Preliminary study on the prevalence of endoparasite infections and vector-borne diseases in outdoor dogs in Bulgaria

The present work was designed to evaluate the prevalence of gastrointestinal parasites and some vector-borne pathogens in dogs in Bulgaria. A total of 172 owned dogs, keeping outside, were included in the study. Fecal samples were examined using standard flotation and sedimentation methods. Blood samples were processed by Knott’s technique, SNAP™ 4Dx Plus Test (IDEXX) and Angio Detect™ Test (IDEXX). The overall prevalence of gastrointestinal parasites was 64.5%. Eggs of hookworms (Ancylostoma sp. and Uncinaria sp.) were the most frequently detected (54.1%), followed by Trichuris vulpis (15.1%), Capillaria sp. (11.0%), Toxocara canis (6.4%), Cystoisospora sp. (4.1%), Sarcocystis sp. (2.3%), Toxascaris leonina (1.7%), Taenia sp. (1.2%) and Linguatula serrata (0.6%). In addition, hookworms were the most commonly involved in the cases of single infection (20.3%). Combinations between Capillaria sp./hookworms and T. vulpis/hookworms were the most common co-infections (4.1% and 2.9%, respectively). Blood samples revealed the presence of antibodies against Ehrlichia sp. (13.4%), Anaplasma sp. (13.4%) and Borrelia burgdorferi (1.7%). Antigens of Dirofilaria immitis and Angiostrongylus vasorum were detected in 10.5% and 0.6% of the samples tested, respectively. Microfilariae of Dirofilaria repens were found in 5.8% of the blood samples. Additionally, the prevalence of D. immitis and Ehrlichia sp. was significantly higher in adult than in young dogs (p<0.05). In contrast, the gender was not considered as a risk factor contributing to the occurrence of infections.