Post mortem examination in horses involves the systematic investigation of a deceased horse to determine the cause of death and evaluate any underlying health conditions. This process, also known as necropsy, is conducted by veterinary pathologists and involves a thorough external and internal examination of the horse's body. During a post mortem, tissues and organs are inspected for abnormalities, and samples may be collected for further histopathological, microbiological, or toxicological analysis. The findings from a post mortem can provide valuable insights into disease processes, inform management practices, and contribute to broader veterinary research. This page compiles peer-reviewed research studies and scholarly articles that explore methodologies, findings, and implications of post mortem examinations in equine veterinary practice.
Whitton RC, Ayodele BA, Hitchens PL, Mackie EJ.Microdamage accumulation leads to subchondral bone injury and/or fracture in racehorses. An understanding of this process is essential for developing strategies for injury prevention. Objective: To quantify subchondral bone microdamage in the third metacarpal bone of Thoroughbred racehorses at different stages of the training cycle. Methods: Cross-sectional. Methods: Bone blocks from the palmar aspect of the medial condyles of third metacarpal bones from 46 racing Thoroughbred horses undergoing post-mortem were examined with micro computed tomography (microCT) to detect calcified microcracks, ...
Nauwelaerts S, Clayton HM.Data describing segmental masses and moments of inertia (MOI) of limb segments are required for inverse dynamic calculations. In horses, these values are usually calculated using regression equations that have been developed from a limited number of horses representing a small number of breeds. The objective of the present study was to evaluate the performance of a scaling method and a pictorial method for estimating of the values of segmental masses, lengths, and MOI in the equine limb segments by comparing their output with the standard technique involving direct measurements. Limbs of 30 ho...
García Liñeiro JA, Graziotti GH, Rodríguez Menéndez JM, Ríos CM, Affricano NO, Victorica CL.The epaxial muscles produce intervertebral rotation in the transverse, vertical and axial axes. These muscles also counteract the movements induced by gravitational and inertial forces and movements produced by antagonistic muscles and the intrinsic muscles of the pelvic limb. Their fascicles are innervated by the dorsal branch of the spinal nerve, which corresponds to the metamere of its cranial insertion in the spinous process. The structure allows the function of the muscles to be predicted: those with long and parallel fibres have a shortening function, whereas the muscles with short and o...
Cullimore AM, Lester GD, Secombe CJ, Campbell K.A 7-year-old Clydesdale gelding was referred with a history of progressive lethargy and ventral oedema. The horse developed diarrhoea after treatment with antibiotics by the referring veterinarian. History, clinical signs, imaging and laboratory findings were consistent with hypertrophic cardiomyopathy complicated by antibiotic-associated colitis. Progression of clinical signs prompted euthanasia and the antemortem diagnosis of hypertrophic cardiomyopathy was confirmed at postmortem examination. Conclusions: Primary HCM is reported as rare in horses, but specific descriptions are lacking. The ...
Hussein HA, Ibrahim A, Ali MF.This study aimed to establish normal ultrasonographic reference values of kidney dimensions in donkeys (Equus asinus) and to describe and evaluate the clinicopathological variations associated with ultrasound-guided renal biopsy. The ultrasonographic dimensions of the right and left kidneys were conducted on 16 donkeys, which were then divided into two groups; eight each for biopsy of the right kidney (RK) and left kidney (LK). Three ultrasonographic cineloops were obtained at 17th intercostal space daily for 3 consecutive days. Renal length, width, and dimensions of the cortex, medulla, and p...
Moeller RB, Crossley B, Pipkin A, Li Y, Balasuriya UBR.A 2-y-old female Grant's zebra ( Equus quagga [ burchellii] boehmi) was presented with a clinical history of depression, anorexia, and weakness of 1-wk duration. Postmortem examination identified ulcers on the tongue and palate; a large abscess adjacent to the larynx; left lung consolidation; mild swelling, darkening, and congestion of the liver with accentuation of the lobular pattern; and edema and congestion of the distal small and large intestines. Histologic examination identified necrotizing bronchopneumonia, necrotizing hepatitis, nephritis, and enterocolitis. Eosinophilic intranuclear ...
