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.
Murray MJ.Hypothyroidism was diagnosed in a neonatal Thoroughbred foal that was weak, hypothermic, and septicemic. Administration of thyroid-releasing hormone elicited attenuated increases in concentrations of free and total triiodothyronine and thyroxine, as compared with a clinically normal, age-matched foal. The foal died of apparent respiratory insufficiency, pre- and postmortem findings compatible with hypothyroidism included hypothermia, large thyroid glands with distended, colloid-filled follicles, and severe, diffuse atelectasis, with thickened alveolar septae and degenerating alveolar squamous ...
Snyder JR, Pascoe JR, Olander HJ, Hinds DM, Young R, Tyler WS.Ten horses were euthanatized before, during, or after surgery to correct severe volvulus of the large colon. At surgery, the colonic serosa changed from blue-gray, blue or purple toward a more normal pink in seven horses after the volvulus was corrected. The mucosa consistently remained black or dark red. Results of postmortem colonic microangiography revealed perfusion of the serosa and the circular and longitudinal muscle layers, but mucosal perfusion was limited by thrombosis in the muscularis mucosae and submucosa. There was evidence of thrombosis of the mesenteric colic vessels in six hor...
Foreman JH, Weidner JP, Parry BW, Hargis A.A 17-year-old Quarter Horse mare was examined nearly 3 years after excision and cryotherapy of a papillary mammary gland adenocarcinoma. The mare had been used for pleasure riding since surgery, but had recently developed progressive dyspnea. The mare had clinical evidence of pleural effusion, but died before further clinical examination and treatment were instituted. Necropsy revealed deep mammary masses with similar nodules in the deep inguinal, renal, and mediastinal lymph nodes and in the lungs, pericardium, visceral and parietal pleurae, and left ovary. The masses were identified as papil...
Marr CM, Love S, Pirie HM, Northridge DB.Regurgitation of blood through the left atrioventricular valve owing to the rupture of one of the chordae tendineae of the valve was diagnosed in a horse with sudden-onset respiratory distress and a holosystolic cardiac murmur. Severe regurgitation was confirmed with Doppler echocardiography and prolapse of part of the valve leaflet was identified with B-mode ultrasonography. The rupture of one of the chordae tendineae of a right accessory cusp of the left atrioventricular valve was confirmed post mortem. Bronchiolitis, multifocal haemorrhages and haemorrhagic fibrous plaques were found in the...
Reef VB, Klumpp S, Maxson AD, Sweeney RW.Two-dimensional real-time echocardiographic examination of a 3-year-old Thoroughbred gelding with pleuropneumonia revealed an intact aneurysm of the right sinus of Valsalva, which was confirmed at postmortem examination. The horse had no clinical signs associated with the aneurysm.
Richey MT, Holland MS, McGrath CJ, Dodman NH, Marshall DB, Court MH, Norman WM, Seeler DC.The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors.
Martineau D, Bowser PR, Wooster G, Forney JL.Sixty-seven adult walleye fish were examined by light and transmission electron microscopy. The fish were affected by a mesenchymal tumor previously termed Walleye Dermal Sarcoma that commonly affects up to 27% of the population seasonally. Biopsies from 24 fish were collected, and complete postmortem examinations were performed on 43 fish. Grossly, the tumors had the appearance of randomly distributed, often clustered, spherical nodules, 2-5 mm in diameter with a smooth and often ulcerated surface. The tumors arose from the superficial surface of scales and consisted of fibroblast-like cells ...
Holt PE, Mair TS.Bladder paralysis and sabulous urolithiasis were diagnosed in 10 horses with urinary incontinence. Additional neurological deficits in the hindquarters were detected in five of them. Treatment by catheter drainage and bladder lavage was unsuccessful, and all the horses were destroyed within 14 months of presentation. Neuritis of the cauda equina was diagnosed post mortem in one horse, but the cause of the paralysis was not identified in the others, although radiography revealed abnormal lumbosacral vertebral angulation in one case.
Mfitilodze MW, Hutchinson GW.A postmortem survey of 57 horses in tropical northern Queensland revealed 41 (89%) infected with intestinal strongyles. Thirty-five strongyle species (8 large strongyles and 27 small strongyles [Cyathostominae]) were recorded of which 9 species are reported from Australia for the first time. The 14 most prevalent small strongyles were Cyathostomum catinatum (in 76% of horses), Cyathostomum coronatum (65%), Cyathostomum pateratum (33%), Cyathostomum labiatum (30%), Cylicostephanus calicatus (70%), Cylicostephanus longibursatus (67%), Cylicostephanus goldi (43%), Cylicostephanus minutus (26%), C...
