Equine health encompasses the study and management of diseases, disorders, and overall well-being of horses. It involves understanding various physiological systems, preventive care, and treatment strategies to maintain optimal health in equine populations. Common areas of focus include nutrition, infectious diseases, orthopedic conditions, and reproductive health. Research in equine health aims to advance knowledge on diagnostic methods, therapeutic interventions, and management practices that improve horse welfare and performance. This page collects peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine health, offering insights into current findings and advancements in the field.
Hinrichs K, Cochran SL, Schelling SH, Steckel RR.A granulosa-theca cell tumor was found in an ovary that had an ovulation fossa and normal ovarian tissue. The ovary was removed from a mare with a history of ovarian enlargement and behavioral changes. The affected ovary had a multicystic appearance on ultrasonographic examination performed before surgery, and an ovulation fossa was not palpable on examination per rectum. However, during surgery, the affected ovary was found to be within normal size limits, with an enlargement on 1 pole, and to contain an ovulation fossa. Atrophy of the infundibulum of the affected ovary helped to confirm the ...
May SA, Hooke RE, Lees P.The presence, in equine synovial fluid, of inhibitors of interleukin-1 (IL-1) activity has been investigated by means of an assay involving IL-1-mediated production of PGE2 by synovial cells. Inhibitors of IL-1 alpha and IL-1 beta were identified in normal synovial fluid and synovial fluid from two horses with early joint disease. Inhibitors of IL-1 alpha were also present in synovial fluid from two horses with long-standing joint disease. However, IL-1 beta inhibitory activity was not present in fluid from the horses with more chronic joint disease. The effect appeared to be specific for IL-1...
Davis SL, Graf M, Morrison CA, Hall TR, Swift PJ.The chemical nature and variations in serum concentrations of growth hormone binding protein (GHBP) from humans, rabbits, and rodents have been reported. To date little is known about the GHBP of domestic animals. Therefore, we initiated these studies to determine whether a serum GHBP was present in domestic animals and to purify the binding protein (BP) from serum of selected species. Using a dextran-coated charcoal separation assay, specific growth hormone (GH) binding was demonstrated in ovine, bovine, chicken, human, goose, porcine, and equine serum (listed in sequence from lowest to highe...
Ojala M, Ala-Huikku J.From 1974 to 1979, seven stillborn foals with internal hydrocephalus were encountered from one Standardbred trotter stallion which sired 239 registered foals. An hydrocephalic foal was also aborted by a daughter of the same stallion. One affected foal from Standardbred trotters and one from a Finnish Horses were also reported. In some cases, the condition caused severe dystocia. Based on field data, possible causes of the defect could neither be proved nor specifically overruled in individual cases. Hydrocephalus was obviously not an autosomal recessive single-locus defect, nor was it X-linked...
Jarvis KA, Steffey EP, Tyler WS, Willits N, Woliner M.Results of recent investigations in humans and dogs indicate that gravity-independent factors may be important in determining the distribution of pulmonary blood flow. To further evaluate the role of gravity-independent factors, pulmonary blood flow distribution was examined using 15-microns radionuclide-labeled microspheres in five prone ponies over 5 h of pentobarbital sodium anesthesia. The ponies were killed, and the lungs were excised and dried by air inflation (pressure 45 cmH2O). The dry lungs were cut into transverse slices 1-2 cm thick along the dorsal-ventral axis, parallel to gravit...
Curtis MB, Eicker SW, Archer RM, Lindsay WA.A 5-year old Arabian mare fell during recovery from general anesthesia after an exploratory laparotomy. This fall resulted in dehiscence of the abdominal closure, and a substantial amount of intestines were exteriorized. Chemical and manual restraints were rapidly used to prevent trauma to the exposed intestines. A second general anesthesia was initiated to clean the intestines and close the incision. Multiple anesthetic problems were encountered, including arterial hypotension and hypoxemia. The horse recovered from the second general anesthesia and surgery, and all complications gradually re...
Gutiérrez Rincón JA, Vives Turcó J, Muro Martínez I, Casas Vaqué I.The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need f...
