Topic:Necropsy
Necropsy, also known as an autopsy, is a systematic examination of a horse's body after death to determine the cause of death and evaluate any disease or injury. This procedure involves a thorough assessment of the horse's organs and tissues, often including histopathological analysis to identify abnormalities at the microscopic level. Necropsy can provide valuable insights into equine health issues, contributing to a better understanding of disease processes, management practices, and potential preventive measures. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, findings, and implications of necropsy in equine veterinary science.
An ovarian interstitial cell hamartoma in a newborn foal. A case of congenital ovarian interstitial cell hamartoma in a thoroughbred foal that died of apparent nutritional myopathy (white-muscle disease) 14 h after birth is described. An incidental finding at necropsy was a pale brown, mushroom-shaped, pedunculated mass (6 x 4 x 3 cm) attached to the left ovary. On the cut surface, the mass had a peripheral rim of dense parenchyma (3-5 mm wide), surrounding a pale gelatinous core. Histologically, the mass consisted of a peripheral zone of densely packed large cells that were quite similar, morphologically, to fetal ovarian interstitial cells, and a c...
Handling forensic necropsy cases. 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...
Seasonal transmission of gastrointestinal parasites of equids in southern Louisiana. Parasite-naive pony foals were used as sentinels to monitor transmission of gastrointestinal parasites of equids in Louisiana during 4 seasons of the year. Two annual periods were studied, 1988-1989 and 1992-1993. Two or 3 foals each season were turned out to graze a contaminated pasture along with resident parasitized mares and their foals. After a grazing period of 8 wk, sentinel ponies were held in a parasite-free box stall for a period of 6 wk to allow parasites to develop, thus enhancing the evaluation of hypobiotic stages. Following this holding period, necropsies were performed for comp...
Cervical stenotic myelopathy in a horse. A 13-year-old, Thoroughbred gelding presented with a 3-year history of progressive ataxia of all 4 limbs. Physical and neurological examinations indicated a compressive lesion affecting the cervical spinal cord. Radiographs confirmed a lesion, and a myelogram a narrowing of the spinal canal at cervical vertebrae (6-7). Necropsy confirmed cervical stenotic myelopathy.
Histoplasmosis in the lung of a race horse with yersiniosis. 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...
World association for the advancement of veterinary parasitology (WAAVP): second edition of guidelines for evaluating the efficacy of equine anthelmintics. These guidelines have been designed to assist in the planning, operation and interpretation of studies which would serve to assess the efficacy of drugs against internal parasites of horses. Although the term anthelmintic is used in the title and text, these guidelines include studies on drug efficacy against larvae of horse bot flies, Gasterophilus spp., which are non-helminth parasites commonly occurring in the stomach of horses. The advantages, disadvantages and application of critical and controlled tests are presented. Information is also provided on selection of animals, housing, feed, d...
Gastrointestinal stromal tumors in equids. Eleven gastrointestinal neoplasms from 10 aged horses and 1 pony were examined grossly, his tologically, immunohistochemically, and (in two cases) ultrastructurally. Clinical signs were associated with two neoplasms, and the other nine tumors were incidental findings at laparotomy or necropsy. The neoplasms were solitary (9/11) or multifocal (2/11), well demarcated, serosal or mural masses of stomach (1), jejunum (1), ileum (3), cecum (5), and/or colon (2). Microscopic examination revealed discrete spindle cells arranged in compact patterns with fascicles and whorls or cribriform pattern with ...
Severe complication after administration of formalin for treatment of progressive ethmoidal hematoma in a horse. 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...
Effects of intra-articular injections of bufexamac suspension in healthy horses. To evaluate the effects of intra-articular (IA) injections of bufexamac in horses, focusing particularly on the effects of bufexamac on articular cartilage. Methods: 20 Standardbreds. Methods: Horses were randomly allocated into 4 groups consisting of 5 horses each, and 20, 60, or 100 mg of bufexamac or 1 ml of sterile saline (0.9% NaCl) solution (control) was injected into 1 intercarpal joint at weekly intervals for 6 treatments (days 0, 7, 14, 21, 28, and 35). Clinical signs and results of hematologic, serum biochemical, and synovial fluid (SF) analyses and radiography were used to evaluate ...