Komosa M, Włodarek J, Dzierzęcka M, Nienartowicz-Zdrojewska A, Tołkacz M.The problem of navicular bone lesions is better understood in warmblood horses. The aim of our research was to compare pathologic lesions of navicular bone of different types of horses divided into age groups. An extra goal was to compare radiographs with anatomical status of navicular bone dissected from the hoof capsule. The study group included 161 horses, out of which 100 individuals were warmbloods, and 61 - coldbloods. In total 280 navicular bones were analysed. The flexor surface, distal border fragments, enthesophytes and the process of obliteration of nutrient foramina were analysed. ...
Kurz JP, Schoenhals KE, Hullinger GA, Van Wettere AJ.Syringomyelia is a form of myelodysplasia defined by the formation of one or more fluid-filled cavities within the spinal cord that do not communicate with the central canal. The defect may be congenital or acquired. Clinical signs correlate to the segment of spinal cord affected and include pain, paresis, proprioceptive deficits, alterations in sensation, scoliosis, and autonomic dysfunction. This report describes the clinical and pathologic changes in a case of acquired syringomyelia in a 10-year-old American Paint Horse mare. The horse had a six-week history of progressive proprioceptive de...
Ter Woort F, Caswell JL, Arroyo LG, Viel L.OBJECTIVE To describe histologic findings in the small airways during postmortem examination of actively racing horses and to quantify the degree of airway inflammation by use of a semiquantitative scoring system. SAMPLE Lung tissues obtained from 95 horses (Thoroughbreds, Standardbreds, and Quarter Horses) that had been actively racing or training. PROCEDURES 10 standardized lung sections were obtained during postmortem examination of 37 horses that had been actively racing or training, and 2 histologic sections of the caudodorsal lung lobes previously collected from each of 58 horses that di...
Johnson AL, Johnstone LK, Stefanovski D.The accuracy of the Lyme multiplex assay for the diagnosis of neuroborreliosis in horses is unknown. Objective: To describe Lyme multiplex results in horses with a postmortem diagnosis of neuroborreliosis. The hypothesis was that paired serum and cerebrospinal fluid (CSF) results and a CSF : serum ratio would allow differentiation of horses with neuroborreliosis from those with other neurologic diseases. Methods: Ninety horses that had neurologic examinations, serum and CSF Lyme multiplex analyses, and postmortem examination of the nervous system performed. Methods: Retrospective study. Data...
Zavodovskaya R, Eckert M, Murphy BG, Stover SM, Kol A, Diab S.Silicate associated osteoporosis (SAO) was diagnosed in an adult horse with the shortest documented exposure to cytotoxic silicates of 2 years. The horse was evaluated for a 6-months history of progressive back tenderness and acute onset of lameness. The horse had a marked (4/5) [American Association of Equine Practitioners scale] left forelimb lameness, moderate (2/5) hindlimb ataxia and weakness, and cervical pain upon palpation. Physical examination did not reveal clinical skeletal deformities or respiratory compromise. Radiographs revealed widespread, discrete, sharply delineated, osteoly...
de Solis CN, Althaus F, Basieux N, Burger D.Sudden death affects the health of horses, the safety of riders and the public perception of animal welfare during equestrian events. Objective: To describe the signalment, clinical history, sudden death episode, rider injuries and causes of sudden death during exercise or closely thereafter in sport and pleasure riding horses. Methods: Retrospective case series based on an online questionnaire. Methods: An online questionnaire was distributed to the veterinary and equestrian community. Connections of animals reported in the press to have died suddenly were sent the survey. Responses were anal...
Lyons ET, Bolin DC, Bryant UK, Cassone LM, Jackson CB, Janes JG, Kennedy LA, Loynachan AT, Boll KR, Burkhardt AS, Langlois EL, Minnis SM, Welsh SC....Parasite infections are more quantifiable postmortem than antemortem in horses. Thus a study was carried out examining dead horses for specific parasite species. Most of the weanling and older horses submitted to the University of Kentucky Veterinary Diagnostic Laboratory (UKVDL) for postmortem examination between November 22, 2016 and March 23, 2017 were examined for certain species of internal parasites. The stomach and duodenum from 69 horses were examined for bots (Gasterophilus spp.). Combined data for both Thoroughbred and non-Thoroughbred (16 other than Thoroughbred breeds/mixed breeds)...
