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.
Szeredi L, Makrai L, Dénes B.The first objective of this study was to develop an immunohistochemical procedure for rapid detection of Rhodococcus equi in impression smears from affected organs of foals on postmortem examination. The second aim was to demonstrate whether R. equi can be detected in smears of tracheal exudates collected from the same foals using an immunohistochemical method. Impression smears and cryostat and paraffin-embedded sections were made from the lungs and mediastinal lymph nodes of three foals (A, B and C) that had died of respiratory disease caused by R. equi, and also from the caudal mesenteric l...
Bouré LP, Pearce SG, Kerr CL, Lansdowne JL, Martin CA, Hathway AL, Caswell JL.To assess the efficacy of laparoscopic adhesiolysis in the treatment of experimentally induced adhesions in foals. Methods: 8 healthy pony foals. Methods: Celiotomy was performed and adhesions created at the jejunoileal junction and at sites 0.5 and 1 m proximal to this junction, using a serosal abrasion method. Ten days after celiotomy, exploratory laparoscopy was performed. Laparoscopic adhesiolysis was performed in the treatment group only (4 foals, randomly selected). Thirty days after the exploratory laparoscopy, a final laparoscopic examination was performed, and the foals were euthanati...
Johnson BJ.Immediately record the findings. A tape recorder would be excellent for this. If none is available, findings should be written down as soon as possible before memory of the examination fades. It is important to record comments on every organ that you examined. Three years from now in a court deposition, it may be difficult for the practitioner to remember if he looked at the adrenal glands or if there was no gross evidence of hyperplasia. When writing a report, it is a good idea to describe the tissue changes rather than just to give an interpretation. An example of the latter would be, "The h...
Katayama Y, Kuwano A, Yoshihara T.A 4-year-old female thoroughbred race horse died of acute peritonitis caused by necrotizing granulomatous duodenitis. Yersinia enterocolitica was immunohistochemically demonstrated in macrophages in granulomas developed in the duodenum, lung, liver and abdominal lymph nodes. The yeast-like fungi were found in the cytoplasmic vacuoles of macrophages in the lung that infiltrated into the granulomas and surrounding alveoli with congestive edema. The yeast-like fungi were positively stained by Gomori-Grocott chromic acid methenamine silver stain and immuno-histochemically stained with anti-histopl...
Saam D.A 9-year-old, quarter horse gelding with obstructive urethrolithiasis was treated with a perineal urethrostomy. The horse's condition deteriorated and abdominocentesis confirmed septic uroperitonitis. The horse was euthanized and postmortem examination revealed peritonitis, a tear in the lateral wall of the bladder, and a nephrolith within the left renal pelvis.
Frees KE, Gaughan EM, Lillich JD, Cox J, Gorondy D, Nietfeld JC, Kennedy GA, Cash W.Formalin was injected into an ethmoidal hematoma in an 18-year-old Arabian gelding. Abnormal neurologic signs were observed within minutes of the injection. The horse did not respond favorably to medical treatment of the neurologic signs and was euthanatized. Postmortem examination revealed erosion and necrosis of the ventral cribriform plate, which appeared to have allowed the injected formalin to reach the rostral portion of the frontal lobe of the brain. Endoscopy and radiography had been performed prior to euthanasia, but neither delineated the cribriform lesion. Before treating large prog...
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...
Johnson JS, Hibler CP, Tillotson KM, Mason GL.An adult horse was euthanatized following a clinical diagnosis of cauda equina neuritis. Significant gross postmortem and histopathologic findings were limited to the sacral spinal cord and cauda equina. The sacral spinal cord, meninges, and spinal nerve roots were expanded and partially effaced by sclerosing granulomatous inflammation with necrosis. The lesion contained numerous nematode larvae and fewer adults with a rhabditiform esophagus having a corpus, isthmus, and valved bulb. Female nematodes were amphidelphic and didelphic with reflexed ovaries. These morphologic features confirm Hali...
Beech DJ, Sibbons PD, Rossdale PD, Ousey JC, Holdstock NB, Chavatte P, Ansari T.Equine lung and kidney organogenesis has not previously been examined with the use of unbiased stereological techniques. The present study examined healthy (control) pony and Thoroughbred lungs and kidneys to establish baseline data of organ development from before birth until maturity at age 3-18 years. Whole left lungs and kidneys were collected from 45 equine postmortem examinations (34 Thoroughbred, 11 pony). Stereological techniques were used to estimate whole kidney, cortex and medulla volume, total glomerular number and volume-weighted mean glomerular volume, lung volume, total terminal...
