The paper presents clinical diagnostic approaches and therapeutic effects of a specific protocol for the treatment of dogs with cardiovascular dirofilariasis in the Belgrade City (Serbia) territory. The study involved 50 privately owned dogs of different breeds, gender, and age, all showing signs of cardio - respiratory disorders. In addition to a general physical examination, blood tests were done to detect microfilaria and adult forms, and X-ray, ECG, and echocardiography were performed as well. At the first examination, 34 out of 50 examined dogs were positive for microfilaria and adult forms. Because of a lack of drug used as „the golden standard“ in dirofilariasis treatment, it involved a combination of doxycycline (10 mg/kg) and ivermectin (6 μg/kg) supported with Advocate - Bayer spot-on. After six months, the first control was performed while continuing treatment with the aforesaid protocol, and the second control was performed after 12 months. Of the 34 treated dogs, all were negative for microfilaria, as early as after the first six months of the treatment (100%). One dog was positive for adult forms of the parasite after six and 12 months. In echocardiography and X-ray examination after 12 months, six dogs showed evident chronic changes. At controls conducted at sixth month and at one year, the implemented therapy was successful in 97.05% (33/34) of primarily infected dogs.