Baird AN, Frelier PF.A Quarter Horse stallion developed an abscess over the left gluteal region after an IM injection of antihistamine. The wound healed with considerable fibrous scarring and some persistent granulation tissue. The lesion was static for 2 years before the granulation tissue went through a 6-month period of progressive enlargement. At that time, histopathologic diagnosis of squamous cell carcinoma was made from excisional biopsy. Six months after diagnosis, the horse had lost body weight and the lesional diameter had further increased, so the horse was euthanatized.
Kamphues J, Meyer H.Following feeding of a new delivery of hay (bought in Southern Germany) 3 horses out of a unit of 17 developed colic within a few days one horse died. Post-mortem there was an intensive accumulation of serous or serous-haemorrhagic fluid in the thorax and abdomen. The hay was heavily contaminated by autumn crocus (colchicum autumnale)--about 1.48% of total mass. Other feedstuffs were of good quality and following removal of the affected hay no further cases of colic occurred. The pathological findings also indicated a colchicine intoxication.
Reef VB, Johnston JK, Divers TJ, Acland H.Cholelithiasis and/or obstructive biliary tract disease was diagnosed ultrasonographically in 8 horses, 5 to 15 years old. Ultrasonographic findings revealed greater than normal amount of hepatic parenchyma in the right side of the abdomen in 8 horses and in the left side in 3 horses. The echogenicity of the liver was greater than normal, and thick distended bile ducts were seen in all horses. Choleliths were imaged ultrasonographically in 6 horses. Subsequently, postmortem findings in 6 horses revealed periportal and intralobular fibrosis, moderate bile duct dilatation, proliferation, and cho...
Ettlinger JJ, Ford T, Palmer JE.Proximal enteritis was diagnosed on the basis of clinical signs of disease in 2 Standard-bred yearlings from the same farm. Large volumes of fluid were repeatedly obtained during gastric decompression. The horses did not respond to treatment with IV administered fluids, antimicrobial agents, cimetidine, and metoclopramide. Postmortem findings confirmed severe focal chronic active duodenitis with stricture formation. An etiologic agent was not identified.
Mair TS, de Westerlaken LV, Cripps PJ, Love S.Samples of faeces and blood were obtained from 66 adult horses with diarrhoea. The results of routine bacteriological, parasitological, haematological and biochemical tests were correlated with the outcome of the cases. Twenty-two (33 per cent) of the horses died or were destroyed as a consequence of the diarrhoea. A diagnosis was reached in only 23 cases (35 per cent), and in nine of them only at post mortem examination. Salmonella typhimurium was isolated from five cases. Statistical analysis revealed significant differences between the horses which survived and those which died in their pac...
Dickson LR, Badcoe LM, Burbidge H, Kannegieter NJ.Forty-eight hours after general anaesthesia was induced by glycerol guaiacolate and thiopentone sodium in 10 horses, the jugular veins were dissected out at post-mortem and examined visually and histologically. All veins showed a marked thrombophlebitis involving the media and intima at the site of injection. The influence of catheter composition, catheter placement and chemical composition on the occurrence of the thrombophlebitis is discussed. It is concluded that the thrombophlebitis was chemically induced.
Schumacher J, Moll HD, Spano JS, Barone LM, Powers RD.Two horses were presented with lethargy, weight loss, anorexia, and swelling of the limbs and ventral body wall. One horse, a 12-month-old American Paso Fino colt, also had acute abdominal pain. The other horse, a seven-month-old Tennessee Walking Horse (TWH) filly passed diarrheic stools during the initial examination. Each horse had low serum protein, neutropenia, and a normal packed cell volume (3.2 g/dl, 1300 cells/ul, and 38%, respectively, for the colt, and 2.4 g/dl, 696 cells/ul, and 44%, respectively for the filly). After intravenously administering plasma, the colt's PCV dropped to 23...
Mair TS, Pearson GR.A 3 1/2-year-old bay gelding of the cob type showed nervous signs and coughing associated with breaking-in and exercise. At post-mortem examination, heavy melanin pigmentation of the meninges of the hind brain and the medulla was identified and, on histological examination, melanin-containing cells were found within connective tissue extending into the medulla. The lesion was considered to be a melanotic hamartoma.
Ohshima K, Satake S, Ono M, Ajito T, Okada K, Numakunai S.A pathological study was performed on osteoarthrosis detected at autopsy in 20 horses whose ages ranged from 21 days to 17 years old. They were asymptomatic on the joints except in 3 animals, and autopsied after death or sacrificed due to accidental fracture or other diseases. Lesions of osteoarthrosis were recognized in all horses, which tended to increase in incidence and severity according to age. Lesions were concentrated at hinged joints such as the elbow, fetlock, and hock. Synovial fossae and ulcerative lesions were observed on each opposite articular cartilage, forming the so-called mi...