Gull T, Schmitz DG, Bahr A, Read WK, Walker M.Diagnostic imaging, including computed tomography, of a two-month-old foal with renal failure indicated that its right kidney was probably absent and that its left kidney was abnormal in shape. The foal was stabilised and released, but three days later its clinical signs recurred. Postmortem examination revealed renal hypoplasia and dysplasia, the first reported case of this condition in an American miniature horse.
Sanders SG, Tucker RL, Bagley RS, Gavin PR.Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encep...
Brounts SH, Rashmir-Raven AM, Black SS.This case report describes a distinctive deep cutaneous lesion in a 1-year-old Quarter Horse filly with hyperelastosis cutis. The horse had a typical clinical presentation of hyperelastic skin associated with a 6-month history of cutaneous wounds that developed following minor cutaneous trauma. Punch biopsies of skin from the affected horse were thinner than similar biopsies from an age- and breed-matched control. Significant microscopic lesions were not seen in cutaneous punch biopsies stained with haematoxylin and eosin and Masson's trichrome stains, but the ultrastructure of the dermis from...
Cantile C, Del Piero F, Di Guardo G, Arispici M.The pathologic and peroxidase immunohistochemical features of West Nile flavivirus (WNV) infection were compared in four horses from the northeastern United States and six horses from central Italy. In all 10 animals, there were mild to severe polioencephalomyelitis with small T lymphocyte and lesser macrophage perivascular infiltrate, multifocal glial nodules, neutrophils, and occasional neuronophagia. Perivascular hemorrhages, also noted macroscopically in two animals, were observed in 50% of the horses. In the four American horses, lesions extended from the basal nuclei through the brain st...
Benders NA, Wijnberg ID, van der Kolk JH.A 10-year-old, non-pregnant Dutch Warmblood mare was referred to the Department of Equine Science because of chronic weight loss, despite good appetite, and dullness. Clinical examination revealed muscle atrophy, trembling of the limb muscles, an abnormal stance in which all four limbs were placed under the body, and an abnormal low head carriage. The plasma vitamin E concentration was markedly decreased (0.2 mumol/l), the electromyographic (EMG) examination was consistent with denervation, and the oral glucose absorption test was below the reference value (40% increase over the resting glucos...
Kyles KW, McGorum BC, Fintl C, Hahn CN, Mauchline S, Mayhew IG.Electromyography was used as an aid to the diagnosis of equine motor neuron disease in a conscious horse while it was under caudal epidural anaesthesia. A muscle biopsy was taken to confirm the diagnosis which was then supported by a postmortem examination.
Bettschart-Wolfensberger R, Jäggin-Schmucker N, Lendl C, Bettschart RW, Clarke KW.The minimum alveolar concentration of desflurane when combined with a continuous infusion of medetomidine at 3.5 microg/kg/hour was measured in seven ponies. Anaesthesia was induced with medetomidine (7 microg/kg intravenously) followed by ketamine (2 mg/kg intravenously) and maintained with desflurane in oxygen. The infusion of medetomidine was started 20 minutes after the induction of anaesthesia. The electrical test stimulus was applied at the coronary band (50 V, 10 ms bursts at 5 Hz for one minute), and heart rates and rhythms, arterial blood pressures, and arterial blood gas tensions wer...
Hafner S, Harmon BG, King T.Ten cecal tumors were identified during the postmortem examination of seven horse carcasses at slaughter (one horse had three tumors). The multinodular and hemorrhagic tumors ranged from 1 to 10 cm in diameter and consisted of spindle cells arranged in thin, interconnected trabeculae that were often separated by sinuses filled with mucinous fluid, erythrocytes, and siderophages. Spindle cells of all tumors were immunopositive for vimentin, neuron-specific enolase, and c-kit protein but lacked reactivity with antibodies to glial fibrillary acidic protein, S100 protein, and desmin. In one tumor,...