Broeckx SY, Spaas JH, Chiers K, Duchateau L, Van Hecke L, Van Brantegem L, Dumoulin M, Martens AM, Pille F.The safety of the intra-articular use of mesenchymal stem cells (MSCs) is scarcely reported. Therefore, the goal of this study was to investigate the safety of a single intra-articular injection with allogeneic chondrogenic induced MSCs combined with equine plasma (=the investigational product: IVP) compared to a saline (0.9% NaCl) placebo control (=control product: CP). Sixteen healthy experimental horses were randomly assigned to receive a single intra-articular injection with either the IVP (n=8) or the CP (n=8) in the left metacarpophalangeal joint. All horses underwent a daily clinical as...
Fortin JS, Royal AB, Kuroki K.A 21-year-old American Saddlebred mare died with a history of weight loss and breathing difficulties of 1 month duration. Post-mortem examination revealed a copious pleural effusion with multifocal to coalescing numerous white to grey nodular masses on the serosal surface of the pericardium, lungs and thoracic cavity. In addition, the left thyroid gland was markedly enlarged. A thoracic mesothelioma and C-cell adenoma with amyloid deposits of the left thyroid gland were diagnosed by histopathology and confirmed by immunohistochemistry employing antibodies against cytokeratin (CK), vimentin an...
Nyaoke AC, Navarro MA, Beingesser J, Uzal FA.A 14-y-old bay Quarter Horse gelding was presented with progressive neurologic signs, elevated rectal temperature, and icterus for 3 d prior to death. Postmortem examination revealed icterus, large amounts of serosanguineous fluid in the abdominal cavity, widespread petechiae and ecchymoses in several organs, and a large, pale, and well-demarcated focus of necrosis in the liver. Histologically, there was coagulative necrosis surrounded by a rim of inflammatory cells and large numbers of gram-positive rods, which were identified as Clostridium novyi by immunohistochemistry. Liver samples tested...
Odriozola ER, Rodríguez AM, Micheloud JF, Cantón GJ, Caffarena RD, Gimeno EJ, Bodega JJ, Gardey P, Iseas FB, Giannitti F.Solanum glaucophyllum, a toxic plant known for its calcinogenic effects, causes enzootic calcinosis in ruminant and monogastric animals. We describe an outbreak of enzootic calcinosis that occurred in a herd of 110 horses grazing pastureland heavily contaminated with S. glaucophyllum in Buenos Aires province, Argentina. Ten horses developed clinical signs, and 6 horses died. Clinical signs included abnormal gait (stiff-legged action, short strides), stiffness, thoracolumbar kyphosis, reluctance to move, wide stance, chronic weight loss, weakness, recumbency, and difficulty standing. Autopsy of...
Kohnken R, Schober K, Godman J, Gardner A, Jenkins T, Schroeder E, Baker P, Dunbar L.A 4-week-old American Quarter Horse colt presented with a recent history of diarrhea and decreased activity level. On initial physical examination, the animal was bright and alert and major findings were limited to a loud systolic heart murmur radiating widely over both sides of the thorax. While in the hospital, the clinical condition of the foal warranted further imaging to determine the cause and extent of cardiac disease. A variety of congenital cardiac malformations were identified during echocardiographic examination and autopsy, including a double outlet right ventricle and a subpulmona...
Civello ANE, Dunkel B, Summers BA, Martineau HM.A neurofibroma of granular cell subtype is described in a 7-year-old horse. The horse had a 3-month history of ataxia affecting the forelimbs and hindlimbs, suggesting a C1-C6 neuroanatomical localization. Post-mortem examination revealed an intradural mass arising from the right sixth cervical spinal nerve and compressing the spinal cord. Histologically, the mass was composed largely of wavy spindle cells (a mixture of Schwann cells, perineurial cells and fibroblasts) intimately associated with ropy collagen fibres. Approximately 25% of the spindle cells were swollen and contained densely-pac...
Zakrajsek E.A recently purchased 16-year-old Thoroughbred mare with a history of recurrent colic and low body weight, also had lameness in 3 limbs, pain at the sacro-iliac joint, and increased corneal opacity of the right eye. Response to supportive therapy was poor and euthanasia was elected. A postmortem examination and histopathology confirmed cyathostomiasis within the large colon and cecum and chronic anterior uveitis of the right eye. Une jument Thoroughbred, âgée de 16 ans et récemment achetée, avec une anamnèse de coliques récurrentes et de faible poids corporel souffrait aussi de boiterie ...
