The study of diseases in horses encompasses a wide range of conditions affecting equine health, including infectious diseases, metabolic disorders, and genetic abnormalities. These diseases can impact various systems within the horse, such as respiratory, gastrointestinal, and musculoskeletal systems, and can lead to significant health challenges. Research in this area focuses on understanding the pathophysiology, diagnosis, prevention, and treatment of equine diseases. Common diseases studied include equine influenza, equine herpesvirus, and laminitis. This page provides access to peer-reviewed research studies and scholarly articles that explore the etiology, clinical presentation, and management strategies of diseases in horses, contributing to the advancement of equine veterinary medicine.
McGavin MD, Fadok VA.Skin biopsy for histologic, immunofluorescent, parasitologic, and bacteriologic examination is a common procedure, but for maximum effectiveness the clinician must realize the importance of precautions to select the correct stage of lesion of different diseases; avoiding creating artifacts during removal and fixation; and give full details of history, clinical diagnosis, and differential diagnoses on the laboratory request sheet. Pathology reports describing the subtleties of histologic changes are difficult to write, particularly if the lesions are not specific. Overly long histologic reports...
Mawhinney I, Bollard A.Detection of Taylorella equigenitalis (CEMO) in the horse uses genital swabs. These swabs traditionally have been put in Amies charcoal transport medium for detection by culture but are also used for PCR. We determined the suitability of swabs without transport medium (Dry swabs) for CEMO PCR compared to swabs in Amies charcoal transport medium. The experiment was a factorial design using swab type and dilution of organism in culture suspensions, done in two parts. Simulated genital swabs were prepared in the laboratory by dipping in pairs into culture suspensions containing T. equigenitalis w...
Bastianello SS, Nesbit JW.The pathological features of biliary atresia in a foal are described. A 4-week-old American Saddler foal was presented for autopsy following an illness characterised by clinical features indicative of hepatic failure. The significant macroscopical lesions occurred in the liver which was extremely enlarged, mottled in appearance and indurated. Bile stasis was evident. Lobular distinction was absent and on sectioning, large bile ducts were absent. A moderate ascites, hydrothorax and hydropericardium and a mild anasarca and intermuscular oedema accompanied the hepatic lesion. The diagnosis of bil...
Guarino C, Pinn-Woodcock T, Levine DG, Miller J, Johnson AL.Cases of cranial nuchal bursitis associated with infection have not been thoroughly described. Here, we describe the case of a 17-year-old mare that was presented for low head carriage, dull demeanor, and resistance to haltering. Imaging supported a diagnosis of nuchal bursitis, and bursoscopy with surgical debridement of the nuchal bursa was performed. was identified by molecular diagnostics in serial samples of the bursal fluid, with no other organisms identified. Serology revealed significant elevation in antibodies directed against OspA of , but not the typical infection markers, OspC an...
Breuil MF, Duquesne F, Sévin C, Laugier C, Petry S.Contagious equine metritis is a horse disease that causes endometrial inflammation due to Taylorella equigenitalis. Since Taylorella asinigenitalis was characterized, genital swab culture has proved to be an insufficient method for distinguishing between the two Taylorella species. Here, we developed an indirect immunofluorescence (IIF) test using polyclonal antibodies. Specificity, sensitivity, and detection limit were assessed using isolated bacteria (55 T. equigenitalis strains, 46 T. asinigenitalis strains and 18 other bacterial species), experimental and genital swabs in comparison to bac...
Schumacher J, Varner DD, Schmitz DG, Blanchard TL.A urethral defect, presumed to communicate with the corpus spongiosum penis, caused hematuria in seven geldings and hemospermia in three stallions. Hematuria in geldings occurred at the end of urination. Hematuria was not observed in stallions with hemospermia. A linear urethral defect was identified, by endoscopic examination, on the convex surface the urethra at the level of the ischial arch of each horse. Cause of the defect was not determined. Two stallions were successfully treated for hemospermia, one by temporary subischial urethrostomy combined with sexual rest for 10 weeks, and the ot...
Sloet van Oldruitenborgh-Oosterbaan MM, Boerma S, van Exel GA, van der Holst W, Merkens HW, van Muiswinkel K, Parlevliet JM, Peters JW....Rectal tears are a relatively rare complication of rectal palpation, mating or dystocia, and idiopathic spontaneous occurrence of rectal perforation has also been described. Rectal tears have been classified in a three or a four-grade system. Immediate recognition of the fact that a tear has been made and prompt action will improve the horses chance of survival, and is the best defence of the veterinarian against legislation. There is no clear explanation why rectal tears sometimes occur. A questionnaire of the Netherlands Equine Veterinary Association revealed that rectal tears occurred both ...