Frye MA, Johnson JS, Traub-Dargatz JL, Savage CJ, Fettman MJ, Gould DH.To determine historical, physical examination, clinicopathologic, and postmortem findings in horses with putative uremic encephalopathy. Design-Retrospective study. Animals-5 horses with renal failure and neurologic disease not attributable to abnormalities in any other organ system. Methods: Medical records from 1978 to 1998 were examined for horses with renal disease and neurologic signs not attributable to primary neurologic, hepatic, or other diseases. Signalment, history, physical examination findings, clinicopathologic data, renal ultrasonographic findings, and postmortem data were revie...
Saville WJ, Stich RW, Reed SM, Njoku CJ, Oglesbee MJ, Wunschmann A, Grover DL, Larew-Naugle AL, Stanek JF, Granstrom DE, Dubey JP.Neurologic disease in horses caused by Sarcocystis neurona is difficult to diagnose, treat, or prevent, due to the lack of knowledge about the pathogenesis of the disease. This in turn is confounded by the lack of a reliable equine model of equine protozoal myeloencephalitis (EPM). Epidemiologic studies have implicated stress as a risk factor for this disease, thus, the role of transport stress was evaluated for incorporation into an equine model for EPM. Sporocysts from feral opossums were bioassayed in interferon-gamma gene knockout (KO) mice to determine minimum number of viable S. neurona ...
van Hoogmoed L, Snyder JR, Pascoe JR, Olander HJ.This report describes the evaluation of uniformity of morphological injury of the large colon following severe colonic torsion in 17 horses presented to the Veterinary Medical Teaching Hospital. In 16 horses, twist occurred at the colonic base and in 1 at the sternal and diaphragmatic flexure. Eleven of the 17 horses were subjected to euthanasia at surgery and 6 of 17 following surgical correction within 4 days postoperatively. The objective of this study was to determine if the degree of histological changes present at the pelvic flexure were uniformly distributed throughout the regions of th...
Spoormakers TJ, IJzer J, Sloet van Oldruitenborgh-Oosterbaan MM.A 22-year-old Dutch Warmblood mare was referred to Utrecht University with progressive left hind limb paresis and hyporeflexia. The preliminary clinical diagnosis was the neurological form of equine herpes virus (EHV-1) infection. Within 1 day of admission, the mare became recumbent and deteriorated rapidly. Postmortem examination revealed an adenocarcinoma of the caecum, with metastases in all regional lymph nodes and extending from the lumbar nodes into the vertebral canal, causing spinal cord compression and destruction of the left 4th and 5th lumbar nerves.
Edwards GB, Kelly DF, Proudman CJ.Twenty-two horses with colic, referred to the University of Liverpool Equine Hospital (1992-1998), were found at laparotomy to have a partial obstruction of the large colon caused by a segmental mural lesion located in the left dorsal colon. The decision to take the horses to surgery was based on rectal examination findings of secondary impaction and mural oedema of the large colon and turbid peritoneal fluid containing large numbers of neutrophils obtained by paracentesis. The affected segment of colon showed oedema and serosal changes varying from erythema to well-defined necrosis. These pat...
Gayle JM, Macharg MA, Smallwood JE.To report the clinical and surgical findings and outcome for horses with strangulating obstruction caused by herniation through the proximal aspect of the cecocolic fold. Methods: Retrospective study. Methods: Nine horses. Methods: Medical records were reviewed for clinical signs, surgical findings and technique, and outcome. Cadaver ponies and necropsy specimens were also used to study the regional anatomy of the cecocolic fold. Results: The ileum and distal jejunum were strangulated in 8 horses, whereas in 1 horse the small intestine and the left ascending colons were incarcerated in a rent ...
Patterson-Kane JC, Tramontin RR, Giles RC, Harrison LR.A 14-year-old Thoroughbred gelding with a history of acute onset of hematuria was presented for necropsy. Transitional cell carcinoma of the urinary bladder with intra-abdominal dissemination was diagnosed. Tumor masses were observed on the splenic capsule and surrounding the distal abdominal aorta. Tumor cells showed diffuse cytoplasmic reactivity for cytokeratin but were negative for epithelial membrane antigen, carcinoembryonic antigen, tumor-associated glycoprotein 72, and vimentin.