Paraschou G, Suárez-Bonnet A, Grove V, Priestnall SL.A peripheral nerve sheath tumour, with features of a benign schwannoma and arising from the endocardium of the right ventricle, was found incidentally during routine post-mortem examination of a 28-year-old gelding donkey. Macroscopically, five round to oval, white to grey and red, firm masses, firmly attached to the endocardium were identified. Microscopically, the endocardium and adjacent subendocardium were infiltrated by a variably demarcated, non-encapsulated mesenchymal neoplasm with features of a benign schwannoma, including concurrent presence of Antoni A and Antoni B areas, nuclear pa...
Bani Hassan E, Mirams M, Mackie EJ, Whitton RC.To investigate the prevalence of microscopic subchondral bone injury in the distal metacarpi/tarsi of Thoroughbred racehorses and associations with recent and cumulative training history. Methods: Metacarpi/metatarsi were obtained from postmortem examination of Thoroughbred racehorses. The severity of palmar/plantar osteochondral disease (POD) was graded in forelimbs from 38 horses and in hindlimbs from a separate cohort of 45 horses. Forelimb samples were embedded in methyl methacrylate and examined using backscattered scanning electron microscopy. Microfracture density in the condylar subcho...
Vienenkötter J, Siudak K, Stallenberger L, Herden C.Being confronted with a case series of renal neoplasia in several horses which was in striking divergence to literature data, we recognized the need of a retrospective study to assess the presence of renal neoplasms in horses. Methods: Anamnestic animal data, necropsy findings and results of histological and immunohistochemical examinations from 2010 through 2015 were collected and evaluated regarding renal neoplasia. Results: Data from postmortem examinations of 1069 horses revealed 20 horses with renal tumors constituting a prevalence of 1.87 %. Primary renal neoplasms built the majority o...
Lamglait B, Vandenbunder-Beltrame M, Trunet E, Lemberger K.Gastric ulcers are common in domestic horses and foals, affecting at least 90% of unmedicated racehorses in active training. Despite these high prevalences in domestic horses, literature about this condition in wild equids is almost nonexistent. The presence of gastric ulcers was evaluated at necropsy in six species of wild equids that died at the Réserve Africane de Sigean, a safari park in the south of France from 2010 to 2016. Among the 55 individuals that died during that period, a description of the gastric mucosa was available in 82% (45/55) of cases. Considering the cases for which a d...
Dyson S, Pinilla MJ, Bolas N, Murray R.There have been no previous studies correlating high-field magnetic resonance imaging (MRI) findings with gross and histological post-mortem examination in horses with hindlimb proximal suspensory desmopathy (PSD). Objective: To determine if adhesions between the suspensory ligament (SL) and adjacent tissues could be detected using high-field MRI and if collagen, adipose tissue and muscle pathology could be differentiated. Methods: Retrospective study. Methods: Nineteen horses with hindlimb PSD were humanely destroyed; 12 limbs of 11 horses with PSD underwent high-field MRI. All lame limbs wer...
Schoppe C, Hellige M, Rohn K, Ohnesorge B, Bienert-Zeit A.Modern imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) have the advantage of producing images without superimposition. Whilst CT is a well-established technique for dental diagnostics, MRI examinations are rarely used for the evaluation of dental diseases in horses. Regarding equine endodontic therapies which are increasingly implemented, MRI could help to portray changes of the periodontal ligament and display gross pulpar anatomy. Knowledge of age-related changes is essential for diagnosis, as cheek teeth and surrounding structures alter with increasi...
Finch SC, Munday JS, Sutherland BL, Vlaming JB, Fletcher LR.AIMS To determine if equine fescue oedema (EFO) induced by grazing Mediterranean-type tall fescue (Lolium arundinaceum) infected with selected endophytes (Epichloë coenophiala) could be prevented by treatment with the corticosteroid, methylprednisolone, and anti-histamine, cetirizine, and to determine concentrations of lolines, specifically N-acetyl norloline (NANL), in grasses grazed by horses that did and did not develop EFO. METHODS Four horses were grazed on AR542-infected Mediterranean tall fescue pasture (from Day 0) for 7 days prior to being subjected to euthanasia. Two of these horses...
