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.
Popović N, Djuricić B, Valcić M.A study of literature concerning Lyme borreliosis related to animals was done. In the research work the epidemiology, pathogenesis, diagnosis and treatment of horses, cattle and dogs affected with Lyme borreliosis have been discussed. The clinical signs of Lyme borreliosis in horses are: chronic weight loss, sporadic lameness, laminitis, low grade fever, swollen joints, muscle tenderness and anterior uvetitis. In addition to these clinical sings, neurological sings such as depression, behavioral changes, dysphagia and encephalitis can be seen in chronic cases. Cattle affected with acute Lyme b...
Hawkins JF, Schumacher JS, McClure SR, Light GS.Small intestinal incarceration through the lateral ligament of the urinary bladder was diagnosed in a 14-year-old, 569-kg, castrated Quarter Horse. The incarceration was corrected by ventral midline celiotomy. Approximately 70 cm of the middle portion of the jejunum was resected and end-to-end, single-layer anastomosis was performed. After surgery, the horse developed signs of adynamic ileus and lameness in the right forelimb. The horse developed laminitis in all 4 feet within 24 hours of surgery. The horse was euthanatized because of poor prognosis for survival. At necropsy, a 4.5-cm rent was...
Alstad AD, Sahu SP, Pedersen DD, Saari DA, Kawaoka Y, Webster RG.An influenza virus, A/equine/Alaska/1/91 (H3N8), was isolated from horses from Alaska with an acute respiratory infection. Pathogenic and serologic studies revealed that this virus is similar to previously isolated equine H3N8 influenza viruses. Antigenic analyses utilizing hemagglutination inhibition and neuraminidase inhibition assays indicated an antigenic drift from the prototype equine H3N8 influenza virus, A/equine/Miami/1/63. Partial sequence analysis of the A/equine/Alaska influenza virus indicated that each of 8 gene sequences are of equine origin.
Schultheiss PC, Collins JK, Carman J.An indirect immunoperoxidase (IP) procedure using the avidin-biotin-peroxidase complex detection technique was developed to detect viral equine herpesvirus-1 (EHV-1) antigen in formalin-fixed paraffin-embedded tissues from aborted equine fetuses. The procedure was applied to liver, lung, and other tissues from 20 cases of confirmed or suspected EHV-1-induced abortions. Specific staining was observed in tissue sections from EHV-1-infected fetuses. Positive IP staining was present in tissues of 7 cases that were also positive by fluorescent antibody (FA) and virus isolation (VI) and that had typ...
van de Moer A, Rice M, Wilks CR.A type-specific monoclonal antibody was produced by immunizing mice with purified equid herpesvirus-1 (EHV-1). The EHV-1 specific mAb reacted with all the EHV-1 strains tested so far by indirect ELISA, immunofluorescence, and immunoperoxidase tests. No reactions were detected with the EHV-4, EHV-2, or EHV-3 strains tested. The indirect immunofluorescence and immunoperoxidase tests showed that the nuclei of infected cells were predominantly stained by this mAb. Triton treatment of the virus and immunogold labeling experiments indicated that the nucleocapsid of EHV-1 was the target antigen of th...
Brocard P, Pfister K.The combined drug Mebendazole plus Trichlorfon (Telmin plus Trichlorfon, Janssen Pharmaceutica, Beerse/Belgium) has been tested in a field trial against naturally acquired Gasterophilus spp. infestations in horses. 44 foals (1 to 1.5 years old, 350-450 kg body-weight) originating from different endemic areas of Switzerland, have been randomly allocated to two groups as follows: 28 foals were treated with Mebendazole plus Trichlorfon, 16 animals served as untreated controls. The drug (paste) was administered and dosed according to the user's instruction. Macroscopic examinations of the digestiv...
Rojas G, Vargas M, Robles A, Gutiérrez JM.Twenty batches of polyvalent antivenom produced at the Instituto Clodomiro Picado were analyzed for turbidity, both before and after freezing-thawing and lyophilization. Eight batches became turbid upon freezing-thawing, and this change correlated with high levels of cholesterol, triglycerides and lipoproteins, especially beta-lipoprotein. Since normal horse serum does not become turbid after freezing-thawing, despite the fact that it has high lipoprotein levels, the possibility was raised that phenol, used as a preservative during serum fractionation, might affect lipoproteins, inducing the a...
Held JP, McCracken MD, Toal R, Latimer F.Aspermia was diagnosed in a 12-year-old Thoroughbred stallion with generalized lymphosarcoma. Invasion of the epididymus by neoplastic cells caused thickening and enlargement of both epididymes. The testes were not affected. The nodular ultrasonographic architecture was similar to that in previously reported cases of infectious epididymitis.