Dierckins MS, Sherman DM, Gendron-Fitzpatrick A.A presumptive diagnosis of paratuberculosis was made in a Sicilian ass on the basis of a history of chronic diarrhea and weight loss, pasture exposure to a heifer with paratuberculosis confirmed by bacterial culture of feces, postmortem identification of granulomatous inflammation of the intestine containing acid-fast organisms, the absence of acid-fast organisms in extraenteric tissues, and the absence of exposure to tuberculosis. The literature on paratuberculosis in equids is reviewed. The potential for cross-species transmission is emphasized. Justification for consideration of Mycobacteri...
Heath SE, Bell RJ, Chirino-Trejo M, Schuh JC, Harland RJ.Four horses from the same farm developed clinical signs of botulism during the winter months; three of these horses died. One horse survived an initial attack and recovered over a three-week period, but died during a second attack. The horse that survived took six weeks to recover. Clinical and postmortem examination ruled out other causes of disease. Confirmation of the diagnosis was made by isolation of Clostridium botulinum type C toxin from the dirt in the bottom of an oak feedtrough used by all horses, and from the colonic contents of one of the horses that died. To our knowledge, this is...
Kramme PM, Ziemer EL.Coccidioidal osteomyelitis was diagnosed in a horse after a 6-month period of coughing, weight loss, and lameness. The horse was euthanatized and the diagnosis was confirmed by gross and microscopic findings.
Mair TS, Taylor FG, Brown PJ.Two horses affected by chronic, intermittent colic were found, at post-mortem examination, to have localized annular thickening of a segment of the duodenum. Histological examination of the lesion in both cases revealed a tumour composed of bundles of oval or spindle-shaped cells that stained as muscle with van Gieson stain. The histological diagnosis was leiomyosarcoma. The tumour had caused partial bowel obstruction in both horses.
Riera FL, Hinrichs K, Hunt PR, Kenney RM.Cervical hyperplasia with prolapse through the vulvar lips was documented in a mare. Postmortem examination indicated that the mass originated from the cervical wall. The surface of the prolapsed mass had histologic features of normal cervix. Cervical hyperplasia can be considered in a list of differential diagnoses in cases of prolapse of the internal genitalia in mares.
Mück WM, Henion JD.The performance of microbore high-performance liquid chromatography and capillary zone electrophoresis, both equipped with on-line tandem mass spectrometric detection capability, was evaluated critically for the determination of endogenous amounts of leucine enkephalin and methionine enkephalin in equine cerebrospinal fluid. Using an identical sample clean-up and enrichment procedure, capillary zone electrophoresis-mass spectrometry is limited in its concentration detection capacity owing to its much smaller injection volume. Leucine enkephalin was identified in post-mortem equine cerebrospina...
Hamir AN, Reef VB.Gross and histopathological findings in a 9-year-old horse implanted with permanent transvenous pacing cardiac catheters, 18 and 34 months before its death, are described. Lesions consisting of extensive fibrino-haemorrhagic thrombi with large numbers of bacterial colonies were present along the electrode wires and on mural and valvular endocardial surfaces of the right heart. There was a locally extensive area of suppurative endocarditis around the attachment site of the atrial electrode, which was loosely attached by a thin band of membranous tissue to the endocardium. The ventricular electr...
Smith BL, Morton LD, Watkins JP, Taylor TS, Storts RW.A 16-year-old cryptorchid Quarter House with colic had a large, lobulated soft-tissue mass to the left of the pelvic inlet. At surgery, 2 large multilobulated pedunculated masses were removed. A large blood vessel enveloped by one of the masses was damaged, and the horse exsanguinated. Postmortem examination of the abdomen revealed the masses to be malignant seminoma, with multiple sites of metastasis.
Cudd TA, Mayhew IG, Cottrill CM.DORSAL midline dysgenesis of the human brain, a complex
pattern of maldevelopment of sulcation and neuronal migration
occurring before 74 days gestation, has been recognised for over
fifty years. The association (68 per cent) of the so-called Dandy-
Walker syndrome (cystic dilatation of the fourth ventricle and
hypoplasia of the cerebellum) with other brain malformations is
common and often includes agenesis of the corpus callosum
(Hart, Malamud and Ellis 1972; Ral et a1 1980). This report
describes the first pre-mortem identification of such a structural
brain anomaly in a Thoroughbr...
Milne EM, Pogson DM, Else RW, Rowland AC.One case of caecocaecal intussusception (case 1) and one case of caecocolic intussusception (case 2) in ponies are described. Case 1 showed mild abdominal discomfort for seven days followed by sudden death whereas case 2 showed continuous moderate pain for three weeks. At post mortem examination, case 1 showed intussusception of the base of the caecum into the body whereas in case 2, the entire caecum had invaginated into the right ventral colon. Histopathological examination showed that the lesions in both animals had been present for a long time.