Del Piero F, Wilkins PA, Timoney PJ, Kadushin J, Vogelbacker H, Lee JW, Berkowitz SJ, La Perle KM.A case of fatal nonneurological equine herpesvirus 1 (EHV-1) infection in a yearling filly is described. Gross lesions included extensive pulmonary edema, prominent laryngeal lymphoid follicles, and congestion and edema of the dorsal third ventricle choroid plexus. Histologically, there was vasculitis, hemorrhage, and edema in the lungs and dorsal third ventricle choroid plexus as well as mild intestinal crypt necrosis with occasional intranuclear inclusion bodies. The perivascular and vascular inflammatory infiltrates were comprised mainly of T lymphocytes and macrophages. EHV-1 antigen was i...
Jacobs AA, Goovaerts D, Nuijten PJ, Theelen RP, Hartford OM, Foster TJ.As part of a search for a safe and efficacious strangles vaccine, several different vaccines and different vaccination routes were tested in foals. The degree of protection was evaluated after an intranasal challenge with virulent Streptococcus equi by clinical, postmortem and bacteriological examinations. Inactivated vaccines containing either native purified M-protein (500 microg per dose) or whole S equi cells (10(10) cells per dose) administered at least twice intramuscularly at intervals of four weeks, did not protect against challenge. Different live attenuated S equi mutants administere...
Tomlinson JE, Redding WR, Sage A.Ultrasonographic examination of the tarsus was performed on four clinically and radiographically normal limbs of adult horses. Particular attention was paid to the articular cartilage surfaces of the trochlear ridges of the talus and the distal intermediate ridge of the tibia. Two separate measurements of articular cartilage thickness were acquired from a longitudinal view at each site. Anatomy was confirmed with post mortem dissection. Ultrasonography was found to be a practical method for imaging the articular cartilage over the trochlear ridges of the talus and distal intermediate ridge of ...
Penraat JH, Allen AL, Fretz PB, Bailey JV.The use of monoiodoacetate (MIA) for arthrodesis of the proximal interphalangeal joint (PIJ) and the effect of exercise on the degree of fusion were investigated. Eight horses received 3 injections (Weeks 0, 3, 6) of MIA (2 mL; 60 mg/mL) into the right or left front PIJ. Peri-operatively, the horses received phenylbutazone, butorphanol, and abaxial sesamoidean nerve blocks to relieve pain. During the study, the horses were monitored for general health, lameness, and swelling around the injection area. Radiographs were taken biweekly to evaluate bony fusion. Horses were randomly divided into no...
Richards AJ, Kelly DF, Knottenbelt DC, Cheeseman MT, Dixon JB.This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had normochromic, normocytic anaemia and some had low levels of plasma proteins, including immunoglobulin G. Antibiotic and supportive treatment was ineffective and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cr...
van de Lest CH, Brama PA, van Weeren PR.This study aimed at the determination of the influence of exercise on the levels of a number of bone morphogenic enzymes in subchondral bone and at the comparison of these data with other (subchondral) bone-related parameters that have been investigated in the same experimental population.Forty-three foals were reared until weaning at 5 months of age under similar conditions, except for the type and amount of exercise. Fifteen foals remained at pasture (Pasture group and also control group), 14 foals were kept in box stalls (Box group) and 14 foals were kept in the same box stalls but were sub...
Versnaeyen H, Saey V, Vermeiren D, Chiers K, Ducatelle R.A 7-year-old warmblood mare showed sudden onset of mild intermittent haemoptysis. Clinical examination revealed no significant abnormalities. Haematological examination showed mild anaemia, hypoalbuminaemia and neutrophilia. Coagulation tests were normal. Endoscopic examination revealed unilateral pulmonary haemorrhage with blood clots in the bronchi and trachea. Treatment with antibiotics was started and the horse was given stable rest. Two weeks later, the horse was found dead with blood and frothy sputum leaking from the nostrils. Post-mortem examination revealed a large thoracic aortic ane...
Binanti D, Livini M, Riccaboni P, Sironi G.A 16-year-old primiparous mare aborted an apparently normal fetus at 240 days of gestation. A large, oval mass, measuring approximately 20 cm × 30 cm × 20 cm, was detected attached to the umbilical cord of the fetus. On the cut surface, the mass showed multifocal cystic structures, foci of mineralization, and diffuse hemorrhages. Histological examination of the mass revealed haphazardly arranged cartilage, bone, mesenchymal stroma, adipose tissue, vascular structures, smooth muscle, ciliated epithelium, squamous cornifying epithelium, and undifferentiated germ cells with areas of necrosis an...