Home WA, Ford JE, Gibson DM.Analysis of 10 cDNA encoding lambda L chains of horse Ig indicated that this species may employ a relatively small number of variable region (V lambda) genes in the splenic B cell population. The V lambda sequences of all of the cDNA analyzed were closely related (> 88% identity at the nucleotide level) and were characterized by a deletion of the amino acid residue at position 3 compared with V lambda sequences so far described in other species. The 10 V lambda sequences could be grouped into three groups, V lambda 1 to V lambda 3, on the basis of a number of linked substitutions. Sequences...
Knowles DP, Kappmeyer LS, Stiller D, Hennager SG, Perryman LE.Horses infected with Babesia equi were previously identified by the presence of antibodies reactive with a merozoite surface protein epitope (D. P. Knowles, Jr., L. E. Perryman, L. S. Kappmeyer, and S. G. Hennager. J. Clin. Microbiol. 29:2056-2058, 1991). The antibodies were detected in a competitive inhibition enzyme-linked immunosorbent assay (CI ELISA) by using monoclonal antibody 36/133.97, which defines a protein epitope on the merozoite surface. The gene encoding this B. equi merozoite epitope was cloned and expressed in Escherichia coli. The recombinant merozoite protein, designated equ...
Brück I, Hesselholt M.The results of clinical, ultrasonic, post mortem examinations and concrement analysis of a case with nephrolithiasis in a horse are described. Problems of diagnosis, etiology and occurrence of nephroliths in the horse are discussed.
Schöl H, Beelitz P, Gothe R.Trichomonads of the oral cavity were found in 9 of 60 investigated horses. Apart from dental tartar, the oral cavity showed no clinical signs in all positive horses. The clinical investigation of these horses additionally revealed colic in 4 and coughing in 4 horses as well as lumbago in 1 animal. By means of scanning electron microscopy the trichomonads were shown to be round or piriform with an average length of 7.6 microns and greatest width of 6.3 microns. They had 4 anterior flagella with an average length of 8.3 microns, an undulating membrane measuring 8.7 microns with no trailing flage...
Lavach JD.The diseases included in this article constitute a wide range of maladies that affect the horse. Certainly, the diseases that are known today to produce ocular lesions are just a few of what will be discovered if attending veterinarians always examine the eyes of patients with systemic diseases.
Peloso JG, Coatney RW, Caron JP, Steficek BA.An obstructive enterolith was diagnosed in an 11-month-old 68-kg miniature horse with a 24-hour history of mild, intermittent colic. Abdominal radiography revealed gas distention of the cecum and the right and left ascending colon, and a radiodense elliptical structure in the area of the left kidney. During exploratory laparotomy, the right dorsal colon was noticed to contain ecchymotic hemorrhage and generalized discoloration in the portion proximal to the location of the enterolith. While exteriorizing the ascending colon, it ruptured caudal to the diaphragmatic flexure in the right dorsal c...
Palmer JE, Benson CE, Whitlock RH.Eighteen ponies were inoculated IV with Ehrlichia risticii-infected P388D1 mouse monocyte cells. Twenty-four hours after onset of fever (rectal temperature > 38.8 C), 9 ponies were treated with oxytetracycline (6.6 mg/kg of body weight, IV, q 24 h) for 5 days. The remaining 9 ponies served as infected nontreated controls. Mean scores of the following variables were not significantly different between groups on the day treatment was begun: rectal temperature, diarrhea, borborygmal sounds, feed intake, mental attitude, and evidence of a hyperresonant area in the abdomen. All ponies were observed...
Blanchard PC, Filkins M.Cryptococcus neoformans was the causative agent of pneumonia in a 9-month-old equine fetus aborted by a healthy American Paint mare. Endometritis was diagnosed on biopsy, and vaginal specimens obtained for culture were Cryptococcus-positive 1 month following abortion but not 5 months after abortion. Infection resolved without treatment between 1 and 5 months after abortion, and the mare was bred the following year and delivered a live premature foal without evidence of Cryptococcus infection.
Maddison JE.Fifty-nine reports of suspected adverse drug reactions (ADRs) were received by the Adverse Drug Reaction Subcommittee of the Australian Veterinary Association from February 1991-March 1992 inclusive. The number of reports received/number of animals involved per species was: dogs (23/24); cats (20/30); horses (4/4); cattle (7/10); sheep (3/745); poultry (1/580); pigs (1/8). Of these, 38 (64%) were classified as definite ADRs and 9 (15%) as probable ADRs. In 10 (17%) reports an ADR could not be substantiated or there was insufficient information available to make a decision. Two reports involved...