Kent MG, Schneller HE, Hegsted RL, Johnston SD, Wachtel SS.The XY Sex Reversal Syndrome of the horse is a condition associated with female or intersexual development in genetic males. In our previous study, 38 sex reversed XY mares were classified according to behavior, gross clinical phenotype, gonadal status, and H-Y phenotype. Four classes were described, ranging from potentially fertile female (Class I) to virilized intersex (Class IV). In the present study, serum testosterone concentrations were measured in 29 sex-reversed XY mares, 3 normal mares and 3 normal stallions. Serums were obtained during the breeding season (March-August), and were sto...
Raisis AL, Hodgson JL, Hodgson DR.Twenty-one compromised neonatal foals hospitalised at the Rural Veterinary Centre (RVC) during 1993 were studied to determine i) serum gentamicin concentrations obtained when gentamicin was administered at 3.3 mg/kg bwt twice daily i.m.; ii) factors which contributed to inter-foal variation in serum gentamicin concentrations achieved and iii) clinical efficacy of gentamicin therapy in foals with confirmed septicaemia. Septicaemia was confirmed in 7 foals with positive blood cultures and suspected in 8 foals with a sepsis score > 11. Peak serum concentrations (Ps) were > 6 microg/ml in al...
Meier HP, Gertsch U, Kohler S.Twin pregnancies are a serious problem in stud medicine as they terminate in most cases in abortion, stillbirth or the delivery of dead or weak and deformed foals. In recent years, the introduction of sonography has greatly improved the management of mares with twin conceptuses, in particular monitoring the phenomenon of spontaneous embryo reduction to a single vesicle. This allows supervision of pregnancy with relatively little expenditure and loss of time. We document the spontaneous reduction to single vesicles of unilateral twin pregnancies in a draught- and a warmblood-mare. In both mares...
Bennett DG.Routine examination of the digestive system relevant to purchase includes gross examination of the feces, auscultation of the abdomen, and examination of the oral cavity and teeth for verification of age and identification of any gross abnormality. Further examination is indicated only when there is a history of diseases such as colic, especially colic surgery, or esophageal obstruction. Special procedures that might be indicated, depending upon the history and findings on the routine physical examination, include rectal palpation of the abdominal viscera; endoscopic examination of the esophag...
Delgado MA, Monreal L, Armengou L, Segura D, Ríos J.Peritoneal D-Dimer concentration can be determined to assess peritoneal fibrinolysis activity in horses with gastrointestinal disorders. However, blood contamination of peritoneal fluid may occur during collection and could alter peritoneal D-Dimer concentration. Objective: Blood contamination in peritoneal fluid does not affect interpretation of peritoneal D-Dimer concentration in horses with colic. Methods: Thirty-four horses with colic and 4 healthy horses. Methods: Peritoneal fluid and blood samples were simultaneously collected upon admission. Then, peritoneal fluid was serially contamina...
Campagnolo ER, Trock SC, Hungerford LL, Shumaker TJ, Teclaw R, Miller RB, Nelson HA, Ross F, Reynolds DJ.Dermatitis consisting of blisters on the nose and other parts of the body was reported among horses at a Midwestern horse show. Some horses also had jaundice, hematuria and anorexia. An outbreak investigation was initiated, and of 239 horses for which information could be obtained, 58 (24%) were found to have been affected. Median duration of illness was 5 days, and all horses recovered. Age, sex, water source, grain source, and stabling location were not associated with illness. The use of wood shavings bedding obtained at the show grounds was the factor most strongly associated with the deve...
Platt H.A retrospective study was carried out on post-mortem and biopsy tissue samples from 26 horses with non-alimentary lymphoma. On the basis of their histopathology and cytology, the cases were grouped into several categories: (1) Lymphoblastic lymphomas (6 cases) and primary lymphoblastic leukaemia (2 cases). (2) Histiolymphocytic lymphomas involving the skin (6 cases) or lymph nodes (3 cases). (3) Lymphomas showing follicular development (4 cases). (4) Plasmacytic lymphomas (4 cases). (5) Lymphocytic lymphoma (1 case). Most affected horses were middle-aged or old but lymphoblastic neoplasms tend...
