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.
Sauer P, Andrew SE, Lassaline M, Gelatt KN, Denis HM.To document changes in antibiotic resistance of organisms in cases of equine bacterial ulcerative keratitis over a 10-year time period. Methods: A retrospective study. Methods: Medical records of equine patients with bacterial ulcerative keratitis seen at the University of Florida's VMTH for the years 1991-2000 were reviewed. Methods: All cases of equine bacterial ulcerative keratitis for the above mentioned years were examined. Bacterial isolates were identified and subjected to Kirby-Bauer disc diffusion method sensitivity tests. Antibiotics used in the sensitivity tests included bacitracin,...
Dias Fde O, Lorosa ES, Rebêlo JM.A precipitin test was employed to study the alimentary tract content of Lutzomyia longipalpis in the intra- and peridomiciliary environments in the municipality of Raposa, Maranh o State, a transmission area for visceral leishmaniasis or kala azar. Out of 2,240 female sandflies captured, 547 (24.4%) had fed on vertebrate blood, with the following proportions: avian (87.9%); rodent (47.2%); human (42.4%); canine (27.6%); opossum (26.6%); and equine (22.5%). Based on a survey of 120 human dwellings, chickens were found to be the most common domestic animals in the peridomicile (28.3%), followed ...
Ikeda T.Ivermectin is an oral semi-synthetic lactone anthelmintic agent derived from avermectins isolated from fermentation products of Streptomyces avermitilis. Ivermectin showed a concentration-dependent inhibitory effect on motility of a free-living nematode, Caenorhabditis elegans (C. elegans). There exist specific binding sites having a high affinity for ivermectin in the membrane fraction of C. elegans, and a strong positive correlation was detected between the affinity for these binding sites and the suppressive effect on motility of C. elegans in several ivermectin-related substances. These re...
Pusterla N, Johnson EM, Chae JS, Madigan JE.Neorickettsia (formerly Ehrlichia) risticii, the agent of Potomac horse fever (PHF), has been recently detected in trematode stages found in the secretions of freshwater snails and in aquatic insects. Insectivores, such as bats and birds, may serve as the definitive host of the trematode vector. To determine the definitive helminth vector, five bats (Myotis yumanensis) and three swallows (Hirundo rustica, Tachycineta bicolor) were collected from a PHF endemic location in northern California. Bats and swallows were dissected and their major organs examined for trematodes and for N. risticii DNA...
Keegan KG, Arafat S, Skubic M, Wilson DA, Kramer J.To investigate continuous wavelet transformation and neural network classification of gait data for detecting forelimb lameness in horses. Methods: 12 adult horses with mild forelimb lameness. Methods: Position of the head and right forelimb foot, metacarpophalangeal (ie, fetlock), carpal, and elbow joints was determined by use of kinematic analysis before and after palmar digital nerve blocks. We obtained 8 recordings from horses without lameness, 8 with right forelimb lameness, and 8 with left forelimb lameness. Vertical and horizontal position of the head and vertical position of the foot, ...
Kaminsky R.The purpose of this review is to illustrate where drug resistance in parasitic nematodes has become a major problem. The mechanisms underlying anthelmintic resistance, the possible reasons for the development of anthelmintic resistance, and recommendations to minimize the further development of anthelmintic resistance in humans will be addressed. Results: Resistance has developed to all drugs of the few anthelmintic classes currently available. Drug resistance has become a major threat to sheep production in Australia, New Zealand, Great Britain and South Africa. In addition, the treatment of ...
Fritz CL, Kjemtrup AM.Despite more than 25 years' experience with Lyme borreliosis, much remains to be learned about this complex zoonosis. Practicing veterinarians, particularly those in the northeastern and upper midwestern states, where Lyme borreliosis is highly endemic, should be familiar with the ecologic features and typical clinical signs of Lyme borreliosis. Interpretation of signs and serologic test results should be made with consideration of the regional prevalence of Lyme borreliosis and the animal's opportunity for exposure to infected Ixodes spp. The availability of recently marketed topical acaracid...
