In the present study it was aimed to investigate some clinical, haematological, biochemical and ECG parameters in dogs with dirofilariosis. A total number of 22 dogs aged 1-9 years at different sexes and breeds allocated to 11 dogs in the group with dirofilariosis and 11 healthy dogs in the control group were used in the study.

Significant increases (p<0.05) in WBC value, pulse and respiratory rates, significant decreases (p<0.05) in RBC, PCV and MCV values and a nonsignificant (p>0.05) decrease in Hb value were determined in the dogs with dirofilariosis. When differential blood tables were observed, a significant increase (p<0.05) in neutrophil, nonsignificant increases (p>0.05) in eosinophili and basophili and significant decreases (p<0.05) in lymphocytes and monocytes were detected in the group with dirofilariosis.

Nonsignificant (p>0.05) decreases for pH, pCO₂ and pO₂ and significant decreases (p<0.05) for HCO₃ and BE values were observed in examined venous blood gases values. Nonsignificant increases (p>0.05) for serum total protein and glucose concentratiaons and significant increases (p<0.05) for serum urea, ALT, AST, CK and AP values were found in the study.

Five dogs with ST segment depression and 2 dogs with PQ intervals prolongation of ECG were observed in dogs with dirofilariosis.

As a result, some changes were detected in haematological, biochemical, venous blood gases and ECG parameters in dogs with dirofilariosis and these changes were tought to be effective in diagnosis and prognosis of this disease.