Greet TR.The paper describes the outcome of 16 cases of short-ileal-ileal intussusception in young Thoroughbred horses. The intussusception was often associated with chronic or intermittent low grade abdominal pain. At laparotomy, only the intussusception was reduced in one horse; in another, a myotomy of the thickened stenosed intussusception was carried out after reduction. In 11 cases as ileocaecal bypass anastomosis was performed proximal to the intussusception after its reduction. One horse was subjected to euthanasia during operation because of irreversible intestinal wall damage and another beca...
Misheff MM, Stover SM, Pool RR.Unicortical corticocancellous bone biopsy specimens 4.5 mm and 6.5 mm in diameter were obtained without long-term complications from the 12th rib in eight standing horses. However, the bone specimens were unsuitable for histologic or histomorphometric evaluation. In in vitro comparisons of biopsy specimens 6.5 mm and 12 mm in diameter, and of unicortical and transcortical biopsy specimens, 12 mm transcortical specimens yielded the most cancellous bone. Transcortical bone biopsy specimens 12 mm in diameter were obtained from eight horses by using power-assisted trephination. The surgical proced...
Hamada M, Takechi M, Itakura C.Langerhans' cells (LC) were investigated immunohistochemically and electron microscopically in normal equine epidermis and 133 equine cutaneous papillomas experimentally induced in five 2-year-old Thoroughbred horses. Class II major histocompatibility complex antigen-positive dendritic LC were found in the normal epidermis and ultrastructurally had the characteristic Birbeck's granules. In the developing phase of the papillomas, LC were significantly decreased in number and size, indicative of a hypofunctional state. In the regressing phase of the papillomas, LC were markedly increased in numb...
Mogg KC, Pollitt CC.Forelimb surface temperatures were continuously monitored in four clinically normal ponies exposed to: (i) constant ambient temperature; (ii) a biphasic change in ambient temperature; and (iii) an incremental increase in ambient temperature. Limb surface temperatures were recorded at the hoof, metacarpus and forearm, and rectal temperature was also measured. Under constant ambient temperature, limb surface temperatures remained relatively constant. A pyrexic episode occurred in one pony under constant ambient temperature conditions and was characterised by an onset phase in which rectal temper...
Major MD, Grant BD, White KK, Ratzlaff MH, Gallina AM, Crawley GR.Mechanical properties of equine suspensory apparatus preparations and three braided synthetic prostheses were evaluated in vitro. Force versus displacement plots and failure modes were recorded from single load-to-failure testing in 18 cadaver limbs before and after replacement of each suspensory apparatus with a prosthesis. Mean load at failure, energy to failure, and stiffness values of polytetrafluoroethylene (PTFE) prostheses were lower than those of the suspensory apparatus and aramid prosthesis. The PTFE prosthesis failed by elongation or rupture of the prosthesis. Mechanical properties ...
McCutcheon LJ, Byrd SK, Hodgson DR.Thoroughbred horses were exercised to fatigue at 40, 85, and 100% of their maximal oxygen consumption (VO2max) on a treadmill and completed a 1,600-m gallop on a track to identify the effect of exercise of various durations and intensities on the ultrastructure of mitochondria and sarcoplasmic reticulum (SR) from the middle gluteal muscle. The percentage of the total area occupied by mitochondria and SR increased in electron micrographs of muscle samples collected at the termination of exercise and at 30 and 60 min of recovery compared with those collected before exercise. Mitochondrial area i...
Orsini PG, Ross MW, Hamir AN.The ventral part of the levator nasolabialis muscle was transposed to the alveolar defect after sinusotomy and tooth extraction in five normal horses and six horses with a tooth root abscess and sinusitis. In the normal horses at weeks 6, 10, 14 and 18, the transposed muscles remained viable and were incorporated into the recipient sites, and orosinus fistulae did not form. Histologically, there was a progressive transition from muscle to fibrous tissue. There was no facial deformity or loss of nasal function at the donor site. A localized abscess was associated with incomplete removal of toot...
Moens Y, Gootjes P, Lagerweij E.The tube-in-tube technique for the functional separation of the lungs in intact anaesthetised adult horses is based on fibre-optic-guided left-sided endobronchial intubation avoiding tracheostomy. It facilitates a valid separation of the two lungs despite variability in bronchial and carinal anatomy. No clinical complications that could be related to its use have been seen.
