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.
Thompson DB, Spradborw PB, Studdert M.Some details of the clinical and postmortem findings of an Arab foal that died as a consequence of adenoviral pneumonia superimposed on a combined immunodeficiency disease are provided. The foal was the 17th in a series of similar deaths that occurred on a farm since 1959. An adenovirus, which by haemagglutination inhibition and serum neutralisation tests was antigenically similar to 2 other equine adenoviruses isolated in Australia, was isolated from a nasal swab taken from the foal when it was 23 days of age.
Kelly DF, Watson WJ.An aged Connemara mare had a neurological illness lasting 3 weeks and characterised by episodes of dullness, head-pressing, staggering gait and hyperexcitability. The signs recurred at intervals of 3 to 4 days, with intervening periods of apparent normality. Post-mortem examination revealed an epidermoid cyst on the dorsal surface of the occipital lobe of the left cerebral hemisphere. The cyst was lined by stratified squamous epithelium and contained desquamated keratinised material and blood. The lesion is considered to be a congenital malformation which enlarges and produces space-occupying ...
Haughey KG, Jones RT.A high frequency of meningeal lesions was found at autopsy in foals dying perinatally. Such lesions are considered an index of injury to the fetal central nervous system, from trauma and/or hypoxia during birth. Their incidence in the sample examined (26 foals) is similar to that observed in the perinatal mortality of lambs and calves.
Palmer AC, Rossdale PD.A neuropathological investigation was carried out on the brains of 18 foals suffering from the neonatal maladjustment syndrome and results were compared with those obtained from the brains of nine foals dying from other causes. Necrosis of the cerebral cortex of an ischaemic nature was found in nine of the neonatal maladjustment foals, frequently accompanied by local haemorrhage. In three of this group of foals there was also necrosis in the diencephalon and brain stem. In the brains of the nine other affected foals there was haemorrhage in the cerebrum and sometimes in the brain stem and cere...
Kramer JW, Nickels FA, Bell T.Examination of effusions from body cavities must include a search for neoplastic as well as inflammatory cells. Neoplastic cells found in the thorax are generally derived from adenocarcinomas or mesotheliomas. Mesotheliomas are relatively uncommon and the neoplastic cells found in effusions are difficult to differentiate from activated cells in inflammatory effusions. An ante-mortem diagnosis of mesothelioma was made in a mare on the basis of the large volume of fluid produced, the pleomorphic mesothelial cells, the polyp formation and the absence of PAS staining material after digestion of th...
Gruys E, Kok HA, Van Der Werff YD.Post-morten examination of a fourteen-year-old mare of the Gelderland breed, which had been treated for severe dyspnoea and had subsequenlty died, revealed the presence of haemothorax, atelectasis of the lung and a metastasized haemangiosarcoma of the left ovary. The haemothorax could have resulted from rupture of one of the metastases.
Moffatt RE, Kramer LL, Lerner D, Jones R.Concentrations of dioctyl sodium sulfosuccinate (DSS) ranging from three to five times the recommended dosage produced severe diarrhea, rapid dehydration and death in seven horses and 66 guinea pigs when administered experimentally per os. Clinicopathological findings indicated hemoconcentration in both horses and guinea pigs. There was a leucocytosis in the guinea pigs given the highest dosages. In all cases the principal finding at necropsy was extreme fluid distention of the intestinal tract. There was histopathological evidence of epithelial denudation and vascular stasis. The LD50 in the ...
Pearson H, Pinsent PJ, Denny HR, Waterman A.The indications for laparotomy in 140 horses are analysed, with particular emphasis on the operative or autopsy findings in 82 cases of colic. In cases of exploratory laparotomy, the overall recovery rate was only 28 per cent but 48 of the 82 animals were considered to have inoperable lesions. The recovery rate and causes of death for each indication are briefly reviewed.
Whitlock RH, Dellers RW, Shively JN.A three-week-old Arabian filly was admitted to the Large Animal Hospital with a respiratory disorder and died despite symptomatic treatment. The necropsy lesions were suggestive of viral pneumonia. An equine adenovirus were isolated from nasal and pharyngeal swabs and from several tissues after death. Typical adenovirus virions were demonstrated by electron microscopy.
