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.
van Schie HT, Bakker EM, Jonker AM, van Weeren PR.To correlate quantitative analysis of ultrasonographic images of normal (injury-free) equine superficial digital flexor (SDF) tendons and equine SFD tendons that have pathologic changes with corresponding histologic sections. Methods: 4 SDF tendons, 2 of which had various stages of tissue integrity. The 2 ipsilateral tendons were used as points of reference. Methods: Tendons were mounted in a custom-made device that permitted sequential scanning, transversely and perpendicular to the tendon long axis. At precise steps of 0.5 mm, transverse ultrasonographic images were collected. Subsequently, ...
Munroe G.Twenty-seven of 167 neonatal thoroughbred foals (16 per cent) were found to have retinal haemorrhages after a careful examination of the entire fundus. Experience in differentiating haemorrhages from other lesions, and the selection of foals from normal populations, were considered to have an important effect on their apparent incidence. Bilateral haemorrhages were more common and there was a significantly higher incidence in female foals. The numbers of haemorrhages ranged between one and 20; 36 per cent of eyes with retinal haemorrhages had the small punctate type and 56 per cent had the spl...
Chapman PS, Green C, Main JP, Taylor PM, Cunningham FM, Cook AJ, Marr CM.A total of 1235 tracheal aspirates taken from 724 thoroughbreds in race training, aged from two to 10 years, were examined cytologically and bacteriologically. An inflammation scoring system on a scale of 0 to 9 was devised to allow the severity of lower airway disease to be assessed from the cytological results. The inflammation scores were closely related to the isolation of bacteria (P<0.001), and the most common bacterial isolates were Streptococcus zooepidemicus, Streptococcus pneumoniae and Pasteurella/Actinobacillus-like species. Lower airway disease was less common in older horses (...
Cogley TP, Cogley MC.A synthetic alpha-2 adrenergic agonist, detomidine hydrochloride, was used in the study of in vivo activity of Gasterophilus intestinalis (Diptera: Gasterophilidae) during migration in the tongue of the horse. Use of the drug allowed the investigator to manipulate the tongue and closely observe the movement patterns and tissue disturbance caused by burrowing first-stage larvae. Detomidine hydrochloride should be utilized in studies of drug efficacy and larval biology, whenever possible, to avoid the need to sacrifice the horse.
Baudena MA, Chapman MR, French DD, Klei TR.Cyathostome development and survival on pasture in subtropical climates of the US have yet to be completely defined and available data on seasonal transmission are minimal. In an attempt to study this phenomenon, a group of pony mares and their foals was maintained on a naturally contaminated pasture in southern Louisiana. Fecal egg counts (FEC) and numbers of infective third stage larvae (L3) kg(-1) dry herbage were recorded biweekly during two time periods, from January 1986 through December 1988, and September 1996 through October 1997. A FEC rise occurred during the late summer-early autum...
Cho HJ, Entz SC, Deregt D, Jordan LT, Timoney PJ, McCollum WH.A potent ELISA antigen was prepared from equine arteritis virus (EAV) by differential centrifugation of EAV-infected cell culture fluid, followed by solubilization of the preparation by Triton X-100 treatment. Using this antigen and a mouse monoclonal antibody against the G(L) protein of EAV, a reliable blocking ELISA (bELISA) was developed for the detection of EAV antibodies in equine sera. The bELISA was evaluated using a total of 837 test serum samples. The relative sensitivity (n = 320) of the bELISA compared to the serum neutralization (SN) test was 99.4%. The bELISA appears to be a highl...
Hung GC, Chilton NB, Beveridge I, Gasser RB.In this study, molecular data sets were used to address the controversies relating to the systematics of strongyloid nematodes of equids utilising morphological data sets. DNA sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2) of ribosomal DNA were determined for 30 species of equine strongyles and the systematic relationships reconstructed using phenetic and phylogenetic tree-building methods. The molecular data provided support for the hypothesis that the genera with large subglobular buccal capsules are ancestral to those with small cylindrical buccal capsules,...