Disseminated metastatic intramedullary melanoma in an aged grey horse. 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...
Radiculomeningomyelitis due to Halicephalobus gingivalis in a horse. 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...
Plasma and bronchoalveolar fluid concentrations of nitric oxide and localization of nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease. To determine concentrations of nitric oxide (NO) in plasma and bronchoalveolar lavage fluid (BALF) and localize nitric oxide synthesis in the lungs of horses with summer pasture-associated obstructive pulmonary disease (SPAOPD). Methods: 7 adult horses with SPAOPD and 6 clinically normal adult horses. Methods: Severity of SPAOPD was determined by use of clinical scores, change in intrapleural pressure (APpl) during tidal breathing, cytologic analysis of BALF, and histologic evaluation of lung specimens obtained during necropsy. Nitric oxide concentrations in plasma, BALF and epithelial lining ...
Laparoscopic surgical technique for repair of rectal and colonic tears in horses: an experimental study. To determine the efficacy of laparoscopic surgical techniques for repair of rectal lacerations in horses. Methods: Experimental study. Methods: Thirty-two segments of equine bowel placed in an equine pelvitrainer, 8 equine cadavers, and 3 normal horses. Methods: In experiment 1, 3 laparoscopic intestinal-repair techniques were evaluated in an equine pelvitrainer: suturing with needle holders, with an automatic suture device, and stapling with a hernia stapler. In experiment 2, descending colon lacerations were sutured laparoscopically using needle holders in a pelvitrainer and in equine cadave...
Renal hypoplasia and dysplasia in an American miniature foal. 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.
Magnetic resonance imaging features of equine nigropallidal encephalomalacia. 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...
Zonal dermal separation: a distinctive histopathological lesion associated with hyperelastosis cutis in a Quarter Horse. 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...
Pathologic and immunohistochemical findings in naturally occuring West Nile virus infection in horses. 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...
Safety of ponazuril 15% oral paste in horses. Ponazuril, a triazine-derivative compound, is proposed as a treatment for equine protozoal myeloencephalitis caused by Sarcocystis neurona. Ponazuril 15% oral paste was administered to 24 horses at 0, 10, or 30 mg/kg body weight for either 28 or 56 days, representing zero, two, and six times the proposed dosage rate and one and two times the recommended duration of treatment, respectively. Serum chemistry analysis, coagulation profile, and hematology measurements were performed weekly and necropsy evaluations, including histopathology, were conducted for all animals at the end of the study. Mi...
Myofibroblasts in the accessory ligament (distal check ligament) and the deep digital flexor tendon of foals. To demonstrate myofibroblasts in the accessory ligament of the deep digital flexor tendon (ie, distal check ligament) and deep digital flexor tendon of clinically normal foals. Methods: Tissue specimens from 25 foals that were necropsied for reasons unrelated to this study and unrelated to musculoskeletal disease. Methods: The distal check ligament and deep digital flexor tendon of both forelimbs were examined histologically. Myofibroblasts were identified by immunohistochemical staining specific for alpha-smooth muscle actin (alpha-SMA). Results: Most of the cells in the distal check ligament...
Scedosporium prolificans infection associated with arthritis and osteomyelitis in a horse. Scedosporium prolificans was associated with arthritis and degenerative osteomyelitis in a 6-year-old Thoroughbred racehorse. The horse was suspected to have an inflammatory lesion of the interosseous tendon, but treatment had resulted in only a minimal response. Shortly after diagnostic arthrocentesis of the left metacarpophalangeal joint was performed, the joint became severely swollen, and radiography of the area revealed lysis of the distal end of the third metacarpal bone, the proximal sesamoid bones, and the proximal end of the proximal phalanx. The horse did not respond to treatment and...
Equine neuronal ceroid lipofuscinosis. Neuronal ceroid lipofuscinosis (NCL) is an inherited, neurodegenerative disorder with fatal outcome in humans. It has also been described in some animal species; this is the first report of NCL in equines. Three horses showed developmental retardation, slow movements and loss of appetite at the age of six months. Neurological symptoms, as well as visual failure in one case, were noticed at the age of 1 year. Due to slowly progressing deterioration, euthanasia was indicated 1.5 years after onset of conspicuous behavior. At necropsy, slight flattening of the gyri and discoloring of the brain was...