Van Dijk JE, Van der Molen EJ, De Smidt AC.A case of avian tuberculosis in a horse, with fatal course, is reported. The animal was imported from Poland and became ill after some weeks, in the beginning showing non-specific symptoms which became more severe until death supervened. Post-mortem examination showed a generalised form of tuberculosis. The most important lesions were seen in the lungs, liver, kidneys, spleen, intestinal tract, bones, bone marrow, and the internal lymph nodes. Beside chronic proliferative tuberculosis of the organs, many exudative foci were found with remarkably abundant acid fast bacilli. Mixed lesions were s...
Harrington DD.Spontaneous Tyzzer's disease is described in quarter horse foals which died suddenly with no clinical history of apparent illness. Significant gross findings included icterus, focal paletan areas in the liver and catarrhal entercolitis. Focal dark red lesions were present in the small intestine of one foal, and the mesenteric lymph nodes of another were enlarged and hyperemic. Histopathologically, the liver showed multiple discrete and confluent foci of necrosis, fatty change, sinusoid congestion and haemorrhage. Bundles of intracytoplasmic bacilli were demonstrated in hepatocytes at the margi...
Else RW, Holmes JR.The normal histology of cardiac tissues has been described by many authors, for example Gross and Kugel (1931), Trautmann and Fiebiger (1952), Gould (1968), Bloom and Fawcett (1969) and Ham (1969). In the horse, a few reports have described microscopic valvular pathology in detail (Ackerknecht 1923, Imre 1933, Ubach and Cler 1944). Experimentally induced lesions have been reported by Wadsworth (1919), Wadsworth and Sickles (1927) and Miller (1944), and endocarditis was described by Winqvist (1945) and Dobin (1959, 1968).
In 1966, Smetzer, Bishop and Smith outlined the valvular pathology ass...
Dixon PM, Nicholls JR, McPherson EA, Lawson GH, Thomson JR, Pirie HW, Breeze RG.An abattoir survey on horses diagnosed as suffering from chronic obstructive pulmonary disease (COPD) on clinical grounds showed that the right ventricular wall thickness was not significantly different from that of normal horses. However, the weight ratio between the left and right ventricles was found to be significantly (P less than 0.001) different in COPD affected, compared with control, horses in a study of 17 physiologically and pathologically confirmed COPD cases, using ventricular weight measurements. No clinical evidence of right heart failure nor post mortem evidence of right heart ...
Reedy SE, Powell DM, Williams NM, Dodson MV, Fitzgerald BP.This paper describes attempts to initiate equine adipocyte cultures from necropsy cases with varying intervals from time of death to isolation and culture. Equine adipocytes were isolated from 21 necropsy cases, regardless of the interval from time after death to establishment in primary ceiling cultures. However, while all cultures produced adipocytes, only 2 attempts to produce long-term equine adipocyte cultures from the subcutaneous rump fat depots were successful and not contaminated. Findings from these experiments indicate that it is possible to collect and culture equine adipocytes fro...
Danton CA, Peacock PJ, May SA, Kelly DF.A 16-year-old showjumping gelding was examined because of a non-painful, slowly progressive caudal thigh swelling, which was associated with 2/10th lameness at the trot. Radiography, real time beta-mode ultrasonography and gamma-scintigraphy of the caudal thigh for the presence of chip fractures, sequestrum formation and, or, abscessation were inconclusive. Radiographic examination of the chest revealed multifocal, nodular cannon ball-like opacities throughout the entire lung fields from which a diagnosis of a primary soft tissue tumour with metastasis to the thorax was made. An anaplastic sar...
Hunt RJ, Allen D, Mueller PO.Heterotopic polyodontia is typically associated with a sinus and a fistulous tract with a secreting membrane which extends to an ectopic tooth attached to the temporal bone. Recommendations for treatment include complete excision of the tract, the dental component, and the lining of the alveolar socket. Iatrogenic cerebral trauma was encountered during surgical extraction of an ectopic tooth. At post-mortem examination a second ectopic tooth was found compressing the right side of the cerebellum.
