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.
Riebold TW.In conclusion, monitoring the depth of anesthesia plays an integral role in the anesthetic regimen. Although the use of sophisticated monitoring equipment has replaced some of the art of anesthesia and made assessment of depth of anesthesia more precise, a vigilant clinician still needs to serve as the animal's advocate. He or she must gather the data that are generated by machines, acquire data that monitoring equipment cannot obtain, assimilate all the facts, and make appropriate changes in anesthetic management.
Tessier GJ, Traynor TR, Kannan MS, O'Grady SM.Equine tracheal epithelium, stripped of serosal muscle, mounted in Ussing chambers, and bathed in plasmalike Ringer solution generates a serosa-positive transepithelial potential of 10-22 mV and a short-circuit current (Isc) of 70-200 microA/cm2. Mucosal amiloride (10 microM) causes a 40-60% decrease in Isc and inhibits the net transepithelial Na flux by 95%. Substitution of Cl with gluconate resulted in a 30% decrease in basal Isc. Bicarbonate substitution with 20 mM N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid decreased the Isc by 21%. The Cl-dependent Isc was inhibited by serosal add...
Payne RC, Sukanto IP, Graydon R, Saroso H, Jusuf SH.During an outbreak of trypanosomiasis in cattle, buffalo and horses on the island of Madura, a survey was conducted to determine the prevalence of Trypanosoma evansi in the region. Blood samples were collected from 130 cattle and 147 buffalo in 5 villages, whole blood was examined for trypanosomes by the microhaematocrit (MHCT) method and serum samples were subjected to an enzyme linked immuno absorbent assay to detect T. evansi antibodies. T. evansi was detected by MHCT in 50% of the buffalo examined and 13% of the cattle, while antibodies were detected in 47% of the buffalo and 30% of the ca...
Saman E, Breugelmans K, Heyndrickx L, Merregaert J.The genome of equine infectious anemia virus (EIAV) contains several small open reading frames (ORFs), the importance of which in the development of the virus is not clear. We investigated the possibility that the largest of these ORFs (ORF S3) is expressed during the course of the viral infection. The ORF S3 information was expressed in Escherichia coli, and the antigen was used to raise monospecific antiserum. A 20-kDa protein expressed in cells producing EIAV was identified as the gene product of ORF S3. Furthermore, sera from EIAV-infected animals specifically recognized this protein, indi...
Wagner AE, Bednarski RM, Muir WW.The hemodynamic effects of high arterial carbon dioxide pressure (PaCO2) during anesthesia in horses were studied. Eight horses were anesthetized with xylazine, guaifenesin, and thiamylal, and were maintained with halothane in oxygen (end-tidal halothane concentration = 1.15%). Baseline data were collected while the horses were breathing spontaneously; then the horses were subjected to intermittent positive-pressure ventilation, and data were collected during normocapnia (PaCO2, 35 to 45 mm of Hg), moderate hypercapnia (PaCO2, 60 to 70 mm of Hg), and severe hypercapnia (PaCO2, 75 to 85 mm of H...
Alexander CS, Keller H.Over 130 cases of equine periodic ophthalmia (p.o.), which were treated as in-patients at the Equine Clinic of the Free University of Berlin in the last 35 years, were examined statistically in relation to the age and gender of the animals involved as well as to the development of the illness and the season in which it arose. As regards aetiology, the extraction of 71 affected Trotters was investigated. Antibodies to toxoplasmosis, leptospirosis and intestinal parasites were found only in some of the patients. Younger animals, aged between one and four years, and male animals (63.6%) were pred...
Kempson SA.Farrier's Formula feed supplement was added to the diet of 18 horses with two types of hoof horn defects. The first group of horses showed sand cracks and crumbling horn around the nail holes; the second group suffered frequent bruising and had flat feet with collapsed heels. Hoof clippings from both groups were studied in the transmission and scanning electron microscopes. All the horses showed a progressive improvement in the gross and microscopic structure of the hoof horn, starting six weeks after the supplementation began. Once good quality hoof horn had grown there was no relapse during ...