AIDS reviewsNovember 6, 2003
Volume 5, Issue 3 156-164
Towers GJ, Goff SP.Pathogenic retroviruses have driven the evolution of several dominant-acting mechanisms able to block infection and protect the host. These are exemplified by the mouse gene Fv1, which encodes a Gag-like protein able to protect against murine leukemia virus (MLV) infection. The block is saturable, occurs after reverse transcription and is directed against the viral capsid gene. Several other mammalian species are also able to block MLV infection with the same capsid specificity. A human gene with this activity has been named Ref1. Recently, primates have been shown to restrict a variety of ret...
Cerri D, Ebani VV, Fratini F, Pinzauti P, Andreani E.Serological data on leptospira infection were reported and discussed. From 1995 to 2001, the blood serum samples of 9885 domestic and wild animals and humans, living in Northern and Central Italy, were examined by the macroagglutination test (MAT) employing bratislava, ballum, canicola, grippotyphosa, icterohaemorrhagiae, pomona, hardjo and tarassovi serovars as antigens. Considering sera with > or = 1:400 antibody titers as positive, 674 (6.81%) animals scored positive. Sheep, horses, pigs and dogs gave the highest number of positive responses, particularly against the serovar bratislava and,...
Kydd JH, Wattrang E, Hannant D.In general, vaccines containing inactivated equine herpesvirus-1 (EHV-1) fail to prevent abortion in pregnant mares following infection with a virulent strain of EHV-1. We have tested the hypothesis that resistance to EHV-1-induced abortion in pregnant mares is associated with high frequencies of EHV-1 specific, major histocompatibility complex (MHC) class I-restricted, cytotoxic T lymphocytes (CTL) in the circulation. To test this theory, three groups of pregnant mares were assembled with varying backgrounds of infection or vaccination in an attempt to mimic the immune status of the general p...
Honnas CM, Dabareiner RM, McCauley BH.Because of the hoof capsule, surgery of the equine foot is often perceived to be quite difficult. Knowledge of the specific disease entities that require surgical intervention as well as an in-depth understanding of the anatomy of the tissues beneath the hoof capsule is a definite prerequisite to successful surgical treatment. This article details the surgical approaches used to treat septic navicular bursitis, septic pedal osteitis, infection of the collateral cartilages, and keratomas. The principles used to treat these conditions can be applied to a variety of other conditions for which acc...
Redden RF.Radiographic examination of the equine foot can provide the veterinarian and farrier with a wealth of information. Positioning and selection of exposure factors are of central importance if one is to produce radiographs of maximum diagnostic value.
Parks A, O'Grady SE.Laminitis is divided into four different phases: developmental, acute, subacute, and chronic. The focus of this article is on treating the laminitic horse after the cessation of therapy for the acute phase, that is, usually 2 to 4 weeks after the onset of clinical signs.
Kohler AK, Stone DM, Hines MT, Byrne BA, Alperin DC, Norton LK, Hines SA.Rhodococcus equi is an opportunistic pathogen in immunocompromised humans and an important primary pathogen in young horses. Although R. equi infection can produce life-threatening pyogranulomatous pneumonia, most foals develop a protective immune response that lasts throughout life. The antigen targets of this protective response are currently unknown; however, Mycobacterium tuberculosis is a closely related intracellular pathogen and provides a model system. Based on previous studies of M. tuberculosis protective antigens released into culture filtrate supernatant (CFS), a bacterial growth s...
Judy CE, Chaffin MK, Cohen ND.To identify features of guttural pouch (auditory tube diverticulum) empyema in horses and compare findings of uncomplicated guttural pouch empyema with guttural pouch empyema complicated by chondroids. Methods: Retrospective study. Methods: 91 horses with guttural pouch empyema. Methods: Medical records of horses with guttural pouch empyema were reviewed. Results: The most common owner complaint and abnormal finding was persistent nasal discharge. Chondroids were detected in 21% (19/91) of affected horses. Streptococcus equi was isolated from the guttural pouch in 14 of 44 horses; for Streptoc...
Olsen SN, Schumann T, Pedersen A, Eriksen L.It was demonstrated in the present study that a simple Baermann technique using disposable materials, was successful in detecting living, motile cyathostome larvae in the faeces of horses.