Bertone AL, Stashak TS, Sullins KE, Ralston SL.Ten normal horses had approximately 95% of the length of the large colon resected with a side-to-side anastomosis between right ventral and right dorsal colon performed with surgical stapling equipment. Four horses died shortly after surgery of colitis (1 horse) or failure of the TA 90 transection staple line (3 horses). Another horse died 4 months after surgery from disseminated streptococcal infection but had recovered well from the colon resection. Five horses survived long term (18 months) with no clinical evidence of adverse effects of the resection. Surviving horses had weight loss and s...
Reynolds DJ, Nicholl TK.A 5 month old colt foal with recurrent pyrexia and a loud pansystolic murmur later developed signs of cardiac failure. Peritoneal fluid and blood samples both demonstrated an extreme leucocytosis and neutrophilia. At post-mortem both a cranial mesenteric arteritis and the congenital cardiac anomaly, Tetralogy of Fallot were found. The detailed clinical and post-mortem findings contributing to the case are described.
Machida N, Nakamura T, Kiryu K, Haramaki S, Too K.A 20-year-old pony mare with persistent ventricular tachycardia (VT) was examined cardiopathologically. At necropsy, the heart was enlarged and rounded with both ventricular dilatation. In a longitudinal section of the ventricular septum, a large grayish white patchy lesion (5 x 25 mm) was detected in the relatively higher portion. Microscopically, the lesion was extensive myocardial fibrosis located in the vicinity of the proximal part of the left bundle branch. Partially the fibrotic lesion was in contact with the branch. Such a lesion might play an important role in creating a suitable back...
Newton-Clarke MJ, Divers TJ, Delahunta A, Mohammed HO.A study was conducted over a 12 month period to assess the specificity and sensitivity of the 'slap test', using endoscopic evaluation, in the detection of cervical spinal cord and caudal brainstem lesions in horses. Fifteen ataxic horses were subjected to the 'slap test' and subsequently examined post mortem. Twelve out of the 15 had histopathological lesions consistent with their clinical signs. Thirteen horses with no history of neurological dysfunction and no histopathological evidence of cervical spinal cord or brainstem disease were used as controls. The laryngeal adductory responses exh...
Medina B AL, Faleiros RR, Martínez A JR.Equine Gastric Ulcer Syndrome (EGUS) occurs with variable prevalence in horses, donkeys, and mules. Due to the particularities of the mucous membranes, the syndrome is made up of Squamous Gastric Disease (ESGD) and Glandular Gastric Disease (EGGD). Given the multifactorial nature and multiple classification systems of the syndrome, significant differences have been reported between prevalence studies performed ante mortem, which are even more remarkable when compared with postmortem evaluations. This study aimed to determine the presence and grade of squamous gastric disease in horses, donkeys...
Damone J, Bass L, Gadomski B, Rao S, Frank C, Moorman VJ.The equine digital cushion (DC) has been a poorly understood structure regarding its mechanical properties and composition. The objective of this study was to develop a sampling technique and to compare the biomechanical and histologic properties of DC between lame and non-lame forelimbs. Both forefeet from horses with induced carpal lameness were radiographed prior to humane euthanasia. Radiographs were used to guide sample collection of two, post-mortem, midline DC samples, palmar and dorsal, via an 8mm biopsy punch. Samples were subjected to compressive testing to determine elastic modulus....
Carpenter AL, Townsend KS, Johnson PJ, Kim DY.An 8-y-old National Show Horse mare was presented for evaluation of pneumonia and laminitis. Harsh bronchovesicular sounds were auscultated throughout both lung fields, and the mare had signs of moderately painful laminitis. Thoracic ultrasonography revealed lung consolidation throughout the dorsal aspect of both lungs, and radiography revealed an extensive diffuse-to-patchy bronchointerstitial lung pattern. The mare's clinical condition rapidly deteriorated, and euthanasia was elected. On postmortem examination, the lungs, omentum, spleen, liver, adrenal glands, kidneys, and femur contained 0...
