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.
Wohlsein P, Pohlenz JF, Davidson FL, Salt JS, Hamblin C.The distribution of viral antigen was studied in various tissues of three ponies, aged 3-4 years, infected experimentally with a virulent strain of African horse sickness virus (AHSV) serotype 4. Tissues were collected from the animals in the terminal stage of the peracute form of the disease and from one noninfected horse, included as a control. A polyclonal antibody with specificity for AHSV, plus the nonstructural protein NS2, was used in a sensitive avidin-biotin-peroxidase-complex (ABC) method performed on formalin-fixed, paraffin-embedded tissue sections. AHSV antigen was located primari...
Saetang T, Treamwattana N, Suttijitpaisal P, Ratanabanangkoon K.A quantitative comparison was made on the fractionation of pepsin-digested horse antivenoms by ammonium sulfate (AS) fractional precipitation and ion-exchange chromatography on Q-Sepharose. In the precipitation process, pepsin digested horse anti-Naja kaouthia serum was precipitated by 30% saturated AS followed by 50% saturated AS. The recovery of antibody activity [as measured by an enzyme-linked immunosorbent assay (ELISA) against the cobra postsynaptic neurotoxin 3] from the 30-50% saturated AS precipitate was 53% with a 1.93-fold purification. For the chromatographic process, the behavior ...
Shin EK, Perryman LE, Meek K.To determine whether a recently developed test would correctly identify horses heterozygous for the severe combined immunodeficiency (SCID) trait. Methods: Case series. Methods: 17 healthy Arabian horses that had previously produced foals with SCID, 1 healthy Arabian foal whose dam and sire had produced foals with SCID, 4 foals with SCID, and 1 healthy non-Arabian foal. Methods: DNA was extracted from leukocytes or fibroblasts, amplified by means of polymerase chain reaction, and hybridized with probes specific for the normal and mutant alleles of the catalytic subunit of DNA-dependent protein...
Sweeney CR, Russell GE.To determine type and frequency of complications associated with use of a one-hole subpalpebral lavage (SPL) system in horses. Methods: Retrospective study. Methods: 150 horses with 156 SPL systems. Methods: Signalment, primary complaint, method used for placement, time SPL system was in place, and complications were retrieved from medical records. Results: Complications were not associated with placement, maintenance, or removal of 66 of 156 (42%) SPL systems. A minor complication was reported in association with 53 (34%) SPL systems, and a serious complication was reported in association wit...
Leroux C, Issel CJ, Montelaro RC.We have investigated the genetic evolution of three functionally distinct regions of the equine infectious anemia virus (EIAV) genome (env, rev, and long terminal repeat) during recurring febrile episodes in a pony experimentally infected with a well-characterized reference biological clone designated EIAV(PV). Viral populations present in the plasma of an EIAV(PV)-infected pony during sequential febrile episodes (18, 34, 80, 106, and 337 days postinfection) were amplified from viral RNA, analyzed, and compared to the inoculated strain. The comparison of the viral quasispecies showed that the ...
Traub-Dargatz J.This article describes the field investigation of horses with nasal discharge (serous, purulent, blood and feed). Flow charts on how to evaluate affected horses, and photographs of the examination procedures and of horses affected with nasal discharge are included.
O'Brien RT, Biller DS.This article addresses the current status and clinical opportunities for portable radiography and ultrasonography. Radiology is indicated for imaging the nasal cavity, larynx, pharynx and thin portions of the neck. In young foals, adequate radiographs of the entire respiratory tract may be possible. Ultrasonography is indicated in superficial parts of the head and neck, the pleural space and diseased parts of the lungfields.
Savage CJ.Defining respiratory disease is not always easy in the horse because auscultation with accurate interpretation of lung sounds can be difficult. However, performing a thorough physical examination, including rebreathing auscultation and percussion of the thorax and sinuses, is very useful in elucidating the problem. Endoscopic examination of the upper respiratory system is also critical for definitively diagnosing certain conditions.
Hoffman AM.The advantages of aerosol medications include the direct, topical application to the target organ (airways); rapid effect; and low systemic availability. There are now more efficient methods for aerosol delivery that facilitate the use of increasingly sophisticated aerosol drugs. This article reviews the principles of aerosol deposition and the pharmacology of current medications.
Keg PR, van Weeren PR, Schamhardt HC, Barneveld A.A pressure-sensitive device was developed to measure the force applied to flexion tests of the distal limb of horses. The mean force applied by a group of experienced clinicians was 150 N which results in a moment on the flexed fetlock joint of about 28.5 Nm. The coefficient of variation of the force applied by one experienced clinician was only about 12 per cent, but the coefficient of variation between clinicians was considerably higher (20 per cent), irrespective of whether the clinicians were considered to be experienced or not. The mean force applied by a group of women examiners (114 N) ...
