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.
Baxi MK, Efstathiou S, Lawrence G, Whalley JM, Slater JD, Field HJ.Neural tissues from specific pathogen-free ponies that had been experimentally infected with equine herpesvirus 1 (EHV-1) were analysed by in situ hybridization. Digoxigenin-labelled EHV-1 BamHI fragments spanning almost the entire EHV-1 genome were hybridized to RNA in tissue sections from latently infected trigeminal ganglia. The BamHI E fragment detected EHV-1 RNA antisense to gene 63 (HSV-1 homologue ICP0) in a small number of neurons. Sixteen other BamHI fragments gave negative results in 20 sections tested with each fragment. Latency associated transcripts (LATs) were localized to the ne...
Chirnside ED, Francis PM, Mumford JA.A series of recombinant fusion proteins derived from equine arteritis virus (EAV) open reading frame (ORF) 7 have been used to define the immunoreactive region of the viral nucleocapsid (N) protein. Reactivities of recombinant N fusion proteins with post-infection equine sera in immunoblots and ELISAs indicate that the major nucleocapsid protein epitope is located within amino acid residues 1-69. In ELISAs two recombinant nucleocapsid fusion proteins containing residues 1-69 (rN1-69) and 1-28 (rN1-28) discriminated between pre- and post-infection, and pre- and post-vaccination serum samples. A...
Kawcak CE, Baxter GM, Getzy DM, Stashak TS, Chapman PL.To measure arterial and venous blood gas, coagulation, and fibrinolysis variables in blood from isolated segments of control and ischemic large colons for the purpose of identifying variables for rapid, indirect assessment of colonic mucosal injury. Methods: Variables were determined at specific intervals during the 4-hour study (3 hours of ischemia and 1 hour of reperfusion). Methods: Seven clinically normal horses between 2 and 15 years old. Methods: Horses underwent laparotomy and occlusion of the lumen and vasculature of the mid-portion of the pelvic flexure of the large colon. During isch...
Den Boon JA, Spaan WJ, Snijder EJ.The expression of the genetic information of equine arteritis virus (EAV), an arterivirus, involves the synthesis of six subgenomic (sg) mRNAs. These are 5' and 3' coterminal since they are composed of a leader and a body sequence, which are identical to the 5' and 3' ends of the genome, respectively. Previously, it has been suggested that cis-splicing of a genome-length precursor RNA is involved in their synthesis. This was reevaluated in a comparative analysis of the sg RNA synthesis of EAV, the coronavirus mouse hepatitis virus (MHV), and the alphavirus Sindbis virus. UV transcription mappi...
Jones JH, Carlson GP.The metabolic power required for sustained exercise in the horse is proportional to running speed. Moderately fast speeds require substantial energy expenditure and result in the generation of a massive metabolic heat load. Quantitative estimates of energy expenditure and heat production of horses at various running speeds were developed using empirically derived data from treadmill studies. Total metabolic power represents the sum of aerobic power indicated by the rate of oxygen consumption and net anaerobic power indicated by the rate of plasma lactate accumulation. These data were applied t...
Ijaz A, Ducharme R.Stallion semen was diluted in five different extenders (dimitro-poulus onze (Dimitro's), Kenney's modified tryode (Kenney's), modified INRA82 (INRA82), egg yolk-citrate-taurine (Citrate) and EZ-Mixin) and evaluated for motility after cooling and storage at 5 degrees C for 0, 24, 48, 72 and 96 h. EZ-Mixin extender was used as control while 70 and 100 mM of taurine were added to Dimitro's, Kenney's and INRA82 to study its effect under conditions of storage at 5 degrees C and varying processing modifications. Motility in INRA82 was 57.0, 58.4, 61.1, and 56.1% after 24, 48, 72 and 96 h, respective...