Abrahamsen EJ, Bohanon TC, Bednarski RM, Hubbell JA, Muir WW.An 8-year-old Quarter Horse gelding was anesthetized for surgical exploration and debridement of a chronic draining wound in the intermandibular space. Anesthesia was without complication other than persistently low PaO2. Severe airway obstruction was evident immediately after extubation, requiring tracheostomy. Endoscopic diagnosis was bilateral arytenoid paralysis, which gradually resolved over the next 7 days. Compression, trauma, or tension of the recurrent laryngeal nerves are the postulated causes of idiopathic laryngeal hemiplegia in horses. The extremely extended position of the head a...
Rikihisa Y, Reed SM, Sams RA, Gordon JC, Pretzman CI.In August 1986, an extensive serosurvey for prevalence of IgG and IgM antibodies against Ehrlichia risticii, the causative agent of equine monocytic ehrlichiosis (EME), was performed at 2 Ohio racetracks, River Downs (RD) and Beulah Park (BP). Of 840 horses at RD and 574 at BP, 13 and 20%, respectively, were IgG antibody-positive (by indirect fluorescent antibody test results), with antibody titer ranging from 1:20 to 1:10,240. The titer observed at highest frequency at both racetracks was 1:80. A higher proportion of horses was ill at RD (operating during the summer months) than at BP (winter...
Gaughan EM, Hackett RP.Over a 10-year period, cecocolic intussusception was diagnosed in 11 of 842 horses undergoing surgical treatment for colic at the New York State College of Veterinary Medicine. Eight horses died or were euthanatized because of poor prognosis determined at surgery or because of postoperative complications. Three horses recovered without complication after manual reduction of the intussusception and partial typhlectomy, using an intestinal stapling device.
Harris PA.An outbreak of muscle stiffness and poor performance among 59 thoroughbreds at a Newmarket flat racing yard was investigated between the beginning of May and the end of June 1986. Over a third of the horses showed signs of muscular stiffness, and 38 had, at one or more of the sampling times, creatine kinase (CK) activities above 200 iu/litre and, or, aspartate aminotransferase (AST) activities above 300 iu/litre when they were sampled six to eight hours after exercise. The following season, at a similar time and stage of training, only four of 39 horses sampled had CK activities between 200 an...
Steffey EP, Woliner MJ, Dunlop C.Circulatory and respiratory effects of five h of constant 1.06 per cent alveolar halothane in oxygen were identified in eight healthy horses, which breathed spontaneously, were otherwise unmedicated and positioned in sternal recumbency. Only a few important significant (P less than 0.05) changes occurred with time. Total peripheral resistance was about 15 per cent lower after two hours of constant dose halothane than after 30 mins of constant dose (P less than 0.05) and accounted for the significant 10 per cent reduction in mean carotid arterial blood pressure. By 5 h, the reduction in resista...
Pemberton AD, Hodgson JC, Gilmour JS, Doxey DL.Isolates were prepared from the sera of 12 horses with acute grass sickness, using methods reported to yield serum fractions associated with neurotoxicity, and their components identified by liquid chromatography and spectroscopy. All isolates were found to contain cortisol and six isolates also contained a degradation product of an analgesic drug, dipyrone. However, no recognised neurotoxin was detected.
Pycock JF, Allen WE.Exudate and uterine flushings were collected at either 30, 60, 120 or 240 mins after intrauterine infusions of Streptococcus zooepidemicus in genitally normal mares during oestrus. Uteri were also flushed without prior induction of endometritis. Protein concentrations in exudate and flushings increased with time and exudate pH decreased with time; the pH of flushings did not alter. Lysozyme and lactate dehydrogenase were present in flushings from non-infected uteri, but concentrations increased with time after infection. Immunoreactive prostaglandin E2 was undetectable before infection, but co...
Snyder JR, Pascoe JR, Olander HJ, Hinds DM, Young R, Tyler WS.Ten horses were euthanatized before, during, or after surgery to correct severe volvulus of the large colon. At surgery, the colonic serosa changed from blue-gray, blue or purple toward a more normal pink in seven horses after the volvulus was corrected. The mucosa consistently remained black or dark red. Results of postmortem colonic microangiography revealed perfusion of the serosa and the circular and longitudinal muscle layers, but mucosal perfusion was limited by thrombosis in the muscularis mucosae and submucosa. There was evidence of thrombosis of the mesenteric colic vessels in six hor...
