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.
Khanna AK, McDonell WN, Dyson DH, Taylor PM.The cardiopulmonary effects of eucapnia (arterial CO2 tension [PaCO2] 40.4 +/- 2.9 mm Hg, mean +/- SD), mild hypercapnia (PaCO2, 59.1 +/- 3.5 mm Hg), moderate hypercapnia (PaCO2, 82.6 +/- 4.9 mm Hg), and severe hypercapnia (PaCO2, 110.3 +/- 12.2 mm Hg) were studied in 8 horses during isoflurane anesthesia with volume controlled intermittent positive pressure ventilation (IPPV) and neuromuscular blockade. The sequence of changes in PaCO2 was randomized. Mild hypercapnia produced bradycardia resulting in a significant (P < 0.05) decrease in cardiac index (CI) and oxygen delivery (DO2), while ...
Milliken JE, Paccamonti DL, Shoemaker S, Green WH.A pseudohermaphrodite horse with aggressive stallion-like behavior and ambiguous external genitalia was gonadectomized. The hypoplastic gonads removed from the abdomen were confirmed by histologic examination to be testes. Examination of blood and fibroblasts revealed a 64,XX karyotype.
Frayne J, Stokes CR.The use of tetanus toxoid as a recall antigen to investigate equine immune responses would be, in theory, a useful and cost-effective model in vitro. However, by using various regimens for culturing peripheral blood mononuclear cells from horses previously immunised with toxoid no proliferative response to the antigen was obtained in vitro, whereas lymph node mononuclear cells from the same animals proliferated significantly in response to it. The lack of response by the peripheral blood mononuclear cells was not due to the presence of a suppressive factor but to a lack of recognition of the a...
Chirnside ED, Francis PM, de Vries AA, Sinclair R, Mumford JA.A recombinant glutathione-S-transferase fusion protein expressing amino acids 55-98 of equine arteritis virus (EAV) GL (rGL 55-98) was tested in an ELISA for its ability to detect serum antibodies to EAV. Host antibodies induced following EAV infection bound the recombinant antigen by ELISA. The ELISA specificity and sensitivity were determined with a panel of equine sera including postinfection and postvaccination samples. A good correlation existed between EAV neutralizing antibody titers and ELISA absorbance values (r = 0.827). The sensitivity and specificity of the ELISA were 99.6 and 90.1...
Maisi P, Paananen M, Koivunen AL.Seventeen trotters, eight healthy and nine with a mild respiratory disease, underwent a submaximal treadmill exercise. Heart rate, breathing frequency, intrapleural pressure difference (IP difference) as well as haematocrit and concentration of lactic acid in blood were monitored before exercise, during exercise and during recovery. The activities of beta-glucuronidase and plasmin, total proteolytic activity and trypsin inhibitory capacity were measured from the tracheal fluid before and after exercise. IP difference significantly increased during exercise and returned to normal values within ...
Ayroud M, Leighton FA, Tessaro SV.Four of five reindeer (Rangifer tarandus tarandus) obtained from a Besnoitia sp.- infected herd at the Assiniboine Park Zoo in Winnipeg, Manitoba, Canada, in October 1989, had evidence of mild dermatitis over the articular surfaces of carpal and tarsal joints. Cysts of Besnoitia sp., either surrounded by inflammatory reactions or without evident host response, were present within the dermis, submucosa of the nasal turbinates, periosteum, tendons, testes and hooves. The light microscopic and histochemical features of Besnoitia sp. from reindeer were indistinguishable from those of other Besnoit...
van Woensel PA, Goovaerts D, Markx D, Visser N.A mouse model was developed for testing the pathogenicity of equine herpes virus-1 (EHV-1) strains. The model was validated with EHV-1 strains that are known to be of a low or high pathogenicity in horses. From all parameters tested, the safety index, which was calculated from the body weights of the mice after infection, proved to be the best predictive parameter. When this parameter was used, good and reliable correlations were found with the pathogenicity of the EHV-1 strains in horses. This method enabled the differentiation between the two experimental EHV-1 strains whose genetic backgrou...