Julia M, Felippe B.The clinical manifestation of recurrent fevers and infections alerts the clinician to the possibility of an underlying immunodeficiency. Common variable immunodeficiency (CVID) in the horse is a rare late-onset, non-familial immunologic disorder of B cell depletion and/or dysfunction with resultant inadequate antibody production. The most common clinical presentations in horses with CVID are recurrent upper and/or lower respiratory infections, meningitis and/or ataxia, cholangiohepatitis, infectious colitis, infectious dermatitis, and severe gastrointestinal parasitism. Immune-mediated and lym...
Arifianto D, Esfandiari A, Wibawan IWT, Amrozi A, Maharani M, Darsono D, Setiadi H, Setiyono A.Horses used for antisera production are repeatedly hyperimmunized to produce high levels of specific antibodies. This prolonged process can lead to various health issues, including amyloidosis, which involves the accumulation of amyloid proteins in organs and tissues, potentially causing organ dysfunction and failure. These horses are often retired when they no longer produce adequate antibody levels. This study aimed to evaluate the impact of prolonged antisera production on the health of retired horses by examining their blood biochemistry and serum amyloid A (SAA) levels, which are indicato...
Witt P, Stas EKL, Hardeman LC, van Proosdij ER, Weerts EAWS, Lloyd-Edwards RA, Veraa S, Kranenburg LC, van den Boom R.A sixteen-year-old Friesian mare was admitted to the university clinic with the following clinical signs: anorexia, weight loss, fever, bilateral nasal discharge, unilateral facial paralysis and a non-healing corneal lesion. Endoscopic examination of the upper airways showed thickening of the proximal portion of the right stylohyoid bone. Computed tomography imaging showed pneumocephalus due to grade 3 unilateral temporohyoid osteoarthropathy (THO) with fracture of the petrous temporal bone. The horse did not improve following medical treatment. Surgical intervention was declined by the owner ...
Kopecka A, Novotna T, Svobodova Z, Drabkova Z.This study describes a case of poisoning by pyrrolizidine alkaloids in a horse. To the best of the author's knowledge, this is the first confirmed case of Senecio ovatus poisoning. A six-year-old 450-kg Irish cob mare was presented to the Equine Clinic of the University of Veterinary Sciences Brno (Czechia) with symptoms of hepatic encephalopathy, which progressively worsened with time despite intensive therapy and led to euthanasia. A complex diagnostic and therapeutic approach including the post-mortem patoanatomical and histopathological examination is described here. Regar...
Charles A, Kerckhove HV, De Maré L, Cassart D, Ficheroulle J, Pouyade GR, Tosi I.A Standardbred racehorse was presented for exercise intolerance, weight loss, pyrexia and facial deformity. Radiography and ultrasonography revealed periostitis and regional soft tissue swelling of maxillary bones. Computed tomography excluded any dental or sinus origin of these abnormalities. Further deformities on distal limbs and skin lesions appeared during hospitalization. Radiography identified bilateral periostitis and soft tissue swelling in the distal radius and metatarsal bones, as observed in the head, suggestive of hypertrophic osteopathy (HO). Skin biopsies revealed granulomatous ...
Primo ALM, Assis DM, Santos VGS, de Melo LRB, da Nóbrega LD, Medeiros Dantas AF, Maciel TA.Cerebellar abiotrophy is a neurodegenerative disease that affects the Purkinje cells of the cerebellum, resulting in premature neuronal death. In horses, its occurrence has been reported mainly in the Arabian breed as a congenital mutation inherited in an autosomal recessive manner. The objective of this study was to describe the case of cerebellar abiotrophy in a Quarter Horse foal. An 8-day-old foal was treated after presenting signs of ataxia, hypermetria, difficulty maintaining a standing position, and decreased menace response. The foal was hospitalized for 26 days, received treatment wit...