Bain FT.Cytology can be a rewarding diagnostic technique in equine practice. The respiratory tract readily lends itself to sampling for cytologic evaluation from the upper to lower regions of the system. This article discusses preservation and staining techniques that will allow the practitioner to present satisfactory samples to the laboratory. General considerations for cytologic analysis are discussed as well as the specific findings for individual disorders of the respiratory tract. The proper use of cytologic findings in conjunction with other diagnostic techniques for the respiratory tract are a...
Hoskinson JJ, Tucker RL, Lillich J, Bertone JJ.While many equine diagnostic imaging procedures can be done in field, some procedures require specialized facilities, equipment or expertise which are generally only available in referral or specialty practices. As client awareness of the availability and advantages of these diagnostic procedures increases, veterinarians are faced with the increasing opportunity to utilize these services to provide optimal patient care. A working knowledge of the value and limitations of these methods is required to help guide veterinarians and clients in the selection of additional, and sometimes costly, diag...
Rush BR.Pharmacologic manipulation of pulmonary immunity plays an important role in primary and adjunct therapy for equine respiratory disease. Frequent exposure to respiratory viral pathogens, strenuous exercise, long distance transport, and inhalation of harmful substances destroy various aspects of the pulmonary defense system and predispose performance horses to development of infectious and noninfectious respiratory disease. Pulmonary immunity may be bolstered by nonspecific immunostimulants to combat primary or secondary immunodeficiency. State of the art technology improves active and passive-s...
Demeulenaere D, Vercruysse J, Dorny P, Claerebout E.The control of naturally acquired cyathostome infections in horses by treatments with ivermectin and moxidectin was evaluated in three field studies. In a first study the efficacy of both drugs was assessed in a faecal egg count reduction test. Both ivermectin and moxidectin demonstrated efficacies greater than 99 per cent for up to 60 days after treatment. In a second study, the period required for strongyle eggs to reappear was estimated in horses treated either with ivermectin or moxidectin. For the horses treated with ivermectin the period varied between 10 and approximately 13 weeks, and ...
Hague BA, Martinez EA, Hartsfield SM.To evaluate effects of a single high dose of gentamicin on neuromuscular function in horses anesthetized with halothane. Methods: 6 healthy adult horses. Methods: Halothane-anesthetized horses were positioned in left lateral recumbency, and the right hind limb was immobilized in a reusable fiberglass cast fixed to a steel frame. The hoof was attached to a force transducer, and resting tension of 0.93 +/- 0.16 kg was maintained. A supramaximal train-of-four stimulus of 2 Hz for a duration of 0.25 millisecond was applied to the superficial peroneal nerve every 20 seconds by a square-wave stimula...
Shimizu A, Kawano J, Yamamoto C, Kakutani O, Anzai T, Kamada M.Pulsed-field gel electrophoresis (PFGE) was used to determine genetic relationships among 15 methicillin-resistant Staphylococcus aureus (MRSA) isolates from mares with metritis and from a stallion with dermatitis in Hokkaido. All the 15 isolates showed phage pattern 6/47/54/75, coagulase type IV, and enterotoxin type A. The restriction endonuclease SmaI cut their genomic DNAs into 15 or 16 fragments ranging in size from 8 to 630 kb. Fourteen of the 15 isolates showed the same PFGE pattern, whereas the remaining one appeared to be closely related. The 9 human MRSA isolates showing the same phe...
Baskett A, Barton MH, Norton N, Anders B, Moore JN.To compare effects of a single dose of pentoxifylline (PTX), flunixin meglumine (FM), and their combination (FM/PTX) in a model of equine endotoxemia. Methods: 24 healthy horses, aged 2 to 15 years. Methods: 4 groups (n = 6/group) received 30 ng of Escherichia coli O55:B5 endotoxin/kg of body weight, i.v., over 30 minutes, and 1 of the following preparations 15 minutes before and 8 hours after endotoxin infusion: FM, 1.1 mg/kg; PTX, 8 mg/kg; FM/PTX, 1.1 mg of FM and 8 mg of PTX/kg; and saline solution bolus (ENDO). Clinical and hematologic variables were measured over 24 hours. Results: Compar...
Kubota T, Inaba Y, Uwatoko K, Akashi H, Fukunaga Y.Equine arteritis virus (EAV) grown on RK13 cell cultures was tested for hemagglutination (HA) with erythrocytes from a variety of species at 4 degrees C, room temperature and 37 degrees C. HA was observed at all temperatures with erythrocytes from mouse and chicken but not with those of cattle, horse, rabbit, guinea pig, mongolian gerbil, goose or chick embryo. Chickens showed an individual variation in agglutinability of their erythrocytes, requiring selection of birds to obtain erythrocytes for HA. The HA activity was enhanced by treatment of virus materials with Tween 80 followed by treatme...