Hinckley KA, Fearn S, Howard BR, Henderson IW.The present study applies near infrared spectroscopy (NIRS) to the haemodynamics of the pedal circulation in normal and laminitic horses. NIRS is a noninvasive technique which uses changes in light absorption at 4 wavelengths to provide information on the changes in cytochrome aa3 (cyt aa3) reduction-oxidation (redox) status, and changes in the tissue concentration of oxyhaemoglobin (O2Hb), deoxyhaemoglobin (HHb) and therefore total haemoglobin (tHb). Other studies have shown NIRS to be sensitive to changes in tissue oxygenation and perfusion in human cerebral and limb circulation. In this stu...
Allen WR, Mathias S, Lennard SN, Greenwood RE.Rapid enzyme-based immunoassays were used to measure concentrations of oestradiol-17 beta and progesterone in daily blood samples recovered throughout oestrus and for a few days after ovulation from 34 Thoroughbred and 8 pony-type maiden, barren and foaling mares. The first detectable fall in oestradiol-17 beta levels occurred in 88% of the mares within the interval -72 to 0 h with respect to ovulation and in 65% of mares within the interval of -48 to 0 h. The results indicated that serial daily hormone assays of this type could, in a high proportion of animals, predict a correct time for a si...
Frankeny RL, Wilson DA, Messer NT, Campbell-Beggs C.Jejunojejunal intussusception occurred after jejunal resection and stapled functional end-to-end anastomosis in two pony mares. In both mares, the lead point of the intussusception was the stapled functional end-to-end (FEE) anastomosis. The stapled free ends of jejunum were oversewn with an inverting suture pattern. A possible explanation for development of the intussusception was the acute angle created in the intestine by the FEE anastomosis. This angulation may have impaired flow of ingesta causing motility changes that predisposed the site to intussusception. Because the oversewn blind in...
Valdez RA, DiPietro JA, Paul AJ, Lock TF, Hungerford LL, Todd KS.The bioequivalence of Strongid C and generic pyrantel tartrate was determined in a controlled study using 30 horses with naturally acquired endoparasitic infections. Three horses were randomly allocated to each of ten replicates based on quantitative nematode and ascarid egg counts and fecal larvae culture results. Horses within each replicate were randomly assigned to one of three treatment groups. Horses in Treatment Group 1 received only oats; horses in Treatment Group 2 received generic pyrantel tartrate pellets (2.65 mg pyrantel tartrate kg-1) mixed with oats; horses in Treatment Group 3 ...
Eichhorn W, Heilmann M, Kaaden OR.An outbreak of clinical disease with abortions, suspected to be equine viral arteritis in Germany was examined serologically and virologically. Three of five animals tested seroconverted to EAV, and EAV was isolated from an aborted fetus. In view of the significant increase in seropositive horses, the need for control measures is emphasized.
Silva RA, Arosemena NA, Herrera HM, Sahib CA, Ferreira MS.This paper reports an outbreak of trypanosomosis due to Trypanosoma evansi in horses of the Pantanal Mato-grossense region of Brazil. Forty-eight horses died (51% mortality) and abortion in one mare was recorded. The clinical signs observed were fever, anemia, conjunctivitis, edema of the legs and lower parts of the body, progressive weakness, loss of condition, and loss of appetite. The diagnosis was confirmed by morphological and biometrical studies.
Ragle CA, Schneider RK.Eleven mares and four mules were ovariectomized by a ventral abdominal laparoscopic technique. This approach required tilting the operative table about 30 degrees elevating the pelvis to allow observation of the ovaries. A triangulation technique with a single laparoscopic portal and four instrument portals was used. The ovarian pedicles were ligated and the ovaries were removed through a single enlarged instrument portal. Females ranged in age from 5 months to 18 years. Mean operative time was 44 minutes (range 20 to 90 minutes); mean operative time of the last seven animals was 26 minutes. S...
Les CM, Stover SM, Willits NH.Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which...