Carvallo FR, Uzal FA, Diab SS, Hill AE, Arthur RM.Respiratory diseases have a major impact on racehorses in training and are often cited as the second most common reason of horses failing to perform. Cases were submitted by the California Horse Racing Board to the California Animal Health and Food Safety laboratory for postmortem examination between January 1, 2005 and December 31, 2014. We determined the demographics of racehorses with fatal pneumonia, characterized the pathologic findings in animals with a postmortem diagnosis of respiratory infection, and determined the most significant pathogens associated with lower respiratory tract dis...
Palmer SE, McDonough SP, Mohammed HO.Between January 1, 2013 and December 31, 2015, findings of a New York State Gaming Commission-Cornell University postmortem examination program were utilized in a multi-disciplinary mortality review process to review 129 racing fatalities at Thoroughbred racetracks operated by the New York Racing Association (NYRA). Musculoskeletal fractures comprised 79% of the fatalities; cardiopulmonary conditions accounted for 12% of the fatalities. Other causes of death included gastrointestinal (3%), respiratory (5%), and central nervous system (2%) conditions. Fetlock failure represented 50% of the musc...
Engiles JB, Stewart H, Janes J, Kennedy LA.As a pathologist, postmortem examination of the equine carpus can be daunting. The anatomy is complex and oftentimes, small or subtle lesions have significant impact on lameness and secondary lesions such as catastrophic musculoskeletal fractures and other injuries. In performance horses, particularly racehorses, the carpus is a common site of injury and source of lameness. Given the predisposition of racehorses to developing carpal disease, familiarity with clinically relevant anatomy and common developmental, degenerative, traumatic, and inflammatory processes are imperative for thorough pos...
Roy RC, Riley CB, Stryhn H, Dohoo I, Cockram MS.Undetected injury of horses sustained during road transport to slaughter is a welfare concern. This study evaluated digital infrared thermography (DT) for the detection of ante-mortem bruising in horses following transport to a slaughter plant. The sensitivity and specificity of DT for the detection of bruises following transport was evaluated. DT images were obtained from 93 horses (2-3 horses per load; 40 loads) at a Canadian federally approved slaughter plant. From an elevated platform 5 m from the horses, left and right lateral DT images, and one caudal pelvic area image were obtained from...
Nollet H, Vanschandevijl K, Van Ham L, Vanderstraeten G, Deprez P.Transcranial magnetic stimulation and measurement of the magnetic motor-evoked potentials (MMEPs) in the thoracic and pelvic limbs of four recumbent horses and one recumbent donkey were used to assess the integrity of the descending motor pathways, in order to confirm or exclude a descending motor tract lesion as the cause of the recumbency. In two of the animals abnormal MMEPs were recorded; in one of the horses a lesion along the cervical spinal cord due to a fracture of the fifth cervical vertebra was diagnosed and confirmed by radiography and postmortem examination; in another horse, damag...
Schambourg MA, Laverty S, Mullim S, Fogarty UM, Halley J.Thoracic trauma occurs in newborn foals and may cause associated clinical signs; this condition remains poorly documented. Objective: The purpose of this study was to describe the pathological features of thoracic trauma in newborn foals presented for necropsy examination between 1990 and 2000. Methods: Necropsy reports of foals with thoracic trauma from 1990-2000 were reviewed. Subject details, clinical signs, thoracic and abdominal lesions were noted and analysed statistically. Results: Sixty-seven (9%) of 760 necropsied foals had thoracic trauma. In 19 foals, fractured ribs were considered ...
Monreal L, Sabaté D, Segura D, Mayós I, Homedes J.The objective was to compare the gastrointestinal and general toxicity of suxibuzone (SBZ) to that of phenylbutazone (PBZ) when administered orally in horses. Fifteen healthy horses were allocated to three treatment groups. One group received a high dose of PBZ for two weeks; the second group was given an equimolecular dosage of SBZ; and a third group received placebo. Horses were daily monitored, and blood samples were collected before and during the study. On day 18, complete post-mortem examinations were performed. One horse treated with PBZ showed clinical signs of NSAID toxicosis. Small o...
Carvalho GM, Ramos CP, Lobato FCF, Guedes RMC, Giaretta PR, Silva ROS.Despite the known importance of Clostridioides (Clostridium) difficile infection (CDI) in animals, there are no published guidelines for the diagnosis of CDI. The performance of the available commercial methods, all standardized for human stool samples, can vary according to the animal species. Thus, the aim of the present study was to review the literature on the detection of C. difficile in pigs, horses, and dogs. The detection of toxins A and B using enzyme immunoassays seems to have low performance in piglet and dog samples, while it shows high sensitivity for the diagnosis of CDI in foal...