Bailey CJ, Reid SW, Hodgson DR, Suann CJ, Rose RJ.Risk factors for musculoskeletal injury in racing Thoroughbreds were investigated in a case-control study conducted at racetracks administered by the Australian Jockey Club. Univariable analysis of 137 cases from the official Veterinary Surgeon's reports and an equal number of randomly selected controls from the Australian Race Results identified field size, barrier position and class of race as being significantly associated with breakdown (P < 0.05). Multiple logistic regression was then used to investigate the effect of each putative risk factor whilst controlling for all others. Horses at ...
Ousey JC, Prandi S, Zimmer J, Holdstock N, Rossdale PD.To determine the effect of diet on energy intake, loss, and metabolism in foals 2 to 7 days old. Methods: 14 pony foals. Methods: Group-A foals suckled their dams, group-B foals were fed milk replacer, and group-C foals were fed by total parenteral nutrition (TPN). Energy balance studies were performed over 8-hour periods on postpartum days 2, 4, and 7. Results: Mean gross energy (GE) intake of group-A foals increased between days 2 and 7. Approximately 3% of GE was excreted in urine and feces, and energy expenditure remained constant. These foals were in positive energy balance, and mean body...
Igel P, Fürst AE, Jackson MA.Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is an increasingly diagnosed degenerative dental disease in aged horses. The primary aim of this retrospective study was to determine the prevalence of EOTRH in horses admitted to the Equine Hospital, University of Zurich, for dental procedures from 2004 to 2017. A secondary goal was to measure and compare interincisal angles on two-dimensional radiographs of horses with EOTRH to determine whether the interincisal angle is associated with age and severity of the disease. Radiographs were assessed for the presence of lysis and/or...
Coutinho da Silva MA.The use of assisted reproductive techniques (ART) has helped owners to produce offspring from valuable mares that were considered infertile using standard breeding techniques. Before referring a mare for an ART, the practitioner should be able to identify the underlying cause of subfertility of the mare. The objective of this review is to provide information regarding embryo transfer, oocyte transfer and intracytoplasmic sperm injection, the three most common ART used in equine practice. Knowing the complexity as well as the risks of these techniques, enables practitioners to refer a subfertil...
Cavani F, Fini M, de Terlizzi F, Cadossi M, Ciminelli L, Ortolani S, Cherubini R, De Aloysio D, Giavaresi G, Cadossi R, Canè V.Osteoporosis involves alterations, not only in density, but also in the architectural organisation of the bone; in particular, trabecular orientation, following the skeletal load directions, lends a high degree of stiffness to the whole bone. We investigated the relationship between trabecular orientation, density, stiffness and ultrasound (US) propagation in two orthogonal directions (par. = parallel to, and ort. = orthogonal to the main orientation of the trabeculae) in cylindrical equine bone specimens (thoracic vertebrae) where a preferential orientation is present. A total of 15 cylinders...
Cock G, Darby S, Freeman DE, Gomez DE.Esophageal obstruction is a common disorder in equids usually caused by intraluminal impaction with roughage and/or other feed material. Esophageal obstructions can also be caused by foreign bodies, but they are rarely reported and information regarding diagnosis and management is lacking. This report describes an esophageal obstruction in a donkey caused by a metallic foreign body removed using endoscopic guidance. Recognition of the foreign body facilitated treatment and underscores the importance of imaging in such cases to prevent dislodgement of the object to more aboral sites where acces...
Galati P, Roperto F, De Vico G, Restucci B, D'Andrea F.Specimens of the tracheal epithelium were obtained from two sites in nine healthy horses by a fibre optic endoscope. Electron microscopic examination of 53,550 cilia revealed that 5.2 per cent of cilia were atypical. Nine hundred and seventeen (1.7 per cent) were compound, 78 (0.15 per cent) were swollen, 27 (0.05 per cent) were intracytoplasmic and 171 (3.35 per cent) had microtubular defects. These microtubular defects (159 peripheral and 12 central) were found in 5103 cross-sectioned cilia.
Marsh JA, Hallett FR, Owen RR.A comparison of methods of preparing the hyaluronic acid of equine synovial fluid for quantitative spectrophotographic analysis is presented. A new method is proposed which appears superior to the previous methods.
Pirie M, Pirie HM, Wright NG.The surface features of the upper respiratory tract of 20 clinically normal horses of various ages and types were studied with scanning electron microscopy. In the rostral part of the nasal cavity, there was a wide zone of non-ciliated epithelium whereas, caudally, the surface was well ciliated. This latter type of epithelium extended into the nasopharynx and guttural pouches although scattered areas of non-ciliated microvillous cells were also found.