Orsini JA, Buonanno AM, Richardson DW, Nunamaker DN.A Salter-Harris type-II fracture of the distal portion of the femur in a 1-year-old Pony of America was repaired by use of lateral plating combined with interfragmentary compression. The configuration of the fracture and the method of internal fixation with a condylar buttress plate were unique and resulted in primary bone healing, seen at the 5-month follow-up examination.
Racklyeft DJ.Transtracheal aspirate (TTA) aerobic microbiology culture results from 30 ponies were compared to protected catheter brush (PCB) culture results obtained from the same ponies. The PCB procedure resulted in significantly fewer (13<0.05) isolates than those obtained by the TTA procedure and the PCB procedure resulted in significantly more samples with no bacteria growth than the TTA procedure. To address the possibility that the volume of tracheobronchial secretion obtained by PCB was insufficient as a microbiological sample, a sterile, double-sheathed, protected aspiration catheter (PAC) was de...
Vörös K, Holmes JR, Gibbs C.This study was performed on 15 horses to validate the cardiac anatomy as imaged with two dimensional echocardiography (2DE) and to determine the accuracy of intracardiac measurements. 2DE images were recorded in five horses in life with a Diasonics DRF100 ultrasound system and a 3.5 MHz transducer in different tomographic planes. After slaughter, the hearts were fixed in 10 per cent formalin. To compare in vivo and in vitro results, the specimens were suspended in a water-filled tank and 2DE images were made using the same transducer positions as in life. In vitro 2DE and autopsy measurements ...
Heinrichs M, Baumgärtner W, Capen CC.Adenomas of the pars intermedia from 19 horses and normal pituitary glands from seven horses were evaluated histologically and immunocytochemically for adrenocorticotropic hormone (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), beta-endorphin (beta-END), proopiomelanocortin (POMC), prolactin, neuron specific enolase, and glial fibrillary acidic protein (GFAP). The 26 horses ranged in age from 7 to 31 years. Histologically, all adenomas had a uniform pattern characterized by cords of large columnar cells forming palisades and pseudoacini separated by a delicate fibrovascular stroma. I...
Mayhew IG, Washbourne JR.Brainstem auditory evoked potential (BAEP) waveforms were recorded as a means of objectively evaluating auditory and brainstem function in horses. BAEP recordings were readily and repeatably recorded from horses, under minimal restraint, using signal averaging equipment. Clearly identified BAEP waveforms were obtained with compression clicks of 30-100 dB (HHL) at 10 Hz applied in the external auditory meatus of one ear and masking white noise (10 dB lower) in the other ear. Vertex positive (upwards) waveforms I through V were obtained with an active, subdermal electrode over the ipsilateral an...
Käsbohrer A, Schönberg A.The prevalence of B. burgdorferi, the causative agent of Lyme Borreliosis in humans, was determined in domestic animals living in Berlin. 189 dogs, 29 cats, 224 horses and 194 cows were investigated. Using the indirect immunofluorescence test (IFT) 5.8% of the dogs and 24.5% of the cows investigated showed a positive reaction at titres of 1:128 or higher. Horses and cats gave negative results. ELISA was more sensitive than IFT. 10.1% of the dogs, 16.1% of the horses and 66% of the local cows showed positive reaction. Domestic animals seem to be in contact with B. burgdorferi and can be a reser...
Sirois J, Kimmich TL, Fortune JE.Ovulation in mares is preceded by a long and variable estrous period. The differentiation of equine preovulatory follicles with respect to steroidogenic capacity and responsiveness to equine gonadotropins was studied by culturing pieces of follicle wall (FW = theca + attached granulosa cells) from preovulatory follicles isolated during late diestrus (day 14 of cycle, n = 5 mares), early estrus (1st-2nd day of estrus, n = 6) or late estrus (4th or 5th day of estrus, n = 6). FW was cultured with or without equine LH, FSH, LH + FSH, or CG (10 or 100 ng/ml) and medium was collected and replaced at...