Palmer JL, Bertone AL, Mansour J, Carter BG, Malemud CJ.The relevance of site and exercise on the biomechanical properties of the articular cartilage from the equine third carpal bone were assessed by creep indentation testing. Six horses were exercised for 30 minutes three times weekly. Another six horses were housed in box stalls and were not exercised. At the conclusion of the study, one third carpal bone from each horse was harvested and the KLM biphasic material properties of cartilage were determined at 12 sites. There was a significant (p < 0.01) effect of site but not exercise on the cartilage aggregate modulus, which was significantly l...
Brinsko SP, Ball BA, Ignotz GG, Thomas PG, Currie WB, Ellington JE.The time of activation of the embryonic genome (maternal-embryonic transition) in equine embryos was investigated by assessing incorporation of 3H-uridine and nucleolar development. In Experiment 1, embryos were recovered from the oviduct (n = 15) and the uterus (n = 3). Recovered embryos were assessed for morphologic development and quality score. Recovered embryos with less than 8 cells (two cells, n = 4; four cells, n = 5; five cells, n = 2) were incubated with 3H-uridine (560 microCi/ml) for 10 hr, while eight-cell embryos (n = 2), morulae (n = 2), and blastocysts (n = 3) were incubated wi...
Bouchard PR, Fortna CH, Rowland PH, Lewis RM.Granular cell tumor (GCT) is a morphologic designation for tumors of varied histogenesis. Most GCTs in human beings are derived from Schwann cells, and rat meningeal GCTs are believed to originate in the neural crest. Three equine pulmonary GCTs from aged horses were studied immunohistochemically with primary antibodies directed against vimentin, cytokeratins (AE1/AE3), S-100, Leu 7, desmin, and neuron-specific enolase (NSE) using a steptavidin-biotin procedure. All three tumors stained similarly with strong and diffuse staining of neoplastic cells for vimentin and S-100 and negative staining ...
Dillon AM, Heath MF.Protein tyrosine phosphorylation (PTP) in thrombin- and platelet-activating factor (PAF)-stimulated equine platelet activation was investigated in the absence and presence of 2 protein tyrosine kinase inhibitors (PTKIs), methyl 2,5-dihydroxycinnamate (MDHC) and genistein. Washed equine platelets aggregated irreversibly in response to thrombin or PAF in an agonist concentration dependent fashion. MDHC produced an MDHC concentration and time dependent inhibitory effect on rate and extent of thrombin- and PAF-induced aggregations, whereas the effect of genistein on the same parameters was only ge...
Gastal EL, Kot K, Ginther OJ.A technique for intrafollicular treatment with a transvaginal ultrasound-guided injection needle was developed using equine chorionic gonadotropin (eCG) as the test substance. An injection was made into one growing follicle of a wave when the follicles were 20 to 23 mm. The treated follicles were injected with 1000 iu of eCG in 0.2 ml saline solution and control follicles were injected with 0.2 ml of the saline vehicle (10 mares per group, 1 follicle per mare). The injection system used an inner 25-gauge needle and an outer 20-gauge needle inserted together through the needle-guide channel of ...
Palfi V, Christensen LS.Twenty-five strains of equine herpesvirus 1 (EHV-1) and one strain of equine herpesvirus 4 (EHV-4) isolated from material from various clinical cases in Denmark, together with reference EHV-1 and EHV-4 strains, were compared by restriction fragment pattern (RFP) analysis and inoculation of baby mice. The RFP analyses revealed that all EHV-1 strains belonged to genome type Ip. Four fetal isolates exhibited genomic characteristics that have been suggested as specific markers of the attenuated strain Rac H, widely used as a live vaccine. As the use of five vaccines against EHV-1 and EHV-4 has nev...
