Filarídeos em cães de uma área costeira turística do Estado de Pernambuco

Abstract

Filarids are nematode parasites affecting different animal species, including domestic dogs, wild canids, domestic and wild felids, and humans. Among the species of medical and veterinary importance affecting dogs, the genera Dirofilaria and Acanthocheilonema stand out, with microfilariae found in the blood and Cercopithifilaria detected on the skin. Blood-feeding arthropod vectors (e.g., mosquitoes, fleas, lice and ticks) transmit these parasites. This study aimed to determine the prevalence of blood and dermal filarial infection in dogs residing in a touristic coastal area of the State of Pernambuco. From February to September 2021, blood samples (n = 245) were collected and analyzed using the modified Knott method to search for circulating microfilariae, followed by the qualitative ELISA test (SNAP® 4Dx® Plus, IDEXX Laboratory, Westbrook, Maine, USA) to detect antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and Dirofilaria immitis antigens. Fragments of skin samples (n = 71) were included in this study, and microscopically and molecularly, they were examined using PCR targeting the 12S rDNA gene to research dermal microfilariae. Microfilariae and D. immitis antigen were detected in 24 animals (9.8%), as well as antibodies to Ehrlichia spp. and Anaplasma spp. showed seroprevalence in 64 (23.2%) and 11 (4.5%) animals, respectively. In the ELISA test, 9 (3.7%) microfilaremic animals obtained negative results. Co-infection among Dirofilaria immitis and other pathogens predominated over isolated infections by D. immitis (χ2 = 4.381; p = 0.0363). No filarial was detected in the skin after microscopic and molecular analyses. Dogs positive for D. immitis were found in four different municipalities, including two (Cabo de Santo Agostinho and Ipojuca), where there is an intense flow of animals and humans attracted by tourist activities in these localities. Data from this study demonstrate that D. immitis is the main filarial nematode infecting dogs in northeastern Brazil's coastal areas. Preventive measures such as repellent collars and microfilaricidal compounds should be used to prevent canine infection associated with correct environmental management in these areas to control vector populations.