Cantor GH, Palmer GH, Fenwick BW.The concentrations of several post mortem aqueous humour chemical constituents were compared with ante mortem serum chemical values in the horse. Urea nitrogen and creatinine values in post mortem aqueous humour were good predictors of ante mortem serum values. Aqueous humour urea nitrogen increased only slightly and creatinine did not change significantly for up to 24 h after death. Formulae were derived for calculating estimated ante mortem serum urea nitrogen and creatinine from aqueous humour values obtained after death. These results from normal horses identify analytes that are accurate ...
Palmisano M, Kulp J, Bender S, Stefanovski D, Robinson M, Johnson A.Eight-hydroxy-2'-deoxyguanosine (8-OHdG), a biomarker of oxidative damage evaluated in human neurodegenerative disease, has potential to correlate with postmortem diagnosis of neuroaxonal dystrophy/degenerative myeloencephalopathy (NAD/DM) in horses. Objective: We hypothesized that 8-OHdG will be higher in CSF and serum from NAD/DM horses compared with horses with other neurologic diseases (CVSM, EPM) and a control group of neurologically normal horses. We also hypothesized that 8-OHdG will be higher in CSF compared with serum from NAD/DM horses. Methods: Fifty client-owned horses with postmor...
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...
Mirck MH, Eysker M, Jansen J.Proceeding on the epidemiology of Strongylidae infection in horses, the effects of combined anthelmintic treatment and moving to non-contaminated pasture in July were studied during 1981 and 1982. This strategy for control was found to be effective as was shown by faecal examination, pasture larval counts and post-mortem worm counts. No significant contamination or worm infection developed in the group of treated ponies moved to celan pasture after July 1. On the permanently grazed pasture the same pattern of infection developed as on the pasture where up to July 1 ponies and subsequently shee...
Gregory MW, Longstaff JA, Giles CJ.Ciliates resembling Polymorphella ampulla (Dogiel, 1929) were found in large numbers in the crypts and lamina propria of the caecum and colon of a one-year-old Thoroughbred gelding that had shown recurring bouts of chronic diarrhoea and weight loss over a 5-month period. A heavy burden of helminths, mainly cyathostomes (trichonemes) was present at post-mortem examination and no significant bacterial pathogens were recovered. It was considered that the Polymorphella (which is normally a commensal organism) had in this case assumed a secondary pathogenic role.
Beccati F, Pepe M, Nannarone S, Tamantini C, Gialletti R.The case report of a 14-month-old Thoroughbred filly with acute onset of severe right hindlimb lameness is presented. The horse had a severe and sudden abduction of the hindlimbs due to a side effect of an overdose of lidocaine, which had been administered in a constant rate infusion after a colic surgery. Transcutaneous ultrasonography and standing radiography of the pelvis revealed proximal and cranial displacement of the greater trochanter and free bone fragments consistent with an apophyseal avulsion fracture of the greater trochanter. The complete diagnosis was obtained with the horse in ...
Welland LM.A 6-year-old, primiparous standardbred mare was presented with a history of intestinal protrusion from the rectum shortly after parturition. A subacute grade IV rectal tear was diagnosed. The unusual nature of the tear led to speculation of a possible owner palpation accident. A grave prognosis was given and the mare was euthanized.
Johnston GM.This research is about a study conducted to understand the causes and frequency of unexpected fatalities due to surgery or anesthesia within a week of surgery in horses, ponies, and […]
Roorda G, van der Kamp JS.A rare case of colic in an eleven-year-old New Forrest mare is reported. As treatment was ineffective, the animal had to be slaughtered. Post mortem examination showed that the colic was due to bilateral haemorrhagic corpus luteum, from which blood (appr. 20 liter) entered the abdominal cavity.
Cranley JC.This research article investigates the varying challenges that have arisen in accurately diagnosing equine hydatidosis, a disease in horses, during post-mortem examinations. The paper focuses on the possible influence of […]
Ettlinger JJ, Ford T, Palmer JE.Proximal enteritis was diagnosed on the basis of clinical signs of disease in 2 Standard-bred yearlings from the same farm. Large volumes of fluid were repeatedly obtained during gastric decompression. The horses did not respond to treatment with IV administered fluids, antimicrobial agents, cimetidine, and metoclopramide. Postmortem findings confirmed severe focal chronic active duodenitis with stricture formation. An etiologic agent was not identified.
Kruger K, Saulez MN, Neser JA, Solberg K.Lead (Pb) intoxication in horses is usually a chronic phenomenon with clinical signs associated with central nervous dysfunction. This report gives details of a case of acute Pb intoxication in a 9-year-old American Saddlebred mare with severe, progressive and ultimately fatal neurological deterioration. During the 4 days of hospitalisation, clinical signs progressed from intermittent headshaking and depression to severe, continuous, uncontrollable manic behaviour. At autopsy, three grey-coloured, hard metal particles were present in the gastrointestinal tract and subsequently found to contain...