Reis JL, de Carvalho EC, Nogueira RH, Lemos LS, Mendoza L.Three cases of equine subcutaneous pythiosis with dissemination to the internal organs were investigated. The subcutaneous lesions were observed on the mammary gland, nostrils and limbs of the infected horses. Histopathological analysis of the infected tissues revealed a strong eosinophilic reaction, with macrophages, mast cells and giant cells. Sparsely septated hyphal filaments of 4-6 microm diameter were identified in the center of the eosinophilic areas. Specific fluorescent antibody against Pythium insidiosum confirmed the hyphae in the infected tissues in three examined horses. In one of...
Dubey JP, Mitchell SM, Morrow JK, Rhyan JC, Stewart LM, Granstrom DE, Romand S, Thulliez P, Saville WJ, Lindsay DS.Sarcocystis neurona, Neospora caninum, N. hughesi, and Toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. The source of infection for N. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for S. neurona, N. caninum, and T. gondii, respectively. Seroprevalence of these coccidians in 276 wild horses from central Wyoming outside the known range of the opossum (Didelphis virginiana) was determined. Antibodies to T. gondii were found only in 1 of 276 horses tested with the modified agglutination test using 1:25, 1:50, ...
Wilkins PA, Palmer JE."Shaker foal" disease, toxicoinfectious botulism of foals, was 1st described as a clinical entity in 1967. The reported mortality rate was 90%, with death occurring within 24-72 hours of the onset of the characteristic clinical signs. The mortality rate decreased when equine-origin botulism antitoxin became available; however, a certain percentage of foals continued to die of respiratory failure. Mechanical ventilation is an important part of the treatment of infant botulism and is essential to the survival of many affected infants. We report a retrospective study of 9 foals with toxicoinfecti...
Vetterling JM, Thompson DE.Kidneys from 5 of 40 ponies (Equus caballus) and from 3 of 14 burrows (Equus asinus) were found infected with Klossiella equi. In addition to previously reported sporogonous stages in epithelial cells of Henle's loop, schizogonic stages in endothelial cells of Bowman's capsule and epithelial cells of the proximal convoluted tubules are described. The association of macro- and micro-gametocytes in syzygy is discounted, and a microgametocyte with 8 to 10 microgametes is characterized. Microgametes in the process of migrating to macro gametes are reported. A life cycle for this parasite is propos...
Samitz EM, Biberstein EL.Thirty-seven local isolates of Actinobacillus suis-like organisms from diseased and clinically normal horses and 1 llama were compared with reference strains of A suis, A lignieresii, A equuli, A capsulatus, A hominis, A (Pasteurella) ureae, and equine A suis-like organisms (ASLO) previously described in literature. Comparison was by cultural characteristics, carbohydrate fermentation, enzyme profiles, and whole-cell protein polyacrylamide gel electrophoresis. Carbohydrate fermentation, determined by API-CH gallery, divided 36 equine ASLO isolates into 6 API-CH biotypes. The llama isolate was ...
Butters A.A 4-day-old, male, American paint foal was presented for abdominal distention, respiratory distress, and diarrhea. Bladder rupture and uroperitoneum were diagnosed following abdominal ultrasonography and abdominocentesis. The defect in the dorsocranial part of the bladder wall was surgically repaired. Un poulain American Paint mâle âgé de quatre jours est présenté pour ballonnement abdominal, détresse respiratoire et diarrhée. Une rupture de la vessie et un uropéritoine sont diagnostiqués après une échographie et une paracentèse abdominale. Le défaut dans la partie dorso-crânial...
Mackenzie RM, de Siger J, Parra D.Two strains of Venezuelan equine encephalitis (VEE) virus were examined for the ability to replicate in, as well as to produce death among donkeys. One, a low passage strain known as strain P676 was originally isolated from mosquitos in Venezuela. The other, strain V-38 was isolated from a horse brain in 1938 and had undergone an unknown number of laboratory passages; it is used extensively for the preparation of inactivated VEE vaccine. Both strains were found to be approximately equal in their ability to infect donkeys. However, a quantity as small as 50% hamster intraperitoneal infectious u...
