Cães que apresentam diversas doenças transmitidas por vetores podem mostrar nenhum ou alguns sinais clínicos inespecíficos. Dependendo da fase da infecção, a confirmação dos agentes envolvidos é necessária. O presente estudo teve como objetivo detectar a presença de Babesia spp., Ehrlichia spp., Anaplasma spp., Hepatozoon spp. e Leishmania spp. em amostras de sangue e carrapatos, coletados em dois cães do Rio Grande do Norte. Esses animais apresentavam sinais clínicos sugestivos de doenças transmitidas por carrapatos, quando foram usadas técnicas moleculares. DNA de E. canis, H. canis e L. infantum foram detectados em amostras de sangue e carrapatos R. sanguineus coletados dos cães. Entre todas as amostras analisadas, duas mostraram a presença de infecções múltiplas por E. canis, H. canis e L. infantum chagasi. Destaca-se a necessidade de um diagnóstico molecular diferencial em cães com sinais clínicos inespecíficos.

Since dogs presenting several vector borne diseases can show none or nonspecific clinical signs depending on the phase of infection, the assessment of the particular agents involved is mandatory. The present study aimed to investigate the presence of Babesia spp., Ehrlichia spp., Anaplasma spp., Hepatozoon spp. and Leishmania spp. in blood samples and ticks, collected from two dogs from Rio Grande do Norte showing suggestive tick-borne disease by using molecular techniques. DNA of E. canis, H. canis and L. infantum were detected in blood samples and R. sanguineus ticks collected from dogs. Among all samples analyzed, two showed the presence of multiple infections with E. canis, H. canis and L. infantum chagasi. Here we highlighted the need for molecular differential diagnosis in dogs showing nonspecific clinical signs.

The vector competence of Culex quinquefasciatus from five localities in Brazil to Dirofilaria immitis was evaluated experimentally. Females from each locality were fed on an infected dog (~ 6 microfilariae/µl blood). A sample of blood fed mosquitoes were dissected approximately 1 h after blood meal. These results demonstrated that all had ingested microfilariae (mean, 4.8 to 24.6 microfilariae/mosquito). Fifteen days after the infected blood meal, the infection and infective rates were low in all populations of Cx. quinquefasciatus. The mean number of infective larvae detected in the head and proboscis of these mosquitoes was 1-1.5. The vector efficiency, the number of microfilariae ingested/number of infective larvae, was low for all populations of Cx. quinquefasciatus. However, the survival rate for all populations was high (range 50-75%). The survival rate of Aedes aegypti assayed simultaneously for comparison was low (24.7%), while the vector efficiency was much higher than for Cx. quinquefasciatus. These data suggest that the vector competence of all assayed populations of Cx. quinquefasciatus to D. immitis in Brazil is similar and that this species is a secondary vector due to its low susceptibility. Nevertheless, vector capacity may vary between populations due to differences in biting frequency on dogs that has been reported in Brazil.

Um inquérito sobre a prevalência da dirofilariose canina foi realizado entre 1.495 cães de 64 localidades na Ilha de São Luís, de 1991 a 1994, através da pesquisa de microfilárias. Desses, 1.358 cães (12,8% positivos) não tinham história pregressa conhecida, sendo 1.265 errantes (10,3% microfilarêmicos) e 93 domiciliados (37,8%). A dirofilariose foi detectada em 46 das localidade, porém a prevalência da infecção aumenta consideravelmente quando se trata de cães da orla marítima, de onde procederam 47% dos animais positivos. Em alguns bairros costeiros, a prevalência é elevada, como em Olho d'Água e Calhau (46% e 43% positivos, respectivamente). A pesquisa de microfilárias em 137 cães estritamente domiciliados (DO) e com história pregressa conhecida (43% microfilarêmicos) permitiu a comprovação da existência de transmissão na Ilha. Este estudo é o primeiro dessa natureza e abrangência realizado no Nordeste do País. Sabendo-se que a dirofilariose é uma zoonose, e diante da elevada prevalência de cães microfilarêmicos, particularmente os domiciliados da orla marítima da Ilha, chama-se a atenção para que se considere tal parasitose como possível causa de lesões pulmonares solitárias na população humana local e naquelas assentadas em áreas com clima e paisagem semelhantes no Nordeste.