Hesselbarth J, Schwarz S.Strains of Staphylococcus (S.) intermedius from dogs, pigeons, horses and mink were typed by comparison of rRNA gene restriction fragment length polymorphisms (ribotyping) and the resulting ribotypes examined by cluster-analysis. Digestion of whole-cell DNA with HindIII resulted in 9 ribotypes with 3 to 4 bands. Separation of isolates from different host animal species was not possible. EcoRI yielded 11 different patterns with 4 to 9 fragments. The EcoRI-ribotypes of all canine strains grouped in one cluster encompassing four closely related ribotypes. Isolates were indistinguishable with resp...
Tannus RJ, Thun R.A total of 259 normally fertile mares were examined gynecologically by means of rectal palpation and ultrasonography in order to record the presence of uterine cysts and pregnancy. The incidence of endometrial cysts was 22.4%. Of the 95 cysts observed during the trial, 87.4% were located in the middle and posterior segments of both uterine horns. The size of all endometrial cysts ranged between 3 and 48 mm. When all mares were assigned to three age groups, A 14 years (n = 26), a significant (P < 0.01) increase in the number of endometrial cysts was observed with advancing age (4.3%, 29.1% ...
van Duijkeren E, Flemming C, Sloet van Oldruitenborgh-Oosterbaan M, Kalsbeek HC, van der Giessen JW.Three rectal faecal samples were taken at 24-hour intervals from 136 horses in order to investigate whether multiple faecal cultures yield a greater number of Salmonella-positive horses compared to single faecal cultures. Of these 136 horses, 89 were suspected of salmonellosis on clinical grounds and 47 belonged to a control group. From the 'Salmonella suspected' group, 22 horses (25%) were Salmonella positive on one or more occasions. Only twelve of these 22 positive horses (55%) were positive at first sampling. Of the control group, only three horses (6%) were positive for Salmonella. Thirty...
Littlewood JD, Whitwell KE, Day MJ.Résumé- Les commémoratifs, les symptômes, l'histologie et la réponse au traitement d'un cheval de 15 ans atteint de lymphome cutané sont décrits. La jument présente de multiples nodules cutanés depuis 11 ans. Un diagnostic de lymphome cutané est poséà l'examen histologique de biopsies réalisées 2 fois à 4 ans d'intervalle. Des marquages immunihistochimiques identifient ces cellules comme appartenant à la lignée T. Ceci est la première description du marquage immunophénotypique d'un lymphome cutané chez le cheval. La jument a été traitée par des glucorticoïdes intralési...
Morley PS, Hanson LK, Bogdan JR, Townsend HG, Appleton JA, Haines DM.Antibodies specific for equine influenza viruses are usually quantified using single radial hemolysis (SRH), hemagglutination inhibition (HI) or virus neutralization (VN). Neutralizing antibodies are thought to provide optimum protection to challenged animals. The purpose of this study was to determine the extent to which SRH and HI assays detect antibodies which neutralize equine influenza viruses. Acute and convalescent sera from 41 horses were analyzed using VN, SRH, and HI assays. These horses were present in a population of Thoroughbred racehorses during an epidemic of upper respiratory t...
Collobert C, Bernard N, Lamidey C.The umbilical skin and ligamentum nuchae of 368 horses were examined post mortem for Onchocerca species. Only four of the horses were infected and pathological changes were observed on the skin of two of them. Thelazia lacrimalis was recovered from 38 (10.3 per cent) of the horses, and animals aged six months to two years were more frequently infected. No ocular lesions were observed. The prevalences of these two nematodes were low when compared with the infection rates reported in the United Kingdom and North America.
Robinson NE, Derksen FJ, Olszewski MA, Buechner-Maxwell VA.Present evidence suggests that chronic obstructive pulmonary disease (COPD) of horses is a delayed hypersensitivity response to inhaled antigens, particularly the thermophilic moulds and actinomycetes that grow in damp hay. Within several hours of exposing COPD-susceptible horses to such hay, neutrophils invade the lung and accumulate in the lumens of airways, particularly bronchioles. The inflammatory response is accompanied by increased levels of histamine in bronchoalveolar lavage fluid, increased plasma levels of the inflammatory mediators thromboxane and 15-hydroxyeicosatetraenoic acid (1...
Parraga ME, Carlson GP, Thurmond M.The present retrospective study was undertaken to determine the frequency of hypoproteinemia and hypoalbuminemia in horses with natural occurring severe liver disease. The study represents a review of case records and laboratory data of 84 horses presented with acute or chronic liver disease to the University of California Veterinary Medical Teaching Hospital between 1973 and 1991. Forty horses (48%) had serum protein concentrations above the maximum reference value (7.7 g/dL). The increase in serum protein concentration was associated with hyperglobulinemia (P = .00005, R2 = .80). Only 13% (1...