O'Callaghan MW, Pascoe JR, Tyler WS, Mason DK.Lungs from 19 Thoroughbred racehorses with a history of exercise-induced pulmonary haemorrhage (EIPH) were studied using several forms of microscopy. Light microscopy of paraffin sections revealed three lesions in the caudodorsal region of the lungs from each horse. These correspond with the location of blue to brown stains seen at necropsy. These lesions include sequelae of bronchiolitis, hemosiderophages and increased connective tissue. Much of each of the lungs appeared normal, especially the more cranial or ventral portions. Foci of eosinophil infiltration were found in seven of the 19 lun...
Johnson PJ, Scotty NC, Wiedmeyer C, Messer NT, Kreeger JM.An 18-year-old Spanish Mustang mare was referred for evaluation of progressive weight loss and persistent hyperglycemia. Clinicopathologic abnormalities included marked hyperglycemia and glycosuria. Serum cortisol concentration was appropriately decreased following administration of dexamethasone, indicating that the horse did not have pituitary pars intermedia dysfunction. Serum insulin and plasma C-peptide concentrations were low, suggesting that hyperglycemia was a result of decreased secretion of insulin by pancreatic beta cells. In addition, glucose concentration did not return to the bas...
Tong L, Stewart M, Johnson I, Appleyard R, Wilson B, James O, Johnson C, McGreevy P.The current project aims to build on knowledge of the nociceptive capability of equine skin to detect superficial acute pain, particularly in comparison to human skin. Post-mortem samples of gluteal skin were taken from men ( = 5) and women ( = 5), thoroughbreds and thoroughbred types (mares, = 11; geldings, = 9). Only sections that contained epidermis and dermis through to the hypodermis were analysed. Epidermal depth, dermal depth and epidermal nerve counts were conducted by a veterinary pathologist. The results revealed no significant difference between the epidermal nerve counts of human...
Gere I, Dixon PM.Peripheral caries (PC) of equine teeth is a poorly described disorder that can cause serious clinical problems if it progresses. Objective: To assess the prevalence, sites and severity of PC in a population of Swedish horses. Methods: A post mortem study of 510 equine skulls was performed in 2 Swedish equine abattoirs. Results: PC only affected the cheek teeth (CT) and was present in 6.1% (31/510) of skulls. It affected mainly the peripheral cementum, and 87% of PC in the 29 affected mature horses occurred in the 3 caudal CT (Triadan 09-11). Concurrent infundibular caries involving most maxill...
McLaughlin BG, McLaughlin PS.Samples of equine vitreous humor were analyzed for urea nitrogen, creatinine, sodium, chloride, phosphorus, calcium, potassium, and magnesium concentrations. Fresh vitreous chemical concentrations were compared to corresponding serum concentrations and expressed as a vitreous to serum ratio. The effects of postmortem time and temperature on the stability of the chemical concentrations were determined by incubation of the samples at 4 degrees C, and 20 degrees C and 37 degrees C for 6, 12, 24, or 48 h. Chemical concentrations were generally more stable at lower temperatures and shorter incubati...
Patterson-Kane JC, Sanchez LC, Uhl EW, Edens LM.A 12-year-old grey Warmblood stallion presented with fever of unknown origin, and anaemia. Five days later it had developed ataxia and become recumbent, and was humanely killed. At necropsy, malignant melanomas were identified in the perineal subcutis, spleen, and thoracic vertebral canal (T10-11). Populations of malignant melanoma cells were scattered throughout medullary cavities of the axial and appendicular skeleton, and were identified grossly as irregular areas of black to grey discoloration. To the authors' knowledge, this is the first report of disseminated intramedullary melanoma in a...
Freel KM, Morrison LR, Thompson H, Else RW.Postmortem and histological examination of the hearts from two horses, a five-year-old Clydesdale gelding and a 15-year-old cob gelding, revealed changes characteristic of arrhythmogenic right ventricular cardiomyopathy. In both cases, on gross examination, the right ventricular endocardium and interventricular septum were almost entirely replaced with a gelatinous yellow fibroareolar tissue. This tissue was histologically a combination of fibrous and adipose tissue that had replaced the normal myofibres and disrupted the Purkinje fibres.