Ibrahim L, Vernemmen I, Buschmann E, van Loon G, Cornillie P.The interatrial septum morphology, shaped by the septum primum and secundum fusion, results in the formation of the fossa ovalis (FO) and its limbus. Incomplete fusion can lead to a patent foramen ovale (PFO), while complete fusion may produce septal ridges and pouches (SPs), with SPs in humans linked to ischemic stroke and atrial arrhythmias. In horses, atrial tachycardia and fibrillation often originate near the FO. This study examines adult equine interatrial septum morphology to enhance understanding the region and guide electrophysiological interventions for equine cardiac arrhythmias. Po...
Brown KA, Engiles JB, de Solis CN, Bills KW, Johnson AL, Davidson EJ.To determine the accuracy of a dorsal ultrasound-guided approach for perineural injection of the sixth and seventh cervical spinal nerves (CSNs) with the use of a clinically relevant volume of injectate (2 mL). We hypothesized that the majority of injections would result in identification of contrast solution in the intervertebral foramen (IVF) on CT and corresponding methylene blue dye staining of the CSN on postmortem evaluation, and distribution of injectate into the epidural space would not occur. Unassigned: 7 horses donated to the University of Pennsylvania New Bolton Center for euthanas...
Vitale V, Velloso Álvarez A, de la Cuesta-Torrado M, Neira-Egea P, Vandecandelaere M, Tee E, Gimeno M, van Galen G.In human medicine, neurological diseases have been associated with transient cardiac abnormalities. In horses, myocardial disease is rarely diagnosed and has been associated with a wide variety of causes. The aim of this article is to describe three horses with no previous cardiac disease, which all developed severe cardiomyopathy following neurological disease. A 5-year-old Shetland pony stallion was diagnosed with cardiomyopathy with arrhythmias following an episode of seizures caused by an accidental intra-arterial xylazine injection. A 20-year-old crossbred mare was hospitalised for an ope...
Marine L, Wilfried P, Joëlle P, Justine J, Axel D, Vinciane T, Benoît V, Laurent G, Luc G, Jean-François K, Nadine A.In situ injection of mesenchymal stem cells appears as a promising treatment of tendinopathies. Tendon-derived mesenchymal stem cells (TDSCs) are widely studied and show a lot of interesting characteristics for clinical use. The aim of this study is to confirm the tenogenic potential of cryopreserved TDSCs and to confirm their ability to produce type I and/or type III collagens fibers in culture. Tendon-derived mesenchymal stem cells are harvested from the tendon no later than 72 h post-mortem. Their tenogenic potential has been assessed by quantitative reverse transcriptase polymerase chain ...
Fennouh C, Mokrani D, Dahmani H, Salhi O, Ouchetati I, Nabi M, Aouina K, Chettih I, Ouchene N, Khelifi Touhami NA.Fasciolosis, a parasitic disease of ruminants, poses significant economic and animal-health challenges in Algeria. This study aimed to assess spatial, temporal, and species-specific patterns of fasciolosis prevalence across diverse agro-climatic zones and to estimate associated economic losses. Between 2013 and 2023, eight wilayas El-Tarf, Skikda, Jijel (Region I), Blida, Mila (Region II), and M'Sila, Medea, Laghouat (Region III) were surveyed. Systematic postmortem inspections of 1,569,392 animals (349,176 cattle; 982,669 sheep; 235,639 goats; 1,882 camels; 26 horses) were performed by qualif...
Mathys RA, Schmitz TR, Geyer H, Borel N, Hilbe M, Ohlerth S, Bischofberger AS.This study described, assessed and correlated ultrasonographic, computed tomographic, and histological findings in the sacroiliac joints of adult Warmblood horse cadavers. In total, 25 joints from 15 horses were examined post-mortem using transrectal ultrasonography and helical computed tomography. Findings on computed tomography were graded in the caudal joint third (caudally) and for the entire joint as mild, moderate, or severe. In total, 11 joints from nine horses were evaluated histologically. All joints (100%) showed abnormalities on computed tomography, and 92% (23/25) displayed abnorma...