A survey on the prevalence of canine heartworm was conducted in 1,495 dogs from Maranhão Island, State of Maranhão, Northeastern Brazil, from 1991 to 1994, by testing for microfilariae in blood. Of the total, 1,358 (12.8% of which were infected) were dogs with no known history; they included 1,265 homeless animals (10.3% with microfilariae) and 93 kept by owners at the time the survey was conducted (37.8% of which were infected). Prevalence is high among dogs captured and/or living along the seashore. Examples of such high coastal prevalence rates were found in Olho d'Água and Calhau (46% and 43%, respectively). The search for microfilariae in blood samples of 137 exclusively domiciliary dogs with a known history showed that 43% of these animals were infected, confirming transmission of heartworm on the island. This was the first survey formally published on canine dirofilariasis in Northeastern Brazil. Since D. immitis is infective to man and prevalence of the parasite is high, particularly along the coast of Maranhão Island, human cases of dirofilariasis may be expected. Local physicians should consider this parasite among the possible causes of solitary lesions in humans living in this area.

Um inquérito sobre a prevalência da dirofilariose canina foi realizado entre 1.495 cães de 64 localidades na Ilha de São Luís, de 1991 a 1994, através da pesquisa de microfilárias. Desses, 1.358 cães (12,8% positivos) não tinham história pregressa conhecida, sendo 1.265 errantes (10,3% microfilarêmicos) e 93 domiciliados (37,8%). A dirofilariose foi detectada em 46 das localidade, porém a prevalência da infecção aumenta consideravelmente quando se trata de cães da orla marítima, de onde procederam 47% dos animais positivos. Em alguns bairros costeiros, a prevalência é elevada, como em Olho d'Água e Calhau (46% e 43% positivos, respectivamente). A pesquisa de microfilárias em 137 cães estritamente domiciliados (DO) e com história pregressa conhecida (43% microfilarêmicos) permitiu a comprovação da existência de transmissão na Ilha. Este estudo é o primeiro dessa natureza e abrangência realizado no Nordeste do País. Sabendo-se que a dirofilariose é uma zoonose, e diante da elevada prevalência de cães microfilarêmicos, particularmente os domiciliados da orla marítima da Ilha, chama-se a atenção para que se considere tal parasitose como possível causa de lesões pulmonares solitárias na população humana local e naquelas assentadas em áreas com clima e paisagem semelhantes no Nordeste.

A survey on the prevalence of canine heartworm was conducted in 1,495 dogs from Maranhão Island, State of Maranhão, Northeastern Brazil, from 1991 to 1994, by testing for microfilariae in blood. Of the total, 1,358 (12.8% of which were infected) were dogs with no known history; they included 1,265 homeless animals (10.3% with microfilariae) and 93 kept by owners at the time the survey was conducted (37.8% of which were infected). Prevalence is high among dogs captured and/or living along the seashore. Examples of such high coastal prevalence rates were found in Olho d'Água and Calhau (46% and 43%, respectively). The search for microfilariae in blood samples of 137 exclusively domiciliary dogs with a known history showed that 43% of these animals were infected, confirming transmission of heartworm on the island. This was the first survey formally published on canine dirofilariasis in Northeastern Brazil. Since D. immitis is infective to man and prevalence of the parasite is high, particularly along the coast of Maranhão Island, human cases of dirofilariasis may be expected. Local physicians should consider this parasite among the possible causes of solitary lesions in humans living in this area.

A new technique was develop to study the anomalous behavior of non parasitic phase of Anocentor nitens on horse host. From the total teleogines was still alive during all experimental period, 89.1% laided eggs on ear host. The eclosion index was 77.05% with 80.0% of eclodibility.The preoviposition period and oviposition period was 3 to 17 days (4.92±0.73 days) and 16 to 41 days (24.38±1.05 days), respectively. The incubation period was 26 to 48 days (34.94±2.92 days). It was confirmed that A. nilens teleogine could laid on ear of horse, when it was dettachment and a factor impossibilited it down on ground.