Dixon PM, Railton DI, McGorum BC.Examination of historical and clinical details of 270 adult horses suffering from a variety of mainly chronic pulmonary diseases showed that the chronic obstructive pulmonary disease (COPD) group (median age 9 years) were the oldest, and that the COPD, chronic idiopathic hypoxaemia and exercise induced pulmonary haemorrhage (EIPH) groups had the longest duration of disease (median durations 7, 12 and 9 months, respectively) with a median disease duration of 2 months for the remaining horses. A history of antecedent respiratory infection was present in 24.3% of all horses. Six out of 12 horses ...
Back W, Schamhardt HC, Hartman W, Barneveld A.In literature, it has been hypothesized that the concussion at impact in the equine forelimb is larger than that in the hind limb, and therefore, eventually more clinical lameness may develop in the distal portion of the forelimbs. As the functional anatomy of the distal forelimb and hind limb segments is similar, a study was undertaken to compare the kinematics of hoof and fetlock in the forelimbs and hind limbs. For this purpose, the trot of 24 clinically normal (sound) horses on a treadmill (4 m/s) was recorded, using modern gait analysis equipment. It appeared that vertical hoof velocity a...
Nickels FA, Sande R.The radiographic and arthroscopic findings in the equine stifle were compared. Survey radiography, contrast arthrography, and arthroscopy were performed on both stifles of 10 horses. Nine of the horses were euthanatized to evaluate the effects of the techniques on the joints. Techniques for double-contrast arthrography and arthroscopy were developed, and the findings were compared. Survey radiography identified only osseous structures. Double-contrast arthrography of the femoropatellar joint demonstrated articular surfaces of the trochlea, patella, and joint capsule. Those of the femorotibial ...
Matas Riera M, Donaldson D, Priestnall SL.The aim of this article was to describe Descemet's membrane detachment (DMD) following phacoemulsification in five equine eyes and to review the human literature on this topic. In the last decade, there has been increased reporting of DMD in the human literature, in particular following cataract surgery. The natural history of DMD remains unknown and although various medical and surgical treatments have been advocated there is no recognized 'gold standard' treatment for DMD. This case series reports the diagnosis of DMD in four horses (5 eyes) in association with phacoemulsification surgery. T...
Hallamaa RE.Mitochondrial changes of healing sarcoids were followed in 17 affected horses. Biopsies of this fibroblastic skin tumour were collected both before and during the treatment and tumour regression. The therapy consisted of the partial excision of tumours, repeated immunizations with autogenous polymerized tumour particles and supportive dietary treatment with stannic chloride and folic acid. Presence of transformed, electron-dense mitochondria in different phases of healing was studied by successive biopsy from regressing tumours. Additionally, the relation of these transformed mitochondria to t...
Munsterman AS, Hanson RR.Bullet wounds in horses can cause a wide array of injuries, determined by the type of projectile, the energy of the bullet on entry, and the type of tissue the bullet encounters. Treatment includes identification of all structures involved, debridement of the permanent cavity, and establishing adequate drainage. Bullet wounds should be treated as contaminated, and broad-spectrum antibiotics, including those with an anaerobic spectrum, are indicated. Although musculoskeletal injuries resulting from gunshots are most common in horses, they carry a good prognosis for survival and return to functi...
Millar H.A 6-month-old filly was presented with unilateral epistaxis. Based on clinical signs, endoscopic examination, and postmortem examination, guttural pouch mycosis was diagnosed. The young age of the filly and the fact that this was the 2nd diagnosis of guttural pouch mycosis on this farm was unusual. Mycose de la poche gutturale chez une pouliche de 6 mois. Une pouliche âgée de 6 mois a été présentée pour épistaxis unilatérale. En tenant compte des signes cliniques, de l’examen endoscopique et de l’examen post-mortem, un diagnostic de mycose de la poche gutturale a été posé. Le je...
Asquith RL, Sharp DC.Double monsters are structurally related to monozygotic twins and the reported frequency of these abnormalities in the equine species is low. Symmetrical, double development in both the cephalic region and caudal trunk was demonstrated along with a common undeveloped cervical mass. Anomalies found in the separate genito-urinary systems added another variant to this case.
