Cases of intoxication are common in the history of the veterinary medicine, mainly in dogs and cats. Appropriate recognition of the clinical signs and pathological findings could characterize cases of intoxication, however laboratorial methods in forensic toxicology is fundamental to establish a definitive diagnosis of the toxic agent. In the present work was made analysis of three cases of pet animals criminally intoxicated by carbamate. Necropsy helps to uncover causes mortis, were verified cardiac respiratory insufficiency and hypovolemic shock in all cases. Histopathology exam of liver, kidney and brain described the main lesions like congestion, degeneration and haemorrhage. Organs show signs of autolysis and putrefaction. Therefore, diagnostic techniques helps veterinarian to make reports for litigation in animal criminal intoxication.