Classification of grossly detectable abnormalities and conditions seen at postmortem in Canadian poultry abattoirs according to a hazard identification decision tree.

This study was designed to review all grossly detectable abnormalities and conditions (GDACs) encountered in poultry in Canadian abattoirs to determine which have potential to cause adverse health effects for the consumer. Review of the literature and consultation with scientists in the field of microbiology, epidemiology, poultry pathology, chemistry, and meat inspection served to generate an inventory of GDACs, and a decision tree containing algorithms was developed to identify GDACs potentially representing a health hazard to consumers. Through the use of the decision tree, GDACs were classified into different categories with regard to the risk they represent to humans. A number of GDACs were identified as being of potential concern from a food safety perspective, namely Erysipelas, fowl cholera, Campylobacteriosis, clostridial diseases, hepatitis/enteritis associated with Helicobacter, Listeriosis, Salmonella infections (nontyphoid infections, Salmonella arizonae, pullorum disease, and fowl typhoid), Staphylococcosis, and Toxoplasmosis. Further characterization--i.e., hazard characterization, exposure assessment, and risk characterization--is required to quantify or better characterize the probability that products derived from affected carcasses may affect the consumer as well as the resulting consequences. Risk assessment is a dynamic process. Results presented in this paper are based on available information and expert opinion. As new information is obtained, the inventory of GDACs and their classification may be modified.

An abattoir survey of urinary bladder lesions in cattle.

Postmortem examination of 21,340 cattle at an Ontario abattoir over a one-year period revealed macroscopic lesions in urinary bladders of 2,296 animals (10.8%). Chronic cystitis, the most frequent finding, was observed in 2,209 cases (10.4%); uroliths were found in 994 (4.7%) of the cattle with chronic cystitis. Other types of urinary bladder lesions included acute cystitis, developmental abnormalities, hyperplasia, neoplasia, emphysema, and a parasitic cystitis.

Melanocytic cutaneous lesions and melanotic regional lymph nodes in slaughter swine.

During a five month period, 220 slaughter swine (at two abattoirs) had gross cutaneous and lymph node lesions suggestive of melanoma. Lymph nodes from 214 and cutaneous lesions from 176 of these pigs were submitted for histological examination. Of the cutaneous lesions, 174 were spontaneously regressing melanomas, and two were nonregressing. Regression usually commenced by infiltration of the lesion by lymphocytes, plasma cells and the formation of giant cells. Of the melanotic lymph nodes, 177 were diagnosed as melanosis, 35 were considered to be metastatic regressing melanomas, and two were nonregressing melanomas. This report indicates a high rate of spontaneous regression in swine melanomas detected at slaughter.

An assessment of condemnations of broiler chicken carcasses.

An epidemiological study was conducted to assess the rates of condemnation and the diagnoses made on condemned broiler chicken carcasses in a federally-inspected abattoir. The first objective was to determine the predictive value of a positive test: the proportion of birds that were truly unfit for human consumption among condemned carcasses. The second objective was to assess the degree of agreement between diagnoses made in the abattoir and diagnoses determined by a detailed gross postmortem examination on the same condemned carcasses. A two-stage convenience sampling technique was used to obtain the birds needed. Fifteen lots of birds were selected and within each of these, approximately 45 condemned carcasses were selected for a total of 680. All the diagnoses made on these birds at the abattoir were recorded and the carcasses individually identified. The sampled carcasses were transported to the Ontario Veterinary College where a panel of three federal veterinarians independently judged whether the birds were fit for human consumption. In addition, a detailed gross postmortem examination was conducted on each carcass. An overall predictive value of a positive test of approximately 70% was found. The degree of agreement among members of the panel of examiners was also tested. The overall agreement was good (Kappa = 0.62 between examiners 1 and 2 and 0.51 between examiners 1 and 3). However, carcasses condemned for specific conditions at the abattoir, namely valgus varus deformity, mutilation, cellulitis and hepatitis showed no agreement beyond chance, while other carcasses condemned for conditions such as cyanosis and bruising showed poor agreement concerning their disposition for at least one pair of examiners.(ABSTRACT TRUNCATED AT 250 WORDS)

Survey of chloramphenicol residues in diseased swine.

Tissue samples from 279 hogs suspected of having received antibiotic treatment were collected at federally-inspected abattoirs and submitted for chloramphenicol residue analysis during August and September 1984. Injection sites (when present), kidneys or muscle samples were tested by one of two gas chromatographic methods. Kidney samples were also tested at the abattoirs by the Swab Test On Premises. Thirty-one animals (11%) were found with detectable levels ranging from 1 part per billion to 5727 ppb. Highest levels were found at the injection sites, while levels in muscle tissue did not exceed 500 ppb. None of the kidneys from animals found to contain chloramphenicol residues produced a positive Swab Test On Premises result attributable to the presence of chloramphenicol. Twelve kidneys from animals free of chloramphenicol residues produced positive Swab Test On Premises results. Of these, five contained penicillin or streptomycin, but antibiotic residues were not detected in the remaining seven. In addition to the samples collected for this survey, samples from eight hogs representing a herd which had been treated for pneumonia were submitted by an abattoir in Manitoba in November 1984. Chloramphenicol levels in these animals ranged from 0.1 to 73 parts per million in the injection sites, and from 0.04 to 21 ppm in the muscle tissues. The survey data indicated that there were a significant number of animals reaching the abattoirs with detectable chloramphenicol residues, and that the Swab Test On Premises procedure was ineffective in detecting these animals.