Bianchi MV, Mello LS, Wentz MF, Panziera W, Soares JF, Sonne L, Driemeier D, Pavarini SP.Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri ...
Quiney L, Stewart J, Routh J, Dyson S.There is a lack of understanding of the pathological and/or physiological nature of lumbosacral region pain. Objective: To describe the gross variations of the osseous and soft tissues of the lumbosacral region and report the histological findings of sections of nerve tissue in affected and control horses. Methods: Descriptive post-mortem case series. Methods: All horses had undergone full clinical and gait assessment, including ridden exercise. Horses with a substantial response to infiltration of local anaesthetic solution around the sacroiliac joint regions were included in the affected gro...
Dyson S, Pinilla MJ, Bolas N, Murray R.There have been no previous studies correlating high-field magnetic resonance imaging (MRI) findings with gross and histological post-mortem examination in horses with hindlimb proximal suspensory desmopathy (PSD). Objective: To determine if adhesions between the suspensory ligament (SL) and adjacent tissues could be detected using high-field MRI and if collagen, adipose tissue and muscle pathology could be differentiated. Methods: Retrospective study. Methods: Nineteen horses with hindlimb PSD were humanely destroyed; 12 limbs of 11 horses with PSD underwent high-field MRI. All lame limbs wer...
Gardner RB, Nydam DV, Mohammed HO, Ducharme NG, Divers TJ.The purpose of this study was to test the hypothesis that horses with right dorsal displacement of the large colon (RDDLC) have elevations in serum gamma glutamyl transferase (GGT) activity when compared with horses with left dorsal displacement of the large colon (LDDLC). Medical records from 37 horses with RDDLC and 48 horses with LDDLC were reviewed. Horses were included for study if the RDDLC or LDDLC was confirmed by exploratory laparotomy or postmortem examination and if a serum GGT measurement was obtained within 24 hours before surgery. The proportion of horses with GGT activity within...
Ter Woort F, Caswell JL, Arroyo LG, Viel L.OBJECTIVE To describe histologic findings in the small airways during postmortem examination of actively racing horses and to quantify the degree of airway inflammation by use of a semiquantitative scoring system. SAMPLE Lung tissues obtained from 95 horses (Thoroughbreds, Standardbreds, and Quarter Horses) that had been actively racing or training. PROCEDURES 10 standardized lung sections were obtained during postmortem examination of 37 horses that had been actively racing or training, and 2 histologic sections of the caudodorsal lung lobes previously collected from each of 58 horses that di...
Boisseau M, Mach N, Basiaga M, Kuzmina T, Laugier C, Sallé G.Equine strongyles encompass more than 64 species of nematode worms that are responsible for growth retardation and the death of animals. The factors underpinning variation in the structure of the equine strongyle community remain unknown. Methods: Using horse-based strongyle community data collected after horse deworming (48 horses in Poland, 197 horses in Ukraine), we regressed species richness and the Gini-Simpson index upon the horse's age, faecal egg count, sex and operation of origin. Using the Ukrainian observations, we applied a hierarchical diversity partitioning framework to estimate ...
Grossman BS, Brobst DF, Kramer JW, Bayly WM, Reed SM.The urine urea nitrogen/plasma urea nitrogen ratio (Uun/Pun), urine creatinine/plasma creatinine ratio (Ucr/Pcr), urine osmolality/plasma osmolality ratio (Uosm/Posm), and fractional excretion of filtered sodium (FENa) were evaluated in 16 horses with acute azotemia to ascertain the significance of each index in the differentiation of prerenal azotemia from renal azotemia. Renal azotemia was diagnosed when renal biopsy or postmortem histologic examination demonstrated evidence of organic renal disease or when azotemia was found in the presence of isosthenuria. The diagnosis of prerenal azotemi...
Maxson AD, Reef VB.A retrospective study of 10 horses with bacterial endocarditis was performed in order to describe the echocardiographic findings in horses with bacterial endocarditis, in conjunction with clinical signs and post mortem findings, and to evaluate the usefulness and the formulation of a prognosis. Echocardiographic and post mortem examinations were performed in 7 horses. Post mortem examination alone was performed in 2 horses and echocardiographic examination alone performed in one horse. No breed or sex predilection was obvious. Mean age +/- s.d. was 2.12 +/- 3.32 years. Predominant clinical sig...