Ferrante PL, Menninger JH, Spencer PA, Kronfeld DS.Four mares fed a low fiber, high soluble carbohydrate diet were used in a crossover design to evaluate the effects of dietary sodium bicarbonate (NaHCO3) supplementation during daily low-intensity submaximal working conditions. Mares were fed the diet at 1.7 times the maintenance energy requirement for mature horses at work. The horses tolerated the diet well and had no clinical abnormalities. Resting venous blood bicarbonate (HCO3), standard HCO3, and base excess (BE) concentrations significantly (P less than 0.05) increased with NaHCO3 supplementation, but no significant changes in resting v...
Kannegieter NJ, Ecke P.A Thoroughbred gelding was referred for treatment of a parotid duct fistula. This had developed after the referring veterinarian had excised a portion of the duct, and ligated the proximal end, as a means of treating a recurring sialocoele. This report describes the successful surgical reconstruction of the excised 15 cm portion of the parotid duct using an interposition polytetrafluoroethylene tube graft.
Lyons ET, Tolliver SC, Drudge JH, Granstrom DE, Collins SS, Stamper S.The activity of moxidectin was evaluated in 1988 and 1989 against natural infections of internal parasites in 20 critical tests (n = 20 equids) and three controlled tests (n = 20 equids). Two formulations, injectable administered intramuscularly (i.m.) or intraorally (i.o.) and gel i.o., were given at dose rates of 0.2, 0.3 or 0.4 mg kg-1 body weight. For the critical tests (all three dose rates evaluated), removals of second instar Gasterophilus intestinalis were 93-100%, except (89%) for the injectable formulation (i.m.) at 0.2 mg kg-1. Removals of third instar G. intestinalis were 88-100% f...
Condò SG, Coletta M, Cicchetti R, Argentin G, Guerrieri P, Marini S, el-Sherbini S, Giardina B.The equilibrium O2-binding properties of the hybrid haemoglobin (Hb) present in vivo in erythrocytes from mule and of its parent Hbs from horse and donkey were compared with special reference to the effect of heterotropic ligands such as Cl-, D-glycerate 2,3-bisphosphate (DPG) and inositol hexakisphosphate. All these Hbs display a decreased effect by polyphosphates, confirming that what has been observed for horse Hb [Giardina, Brix, Clementi, Scatena, Nicoletti, Cicchetti, Argentin & Condò (1990) Biochem. J. 266, 897-900] is common to other equine species, at least from a qualitative sta...
Govan JR, Sarasola P, Taylor DJ, Tatnell PJ, Russell NJ, Gacesa P.The isolation and characterization of a mucoid, alginate-producing strain of Pseudomonas aeruginosa from a nonhuman host, namely, in chondroids from an equine guttural pouch, is reported for the first time. Pure cultures of P. aeruginosa 12534 were isolated from a 17-month-old pony mare with a history of chronic bilateral mucopurulent nasal discharge from the right guttural pouch. Transmission electron microscopy of chondroids showed mucoid P. aeruginosa growing as microcolonies within a matrix of extracellular material. On the basis of expression of the mucoid phenotype under different growth...
McKinnon AO, Brown RW, Pashen RL, Greenwood PE, Vasey JR.THE name inhibin was first used around 60 years ago for a water-soluble. non-steroidal, gonadal factor that would regulate follicle-stimulating hormone (FSH) secretion through negative feedback McUullagh 1930. Inhihin is now defined as a glycoprotein hormone, consisting of two dissimilar, disulphide-linked, subunits termed at and 13 1 Burger and Igarashi 1988). Effective methods for blocking inhibin production could provide useful means by which FSH secretion, and therefore ovarian function and fertility, could be improved in the female. Increased ovulation rates have been demonstrated in shee...
Lalatta-Costerbosa G, Barazzoni AM, Clavenzani P, Petrosino G, Callegari E, Bortolami R.The articularis humeri (AH) muscle of the horse is a small muscle composed of histochemically identified type I and IIA extrafusal fibers and a large number of muscle spindles. A total of 150 complete spindles with both spindle poles available were examined in serial transverse sections. On the basis of myosin ATPase-staining reactions after alkaline and acid preincubations, four types of intrafusal fibers, namely, bag1, bag2, "mixed" bag, and chain fibers, were identified. A high proportion of the spindle population (62.6%) consisted of multiple-bag spindles containing three or more (up to si...
