HU) value of soft tissues in the foot. Methods: Sixteen normal Jeju horses (mean age: 4.25 years; mean body weight: 282.06 kg) without lameness were examined using CT. After CT scanning, the angles and lengths ...
Satué K, Fazio E, Velasco-Martínez MG, Barbiera G, La Fauci D.Growth hormone (GH) influences follicular development mainly by stimulating insulin-like growth factor 1 (IGF-1), which acts systemically and locally within the ovary. However, the metabolic profile of follicular fluid (FF) in mares, particularly markers such as fructosamine (FRUCT), an indicator of glucose metabolism, remains poorly characterized. This study aimed to evaluate GH, IGF-1, and FRUCT concentrations in plasma and FF and their variation across follicle sizes. Sixty ovaries were collected during the breeding season from 30 clinically normal mares raised for meat production. Blood sa...
Henshall C, McGreevy P, Shea G, Doherty O, Christensen JW, Fenner K, Warren-Smith A, McLean A.The use of horses for sport is under scrutiny due to evidence that common practices such as tight nosebands may impair horse welfare. Restrictive nosebands prevent horses from performing normal comfort behaviour such as coughing and yawning. To address these concerns, the International Society for Equitation Science (ISES) developed a noseband tightness-checking device, the ISES "taper gauge," along with a validated method that assesses how far the device can be inserted beneath the noseband at the dorsal midline of the nasal planum. However, citing concerns about the reliability of dorsal mid...
Eren G, López-Albors O, López Corbalán M, Latorre R.Digital technologies have improved the visualization of anatomical structures for veterinary education and clinical practice. In this study, a detailed three-dimensional anatomical model of the equine palmar metacarpal region was generated using E12-based epoxy sheet plastination combined with digital reconstruction in Amira V5.6 software. Serial cross-sections of the metacarpal region provided high-resolution visualization of bones, tendons, ligaments, nerves, vessels, fasciae, and synovial structures, with minimal shrinkage or deformation, ensuring improved anatomical accuracy. These section...
Nocera I, Cingottini D, Di Franco C, Sala G, Bindi F, Spadari A, Rinnovati R, Vitale V, Jose-Cunilleras E, Sgorbini M.Several studies investigated risk and prognostic parameters for horses with colic; however, the consensus is still debated. The present work aimed to investigate colic outcomes and to identify risk factors in horses referred for colic. In this multicenter retrospective study, 236 clinical records of equids referred for colic at three different equine centers were reviewed. The following data were collected: history, signalment, physical examination at the time of admission, hematological and biochemical analysis, diagnosis, SIRS status and 0-6 point-scale SIRS score, colic type, treatment atte...
Jung Y, Yoon M.Oxytocin (OXT) plays a crucial role in regulating the serotonin (5-HT) system and behavior. Although previous studies have reported significant relationships among OXT, 5-HT, and behavioral responses, the effects of OXT on 5-HT concentrations and behavioral traits in horses remain poorly understood. This study aimed to investigate the effects of intravenous OXT administration on plasma 5-HT concentrations and trainability in horses. A crossover design was employed using eight horses, each receiving either a 10-IU intravenous dose of OXT or normal saline. Blood samples were collected at baselin...
Schmidt S, Swagemakers JH, le Jeune SS.The cervical vertebral column in horses plays a crucial role in movement, posture, and performance and disorders affecting it can cause pain, ataxia, or lameness. This review discusses major acquired (traumatic, infectious, neoplastic) and degenerative (osteoarthritis, foraminal stenosis, intervertebral disc disease) conditions. Acquired lesions often arise from trauma, bacterial infection, or neoplasia, with clinical signs ranging from neck pain to neurologic deficits. Degenerative disorders, particularly osteoarthritis of articular process joints, are common in the caudal cervical spine and ...
Starrett A, Arnold CE, Burr A, Sarturi JO, Leatherwood JL, Pilla R, Awosile BB, Chaffin MK.To quantify gastrointestinal motility at 3 anatomic locations of the large colon in healthy horses fed 2 diets. Unassigned: 12 American Quarter Horses were enrolled in a prospective crossover study. Horses received either a complete pelleted diet fed at 1.35% body weight (BW) per day or Coastal Bermudagrass hay fed at 2% BW with 0.5% to 0.7% BW of complete pelleted feed. Each diet was fed for 13 days prior to motility assessment. Two ultrasonographers recorded the frequency of contractions at the sternal flexure of the large colon, left ventral colon, and cecum for 4 consecutive, 1-minute peri...
Aimonetti E, Genton M, Lischer CJ, Rossignol F.To determine the benefit of using a three-dimensional (3D)-printed titanium aiming device for placing two 5.5-mm transarticular screws during proximal interphalangeal joint (PIPJ) arthrodesis in equine species. Methods: Ex vivo study. Methods: A total of 40 cadaveric forelimbs from adult horses. Methods: A senior surgeon and a first-year resident each performed 20 constructs: 10 using the device and 10 using a freehand technique. Procedure duration and number of intraoperative radiographs were recorded. Final radiographs were evaluated by an ECVS-certified surgeon unaware of treatment group, b...
Teague P, Dark M, Verdugo D, Freeman D, McFarlane D.The equine pancreas remains understudied, particularly in the context of endocrine disease. This study aimed to characterize regional islet distribution and composition in the normal equine pancreas and investigate how hyperinsulinemia (HI) and pituitary pars intermedia dysfunction (PPID) influence pancreatic islet morphology and hormone expression. In the first experiment, pancreas samples from eight healthy horses were collected and analyzed across three anatomical locations: left lobe, body, and right lobe. The left lobe exhibited a greater relative islet area and perimeter compared to the ...
Bramall LM, Hinnigan GJ, Wattam AD, Owen KR.This case report describes the successful hemithyroidectomy of the largest equine solid follicular adenoma described in the veterinary literature to date. A 19-year-old thoroughbred mare was referred to Oakhill Veterinary Centre for the surgical removal of a large, left-sided thyroid gland measuring 26cm in diameter. Pre-operative considerations, the hemithyroidectomy surgical technique as well as the intra- and post-operative complications encountered, are discussed. Following surgery the horse had no long-term complications and continues to thrive four and a half years post-operatively.
Folgmann MS, Stock KF, Feige K, Delling U.Current studies on the health status of young German Warmblood stallions are lacking. Objective: To evaluate the prevalence of radiographic findings at licensing examinations of Warmblood candidate stallions and quantify the environmental influences on the distribution of recorded findings. Methods: In this retrospective observational study, records of 1693 radiographic examinations performed on 1678 German Warmblood stallions presented for licensing in 2018-2020 were reviewed. Data were provided by all German Warmblood horse-breeding associations and their official veterinarians. The collecti...