Marzok M, Kandeel M, Babiker H, Alkhodair KM, Farag A, Ibrahim H, El-Ashker M, Alghuwainem Y, El-Khodery S.The purpose of this study was to provide a systematic meta-analysis on echocardiographic measurements in normal Thoroughbred and Standardbred horses. The current systematic meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). All the available published papers on the reference values of echocardiographic assessment via M-mode echocardiography were searched, and fifteen studies were finally selected for analysis. In both fixed and random effect, the confidence interval (CI) for the interventricular septum (IVS) was 2.8-3.1 and 4.7-7.5; for the ...
Wagstaff KH, Dickson SL, Bailey A.The history of WEE surveillance in Utah is reviewed, beginning with the 1933 outbreak involving 3,958 horses. The step by step formation of the Utah Mosquito Abatement Associations surveillance program from 1957 to the present is discussed. Results of an enlarged sentinel chicken flock surveillance program in Utah during 1983 (3 sero-conversions in September), 1984 and 1985 (no sero-conversion) show the lack of WEE activity in the surveillance area.
Breuer J, Schmoll F, Uhlig A, Schusser GF.Equine proliferative enteropathy (EPE) caused by Lawsonia (L.) intracellularis is an emerging disease in foals, particularly in North America. Since a case report in Germany exists, the objective of this study was to examine the incidence of L. intracellularis-antibodies in healthy horses from two German breeding farms. In group 1, serum samples from 24 (year 1) and 16 (year 2) Haflinger mares and their foals were taken. In group 2, over a period of five months, serum samples of six warmblood mares and foals were collected monthly from birth until the foals became seronegative. Serum samples w...
Hazard GH, Hughes KL, Penson PJ.Contagious equine metritis (CEM) was first diagnosed in Australia in August 1977 and it has since been found on 6 farms in 3 states, having been isolated from about 24 mares and 2 stallions. Details are given of the epidemiology and control procedures used to combat CEM on one farm. Difficulty was experience in successfully treating one infected stallion; this was thought to be associated with inadequate cleaning and treating of the diverticulum of the urethral fossa. Introduction of the disease has had far-reaching consequences and may well result in the adoption of routine bacteriological te...
Wagner IP, Hood DM, Hogan HA.To determine whether the bending modulus and yield strength of the outer stratum medium (SM) differed from those of the SM zona alba (SMZA) and to what degree they differed. In addition, a comparison was made among our values and values reported elsewhere. Methods: 10 normal equine feet. Methods: A 3-point bending technique was used to determine the bending modulus and yield strength of the outer SM and SMZA. Efforts were made to minimize biological and technical factors that could influence the bending modulus. Results: Bending modulus of the outer SM was (mean +/- SD) 187.6 +/- 41.3 MPa, whe...
Stevenson AJ, Weber MP, Todi F, Mendonca M, Fenwick JD, Young L, Kwong E, Chen F, Beaumier P, Timmings S.The variability in plasma and urine equine procaine measurement between three independent laboratories using current methods led to the development of a sensitive, reliable, and reproducible high-performance liquid chromatographic method. Standardbred mares were administered either a penicillin G procaine preparation intramuscularly or procaine hydrochloride subcutaneously, and blood and urine were collected at defined time intervals. By HPLC the detection limits for procaine in plasma and urine were 1 and 10 ng/mL, respectively. In contrast procaine in plasma could not be detected by GC-NPD, ...
Bain FT.Cytology can be a rewarding diagnostic technique in equine practice. The respiratory tract readily lends itself to sampling for cytologic evaluation from the upper to lower regions of the system. This article discusses preservation and staining techniques that will allow the practitioner to present satisfactory samples to the laboratory. General considerations for cytologic analysis are discussed as well as the specific findings for individual disorders of the respiratory tract. The proper use of cytologic findings in conjunction with other diagnostic techniques for the respiratory tract are a...