The Journal of physiologyFebruary 16, 2000
Volume 523 Pt 1, Issue Pt 1 131-138 doi: 10.1111/j.1469-7793.2000.t01-3-00131.x
Wang YX, Kotlikoff MI.1. The signalling pathway underlying histamine activation of non-selective cation channels was investigated in single equine tracheal myocytes. Application of histamine (100 microM) activated the transient calcium-activated chloride current (ICl(Ca)) and sustained, low amplitude non-selective cation current (ICat). The H1 receptor antagonist pyrilamine (10 microM) blocked activation of ICl(Ca) and ICat. Simultaneous application of histamine (100 microM) and caffeine (8 mM) during H1 receptor blockade activated ICl(Ca), but not ICat. Neither the H2 receptor antagonist cimetidine (20 microM) nor...
Baptiste KE, Naylor JM, Bailey J, Barber EM, Post K, Thornhill J.Athletic animals must keep their brains cool during exertion because this organ can be damaged irreversibly by hyperthermia. But how horses do this has remained a mystery, as they don't appear to have thermoregulatory dervices like those found in other animals. They do, however, have a unique anatomical arrangement of their internal carotid arteries, which supply blood to the brain: these are enveloped by a pair of air-filled guttural pouches. Here we show that horses use their guttural pouches to cool these important arteries during exercise, keeping the brain from overheating.
Brama PA, TeKoppele JM, Beekman B, van El B, Barneveld A, van Weeren PR.To investigate the role of stromelysin (MMP-3) activity in synovial fluid (SF) at different stages of development and in common joint disorders in the horse. Methods: Stromelysin activity was determined with a fluorogenic enzyme activity assay in SF of normal joints of fetal, juvenile and adult horses, and in SF of horses suffering from the developmental orthopaedic disease osteochondrosis (OC) or osteoarthritis (OA). Additionally, MMP-3 activity was expressed as a ratio of previously reported general MMP activity in the same SF samples. Results: The levels of active stromelysin were 30-fold t...
Brama PA, Tekoppele JM, Bank RA, Karssenberg D, Barneveld A, van Weeren PR.The aim of this study was to evaluate topographical differences in the biochemical composition of the extracellular matrix of articular cartilage of the normal equine fetlock joint. Water content, DNA content, glycosaminoglycan (GAG) content and a number of characteristics of the collagen network (total collagen content, levels of hydroxylysine- (Hyl) and the crosslink hydroxylysylpyridinoline, (HP) of articular cartilage in the proximal 1st phalanx (P1), distal 3rd metacarpal bone (MC), and proximal sesamoid bones (PSB) were determined in the left and right fetlock joint of 6 mature horses (a...
Sandin A, Skidell J, Häggström J, Nilsson G.The present study was performed to estimate retrospectively the prevalence of gastric ulceration in necropsied Swedish horses and to evaluate some potential risk factors. Horses (n = 3715) older than age one year and necropsied 1924-1996 were included. Information about breed, gender, age, season of death, clinical signs of colic, Gasterophilus larvae and documentation of diseases in different organs was recorded. Data on size, number and anatomical distribution of gastric ulcers were also obtained. The cold-blooded horses and the Standardbreds were the 2 most dominating breeds in our material...
Dixon PM, Tremaine WH, Pickles K, Kuhns L, Hawe C, McCann J, McGorum BC, Railton DI, Brammer S.Of 400 horses referred because of dental disorders, 349 cases were diagnosed as suffering from primary disorders of their cheek teeth. Details of 104 of these cases are presented, including 44 cases with abnormalities of wear, 26 cases with traumatic damage, 24 cases with idiopathic fractures and 10 cases with miscellaneous cheek teeth disorders including oral tumours. The long-term response to treatment was excellent in most cases, even in cases with residual secondary periodontal disease.
Murray RC, Janicke HC, Henson FM, Goodship A.Processes involved in equine carpal osteochondral injury have not been established. In other species, fibronectin appears important in chondrocyte-matrix interactions, and levels are increased in osteoarthritis. This investigation aimed to (a) describe fibronectin immunoreactivity in the middle carpal joint of 2-year-old Thoroughbreds, (b) determine topographical variations, (c) compare strenuously trained (Group 1) or gently exercised horses (Group 2) and (d) describe sites with early osteoarthritis. Group 1 (n = 6) underwent a 19 week high intensity treadmill training programme. Group 2 (n =...