Appel G, Burdinski K.It is reported on a case of tyzzer's disease (infection with Bacillus piliformis) in a pony foal in Schleswig-Holstein. The clinical and pathologic-anatomical findings are described and discussed.
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...
Barber SM.A three year old Thoroughbred filly was examined because of bilateral nasal discharge and external swelling of the left laryngeal area. Endoscopy revealed an enlarged left arytenoid cartilage, left laryngeal hemiplegia and drainage of purulent material into the lumen of the larynx. Radiographs showed a large fluid and gas filled cavity overlying the caudal larynx and cranial trachea. Surgical drainage and debridement of the abscess led to complete healing by secondary intention. Laryngeal ventriculectomy was performed as a treatment for left laryngeal hemiplegia, but a grave prognosis for resp...
Bryans JT.The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under e...
Soza-Ossandón P, Rivera D, Allel K, González-Rocha G, Quezada-Aguiluz M, San Martin I, García P, Moreno-Switt AI.Healthcare-associated infections caused by Staphylococcus, particularly Staphylococcus aureus, represent a high risk for human and animal health. Staphylococcus can be easily transmitted through direct contact with individual carriers or fomites, such as medical and non-medical equipment. The risk increases if S. aureus strains carry antibiotic resistance genes and show a phenotypic multidrug resistance behavior. The aim of the study was to identify and characterize methicillin resistant coagulase-positive staphylococci (MRSA) and coagulase-negative staphylococci (MRCoNS) in equine patients an...
Macpherson ML, Bailey CS.Placental infections in the mare are a diagnostic and therapeutic challenge. The following article will review techniques for identifying placental infections, approaches for treating placentitis, and methods for managing these mares after foaling.
Parente EJ, Martin BB, Tulleners EP.Many disorders of the upper respiratory tract which cause severe
respiratory compromise and poor performance have been
described in the equine athlete (Williams et al. 1990; Morris 1991;
King et al. 1994). Until recently, the diagnosis of upper respiratory
tract dysfunction was based on observations made during resting
endoscopic examination; and conclusions regarding the extent and
exact nature of the dysfunction during exercise were often
inaccurate. This report describes 2 horses presented to the George
D. Widener Hospital in which no significant abnormalities were
noted during res...
Rola J, Socha W, Zmudzinski JF.Nucleotide and amino acid sequences of ORFs 5, 6 and 7 of EAV during persistent infection in the stallion of the Malopolska breed were analysed in the study. A total of 11 blood and semen samples were collected between 2004 and 2011. The titre of specific EAV antibodies in this carrier stallion was maintained at a high level throughout the study and was equal approximately 1:128. The sequence analysis of ORF5 showed 16 variable sites including 12 with synonymous substitutions and 4 with non-synonymous substitutions. The degree of nucleotide sequence identity among the strains ranged from 98.92...
Kuwano A, Niwa H, Arai K.To establish a new system to isolate keratolytic bacteria from the hoof wall cavity () of a racehorse, we invented the horn powder agar-translucency (HoPAT) test and horn zymography (HZ). Using routine bacteriological techniques and these methods, we isolated five strains of keratolytic soil bacteria, which were then identified by means of 16S ribosomal RNA (rRNA) gene sequencing analysis. The findings from the study on the horse suggested that Brevibacterium luteolum played the main role in the local fragility of the hoof, eventually forming a in coordination with four other strains of kerat...
Yoshimura S, Barber SM, Tucker ML, Bracamonte JL, Mund SJK, Thomas KL.To describe a new technique to repair a sinocutaneous fistula with a masseter muscle transposition flap. Methods: Case report. Methods: One 13-year-old thoroughbred stallion. Methods: One 13-year-old stallion with a 3.5 × 6-cm sinocutaneous fistula over the right caudal maxillary sinus was treated with a transpositional masseter muscle flap. This repair consisted of a commercial wound matrix dressing placed directly over the hole in the maxilla and secured with suture material; a cancellous bone graft collected from the right tuber coxa placed on the dressing; and a portion of the superfi...
Pascoe RR.The death of a 60-day-old foal due to massive haemorrhage associated with erosion of the left umbilical artery into the left ureter is reported. Surgical repair attempts are described together with post-mortem findings.