Evans GP, Behiri JC, Vaughan LC, Bonfield W.The behaviour of cortical bone under load is strain rate-dependent, i.e. it is dependent on the rate at which the load is applied. This is particularly relevant in the galloping horse since the strain rates experienced by the bone are far in excess of those recorded for any other species. In this study the effect of strain rates between 0.0001 and 1 sec-1 on the mechanical properties of equine cortical bone were assessed. Initially, increasing strain rates resulted in increased mechanical properties. Beyond a critical value, however, further increases in strain rate resulted in lower strain to...
Stevenson AJ, Weber MP, Todi F, Young L, Beaumier P, Kacew S.Plasma and urinary concentrations of procaine were examined in Standardbred mares after subcutaneous administration of various doses (80 mg to 1600 mg) of procaine hydrochloride. Regardless of dose, peak plasma procaine values occurred within 1 h, but remained detectable in a dose-dependent manner, with procaine present at 1 h with the 80 mg dose and 6 h at the 1600 mg dose. Similarly, peak urinary procaine concentrations were attained within 1.5 to 3 h, irrespective of dose, while detection time was dose-dependent, being 23 h for 80-200 mg doses but as long as 30-54 h with the 1600 mg dose. W...
Nakamura T, Kiryu K, Machida N, Iwata T, Oikawa M, Kaneko M.The common, external, and internal carotid and occipital arteries were examined histologically at the trifurcation of the common carotid arteries in 13 Thoroughbred foals (0 to 30 days old) and 64 Thoroughbred adults (2 to 4 years old). Calcification in the media of the common carotid and external carotid arteries was observed in 3 of the 13 foals and in 30 of the 64 adult horses. Calcification resembled that seen in Mönckeberg's arteriosclerosis in human beings, the cause of which is unknown.
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Glanville RJ, Christie B.The equine influenza (EI) outbreak presented many challenges that required high-level coordination and decision making, as well as the development of new approaches for satisfactory and consistent resolution. This paper outlines the elements of the national coordination arrangements, preparatory arrangements in place prior to the outbreak that facilitated national coordination, and some of the issues faced and resolved in the response.
Mugnier S, Boittin S, Douet C, Monget P, Magistrini M, Goudet G.In human and rodents, sperm-zona pellucida binding is mediated by a sperm surface Galactosyltransferase that recognizes N-Acetylglucosamine residues on a glycoprotein ZPC. In large domestic mammals, the role of these molecules remains unclear: in bovine, they are involved in sperm-zona pellucida binding, whereas in porcine, they are not necessary. Our aim was to clarify the role of Galactosyltransferase and N-Acetylglucosamine residues in sperm-zona pellucida binding in ungulates. For this purpose, we analyzed the mechanism of sperm-zona pellucida interaction in a third ungulate: the horse, si...
Gimeno BF, Bariani MV, Laiz-Quiroga L, Martínez-León E, Von-Meyeren M, Rey O, Mutto AÁ, Osycka-Salut CE.Cryopreservation by negatively affecting sperm quality decreases the efficiency of assisted reproduction techniques (ARTs). Thus, we first evaluated sperm motility at different conditions for the manipulation of equine cryopreserved spermatozoa. Higher motility was observed when spermatozoa were incubated for 30 min at 30 × 106/mL compared to lower concentrations (p < 0.05) and when a short centrifugation at 200× g was performed (p < 0.05). Moreover, because sperm suitable for oocyte fertilization is released from oviduct epithelial cells (OECs), in response to the capacitation process, we e...
Katayama Y, Oikawa M, Kaneko M, Yoshihara T, Yoshikawa H, Yoshikawa T.Three monoclonal antibodies capable of individually recognizing chondrocytes, osteoblasts and osteocytes were prepared. EB-1 reacted with a 55-kDa antigen on the chondrocyte membrane, EB-2 with a 110-kDa antigen on the membrane of osteoblasts and/or partial osteocytes, and EB-3 with a 130-kDa antigen on the membrane of osteocytes. These monoclonal antibodies may be useful probes for studying the differentiation and maturation of osteogenic cells.