Fussell D, Bizikova P, Breuhaus B, Harris RA, Moore AR, Chen L, Linder KE.Bullous amyloidosis is a rare disease in humans that has not been described in a veterinary species in the peer-reviewed literature. The human disease is characterised by haemorrhagic vesicles and bullae on the skin and mucosae, which form due to amyloid deposition. Objective: To describe the clinical features, laboratory analysis and histopathological features of an unique presentation of bullous disease in a horse. Methods: A 17-year-old thoroughbred mare presented for weight loss and severe oral cavity ulcers. Methods: Investigations involved haematological evaluation, chemistry profiles, g...
May-Davis S, Gee C, Brown WY.Ultrasound is a well-established modality in equine investigative and diagnostic procedures. Although to date, it has not been utilized in examining the attachments of the equine nuchal ligament lamellae (NLL) onto the cervical vertebrae, for which a noninvasive technique is currently lacking. This study presents a standardized methodology for investigating the equine NLL using ultrasonography, and further evaluates the ultrasound images against postmortem dissection in two nonrelated horses. The ultrasound images in both horses clearly presented the attachment points of the NLL to the dorsal ...
Buote M.A 2-month-old foal was presented with clinical signs of colic. Gastroduodenal ulceration was suspected. A poor response to medical treatment and signs of gastroduodenal obstruction led to celiotomy and an attempted bypass procedure. The foal was euthanized and postmortem examination revealed gastric ulceration, segmental duodenal stenosis, and severe chronic cholangiohepatitis and pancreatitis.
Thurman JD, Johnson BJ, Lichtenfels JR.Arteriosclerosis caused by Dirofilaria immitis adult parasites was diagnosed in a 20-month-old Quarter horse stallion that died from cantharidin toxicosis. Microscopically, the pulmonary vascular changes were typical of those described as "proliferative endarteritis" in D immitis-infected dogs.
Harps O, Brumhard J, Bartmann CP, Hinrichs U.An abdominal tumor was suspected after clinical evaluation in an eight-year-old, bay-coloured hannoveranian gelding. The diagnosis was based on the symptoms of ascites, on the results of the transcutaneous abdominal ultrasound examination and on the characteristic changes in the serum-electrophoresis. Postmortem a peritoneal mesothelioma was diagnosed. This primary tumor of the peritoneum is rarely described in horses.
Clayton HM, Duncan JL.From June to October 1978 four pony mares and foals and two donkey mares and foals grazed a paddock contaminated with Dictyocaulus arnfieldi larvae. No signs of respiratory disease were seen in the foals but within 11 weeks of exposure to the paddock all six developed patent lungworm infections. In October 1978 one donkey and two pony foals were killed. At post mortem examination parasites in various stages of development and measuring up to 8 cm in length were found in the lungs. At this time the three surviving foals were stabled for the remainder of the experiment. Two of these ceased passi...
Wolgien D, Keller H.The anesthesia routine in the horse is briefly explained. 35 postanesthetic complications resulted from the total of 4364 cases of anesthesia. They are evaluated by means of the duration of anesthesia, the time of paresis, the exemplary courses of enzymes as well as the distribution of race and sex and their ratio towards all cases of anesthesia. Finally a list of demands concerning the operative and postoperative phases is compiled to minimize postoperative myositis (PAM) and lameness (PAL).
Baker SJ, Johnson PJ, David A, Cook CR.Chronic gastroesophageal reflux disease was diagnosed in a 22-year-old female Tennessee Walking Horse that had signs of bruxism and ptyalism. Esophageal ulceration was detected via endoscopy. Compared with the damage to the proximal portions of the esophagus, the severity of the ulceration increased toward the gastroesophageal junction. Esophageal ulceration attributable to chronic gastric acid reflux is usually secondary to pyloric outflow obstruction in horses. In the horse of this report, there was no evidence of either a chronic pyloric or duodenal obstruction that could have resulted in e...
Parry BW.The clinical, surgical and/or necropsy diagnosis of 79 horses admitted to a referral clinic for evaluation of colic are reported. Twenty-one horses were presented with conditions amenable to medical treatment and all were subsequently discharged. Exploratory laparotomies were performed on 44 horses during the present study, in some cases as a diagnostic procedure preceding euthanasia. In general, in surgical cases the mortality rate was highest for problems involving the small intestine, followed by those affecting the large colon and then the small colon. Postoperative sequelae included perit...