Mizuguchi Y, Kato A, Aizu M.In this case report, two horses with chronic refractory infections in the tuber calcanei were successfully managed via intravenous antibiotic regional limb perfusion through the lateral saphenous vein after failure of conventional treatment approaches, including surgery and intravenous regional limb perfusion using the cranial branch of the medial saphenous vein. Surgical delay in these cases may have allowed the development of chronic infection, which prevented the conventional regional perfusion from working effectively. The spatial difference of the vessels relative to the tuber calcanei po...
Sponseller BA, Clark SK, Friedrich RA.Determining mechanisms of viral escape to particular epitopes recognized by virus-neutralizing antibody can facilitate characterization of host-neutralizing antibody responses as type- versus group-specific, and provides necessary information for vaccine development. Our study reveals that a single N-glycan located in the 5' region of the Wyoming wild-type equine infectious anemia virus (EIAV) principal neutralizing domain (PND) accounts for the differences in neutralization phenotype observed between PND variants, while variations in charged amino acids within the PND do not appear to play a ...
Mair TS.Eight horses with Grade 3b rectal tears of the peritoneal part of the rectum or small colon were treated by a combination of medical therapy and dietary manipulation. All of the horses developed septic peritonitis during the course of treatment. Medical therapy consisted of a combination of penicillin, gentamicin and flunixin meglumine administered parenterally, metronidazole administered orally and liquid paraffin administered by nasogastric tube. Some horses also received fluid and electrolyte therapy i.v., plasma and heparin i.v. All horses were maintained on a laxative diet. Six of the 8 h...
Lyons ET, Drudge JH, Tolliver SC.Critical tests of the activity on large strongyles, ascarids, mature pinworms, and bots were carried out in 11 horses intraorally treated with a paste formulation of thiabendazole. The dose level of 44 mg/kg was administered to 3 horses, and the dose level of 88 mg/kg to 8 horses. Removals of Strongylus vulgaris and mature Oxyuris equi were 100% at the 2 dose levels, and efficacy against Strongylus edentatus varied from 95 to 99% and 89 to 100% for the 44- and the 88-mg/kg dose levels, respectively. Strongylus equinus was completely removed from the 1 infected horse treated at the dose level o...
Rückert C, Kriete M, Jaenicke S, Winkler A, Tauch A.The complete genome sequence of the type strain Corynebacterium uterequi DSM 45634 from an equine urogenital tract specimen comprises 2,419,437 bp and 2,163 protein-coding genes. Candidate virulence factors are homologs of DIP0733, DIP1281, and DIP1621 from Corynebacterium diphtheriae and of sialidase precursors from Trueperella pyogenes and Chlamydia trachomatis.
Rice HC, Brokken MT, Hostnik ET, Bertone AL. The aim of this study was to evaluate the injection of a bone substitute material (BSM) into an impact lesion in the palmar condyle of the third metacarpal bone. Methods: This was an controlled study performed on six horses. Methods: Medial metacarpal condyles were exposed via arthrotomy and a compressive lesion created in anaesthetized horses using 80 psi (27.6 MPa) onto the articular surface ( = 12). Paired limbs were randomly selected as a control or for extra-articular injection of BSM towards the subchondral bone near the compressive lesion. Parameters of the surgical tech...
Stewart JH, Rose RJ, Barko AM.The effect of oxygen administration on blood gas values was examined in six newborn foals from birth to seven days old. Three variables were studied: the effect of increasing age on the ability to elevate arterial oxygen tension (Pao2), the effect of duration of oxygen delivery on Pao2 and the effect of method of administration. The results demonstrated a significant effect of age on the ability to increase Pao2 values, with the highest Pao2 values being found at seven days old. The duration of oxygen administration caused little change in Pao2 values; peak values were reached after 2 mins of ...
Landolt G, Feige K, Schöberl M.The present study describes the poisoning due to Robinia pseudoacacia in two horses. One of the horses showed mainly intestinal symptoms such as decreased intestinal motility and obstipation of the pelvic flexure. In the second animal central nervous symptoms were predominant. It showed intermittent phases of somnolence alternating with phases of excitation and head pressing. In addition mydriasis and a lacking menace response could be observed. Sensation to the head and the spinal reflexes were reduced. Symptomatic treatment was initiated in both animals and recovery occurred within 2 days.
