Causes of death in pigs during pre-slaughter

O presente trabalho avaliou a mortalidade de suínos no pré-abate através de análises anatomopatológica a fim de identificar as causas envolvidas. O estudo foi realizado durante os períodos de verão e inverno do ano de 2015 em um frigorífico do estado do Rio Grande do Sul que conta com Serviço de Inspeção Federal e está localizado na região do Vale do Taquari. No verão, foram contabilizadas 141 mortes do total de 117.260 (0,12%), enquanto que, no inverno, foram 75 mortes do total de 127.286 (0,05%). Dos 216 suínos mortos nos dois períodos, 170 foram submetidos a necropsia. Amostras foram examinadas no laboratório do Setor de Patologia Veterinária da Faculdade de Veterinária da Universidade Federal do Rio Grande do Sul. Entre as causas de morte diagnosticadas, as úlceras gástricas na região do quadrilátero esofágico e piloro foram as mais frequentes, sendo 29,2% (31/106) no verão e 32,8% (21/64) no inverno. As alterações pulmonares, como pneumonia enzoótica, influenza, broncopneumonia bacteriana e pleurite, foram o segundo diagnóstico mais frequente, sendo observado 15,1% (16/106) no verão e 18,8% (12/64) no inverno. A insuficiência cardíaca, incluindo pericardite bacteriana, endocardite bacteriana, cardiomiopatia hipertrófica, miocardite, infarto do miocárdio e neoplasia, apresentou-se em uma frequência de 14,2% (15/106) no verão e 9,4% (6/64) no inverno. A dilatação gástrica aguda causada pelo excesso de ração no estômago também foi um importante diagnóstico obtido, sendo 8,5% (9/106) no verão e 4,7% (3/64) no inverno. Rupturas de fígado foram observadas em 5,7% das mortes (6/106) no verão e 7,8% (5/64) no inverno, enquanto que rupturas de baço foram observadas em 0,9% das mortes (1/106) no verão e 1,6% (1/64) no inverno, representando diagnósticos importantes, mas pouco descritos na literatura como causa de morte. A enteropatia proliferativa foi diagnosticada em 5,7% dos casos (6/106) no verão e 4,7% (3/64) no inverno. A torção de mesentério foi responsável por 3,8% (4/106) das mortes ocorridas no verão e 6,2% (4/64) no inverno. Em menor frequência observaram-se as polisserosites, presente em 2,8% (3/106) dos suínos mortos no verão e 3,1% (2/64) no inverno. Já a fratura de fêmur somente foi observada em 0,9% dos casos (1/106) no período de verão. Casos inconclusivos representaram 13,2% (14/106) no verão e 10,9% (7/64) no inverno. Também se observou que a mortalidade pré-abate nas duas épocas do ano avaliadas ocorre mais em suínos que estão no período de descanso (64,5% (139/216) do que durante o transporte (35,5% (77/216).The present study evaluated the mortality of pigs just prior to slaughter through histopathological analysis in order to identify the causes of death. The study was conducted during the summer and winter of 2015 in a slaughter that has Federal Inspection Service in Rio Grande do Sul State located in Taquari Valley. During the summer, 141 deaths were accounted from the total deaths of 117 260 (0.12%), while, in the winter, it were 75 deaths from the total of 127.286 (0.05%). Of the 216 carcasses of dead animals in both periods, 170 were analyzed. Samples were examined in the laboratory of the Veterinary Pathology Sector of the Veterinary School of the Federal University of Rio Grande do Sul. Among the causes of death diagnosed, gastric ulcers in the esophageal quadrilateral region and pylorus were the most frequent, which represented 29.2% (31/106) in the summer and 32.8% (21/64) in winter. Pulmonary disorders such as enzootic pneumonia, influenza, bacterial pneumonia and pleuritis, were the second most frequent diagnosis, observed in 15.1% (16/106) in the summer and 18.8% (12/64) in the winter. Heart failure, including bacterial pericarditis, bacterial endocarditis, hypertrophic cardiomyopathy, myocarditis, myocardial infarction and neoplasia, had a frequency of 14.2% (15/106) in the summer and 9.4% (6/64) in the winter. Acute gastric dilatation caused by excess food in the stomach was also an important diagnosis, with 8.5% (9/106) in the summer and 4.7% (3/64) in the winter. Liver ruptures were observed in 5.7% of deaths (6/106) in summer and 7.8% (5/64) in the winter, while spleen ruptures were observed in 0.9% of deaths (1/106 ) in summer and 1.6% (1/64) in the winter, representing important diagnoses, however it is rarely reported in the literature as a cause of pig death. Proliferative enteropathy was diagnosed in 5.7% of the cases (6/106) in the summer and 4.7% (3/64) in the winter. Mesenteric torsion was diagnosed in 3.8% (4/106) of deaths in the summer and 6.2% (4/64) in the winter. Polyserositis were observed in lower frequency, 2.8% (3/106) of dead pigs in the summer and 3.1% (2/64) in the winter. Femur fracture was only observed in 0.9% of cases of death (1/106) in the summer period. Inconclusive cases accounted for 13.2% (14/106) in the summer and 10.9% (7/64) in the winter. It was also noted that pre-slaughter mortality in both seasons of the evaluated year occurs more in pigs that are in the rest period (64.5% (139/216) than during transportation (35.5% (77/216)