Kirschvink N, Art T, Smith N, Lekeux P.To test whether isoprostanes could be used as markers of oxidative stress in horses, their concentration was determined in plasma and in pulmonary epithelial lining fluid (PELF) in 3 models of oxidative stress: (1) strenuous exercise, (2) acute COPD crisis and (3) exercise combined with COPD crisis. Four horses were investigated twice, once in crisis and once in remission. The animals underwent a standardised treadmill exercise test. Isoprostane assessment was performed in plasma and bronchoalveolar lavage fluid 24 h before and 1 h after exercise and in plasma also immediately after exercise. ...
Birch HL, McLaughlin L, Smith RK, Goodship AE.The equine superficial digital flexor tendon (SDFT) functions as an energy store during high-speed gaits reducing the energetic cost of locomotion. To enable the SDFT to function effectively, the appropriate mechanical properties are essential. We tested the hypothesis that the SDFT does not undergo gross hypertrophy in response to high-intensity exercise whereas tendons not involved in energy storage undergo adaptive hypertrophy. Two groups (n = 6) of Thoroughbred fillies were trained at high-intensity on a high-speed equine treadmill for 5 months (short-term study) or 18 months (long-term st...
Hobo S, Hiraga A, Birks EK, Takahashi T, Hada T, Jones JH.A study was undertaken to find if the reason why horses hypoventilate when running is that they experience expiratory flow limitation due to dynamic airway closure. To test this hypothesis, we measured peak expiratory flows on a Thoroughbred galloping on a treadmill and hypoventilating and compared those flows with the peak dynamically-limited flow that the same horse could achieve during a forced expiratory flow-volume manoeuvre. At the approximate lung volumes at which the horse was ventilating while running, it did not appear to be mechanically limited and appeared to have reserve capacity ...
Smith RK, Birch H, Patterson-Kane J, Firth EC, Williams L, Cherdchutham W, van Weeren WR, Goodship AE.In human athletes, conditioning, training and competition are commenced before skeletal maturity. Yet in equine athletics, racing of young (age 2 years) horses remains contentious. Tendon injury persists as major causes of wastage in equine athletes. Minimising injury and associated welfare issues could involve a radical approach to the timing and implementation of conditioning and training. Tendons were examined from Thoroughbreds, Dutch Warmblood foals, working horses and also a group of wild horses to evaluate effects of age, function and exercise. Gross mechanical properties did not differ...
Valberg SJ, Mickelson JR, Gallant EM, MacLeay JM, Lentz L, de la Corte F.The purpose of this study was to determine if chronic exertional rhabdomyolysis (ER) in Quarter Horses and Thoroughbreds represents one or several distinct myopathies. Eighteen Quarter Horses and 18 Thoroughbreds with ER were selected from cases presented to the Veterinary Hospital on the basis of a history of ER, assessment of muscle histopathology, and serum CK activity before and 4 h post exercise. In addition, 2 of 3 of the following parameters were evaluated: muscle glycogen concentrations, thyroid hormones (T3, T4), fractional excretion (FE) of sodium, potassium and chloride. The CK resp...
Hiraga A, Hobo S, Birks EK, Takahashi T, Hada T, Smith BL, Carr EA, Pascoe JR, Jones JH.Three mature Thoroughbred horses were prepared surgically with ultrasonic sonomicrometer crystals affixed to their ventricular pericardia. Signals from crystals recorded dimensions of axes across the left ventricle. Cubic algorithms were fitted to dimensional data to generate volume estimates that matched stroke volumes simultaneously measured using the Fick principle. As horses stood at rest or exercised at various intensities (approx 7, 12, 24, 47 and 100% maximal rate of O2 consumption VO2max[), left ventricular dimensions were recorded and 20 consecutive diastolic and systolic volumes calc...
