Causes of death and reasons for euthanasia in dogs from the midland region of the Midwest of Rio Grande do Sul State, Brazil (1965-2004)

The main objective of this study was to investigate the prevalence of diseases culminating with death or motivating euthanasia of dogs from the midland region of the Midwest of Rio Grande do Sul State, Brazil. The necropsy files of the Laboratorio de Patologia Veterinaria (LPV) of the Universidade Federal de Santa Maria (UFSM) were accessed and necropsy protocols of dogs necropsied between January 1965 and December 2004 were reviewed. During this period 4,844 reports of canine necropsies were filed at the LPV-UFSM. The case distribution in relation to the disease categories diagnosed was as follows: infectious and parasitic diseases (1,693 [35.0%]); neoplasms (378 [7.8%]); disorders caused by physical agents (369 [7.6%]); degenerative diseases (342 [7.1%]); poisonings and toxinfections (112 [2.3%]); euthanasia due to convenience (101 [2.1%]); metabolic and endocrinological diseases (97 [2.0%]); iatrogenic disorders (83 [1.7%]); developmental disorders (25 [0.5%]); immune mediate diseases (10 [0.2%]); and nutritional disorders (6 [0.1%]). Other disorders, including multifactorial or idiopathic diseases contributed 80 (1.6%) cases. In 1,548 (32.0%) out of the 4,844 cases it was not possible to establish either cause of death or reason for euthanasia. Infectious and parasitic diseases (mainly canine distemper, parvoviral enteritis and intestinal parasitism), neoplasia (mainly mammary neoplasms and lymphoma), disorders caused by physical agents (mainly accidents caused by automotive vehicles) and degenerative diseases (mainly chronic renal failure, cirrhosis, and congestive heart failure) were the main disease categories causing death or motivating euthanasia in dogs of this midland region. However, when cases were evaluated in relation with the age of the dog, the disease prevalence differed. The main causes of death in puppies were infectious and parasitic disease (mainly parvoviral enteritis, canine distemper, and intestinal parasitism). In adult dogs the most important causes of death were canine distemper, neoplasia and trauma. In age dogs, approximately half of the deaths could be attributed to neoplasia and degenerative disease.