Martin EM, Duck FA, Winlove CP.We have previously shown that MHz frequency ultrasound causes contraction of the carotid artery in vitro. We now extend this investigation to equine mesenteric arteries and investigate the cellular mechanisms. In vitro exposure of the large lateral cecal mesenteric artery to 4-min periods of 3.2 MHz continuous wave ultrasound at acoustic powers up to 145 mW induced reversible repeatable contraction. The magnitude of the response was linearly dependent on acoustic power and, at 145 mW, the mean increase in wall stress was 0.020 ± 0.017 mN/mm(2) (n = 34). These results are consistent with our p...
Gall D, Nielsen K, Bermudez RM, Muñoz del Real MC, Halbert G, Groulx R, Moreno F, Chow EY, Checkley SL.An indirect enzyme-linked immunosorbent assay (IELISA) was developed for the detection of equine serum antibodies to lipopolysaccharide of Salmonella enterica subsp. enterica serovar Abortusequi (LPS), a causative organism of Equine Paratyphoid. The data presented demonstrates that horses immunized with S. abortusequi LPS developed antibodies detectable by the IELISA. By comparison, the tube agglutination test (TAT) did not detect antibody to S. abortusequi LPS as consistently as the IELISA. The data suggests that the IELISA may be a more suitable test for the detection of serum antibodies to ...
Buffa EA, Van Den Berg SS, Verstraete FJ, Swart NG.Over a 10-month period, 24 randomly selected riding horses were fed various amounts of biotin. Statistically significant improvements in growth rates and hardness of hooves were produced by biotin supplementation. Greater growth rates and hardness were achieved at a daily dose of 15 mg than at 7.5 mg. Increased hoof hardness was greatest in the hoof quarters and toe. No ring formation occurred in hooves of horses fed biotin intermittently.
Sweasey D, Patterson DS, Leadon DP.The lipid content of spinal cord, expressed as a percentage of adult values, was considerably higher for newborn foals than for several other species and traces of esterified cholesterol (type A) were only rarely present in horse fetal cord (from 270 days gestational age onwards). This suggested that, at birth, the spinal cord is neurochemically more 'mature' in the horse than in cattle, sheep and pigs. Data for premature foals revealed no lipid abnormality suggestive of myelin immaturity or degeneration.
Puigdemont A, Riu JL, Guitart R, Arboix M.The propafenone kinetics after intravenous (i.v.) administration have been studied in the horse by a comparative analysis of compartmental and noncompartmental models. The pharmacokinetic parameters showed a large distribution (Vdss = 1021 +/- 211 L) and a high clearance (CI = 7019 +/- 1746 mL/min) of the drug. The plasma concentrations were very low, under 1 microgram/mL, in most cases; after 30 min these concentrations can be considered as nonefficient for the treatment of arrhythmia. There were no significant differences between pharmacokinetic parameters found with the use of compartmental...
Bulak K, Łopuszyński W, Lutnicki K, Pomorska-Zniszczyńska A, Śmiech A, Jodłowska-Jędrych B.Granular cell tumor (GCT) is a soft tissue neoplasm characterized by abundant intracellular eosinophilic granules. The majority of GCTs are benign, although some display malignant behavior. Furthermore, GCTs may mimic other neoplasms. The clinical course and biology of GCTs are poorly understood. Regarding the histogenesis of GCT, a Schwann cell origin is currently favored in light of immunohistochemical and ultrastructural analyses. However, based on literature data, some of the primitive GCTs show non-neural origin; therefore, the histogenesis of this tumor has remained enigmatic. Granular c...
Aitken MR.The following article provides an overview of the last 5 years of research and innovation within the field of equine colic surgery, focusing on new techniques, new or recently described lesions, prevention of lesion recurrence or postoperative complications, and updates in prognoses. Early surgical intervention is an important factor in horse survival.