Rejnö S.LDH is an intracellular enzyme, which when cells degenerate is released to the extracellular spaces and body fluids. Cells and organs in the mammalian body differ from each other with respect to their LDH isoenzyme patterns. These circumstances have led to the use of LDH isoenzyme determinations in laboratory diagnostic work. In the present investigation total LDH activity and LDH isoenzyme distribution in equine synovial fluid from healthy joints, joints with serous arthritis, osteochondrosis dissecans and arthrosis, were determined. The fluids from the diseased joints differed from normal sy...
Bauerfeind R, Wieler LH, Weiss R, Baljer G.From April 1990 through June 1991 clinical salmonellosis and asymptomatic faecal excretion of Salmonella spp. were seen in hospitalized horses at two veterinary hospitals. 76 Salmonella strains from hospitalized horses and 18 strains from horses without any clinical contact were characterized by serotyping and plasmid profile analysis. From April 1990 through January 1991 97.8% of the hospitalized horses were infected with strains of S. typhimurium var. Copenhagen, which were closely related according to their similar plasmid patterns. Other strains of S. typhimurium var. Copenhagen and seroty...
Spyrou V, Papanastassopoulou M, Koumbati M, Nikolakaki SV, Koptopoulos G.Molecular analysis of the regulatory and structurally important genetic segments of equine infectious anemia virus (EIAV) in mules is presented. We have previously reported clinicopathological and laboratory findings in mules infected with EIAV, both naturally and after experimental inoculation. In this study the fragment coding for integrase, gp90, tat and the fusion domain of gp45 of the proviral genome from these animals was sequenced and compared with one another and with that of EIAV strains already published in the literature. Significant variations were observed mainly in the sequences ...
Dias De Castro LL, Oliveira Júnior GA, Perez BC, Carvalho ME, De Souza Ramos EA, Ferraz JBS, Molento MB.Cyathostomins are considered one of the most important parasites of horses. A group of horses within a herd can be responsible for eliminating the majority of parasite eggs. This phenotype might be explained by genetic factors. This study aimed to identify genomic regions associated with fecal egg count (FEC) and hematological parameters by performing a genomic-wide association study (GWAS) in Thoroughbred horses naturally infected with cyathostomins. Packed cell volume (PCV), differential leukocyte, and FEC were determined from 90 horses. All animals were genotyped using the Illumina Equine 7...
Dixon PM, McGorum B.Two horses on separate farms developed severe obstructive pulmonary disease in successive years during the early summer months. In both cases clinical remission of the respiratory distress was achieved by moving the animals to different environments. The suggested aetiology for this outdoor chronic respiratory disease is a pulmonary allergy to pollen. Both animals were also shown to suffer from classical chronic obstructive pulmonary disease, i.e., obstructive pulmonary disease in the presence of hay and, or, straw.
Betteridge KJ, Raeside JI, Waelchli RO, Christie HL, Hayes MA.Sixteen cases of spontaneous pregnancy loss (11 of singletons and five of pairs of twins) are described. The losses occurred between gestation Days 13 and 25 in 12 mares being monitored almost daily by transrectal ultrasonography (for measurement of conceptus growth) and blood sampling (for determination of maternal plasma progesterone concentrations as evidence of luteolysis) in experimental studies of early pregnancy. In 10 of the 16 cases the uterus was flushed and eight conceptuses were recovered for morphological assessment. Five of the 11 losses of singletons occurred before Day 16 and, ...
Dorman DC, Haschek WM.Toxicosis attributable to propylene glycol (1,2-propanediol) was suspected in an 8-year-old 450- to 500-kg male Quarter Horse. Clinical signs of toxicosis developed within 15 minutes of the accidental iatrogenic oral administration of 3.8 L of propylene glycol. Clinical signs of toxicosis included salivation, sweating, ataxia, and signs of pain. Additionally, at 24 hours after propylene glycol ingestion, the horse became increasingly atactic, had an abnormal breath odor, developed rapid shallow breathing, and was cyanotic. The horse died of apparent respiratory arrest 28 hours after the propyl...