Mogg TD, Pollitt CC, Willmore JP, Thompson H.Three groups of horses and ponies (N = 13, 13 and 12) were treated with ivermectin paste (0.2 mg/kg p.o.), avermectin B1 solution (0.2 mg/kg p.o.), or fenbendazole suspension (10 mg/kg via nasogastric tube). The avermectin B1 was a 1% solution in a propylene glycolglycerol formal base. Faecal strongyle egg counts were performed before, and 14, 28, 42, 56 and 70 d, after treatment. Full-thickness skin biopsies from the neck, pectoral and umbilical regions were examined for Onchocera microfilaria before treatment, and again 14 and 70 d later. Ivermectin therapy produced a significant (P less tha...
Woods J, Bergfelt DR, Ginther OJ.The effects of pre-ovulatory and post ovulatory insemination on pregnancy rate and embryonic-loss rate were studied in 268 mares in two experiments. Within each experiment mares were randomised within replicates as follows: to be inseminated on the day the pre-ovulatory follicle reached 35 mm (pre-ovulatory group), to be inseminated on the day of ovulation (Day 0 group), and to be inseminated on the day after ovulation (Day 1 group). Ultrasonic pregnancy diagnoses were performed on Days 11, 12, 13 and 14 (Experiment 1) and Days 11, 12, 13, 14, 15, 20 and 40 (Experiment 2). Combined for the two...
Arden WA, Slocombe RF, Stick JA, Parks AH.Morphologic changes in equine jejunal segments subjected to 1 hour of ischemia and 1 hour of reperfusion, and protective effects of systemic administration of dimethyl sulfoxide (DMSO; 1 g/kg of body weight) were investigated in 18 ponies, using light microscopy and scanning and transmission electron microscopy. Ponies were allotted to 4 groups: group 1--control (n = 3); group 2--DMSO (n = 3); group 3--ischemia (n = 6); and group 4--ischemia and DMSO (n = 6). In each pony, 2 jejunal sections were evaluated. The first section was obtained prior to induction of ischemia, and the second was obtai...
Carter SW, Robertson SA, Steel CJ, Jourdenais DA.Six healthy foals underwent instrumentation for measurement of the cardiopulmonary effects of sedation with 1.1 mg/kg bodyweight xylazine hydrochloride given intravenously. Responses to xylazine in foals at 10 and 28 days of age were not significantly different. Foals became sedate and markedly ataxic, and four of the six foals became recumbent. Heart rate decreased significantly but no arrhythmias were detected. Arterial blood pressure increased initially and then fell significantly below pre-injection values. Changes in respiratory airflow, upper airway obstruction and respiratory noise were...
Bohanon TC, Beard WL, Robertson JT.Case records of 27 draft horses with laryngeal hemiplegia were reviewed. Twenty-one horses were treated by ventriculectomy with or without prosthetic laryngoplasty, and 17 owners were contacted to determine the results. Fifteen horses improved after surgery and were able to perform to the owners' expectations. Performance improved significantly and hospitalization was shorter after ventriculectomy alone. Results of this study indicate that the clinical signs of exercise intolerance and excessive inspiratory noise associated with left laryngeal hemiplegia in draft horses can be treated successf...
Soma LR, Stefonovski D, Robinson MA, Tsang DS, Haughan J, Boston RC.A retrospective study was conducted to establish the prerace venous acid-base and blood gas values of Standardbred horses at rest using big data analytics. Methods: Venous blood samples (73,382) were collected during seven racing seasons from 3 regional tracks in the Commonwealth of Pennsylvania. Horses were detained 2 hours prior to race time. Methods: A mixed-effects linear regression model was used for estimating the marginal model adjusted mean (marginal mean) for all major outcomes. The interaction between age and gender, track, and the interaction between month, treatment (furosemide), a...
Constant SB, Larsen RE, Asbury AC, Buoen LC, Mayo M.A bilateral cryptorchid stallion with mild development of mammary glands was identified as an XX male by karyotyping. Necropsy revealed underdeveloped accessory sex organs and hypoplastic, inguinally located testes that were deficient of spermatogonia. Evaluation of routine hormonal profiles (without karyotyping) would have failed to diagnose this syndrome.