Barban PS, Gol'din RB, Misenzhnikov AV, Prusakova ZM, Pantiukhina AN.The authors present the results of immunization of horses-producers with a commercial antigen and the yolk culture of the living R. sibericus (strain K1) for the purpose of obtaining specific immune sera for many purposes. It was shown that the original combined scheme of immunization and reimmunization of horses, successfully approved in the preparation of immune sera to Rickettsia prowazeki also proved to be highly effective for obtaining the antisera to R. sibericus. Sera obtained after the primary immunization of horses could be successfully used as diagnostic sera, but they were of no use...
Toombs-Ruane LJ, Riley CB, Rosanowski SM, Kendall AT, Benschop J.Decreased efficacy of veterinary antimicrobials and increased prevalence of multi-drug resistance (MDR) is of concern, but little is known of antimicrobial resistance encompassing the New Zealand (NZ) equine population. Recent concerns have arisen over the emergence of multi-resistant bacteria [1], especially on NZ stud farms where antibiotics are frequently used for respiratory disease without veterinary input [2]. Objective: To describe bacterial culture and antimicrobial sensitivity results from respiratory samples submitted of young horses (4 weeks to 3 years old). Methods: Retrospective s...
Littlejohn A.Twenty cases of chronic cough originating in the lung and associated with loss of performance were clinically examined. The physical signs observed were compared with those observed in a control series of 38 clinically normal horses. Reduced work tolerance, coughing for more than 3 months and abnormal pulmonary sounds (râles) were primary signs of chronic obstructive pulmonary disease (COPD). Forced abdominal expiratory efforts and pumping of the anus were regarded as confirmatory signs. Neither nasal discharge nor increased marginal distance was found to be a reliable sign of COPD. The mean ...
Dik KJ, Németh F, Merkens HW.The radiological and clinical interpretation of alterations of the navicular bone, the interaction of radiological and clinical symptoms in relation to the age of the animal, the influence of work-load on this interaction and the possibility of predicting navicular disease at an early stage are discussed. The discussion is based on experience in a study of 130 horses.
Friesen KM, Johnson GD.Reproductive potential was assessed for stable fly cohorts fed cattle, chicken, or horse blood. Flies provided chicken blood oviposited 20% more eggs per day than did those fed cattle or horse blood. However, flies provided cattle or horse blood were fecund 50% longer. When both egg viability and number of eggs produced were considered, lifetime reproductive potential was almost twice as high for flies fed cattle or chicken blood than for flies fed horse blood. Maternal investment, which took egg production and volume into account, was higher in cohorts fed cattle blood (70 mm3) when compared ...
Giri DK, Quist EM, Ambrus A, Gold J, Porter BF, Bratton GR, Storts RW.A 5-day-old quarter horse colt with a history of hypothermia, agonal breathing, and diarrhea was euthanized. At necropsy, numerous slightly raised, discrete, closely approximated submucosal nodules were observed in the colon and small intestine. Histologically, these nodules were composed of expanded submucosal mesenchyme that contained numerous neurons either individually or in ganglia. Thirty-two percent of these ganglia included 8 or more neurons, in contrast to 6% in an age-matched foal. Some nodules had necrosuppurative inflammation with vasculitis, thrombosis, and bacterial colonization....
Slocombe JO, McCraw BM.Sixteen pony foals were reared worm-free and inoculated with Strongylus vulgaris. On day 7 after inoculation, 12 ponies were given a fenbendazole 10% suspension at dose rate of 50 mg/kg of body weight by stomach tube. On day 8 after inoculation, 8 of these ponies were given the 2nd treatment of the anthelmintic and on day 9, 4 of these ponies were given the 3rd treatment. (The other 4 of the 16 ponies were given only tap water, as controls.) The ponies were necropsied at death or on day 28 after inoculation. Fenbendazole was effective in minimizing the appearance of clinical signs associated w...
Moll HD, Schumacher J, Dabareiner RM, Slone DE.Three horses underwent exploratory celiotomy because of signs of acute abdominal pain. At surgery, all horses were diagnosed as having left dorsal displacement of the large colon. Each surgery was complicated by fibrous adhesions of the spleen to the body wall. All horses had previously undergone abdominal surgery for colic. In these cases, it appeared that the left large colon displaced cranially and then entered the renosplenic space from a cranial to caudal direction. Adhesions of the spleen to the body wall would prevent correction of left dorsal displacement of the large colon by the roll...