Neodymium:yttrium aluminum garnet laser ventriculocordectomy in standing horses. To develop a technique for neodymium:yttrium-aluminum-garnet (Nd:YAG) laser ventriculocordectomy in standing horses and document healing in horses undergoing laser ventriculocordectomy. Methods: 6 horses between 2 and 32 years old. Methods: Under endoscopic guidance, the left laryngeal ventricle was everted with grasping forceps and excised with an Nd:YAG laser, using 60 watts of power in a noncontact fashion (6,403 to 9,197 Joules). Following removal of the ventricle, the vocal cord was photoablated. Horses were examined endoscopically 2, 7, 14, 21, 30, and 47 days after ventriculocordectomy,...
Septicemia and peritonitis due to Actinobacillus equuli infection in an adult horse. Actinobacillus equuli is a rare cause of peritonitis in adult horses. Septicemia and peritonitis due to A. equuli were diagnosed at necropsy in an 8-year-old Saddlebred mare. The origin of the infection was not known; however, small necrotic colonic mucosal lesions presumed to have been caused by phenylbutazone treatment may have allowed bacterial invasion. A good response to antimicrobial treatment has been documented in the small numbers of previously reported acute cases of peritonitis. Because it is potentially treatable, it is important for pathologists and clinicians to identify horses w...
Small intestine large granular lymphoma in a horse. A 12-year-old Appaloosa gelding was referred to the Texas Veterinary Medical Center with a history of chronic diarrhea and weight loss. At necropsy, numerous oval, craterlike ulcers were observed throughout the small intestine. Histologically, these lesions were composed of a neoplastic proliferation of round cells with intracytoplasmic phosphotungstic acid-hematoxylin-positive granules. The tumor cells stained positively for the CD3 antigen and negatively for a B-cell marker. A diagnosis of large granular lymphoma was based on the morphologic and immunohistochemical characteristics of the neo...
Gastrointestinal stromal tumors of the equine cecum. 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,...
Efficacy of moxidectin 2 per cent gel against naturally acquired strongyle infections in horses, with particular reference to larval cyathostomes. The efficacy of moxidectin 2 per cent equine gel against naturally acquired strongyle infections was assessed in 18 ponies which had grazed on contaminated pasture before being housed for eight weeks. Twenty-four hours before the treatment, two randomly selected ponies were euthanased and their worm burdens were determined. Eight of the remaining 16 ponies were treated with moxidectin 2 per cent gel while the other eight were given a placebo gel. Eight weeks later the 16 animals were necropsied and their worm burdens established. A 100 per cent efficacy was recorded against adult and lumenal L...
Incidence of polysaccharide storage myopathy in draft horse-related breeds: a necropsy study of 37 horses and a mule. Skeletal muscle samples from 38 draft horse-related animals 1-23 years of age were evaluated for evidence of aggregates of glycogen and complex polysaccharide characteristic of equine polysaccharide storage myopathy (EPSSM). Cardiac muscle from 12 of these horses was also examined. Antemortem serum levels of creatine kinase (CK) and aspartate aminotransferase (AST) from 9 horses with EPSSM and 5 horses without EPSSM were compared. Skeletal muscle from 17 horses contained inclusions of periodic acid-Schiff (PAS)-positive, amylase-resistant complex polysaccharide. Similar inclusions were also pr...
Putative uremic encephalopathy in horses: five cases (1978-1998). 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...
Immunoconversion against Sarcocystis neurona in normal and dexamethasone-treated horses challenged with S. neurona sporocysts. Equine protozoal myeloencephalitis is a common neurologic disease of horses in the Americas usually caused by Sarcocystis neurona. To date, the disease has not been induced in horses using characterized sporocysts from Didelphis virginiana, the definitive host. S. neurona sporocysts from 15 naturally infected opossums were fed to horses seronegative for antibodies against S. neurona. Eight horses were given 5x10(5) sporocysts daily for 7 days. Horses were examined for abnormal clinical signs, and blood and cerebrospinal fluid were harvested at intervals for 90 days after the first day of chall...
Evaluation of uniformity of morphological injury of the large colon following severe colonic torsion. 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...