Weldon AD, Zhang C, Antczak DF, Rebhun WC.Selective IgM deficiency was diagnosed in a 3-month-old Standardbred colt that was referred for chronic respiratory tract disease. Immunoglobulin quantification revealed normal IgG and IgA concentrations, but undetectable IgM concentration. Stimulation of blood lymphocytes with the T-cell mitogens concanavalin A and phytohemagglutinin yielded results within the normal range. However, stimulation with the B-cell mitogen lipopolysaccharide produced no response. A B-cell defect similar to that associated with several immunodeficiency disorders in people was suggested as the cause of the IgM defic...
Hinrichs K, Spensley MS, McDonough PL.To investigate a model for equine endometritis, 12 mares with normal reproductive tracts were divided into 2 groups. All mares received progesterone in oil, 250 mg im, daily. At 5 days after initiation of progesterone administration, the uteri were inoculated with 10(6) colony forming units of Pseudomonas aeruginosa. The day of inoculation was designated Day 0. On Day 6, endometrial swab samples yielded P. aeruginosa in 5 mares; samples from the other 7 mares yielded heavy growth of Escherichia coli, Streptococcus zooepidemicus, Klebsiella pneumoniae, Enterobacter spp., Citrobacter diversus, S...
Fitzpatrick JL, Bailey M, Harbour DA, Stokes CR.Adult ponies which were fed ovalbumin (OVA) daily for 2 weeks had significantly greater serum anti-OVA IgG (P = 0.001) and antigen specific lymphocyte responses (P = 0.031) after intramuscular injection with OVA given with saponin than control ponies which had not been fed the antigen. This suggests that, despite the lack of evidence of B- or T-cell activation in peripheral blood during the period of OVA feeding, the animals were primed for an active secondary immune response. Adult ponies were challenged with equine rotavirus, strain H-2, but no statistically significant differences were foun...
Moore RM, Schneider RK, Kowalski J, Bramlage LR, Mecklenburg LM, Kohn CW.Bacterial culture and susceptibility results were analysed from 233 horses with septic arthritis/tenosynovitis or osteomyelitis that developed after fracture repair. Antibiotics were deemed highly effective, effective or ineffective if > or = 85%, 70-84.9% or < 70% of the isolates were susceptible respectively. In total, 424 bacterial types were isolated; 386 were aerobic or facultative and 38 were anaerobic. Enterobacteriaceae (28.8%) were the most common bacterial group isolated, followed by non-beta-haemolytic streptococci (13.0%), coagulase-positive staphylococci (11.8%), beta-haemol...
McConnico RS, Roberts MC, Tompkins M.A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.
Stadler P, Weinberger T, Kinkel N, Deegen E.B- and M-mode echocardiography was performed on 38 horses. 34 patients had systolic heart murmur with the point of maximal intensity over mitral valve. Additionally, 17 of these patients were examined with the pulsed wave doppler echocardiography (Vingmed 200). In 26 patients with cardiac murmur and in 4 patients without cardiac murmur a mitral valve insufficiency was diagnosed by echocardiography. In 8 horses with a systolic murmur over mitral valve M- and B-mode evaluation could not reveal a haemodynamic importance of the murmur. The diagnosis of MVI was based on a dilation of left atrium wi...
Foley JP, Legendre AM.Itraconazole, a tricyclic azole effective against a number of deep mycotic diseases, was used to treat a Quarter Horse filly with coccidioidomycosis. The horse was almost normal after 90 days of treatment. Five months after discontinuing itraconazole treatment, the filly had severe neck pain and neurologic signs from recurrence of coccidioidomycosis and was treated with itraconazole for an additional 6 months. Her clinical condition improved to almost normal and the filly has remained normal for 2 years. There was no evidence of drug toxicity.
Eberhardt C, Gerhards H.The three tests (EQUI Z-Test, AGLUTINADE FOAL IMMUNITY, CITE Foal IgG-Test) were evaluated for their accuracy and usefulness in the field. Single radial immunodiffusion was used as reference method. All tests were easily and rapid to perform and results were obtained within a few minutes. It was easy to get the results of the CITE Foal IgG-Test, but use of the EQUI Z-Test and the FOAL AGLUTINADE IMMUNITY-Test needed some practice to get correct results. Results obtained by the CITE Foal IgG-Test correlated to single radial immunodiffusion in 94%, those obtained by FOAL AGLUTINADE IMMUNITY-Test...