Schild CO, Nyaoke A, Asin J, Henderson EE, Blea JA, Stover SM, Uzal FA.Radial fractures are relatively uncommon (0-1%) injuries in postmortem studies of racehorses, and few cases have been published. We describe here a series of 42 cases of radial fractures observed in California racehorses. Autopsy findings from all racehorses submitted for postmortem examination between 2006 July 1 and 2022 June 30 that had a recorded radial fracture were evaluated. We included 42 horses (30 Thoroughbreds, 12 Quarter Horses), most of which were 3-5-y-old. Catastrophic radial fracture was observed in 30 (71%) horses; in the remaining 12 (29%) horses, the fracture of the radius w...
Ryu SH, Forbes E, Kim BS, Park KT.Five previously healthy horses in Korea, including a 19-year-old mixed-breed gelding, a 16-year-old mixed-breed mare, a 13-year-old Thoroughbred gelding, a 12-year-old Belgian warmblood mare, and a 12-year-old Andalusian mare, developed subcutaneous abscesses in the left neck after receiving intramuscular vaccination without prior skin disinfection. The vaccination used was Equivac® 2 in1, containing toxoid and cell-free extract. Within one week, the horses developed localised swelling and/or abscessation at the injection site. One case involved a ruptured abscess, while the others presente...
Bosch K, Zsoldos RR, Hartig A, Licka T.The influence of soft tissue structures, including ligaments spanning one or more intervertebral junctions and the nuchal ligament, on motion of the equine cervical joints remains unclear. The present study addressed this using four post-mortem horse specimens extending from head to withers with all ligaments intact. Three-dimensional kinematics was obtained from markers on the head and bone-anchored markers on each cervical and the first thoracic vertebra during rotation, lateral bending, flexion and extension of the whole head, and neck segment. Yaw, pitch, and roll angles in 8 cervical join...
Siwinska N, Ciaputa R, Dlugopolska D, Paszkowska M, Haider W, Schwegler K.Primary hepatic neoplasms are rare in horses and often have a poor prognosis due to non-specific clinical signs and delayed diagnosis. This report describes two cases of primary hepatic neoplasia in young horses. The first case was a yearling Hanoverian filly presenting with non-specific clinical signs, including poor weight gain and inappetence, ultimately diagnosed with hepatoblastoma based on ultrasonographic findings and histopathological examination. The second case was a three-year-old Polish Sport Horse stallion that died suddenly, with post-mortem examination revealing advanced cholang...
Healy SR, Yaffy D, Miller HG.Setaria equina is a species of filarial nematode parasite transmitted by mosquitoes, which infects horses and other equids. Adult worms reside in the abdominal cavity with apparently little pathogenic significance, but larvae can migrate to other regions of the body with resulting clinical disease. Cases in the UK are rare, with the last published report in 2001. A recent case of S. equina infection was detected in a 13-year-old, UK-resident mare during postmortem examination in Hertfordshire, UK. Adult worms were collected from the abdominal cavity, their DNA extracted and subjected to PCR an...
Vieira GS, Peneiras ABV, Soares TSC, Alonso MA, Curcio BR, Fernandes CB, Oliveira RA.Advancements in equine neonatology enable continuous monitoring of mares throughout pregnancy. However, reference values for oxygenation and biochemical parameters in newborn foals remain limited. Objective: This study aimed to assess the oxygenation status of healthy Mangalarga Marchador foals from birth to 24 h postpartum by evaluating blood gas analysis, Apgar scores, and biochemical and hematological parameters. Methods: Thirty healthy Mangalarga Marchador foals were evaluated. Blood samples were collected from the umbilical artery at birth (T0) and from the dorsal metatarsal artery at 15 ...
Giessen EJM, Stas EKL, Grinwis GCM, Veraa S.A 3-month-old Friesian colt presented with severe, progressive distal limb lameness in two limbs. Radiographic and postmortem full-body CT imaging revealed severe articular deforming osteolysis and osteoproliferation at the dorsodistal navicular bone margin and the adjacent distal phalanx proximo-palmar/proximo-plantar margin in two limbs, with the remainder of the distal interphalangeal joint being unaffected. Multiple other joints showed small osteolytic subchondral defects. Postmortem histopathological examination confirmed focal joint disease of both distal interphalangeal joints, without ...
