The city of Annapolis in the State of Goiás has several environmental parks that serve as habitat and refuge for many wild animals. The parks represent the last refuge for some species such as the monkey - star, possum, armadillo, the capuchin monkey, owl, lapwing, among others. Plays also an important role for climate mitigation and ecosystem preservation, and represents an important recreational area for residents. In recent months has increased the mortality rate of non-human primates, such as capuchin monkeys and marmosets and also possums in the parks environmental Ipiranga, Matinha and Central Park. Because of suspected poisoning or yellow fever were performed necropsies and collected materials as fragment of brain, kidney, spleen and liver 15 Callithrix penicillata and forwarded to the Instituto Evandro Chagas in Pará for the diagnosis of death. The search of the genome of virus and yellow fever virus using the technique of reverse transcription with polymerase chain reaction RT-PCR in 15 samples of brain, heart, kidney, spleen and liver of non-human primate were negative, indicating that the animals were not carriers of yellow fever. At necropsy lesions were found as petechiae on the pancreas and gut content pigment indicator of a strychnine poisoning.