Peloso JG, Stick JA, Nickels FA, Lumsden JM, Derksen FJ.A 2-year-old 400-kg Standardbred colt with a history of exercise intolerance was determined to have dorsal displacement of the soft palate (DDSP). Standing endoscopy revealed a soft, flaccid, and hypoplastic epiglottis and arytenoid cartilages that moved symmetrically and abducted fully. Lateral laryngeal radiography was used to calculate a corrected thyroepiglottic length of 6.48 cm. Videoendoscopy during exercise on a high-speed treadmill at standardized treadmill speeds was performed weekly for 3 consecutive weeks. The soft palate dorsally displaced at each examination. A sternohyoideus/ste...
Witarski W, Kij B, Nowak A, Bugno-Poniewierska M.A hucul mare with reproductive abnormalities was examined during karyotype analysis. The karyotype was analysed based on evaluation of 860 metaphase plates in chromosome preparations. The use of fluorescence in situ hybridization (FISH) with an X chromosome painting probe showed premature X chromosome separation in 9.5% cases of examined chromosome spreads. In this report, we present the first identify premature centromere division (PCD) as a possible cause of abnormal X chromosome morphology in horses and as a probable cause of reproductive difficulties.
Moulay S, Zientara S, Sailleau C, Cruciere C.In order to develop a non-radioactive dot-blot hybridization assay, for the detection of African-horse sickness virus (AHSV), genome segment 7 from 9 serotypes was amplified by RT-PCR. The resulting PCR products were denatured, immobilized on nylon membranes and then hybridized to a non-radioactive digoxigenin-labelled probe. This probe (265 bp in length) was generated by nested-PCR using genome segment 7 of AHSV, serotype 4 as a template. The dot-blot was visualized by chemiluminescence. Positives were obtained from the PCR products amplified from all 9 AHSV serotypes, but not from any other ...
Coultous RM, Raftery AG, Shiels BR, Sutton DGM, Weir W.Sarcocystis fayeri is a canine protozoan parasite with an equine intermediate host. Historically classified as an incidental pathogen, recent literature has described the toxic effects of Sarcocystis fayeri in human food poisoning, and highlighted potential involvement in equine neuromuscular disease. Until now, horses were believed to be the exclusive intermediate host. This study reports the first molecular confirmation of S. fayeri in a donkey, and gives rise to the consideration of donkeys being a potential reservoir for the parasite. This finding is of particular importance in understandi...
Schultze AE, Sonea I, Bell TG.Although primary malignant pulmonary neoplasia of horses is rarely encountered, this diagnosis was confirmed in 2 horses on the basis of necropsy and histopathologic findings. One horse, with cystic mucinous adenocarcinoma, had respiratory tract and neurologic signs directly attributable to the neoplasm, and a tentative antemortem diagnosis of pulmonary neoplasia was made. The other horse, with anaplastic bronchogenic carcinoma, did not have clinical signs of pulmonary neoplasia.
Pellegrini A, Hägeli G, von Fellenberg R.Addition of perchloric acid (6.4% w/v final concentration) to horse alpha 1-proteinase inhibitor or to horse plasma neither precipitated nor inactivated alpha 1-proteinase inhibitor. None of the isoinhibitors of alpha 1-proteinase inhibitor was altered by dilute perchloric acid. This unexpected behavior led to a simplified procedure for the purification of horse alpha 1-proteinase inhibitor, consisting of removal of the bulk of plasma proteins, by perchloric acid precipitation and by gel filtration on Sephadex G-75 and G-200. The resulting preparations of alpha 1-proteinase inhibitor were immu...
AbouEl Ela NA, El-Nesr KA, Ahmed HA, Brooks SA.Severe combined immunodeficiency (SCID) is a fatal genetic disorder and one of the common genetic diseases of the Arabian horse. The genetic mutation responsible for this disease is a five base pair deletion (TCTCA) in the DNA-protein kinase catalytic subunit gene. Severe combined immunodeficiency is a recessive autosomal genetic disorder with 25% chance inheritance of the disease among the progeny of carrier parents. It causes complete absence of certain immune cells, like B and T lymphocytes, leaving foals with immunodeficiency and exposing them to early death within 4 to 6 months. This stud...