Firth EC, Alley MR, Hodge H.Two cases of Rhodococcus equi infection in foals are described, in which osteomyelitis was a feature. Because rhodococcal infection is usually low grade and chronic, and because the signs of early metaphysitis can be subtle, any articular or periarticular swelling in a foal from a farm with a history of rhodococcosis should be strongly suspected to be associated with R equi until proven otherwise.
Hedell R, Andersson MG, Faverjon C, Marcillaud-Pitel C, Leblond A, Mostad P.A potentially sensitive way to detect disease outbreaks is syndromic surveillance, i.e. monitoring the number of syndromes reported in the population of interest, comparing it to the baseline rate, and drawing conclusions about outbreaks using statistical methods. A decision maker may use the results to take disease control actions or to initiate enhanced epidemiological investigations. In addition to the total count of syndromes there are often additional pieces of information to consider when assessing the probability of an outbreak. This includes clustering of syndromes in space and time as...
Dziezyc J, Taylor L, Boggess MM, Scott HM.To determine the effect of ocular blinkers on driving horses' reactions to visual and audible stimuli. Methods: Balanced crossover trial with horses randomly assigned to either wear blinkers or not wear blinkers first or second, then subjected to repeated sequences of four distinct stimuli (chain rattle, cap gun, umbrella opening, and shaking of an aluminum can containing coins). Two weeks later, this process was repeated with the ordering of wearing blinkers reversed. Methods: Eight driving horses of various breeds. Methods: Responses were recorded quantitatively as inter-beat times (the time...
Frisbie DD, Sandler EA, Trotter GW, McIlwraith CW.To determine response of interleukin-1alpha (IL-1alpha)-conditioned equine articular cartilage explants to insulin-like growth factor-1 (IGF-1). Sample Population-Cartilage from the trochlea and condyles of the femur of a clinically normal 4-year-old horse. Methods: Effects of IGF-1 (0 to 500 ng/ml) after addition of IL-1alpha were evaluated by assessing matrix responses, using a sulfated glycosaminoglycan (GAG) assay, matrix 35SO4 GAG incorporation, and release of GAG. Mitogenic response was assessed by 3H-thymidine incorporation into DNA and fluorometric assay of total DNA concentration. Res...
Nocera I, Puccinelli C, Sgorbini M, Bagnoli E, Citi S.In adult horses, specific ultrasound (US) features and reference values have been reported for the appearance of the joint cartilage and thickness according to the type of joint, such as femoropatellar and tarsocrural. The US appearance of the fetlock has been described in several diseases. The present research evaluates the US features of the metacarpal/tarsal-phalangeal joints in healthy racehorses according to age and breed, since no information is available in the literature. Seventy-one fetlocks in 28 healthy horses (15/28 thoroughbreds and 13/28 standardbreds) were assessed. The horses w...
Buffington CA, Knight DA, Kohn CW, Madigan JE, Scaman PA.The effects of 2 liquid formula diets differing in protein source were evaluated in orphan foals. The response of 7 foals fed a diet containing casein as the protein source, and 6 foals fed a diet containing a combination of whey and casein, was compared with the response in a reference group of 8 mare-raised foals. Orphaned foals were fed 150 kcal/kg of body weight/d, divided into 6 equal feedings of 25 kcal/kg. Formula intake was comparable among the experimental groups, and foals fed the liquid formula diet grew as well as mare-raised foals. There was no difference among groups in mean dail...
Schlindwein X, Werneburg I.We compared embryogenesis of five species of domesticated even-toed and one odd-toed ungulate and used a phylogenetic framework to contextualize such comparison. Organ systems that occur relatively earlier in embryogenesis generally have more time to develop and therefore are found to be more mature at birth when compared to structures that appear later in development. We hypothesized that the less mature the animals' organs are at birth, the more they are susceptible to artificial selection. The horse had the most mature organs at birth, followed by cattle, reindeer, sheep/goat, and pig. This...
