An evaluation of methods for the detection of spinal cord in product derived from advanced meat recovery systems

This study investigated the usefulness of immunohistochemistry, histochemistry, and polarization microscopy in documenting the presence of spinal cord in ground product produced by advanced meat recovery systems (AMRS). A battery of diagnostic stains proved most helpful for definitive documentation of spinal cord in the AMRS product. Antibodies to neurofilament and glial fibrillary acidic proteins were useful for highlighting the presence of neural tissue in comminuted product but when used alone did not definitively differentiate central nervous system tissue from peripheral nerve. Polariscopy, trichrome staining, and immunostaining for synaptophysin were very useful for differentiating spinal cord from peripheral nerve. Spinal cord was found in 2 of 196 AMRS samples when only hematoxylin and eosin staining was used. In a later immunohistochemical subset of the survey study, spinal cord was found in 7 of 17 AMRS samples. More recently, spinal cord tissue has been found in 3 of 26 regulatory samples using hematoxylin and eosin stains combined with immunohistochemical techniques.

A retrospective study of pancreatic tumors in slaughter cattle

Sixteen primary pancreatic tumors were found in a retrospective study of bovine pancreatic lesions detected in slaughtered cattle. Eleven islet cell tumors and three pancreatic exocrine carcinomas were identified based on light microscopy and immunohistochemistry. Nine of 11 islet cell tumors were classified as malignant. Metastatic sites included iliac, mediastinal, hepatic, and mesenteric lymph nodes, peritoneum, mesentery, and liver. Six cows with multiple islet cell tumors also had pheochromocytomas. All 11 islet cell tumors had positive immunoreactivity to insulin and somatostatin. Three tumors also contained cells immunoreactive for glucagon and two tumors contained pancreatic polypeptide immunoreactive cells. Immunoreactivity of tumor cells in metastatic sites was similar to their respective primary tumors. All exocrine pancreatic carcinomas metastasized widely and were immunonegative for insulin, somatostatin, glucagon, and pancreatic polypeptide. No mixed endocrine-exocrine tumors were identified. None of the endocrine or exocrine tumors contained amyloid. Additional primary tumors of the bovine pancreas included one neurofibroma and one neurofibrosarcoma. Additional cases with lesions of the bovine pancreas included nodular hyperplasia in 15 cows, exocrine acinar atrophy and fibrosis in four cows (two of which also had pancreatic lithiasis), pancreatitis in one cow, peripancreatic fibrosis in two cows, pancreatic steatosis in one animal, and pancreatic hemorrhages in one cow.

Accumulation of 2,8 dihydroxyadenine in bovine liver, kidneys, and lymph nodes

A variety of tissues from 20 cattle slaughtered at federally inspected facilities contained abundant light green to greenish-yellow material. Gross lesions were most common in the liver and hepatic lymph nodes. Less frequent lesions were present in the mediastinal, renal, intercostal, and gastric lymph nodes. The material was most prominent in the portal triads, and in the medullary sinuses of the lymph nodes, at times occupying up to one half of the nodal mass. Renal calculi were present in one animal. Histologically, the condition was characterized by the intracytoplasmic accumulation of innumerable brown, acicular crystals in hepatocytes, macrophages, and renal tubular epithelial cells. Less frequent large aggregates of extracellular crystals were found in the lumens of renal tubules and in portal triads. Crystals were highly birefringent when examined using polarized light. The crystals were identified as 2,8 dihydroxyadenine using X-ray diffraction, electron diffraction, infrared spectroscopy, and mass spectrometry. In mammals, adenine is normally converted to adenylate by the enzyme adenine phosphoribosyltransferase. When adenine phosphoribosyltransferase is absent, deficient, or inhibited, adenine is oxidized to 2,8 dihydroxyadenine, which is extremely insoluble at physiological pH. In human beings, an autosomal recessive disease known as 2,8 dihydroxyadeninuria is caused by a deficiency of adenine phosphoribosyltransferase.

Proventricular hemangiosarcoma identified in a broiler at slaughter

A discrete circumscribed red nodule present on the surface of the proventriculus of a 7-week-old broiler was diagnosed as a hemangiosarcoma. Histologically, discrete islands and dense sheets of anaplastic ovoid to spindle-shaped basophilic cells surrounded irregular vascular clefts and spaces. Mitotic figures were focally numerous, and extension into the tunica muscularis of the proventriculus was seen. Neoplastic islands were also present in the tunica mucosa and the adjacent mesentery.

Neurofibrosarcoma and leiomyosarcoma in slaughterhouse broilers

Two uncommon neoplastic lesions--a neurofibrosarcoma and a leiomyosarcoma--were found in 7-week-old slaughterhouse chickens. Grossly, the neoplasms both appeared as locally extensive, nodular lesions that displaced the mesentery and abdominal viscera. Histologically, these tumors were anaplastic and invasive into the surrounding tissues.

Polymelia in a broiler chicken

A polymelus monster was observed in a 7-week-old slaughterhouse chicken. The supernumerary limbs were smaller than the normal appendages but contained an equal number of digits.

Zygomycosis in the duck

The fungal disease zygomycosis was diagnosed in the thoracic cavity of two 7-weeks-old ducks. In the first case, the diagnosis was based on examination of granulomas that were found to contain fungal hyphae characteristics of zygomycetes. The second case was diagnosed using similar criteria along with the subsequent culture of Mucor sp. from the lesion. To attain a definitive diagnosis of zygomycosis, the fungal hyphae found during histologic examination must be differentiated from Aspergillus sp. and Dactylaria gallopava.

Focal failures of endochondral ossification in the broiler

Two types of cartilaginous lesions were observed in a flock of 400 broilers separated into four groups and fed diets containing different energy and NH4Cl contents. The lesions appeared morphologically, histologically, and etiologically different. One lesion found in the vertebrae of 10 birds consisted of focal thickenings and necrosis of growth cartilages. Affected birds were predominantly faster-growing broilers fed diets without supplemental NH4Cl. The vertebral lesions were similar to osteochondrosis as described in mammals. A second lesion consisting of cones of retained cartilage was present in various long bones of 27.5% of all birds examined. The peak incidence of these dyschondroplastic lesions occurred in the slowest-growing group of 4-week-old birds fed diets containing 3% NH4Cl: 70% of these birds had dyschondroplasia. No positive correlation was found between the incidence of the vertebral lesions of osteochondrosis and the appendicular lesions of dyschondroplasia.