Bayly WM, Redman MJ, Sides RH.It has been postulated that the hypoxaemia and hypercapnoea that characterize strenuous equine exercise are partly due to flow limitations imposed by high breathing frequencies (fb), and that gas exchange would be improved if fb could be lowered. To evaluate this possibility, 6 Thoroughbred horses underwent 4 incremental treadmill exercise tests at inclines of 0, 5, 10 and 25%, respectively. In the test, horses were given a warm-up for 2 min, then ran sequentially for 1 min each at 60, 100 and 115% VO2max. Oxygen consumption (VO2), blood gas tensions (PaO2, PaCO2), fb, tidal volume (VT), minut...
Audigié F, Pourcelot P, Degueurce C, Denoix JM, Geiger D.This study was undertaken to evaluate the flexion-extension movements of the back in a group of sound trotting horses. Using a 3-D kinematic analysis system, 13 clinically sound horses fitted with 5 skin markers placed on the dorsal midline of their trunk were recorded while trotting on a track in the conditions of the routine lameness examination. These markers were used to calculate 3 back angles (thoracic, thoracolumbar and lumbosacral angle). These back angles were then filtered using Fourier series. To evaluate the repeatability of flexion-extension movements, the intra- and inter-individ...
Dunnett M, Harris RC.The aim of this work was to test the hypothesis that in vivo carnosine biosynthesis is dependent upon endogenous beta-alanine availability, by studying the effect of sustained dietary beta-alanine supplementation in the horse on the carnosine concentration in types I, IIA and IIB skeletal muscle fibres. The diets of 6 Thoroughbred horses were supplemented 3 times/day with beta-alanine (100 mg/kg bwt) and L-histidine (12.5 mg/kg bwt) for a period of 30 days. Percutaneous biopsies of the m. gluteus medius from a depth of 6 cm were taken on the days immediately before and after the supplementatio...
Drevemo S, Johnston C, Roepstorff L, Gustås P.Nerve blocks and intra-articular anaesthesia are used extensively as routine methods in lameness evaluation. The method is based on the assumption that the technique itself does not change the movement pattern. The aim of this study was to carry out a quantitative kinematic study to confirm or reject the hypothesis that high palmar digital nerve block (HPDN) and intra-articular fetlock joint anaesthesia (IAF) influence significantly the movement pattern of the horse. Seven Standardbred horses trotting at 4.5 m/s were recorded at 240 Hz on a treadmill before and after anaesthesia by use of a Pr...
Easley JR.The erythrogram (erythrocyte histogram) and red cell distribution width (RDW) were evaluated in 5 purebred horses and 1 pony of mixed breeding with experimentally induced anemia. Four horses were studied for 6 weeks after 20% of their estimated blood volume was removed on each of 2 consecutive days (40% total blood loss; acute blood-loss group). Two horses were given acetylphenyl hydrazine IV daily, until acute Heinz body hemolytic anemia was induced; the 2 horses were then evaluated for 6 weeks. One horse and the pony had 20% of their estimated blood volume removed via phlebotomy once each we...
Eades SC, Stokes AM, Moore RM.To evaluate changes in digital vascular function in horses with carbohydrate overload (CHO)-induced laminitis and determine the effects of an endothelin (ET) receptor antagonist and nitroglycerin on laminitis-associated vascular dysfunction. Methods: 20 adult horses without abnormalities of the digit. Methods: Hemodynamic variables were recorded before (baseline) and hourly after all horses were administered a CHO ration via nasogastric tube. In 4 groups of 5 horses each, saline (0.9% NaCl) solution or ET receptor antagonist (10(5)M in digital blood) was administered into the digital arterial ...
Todhunter RJ, Stick JA, Trotter GW, Boles C.Esophageal strictures developed in 7 horses that were treated for esophageal obstruction. A soft diet was fed to all horses, with intermittent nasogastric tube feeding in one, and medication included nonsteroidal anti-inflammatory drugs. Maximal reduction in esophageal lumen diameter was evident by 30 days following circumferential esophageal ulceration, after which lumen diameter increased rapidly. Five horses were clinically normal by 60 days after the esophageal injury. Two horses were euthanatized at the owner's request, 16 and 17 days after the original insult.