Cohen JM, Schneider RK, Zubrod CJ, Sampson SN, Tucker RL.(1) To describe the clinical signs and abnormalities observed on magnetic resonance imaging (MRI) in 7 horses with desmitis of the distal digital annular ligament (DDAL); (2) to describe the normal magnetic resonance (MR) appearance and thickness of the DDAL in health; and (3) to describe a tenoscopic surgical technique for treating horses with desmitis of the DDAL. Methods: Retrospective study. Methods: Horses (n=7) with desmitis of the DDAL. Methods: MR examinations of 20 sound horses were reviewed to determine the normal appearance of the DDAL. Dimensions obtained from these images were com...
Asmis R, Jörg A.Horse eosinophils preincubated with 3H-labelled acetate and stimulated with the Ca2+ ionophores ionomycin or A23187 form a radioactive compound, which we have shown to be 1-O-alkyl-2-[3H]acetyl-sn-glycero-3-phosphocholine (platelet-activating factor). We could detect no 1-O-acyl-2-[3H]acetyl-glycero-3-phosphocholine in the radioactive fraction. The formation of platelet-activating factor was strongly correlated to the generation of leukotriene C4, the main arachidonate metabolite in horse eosinophils, suggesting that platelet-activating factor and leukotriene C4 have a common precursor pool (1...
Montelaro RC, West M, Ivey M.Representative glycoproteins including fetuin, protein A, ovalbumin, alpha 1 acid glycoprotein, and the major glycoprotein of equine infectious anemia virus were labelled with 125I by the chloramine-T or Bolton-Hunter procedure and their binding to immobilized Con A or lentil lectin compared to untreated samples of each glycoprotein. Glycoprotein modification was no greater than one substituted residue per protein molecule. Yet the radioiodinated glycoproteins typically displayed only 0-50% of the lectin binding observed with untreated samples. These results indicate that lectin glycoprotein b...
Ludewig T.Corpora amylacea are present in all the mammary glands of the investigated animals (ewe, goat, and mares). Generally, they are comparable to the cow regarding to its distribution, frequency, size, morphological structure, and staining properties. Corpora amylacea occur most frequently in the ewe, and in non-lactating mammary glands. In lactating mammary glands they are mostly situated in the alveoles. During gestation they are located outside of the alveoles and in the interalveolar connective tissue. Only in very few cases corpora amylacea are found inside and outside of the alveoles in the s...
McElhone RL, Meakin GE, French JC, Alexander T, Morgan RM.A study was designed to investigate the effects of external variables, including blood type, flooring surface, footwear tread depth and blood dryness, on the appearance of blood-based footwear marks, with particular reference to simulating a specific casework scenario. Results showed that footwear marks left in human blood tended to be of greater quality than those in equine blood, highlighting a potential issue in applying data generated with equine blood to human bloodstains in casework. Footwear tread effects were also dependent on blood type, but the type of flooring surface did not affect...
Recent outbreaks of equine infectious anaemia and equine viral arteritis in the UK. Update on the equine infectious anaemia situation in Europe. West Nile virus reported in several Mediterranean countries. Current and future approaches to equine viral arteritis control in the UK. These are among matters discussed in the quarterly equine disease surveillance report for April to June 2010, prepared by Defra, the Animal Health Trust and the British Equine Veterinary Association.
Rossdale PD.The place of clinical research in the veterinary profession is discussed against the author's personal experiences and in the context of how research workers, clinicians, teachers and veterinary students might be brought into a more cohesive unit through the development of a Faculty of clinical research and experimental medicine. It is argued that students should receive training in research and teaching and that efforts should be made to break down the attitude of "them" and "us" which tends to separate the clinicians and academics.
Hoolahan DE, White SD, Outerbridge CA, Shearer PL, Affolter VK.Alopecia areata (AA) causes hair loss due to inflammatory changes within and around hair bulbs and lower portions of the hair follicles. Documentation of AA in horses is limited to a few case reports. Objective: The aim of this retrospective study was to characterize equine AA by describing patterns in age, sex, breed and lesion distribution in a series of cases. An attempt was made to characterize the long-term course of the disease by surveying owners of affected horses. Methods: Computerized records from 1 January 1980 to 1 July 2011 yielded 15 horses. Methods: Descriptive statistics were c...