Crabill MR, Watkins JP, Schneider RK, Auer JA.To determine the technique used, and the outcome for, double-plate fixation of comminuted fractures of the second phalanx of horses. Methods: Retrospective analysis of medical records. Methods: 10 horses with comminuted fractures of the second phalanx that were treated by use of double-plate fixation. Methods: Two 4- to 6-hole dynamic compression plates were abaxially placed to achieve arthrodesis of the proximal interphalangeal joint and fixation of the fracture of the second phalanx. Results: Arthrodesis and fracture healing were detected in all horses. Conclusions: Horses with comminuted fr...
Corda A, Columbano N, Secchi V, Scanu A, Parpaglia MLP, Careddu GM, Passino ES.Thrombophlebitis and thrombosis are the most common causes of jugular vein occlusion in horses. Medical and surgical treatments aim to recanalize the occluded vessel and reduce proximal venous congestion and edema. The present report describes a clinical case of equine jugular vein thrombosis (JVT) with complete vein occlusion diagnosed by saline contrast ultrasonography (SCU) and confirmed by contrast venography. Our results demonstrated that the SCU test can be easily performed and objectively interpreted using standard ultrasound equipment; it is not expensive and it does not require x-ray...
Rebhun WC, Mirro EJ, Georgi ME, Kern TJ.Habronemic blepharoconjunctivitis was characterized clinically by raised yellow gritty plaques in the palpebral and bulbar conjunctivae. Lid granulomas and blepharitis were observed in some cases. On histologic examination, mast cells, eosinophils, and collagenolysis was found in most sections, but if only one section was examined an erroneous diagnosis of mastocytosis could have been made. Treatment consisted of larvicidal mixtures for lid lesions and organophosphate ophthalmic drops along with corticosteroids for the conjunctivitis. If the cornea was damaged by the gritty conjunctival plaque...
Cornick JL.A 2-year-old Trakehner filly with pulmonary histoplasmosis is presented. Clinical signs included weight loss, intermittent fever, dyspnea and depression. Diagnosis was based on thoracic radiography, transtracheal wash cytology and lung aspirate cytology. A 5-week regimen of Amphotercin-B administered intravenously resulted in clinical recovery and return of the animal to normal activity. A brief review of histoplasmosis in man and animal is included.
Wyse CA, Nixon C, McLaughlin M, Dowell FJ, Philbey AW.The aim of this study was to characterise the expression of haem oxygenase-1 (HO-1) in healthy lung tissue from horses and to measure its activity. Samples of lung tissue were collected from six horses euthanased for reasons other than respiratory disease. HO-1 expression and activity were detected in type II alveolar epithelial cells, macrophages and neutrophils in all the samples examined. The activity was dependent on the presence of NADPH and inhibited quantitatively by the addition of increasing concentrations of a competitive inhibitor of HO-1, tin mesoporphyrin IX.
Olivier A, Wannenburg J, Gottschalk RD, van der Linde MJ, Groeneveld HT.A shoe was designed to combine the advantages of a reverse shoe and an adjustable heart bar shoe in the treatment of chronic laminitis. This reverse even frog pressure (REFP) shoe applies pressure uniformly over a large area of the frog solar surface. Pressure is applied vertically upward parallel to the solar surface of the frog and can be increased or decreased as required. Five clinically healthy horses were humanely euthanased and their dismembered forelimbs used in an in vitro study. Frog pressure was measured by strain gauges applied to the ground surface of the carrying tab portion of t...
Kaneps AJ, O'Brien TR, Redden RF, Stover SM, Pool RR.The distal phalanx and metacarpal physis of both forelimbs of 32 Thoroughbred foals 3-32 weeks of age were radiographed to identify those limbs with osseous bodies at a palmar process (PP) of the distal phalanx. Osseous bodies (ossicles) were identified radiographically in 19% of the foals. Sixteen of the 32 foals were selected for microradiographic and histological evaluation: 6 foals with radiographic evidence of ossicles and 10 foals without. Fourteen ossicles of the PP were observed radiographically. Ossicles were either a triangular bone fragment at the palmar aspect of the distal angle o...
Malalana F.Ocular abnormalities are a common finding in aged horses. Although these seldom cause overt visual deficits detected by their owners, they can be a source of chronic or acute discomfort so early detection, and treatment when available, is essential. Some of these abnormalities are specific to old horses, whereas others are a result of ongoing disease or inflammation that started earlier in life but that becomes more evident when the damage sustained to the eye is advanced. If vision is significantly affected, consideration of human safety and animal welfare is paramount.
Jackson K, Kelty E, Tennant M.Equine peripheral caries can be a significant welfare issue in affected horses. Recent work has shown that complete reversal of the condition may be possible if the primary risk factor can be identified and corrected. Determining whether caries are active (deteriorating) or inactive (improving) is of vital importance when formulating a management and treatment plan. A new grading system is proposed that looks at whether caries are likely active or inactive to assist clinicians deciding whether intervention is required. Objective: To examine the reliability of an alternative grading method for ...