Alves RM, van Rensburg LJ, van Wyk JA.The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9,500 metacercariae. No clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and 28-34 weeks post-infestation with F. gigantica, respectively. The results...
Borchers K, Wolfinger U, Lawrenz B, Schellenbach A, Ludwig H.Neuronal and lymphoid tissues of 15 randomly selected horses were analysed post mortem by liquid nested-PCR to study the tropism of equine herpesvirus 4 (EHV-4). In four animals the trigeminal ganglia and in one case the lung were positive. Using a direct in situ PCR the EHV-4 genome was localized in the nuclei of neurons and in the bronchiolar as well as alveolar epithelium of the lung. In none of these tissues could infectious virus or viral antigens be detected. Applying the more sensitive liquid RT-PCR, however, an acute infection was demonstrated in one of the trigeminal ganglia by amplif...
Tiwary AK, Puschner B, Kinde H, Tor ER.A 2-year-old bay Thoroughbred colt was found dead overnight in its stall without a known history of any illness, existing disease, or toxicant exposure. No information on the clinical signs before this animal's death was reported. A full necropsy was performed the next morning and revealed a mild to moderate degree of endocardial hemorrhages in both ventricles. Microscopic examination of the heart showed an acute mild multifocal necrosis of papillary muscles and ventricles. The stomach content contained approximately 2% Taxus alkaloids as determined by gas chromatography/mass spectrometry. In ...
Andersen MS, Clark L, Dyson SJ, Newton JR.Post anaesthetic colic is a recognised risk of general anaesthesia (GA), but causes are poorly understood. Objective: To identify risk factors for development of colic following GA for magnetic resonance imaging (MRI) or nonabdominal surgery and to test whether the use of perianaesthetic morphine was associated with an increased risk of post anaesthetic colic. Methods: A total of 553 anaesthetic and clinical records of 500 horses anaesthetised at the Animal Health Trust were analysed, 342 (62%) involved MRI and 211 (38%) nonabdominal, predominantly orthopaedic surgery. Multivariable logistic r...
Songer JG, Trinh HT, Dial SM, Brazier JS, Glock RD.A 14-year-old Quarter Horse with a 48-hr history of colic was euthanized after failure to respond to treatment. At necropsy, cecal and colonic mucosae were congested throughout, and there was segmental edema and significant thickening of the intestinal wall. Excessive numbers of mononuclear cells were found in mucosal lamina propria. Submucosal hemorrhage was diffuse and extensive, and Clostridium difficile toxins A and B were detected. Large numbers of C. difficile were isolated, and genetic characterization revealed them to be North American pulsed-field gel electrophoresis type 1, polymeras...
Du Toit N, Kempson SA, Dixon PM.Post-mortem examination of 19 donkey skulls showed that donkeys have a greater degree of anisognathia (27% width difference between upper and lower jaws) compared to horses (23%). Teeth (n=108) were collected from 14 skulls and examined grossly and by computed axial tomography (CAT). A greater degree of peripheral enamel infolding was found in mandibular cheek teeth (CT) compared to maxillary CT (P<0.001). A significant increase in peripheral cementum from the apical region to the clinical crown was demonstrated in all CT (P16 years) than in the younger (<15 years) donkeys studied. Based...
Platt H, Singh H, Whitwell KE.A description is given of the pathological changes present in 8 mares which died or were euthanased in the course of an outbreak of paralysis on a Thoroughbred studfarm. In all cases the principal changes were in the central nervous system (CNS) and consisted of a severe and widespread vaculitis in the brain, cord, sheaths of nerves, capsules of ganglia and occasionally elsewhere in the body. Associated with the damage to vessel walls there was haemorrhage and exudation of plasma into the perivascular tissues. Involvement of neurones was minimal and no neuronophagia was present. Six cases had ...
Brenner S, Whitcomb MB.The clinical and ultrasonographic features of seven horses with coxofemoral subluxation are presented. Affected horses included five adult geldings (11-20 years), one large pony (6 years) and a 3-month-old filly. All were lame at the walk except for the pony with grade 3/5 lameness. Lameness was acute in all horses, but three horses progressed after initial improvement. Crepitus, muscle atrophy, and pelvic asymmetry were inconsistent findings. Ultrasonographic diagnosis of subluxation required dynamic visualization of femoral head displacement from the acetabulum while placing weight on the af...