Shull RM.Hemolytic or blood loss anemia was induce in six ponies and red blood cell concentrations of creatine, glucose-6-phosphate dehydrogenase (G-6-PD), lactate dehydrogenase (LDH), and aspartate transaminase (AST) were measured during the ensuing regenerative period. Creatine and G-6-PD levels correlated well and increased concentration of either was good indication of increased erythrogenesis. Erythrocyte LDH levels were of value in assessing the response to hemolytic anemia but not to blood loss anemia. The difference may be, at least in part, the result of differing degrees of regenerative effor...
Ziska SM, Schumacher J, Duran SH, Brock KV.To develop a high-speed, continuous-flow, automated plasmapheresis procedure for the high-volume harvest of equine plasma in accordance with current good manufacturing practice. Methods: 143 horses (predominantly draft breeds) between 3 and 10 years of age at the time of purchase. Methods: Adaptations were made to automated plasmapheresis instruments and sterile disposable collection sets, which allowed for dual-instrument, continuous-flow operation. Donor horses were connected to the apparatus via 2 catheters (1 inserted in each jugular vein). The instruments removed whole blood from donors, ...
Beech DJ, Sibbons PD, Rossdale PD, Ousey JC, Holdstock NB, Chavatte P, Ansari T.Equine lung and kidney organogenesis has not previously been examined with the use of unbiased stereological techniques. The present study examined healthy (control) pony and Thoroughbred lungs and kidneys to establish baseline data of organ development from before birth until maturity at age 3-18 years. Whole left lungs and kidneys were collected from 45 equine postmortem examinations (34 Thoroughbred, 11 pony). Stereological techniques were used to estimate whole kidney, cortex and medulla volume, total glomerular number and volume-weighted mean glomerular volume, lung volume, total terminal...
Rucker A.In the chronic-laminitic foot, severe soft-tissue compression and compromised circulation can result in osteitis and sepsis at the margin of the distal phalanx. Resultant inflammation and sepsis may cause the coronary corium to swell, drain, or separate from the hoof capsule, usually within 8 weeks of laminitis onset. Slow-onset cases of soft-tissue impingement can develop secondary to distal phalanx displacement due to lack of wall attachment. With either presentation, partial upper wall resection is required to reverse compression and vascular impingement by the hoof capsule. If the patholog...
Hagen J, Hartnett C, Houchins JP, Giguère S, Kalyuzhny AE.Human and mouse immune system cells are the most frequently used specimens in ELISPOT assays. In an effect to expand the application of ELISPOT assay to other species, we developed matched antibody pairs for ready-to-use kits designed for studying the frequency of equine IFNγ- and IL-4-secreting peripheral blood mononuclear cells (PBMCs). Equine PBMCs were stimulated with either concanavalin A (Con A) or calcium ionomycin mixed with phorbol 12-myristate 13-acetate (CaI + PMA). We found that Con A, in general, had a more profound stimulating effect than CaI + PMA on IL-4 secretion, whereas bot...
Hort I.In this study the treatment of a mandibular fracture in a 26 year old Arab horse, the history during the subsequent 4 years and the anatomical post-mortem findings are presented and described.
Wagner B, Radbruch A, Richards C, Leibold W.In order to define equine immunoglobulins (Igs) and to produce monoclonal reference Igs we fused equine peripheral blood mononuclear cells with X63-Ag8.653 non Ig producing murine myeloma cells. A total of 29 equine Ig producing equi-murine heterohybridomas were obtained, of which ten expressed equine Ig for more than 3 months. One of these heterohybridoma lines produced monoclonal IgM, an equine isotype which has not been available in monoclonal form before. Four lines secreted equine IgG of two distinct Ig heavy chain types as assessed by the molecular weight (MW), while the remaining five l...
Pope DC, Heslop CH.An outbreak of myoglobinuria under unusual circumstances in a group of four horses, together with the events leading up to the diagnosis, is described, and a brief mention of two previously recorded similar cases is made.