Davis W, Caniglia CJ, Lustgarten M, Blackwelder T, Robertson I, Redding WR.Lateral digital flexor tendonitis is a rarely reported cause of hind limb lameness in performance horses. The purpose of this retrospective study was to describe clinical and diagnostic imaging findings for a group of horses with lateral digital flexor tendinitis within the tarsal sheath. Equine cases with a diagnosis of lateral digital flexor tendonitis and magnetic resonance imaging (MRI) studies of the affected region were retrieved from North Carolina University’s medical record database. Recorded data for included horses were signalment; findings from history, physical examination, lame...
Nassar M.The present longitudinal study ascertained training-associated transformations in the neural underpinnings of diagnostic reasoning, using a simulation game named "Equine Virtual Farm" (EVF). Twenty participants underwent structural, EVF/task-based and resting-state MRI and diffusion tensor imaging (DTI) before and after completing their training on diagnosing simulated veterinary cases. Comparing playing veterinarian versus seeing a colorful image across training sessions revealed the transition of brain activity from scientific creativity regions pre-training (left middle frontal and temporal...
Lindner A, Will Y, Chrispeels J.Reference values for Cortisol, T4 and T-Uptake, determined with the Fluorescence-Polarization-Immunoassays (FPIAs) in blood-plasma of different horse groups were established. The highest Cortisol values were measured in blood samples from thoroughbred racehorses and riding horses taken between 7 and 8 a.m. (181 +/- 37 and 268 +/- 43 nmol/l), the lowest gained between 5 and 6 p.m. (69 +/- 45 and 85 +/- 32 nmol/l respectively). Peak values for T4 in riding horses were found in blood samples collected between 1 and 2 p.m. (28.2 +/- 5.7 nmol/l) followed by the samples taken at 5-6 p.m. and 7-8 a.m...
Brown MP, Gronwall RR, Cook LK, Houston AE.Ormetoprim (OMP)/sulphadimethoxine (SDM) combinations
have been used in the treatment of fowl cholera, colibacillosis,
salmonellosis, infectious coryza, and other bacterial infections in
poultry (Mitrovic et al. 1969; Maestrone et al. 1979). The drug
combination has also been used in the treatment of colibacillosis
in neonatal pigs (Brandt and Maestrone 1980) and Pasteurella
pneumonia in cattle (Ames et al. 1987). Serum concentrations and
pharmacokinetics of SDM (Oh-Ishi and Nakajima 1964; Durr et
al. 1980) and OMP/SDM (Brown et al. 1989) after intravenous or
oral administration to ad...
Caudron I, Grulke S, Farnir F, Aupaix R, Serteyn D.This study is part of a work to develop a radiographic method that defines objectively the individual conformation of an equine digit and its appropriate trimming. The authors used isolated distal limbs on a rotation support to study the influence of induced foot rotations on several angles measured from specific radiographs. The results of this work enabled the authors to quantify the rotation of the proximal phalanx compared to the distal, and to determine exactly the possible rotation in the distal interphalangeal joint. It was also observed that, faced with a forced rotation of the foot, t...
Braus BK, Lehenauer B, Tichy A, Nell B, Schwendenwein I.Cytology plays a major role in the diagnosis of ocular surface diseases. Objective: To compare 2 cytological sampling methods for obtaining corneal and conjunctival cell samples regarding irritation for the patient, invasiveness, sample quality and diagnostic equivalence. Methods: Observational prospective study. Methods: In 5 healthy horses, conjunctival and corneal samples were taken bilaterally by impression cytology sampling (ICS) and cytobrush sampling (CBS). Irritation and invasiveness were assessed with an eye irritation and an epithelial damaging score system, respectively. Sample qual...
Cutler TJ.Ophthalmic conditions of the older horse are becoming increasingly common as geriatric care advances. The close relation between the eye and other structures of the head exposes the globe to direct expansion of clinical disease and raises management issues. Integrating an ophthalmic and fundic examination into the annual evaluation should reward the investment, permit enhanced patient care, and potentially provide early identification of systemic conditions. Surgical and medical management of neoplastic conditions is most successful with early identification and therapy. It is hoped that this ...
