Detecção de anticorpos anti-Leishmania infantum, Neospora caninum e Toxoplasma gondii em cães necropsiados no hospital veterinário da UFSM

Abstract

The dog (Canis lupus familiaris) can be infected by a variety of protozoa and may develop clinical signs or remain asymptomatic. Due to the proximity of this kind with the man some protozoa present zoonotic potential, as researchers studied, including Leishmania infantum, Neospora caninum and Toxoplasma gondii. L. infantum, it is responsible for causing visceral leishmaniasis in several species, including the dog and the man with deleterious impacts on public health. The dog is considered the urban reservoir of the parasite, and it is recommended the euthanasia of seropositive, including asymptomatic. N. caninum and T. gondii are widely distributed protozoa. These agents, when affecting dogs, can cause neurological, gastrointestinal, respiratory and muscle disturbs. N. caninum is a protozoan of great economic importance and may cause reproductive problems in farm animals and the dog is the definitive host of this agent. T. gondii is an opportunistic microorganism, a zoonotic potential, with world-occurrence. The dogs as well as humans, are considered intermediate hosts, infection may be more severe in pregnant women and immunocompromised individuals. This study aimed to research anti-Leishmania infantum antibodies, Neospora caninum and Toxoplasma gondii in autopsied dogs; and to determine the occurrence of infection in animals from Agudo, Jaguari, Júlio de Castilhos, Mata, Santa Maria, Santiago, São Martinho da Serra, São Vicente do Sul and Tupanciretã, towns in the central region of Rio Grande do Sul (RS). In addition, there were correlated epidemiological data on sex, age, race, origin and occurrence of these protozoa in the seasons, with the pathological lesions. The animals were necropsied during routine at Pathology Laboratory in the Universidade Federal de Santa Maria, from November 2014 to April 2016. For detection of seropositive dogs, the Indirect Immunofluorescence Antibody Test (IFAT) was performed on stored samples in serum bank Analysis Laboratory in Veterinary Clinics. It analyzed 78 samples, where 53/78 (67.9%) were seropositive, demonstrating the presence of antibodies to one or more of the agents in the population studied. The occurrence of antibodies to L. infantum, N. caninum and T. gondii was 26/78 (33.3%) 29/78 (37.1%) and 34/78 (43.5%) respectively. Mono infections observed in 5/53 (9.4%) of L. infantum, 10/53 (18.8%) to N. caninum and 11/53 (20.7%) T. gondii, while the coinfection appeared in 27/53 (50.9%) of the dogs were detected in 4/53 (7.5%) L. infantum + N. caninum, 8/53 (15.0%) L. infantum + T. gondii, 6/53 (11.3%) N. caninum + T. gondii and 9/53 (16.9%) L. infantum + N. caninum + T. gondii, affecting animals of different ages, without predominance sex or race. There were no pathological characteristic lesions, featuring animals as asymptomatic, indicating a role for these sentinels of dogs these diseases. This study contributed to a better understanding of the epidemiology of protozoa and noted the emergence of visceral leishmaniasis in animals from areas considered harmless. In addition, this work can support the public health services in the adoption of preventive measures, avoiding possible cases of autochthonous leishmaniasis in central RS.