Jones DM.A short account of the natural history of the wild Equidae is given as a background to their management in captivity. In general the approach to their husbandry and veterinary care is similar to that for the domestic horse. A mixture of etorphine and acepromazine has been found to be the most effective for handling and conventional methods of anaesthesia can be safely superimposed on these if required. The data collected at Whipsnade on the haematology and biochemistry of these species is summarised in tabular form and an analysis is included of the post-mortem examinations of 105 equine carca...
Dawson J, Lees P, Sedgwick AD.Equine polymorphonuclear (PMN) and mononuclear (MN) leucocytes were separated on Percoll gradients and used to study the chemoattractant properties of the polar ether-linked phospholipid, platelet activating factor (PAF). Six concentrations of PAF ranging from 1 ng/ml to 100 micrograms/ml were studied in each of two in vitro assay systems, the agarose microdroplet and a microfilter technique. Very significant (p less than 0.01) increases in the movement of both PMN and MN cells were obtained with most concentrations of PAF. In two instances there was no apparent concentration-response relation...
Firth EC.A case of vesical calculus in which haematuria was not a presenting sign is described. Methods of removal of vesical calculi are discussed. In this case, urethral sphincterotomy facilitated delivery.
Magdesian KG, Wilson WD, Mihalyi J.To determine disposition kinetics of amikacin in neonatal foals administered high doses at extended intervals. Methods: 7 neonatal foals. Methods: Amikacin was administered (21 mg/kg, i.v., q 24 h) for 10 days. On days 1, 5, and 10, serial plasma samples were obtained for measurement of amikacin concentrations and determination of pharmacokinetics. Results: Mean +/- SD peak plasma concentrations of amikacin extrapolated to time 0 were 103.1 +/- 23.4, 102.9 +/- 9.8, and 120.7 +/- 17.9 microg/mL on days 1, 5, and 10, respectively. Plasma concentrations at 1 hour were 37.5 +/- 6.7, 32.9 +/- 2.6, ...
Asbury AC, Schultz KT, Klesius PH, Foster GW, Washburn SM.Ten mares, 5 resistant and 5 susceptible to bacterial endometritis, were examined for differences pertaining to the efficiency of phagocytosis of bacteria by neutrophils in the uterus. An assay for chemiluminescence was used to evaluate various schemes of opsonization and relate them to phagocytic rate. 123I-labelled albumin was used to measure protein migration to the inoculated uterus. Neutrophil numbers moving to the uterine lumen were determined. Before inoculation resistant mares were found to have substances in their uterine secretions that opsonized bacteria, resulting in effective phag...
van Brantegem L, de Cock HE, Affolter VK, Duchateau L, Govaere J, Ferraro GL, Ducatelle R.Early diagnosis and monitoring progression of chronic diseases in elastin-rich tissues, such as chronic progressive lymphoedema in draught horses and chronic obstructive pulmonary disease (COPD) is still a real challenge in the horse. Use of an enzyme-linked immunosorbent assay (ELISA) to detect anti-elastin antibody (AEAb) levels might be useful to assess the status of such diseases. Baseline levels, representing physiological breakdown of elastin in normal horses, are not available at present. Objective: Levels of AEAb in healthy horses are generally low and follow the same age-related patte...
Newman AW.Clinical pathology results are only as good as the quality of samples and accompanying information submitted to the diagnostic laboratory. The frustration of nondiagnostic or equivocal test results can often be avoided by taking the time to follow sample handling and submission guidelines. This article discusses preanalytical errors that commonly affect the accuracy of hematology, chemistry, and cytology testing, and offers practical tips for preventing these errors and maximizing diagnostic yield.
Hudson NP, Pearson GT, Mayhew IG, Proudman CJ, Burden FA, Fintl C.Intestinal motility disorders are an important problem in horses and donkeys and this study was carried out in order to evaluate the enteric neurons in animals with and without intestinal disease. Surplus intestinal tissue samples were collected from 28 horses undergoing exploratory laparotomy for colic. In addition, surplus intestinal samples from 17 control horses were collected immediately following humane destruction for clinical conditions not relating to the intestinal tract. Similar samples were also collected during routine post-mortem examinations from 12 aged donkeys; six animals wer...
Sergeant ES, Wilson G.To quantify the probability of freedom from equine influenza (EI) in New South Wales (NSW), Australia, based on analysis of polymerase chain reaction (PCR) testing. Methods: Testing in the infected areas of NSW during the period 1 January to 30 April 2008. Results: Data from the random survey were collated and analysed to provide estimates of the probability of detecting EI if it was present at a prevalence ranging from 0.01% to 0.5%. The sensitivity estimates were then combined with a prior estimate of the probability of freedom in a simulation model, to estimate the posterior probability of ...