Dickinson CE, Lori DN.In the absence of debilitating medical problems, the geriatric horse can maintain a normal body condition when provided with an appropriate diet, adequate shelter, and preventive health care that includes regular dental care and deworming. Failures in management can lead to inadequate nutritional support, exposure to adverse environmental conditions, advanced dental disease, parasitism, and failure to detect developing medical problems. All these circumstances can lead to loss of condition and debilitation in the aged horse. Weight loss in the aged horse should be approached with an understand...
Busechian S, Marchesi MC, Vuerich M, Corsalini J, Nannarone S, Arcelli R, Ortolani F, Rueca F, Gialletti R.Ureteral endoscopy is a routine procedure in human medicine, whereas the reports of this procedure on horses are few and far between. The aim of this paper is to describe the endoscopic technique to evaluate the ureters in standing, sedated horses. An endoscopy of the ureters and lower urinary tract was performed using flexible endoscopes on 4 horses, 3 mares and one gelding. The animals were sedated with alpha-2-agonists and an epidural anaesthesia was given. An endoscopy of the ureter in the horse is easy to perform, causes the animal no adverse effects and could provide significant informat...
Shoemaker RW, Wilson DG, Fretz PB.To describe and evaluate a technique involving a dorsal approach for the removal of the nasal septum in adult horses. Methods: Retrospective clinical study. Methods: Four client-owned horses. Methods: Access for partial nasal septum resection was through a dorsal nasal bone flap. Septum resection was performed because of reduced airflow from septal deviation and/or thickening caused by traumatic insult or neoplasia. Preoperative clinical signs and diagnostic results were recorded. Intra- and postoperative complications were noted and follow-up information was obtained from telephone interviews...
Wagner IP, Heymering H.This article attempts to provide a historical perspective regarding equine laminitis. It is designed to cover, as completely as possible, the historical record of, and the research advances made, in regards to acute and chronic laminitis. With respect to the historical record, the names given to this disease, the postulated etiologies, and the various treatment protocols are discussed. This article demonstrates the historical longevity of this disease and establishes a background for the current understanding of the disease's pathologic mechanisms and treatments.
Goncarovs KO, Miskovic Feutz M, Perez-Moreno C, Couetil LL.One proposed nonmedical therapy for recurrent airway obstruction (RAO) in horses is a handheld acoustic device that propels sound waves from the nose down the tracheobronchial tree where it is intended to dislodge mucous and relax bronchospasm, permitting clearance of mucoid secretions. Objective: To evaluate the effectiveness and safety of this device when used as per the manufacturer's recommendations as a treatment for RAO. Methods: Nine adult horses previously diagnosed with RAO. Methods: Prospective, cross-over clinical trial. Horses were exposed to a dusty environment until airway obstru...
Guan F, Uboh CE, Soma LR, Luo Y, Li R, Birks EK, Teleis D, Rudy JA, Tsang DS.Clenbuterol (CBL) is a potent beta(2)-adrenoceptor agonist used for the management of respiratory disorders in the horse. The detection and quantification of CBL can pose a problem due to its potency, the relatively low dose administered to the horse, its slow clearance and low plasma concentrations. Thus, a sensitive method for the quantification and confirmation of CBL in racehorses is required to study its distribution and elimination. A sensitive and fast method was developed for quantification and confirmation of the presence of CBL in equine plasma, urine and tissue samples. The method i...
Lazareva Y, Rayisyan M, Mironova E.Keratitis is a common cause of eye diseases in horses, often resulting in complete loss of vision. The purpose of this article is to study the features of the clinical picture of primary and secondary keratitis in horses, depending on the form of the course of the disease. The study was conducted in 2019 at 22 private horse breeding farms. The study involved 80 horses with keratitis, which were divided into two equal groups depending on the diagnosis of primary or secondary keratitis. The effectiveness of the therapies was compared 1, 3, and 6 months after the start of treatment. Following a 1...