Rising heartworm cases in Bulgaria signal climate-driven threat to dogs’ health

Veterinary specialists in Bulgaria warn that climate change and improved diagnostics are causing a surge in heartworm infections among dogs, highlighting the need for early prevention and regular testing.

Veterinary specialists in Bulgaria say heartworm infection in dogs is becoming a more serious clinical issue, with Dr Dimityr Yanovski warning that cases are now being seen across the country rather than mainly in the south. He links the rise to changing climate conditions that favour mosquito vectors, as well as better diagnostics that are picking up infections earlier.

Dr Yanovski, who leads a Sofia clinic and has nearly two decades of experience, said many of the worst cases involve animals that were never tested or treated until severe cardiac damage had already developed. At that stage, prognosis is poor and treatment is complex, requiring multiple drugs, close monitoring and prolonged rest.

International veterinary guidance broadly supports his warnings. Cornell University and Merck Veterinary Manual both note that heartworm is transmitted by mosquitoes, can cause lung and heart vessel damage, and may progress to right-sided heart failure if left untreated. The American Kennel Club and petMD also stress that prevention is far more effective than treatment, with year-round prophylaxis and routine veterinary checks recommended.

Dr Yanovski said owners often underestimate the seriousness of the disease, misunderstanding how it spreads and how late symptoms can appear. His advice is blunt: prevention should begin early, under veterinary supervision, with regular testing continuing even in dogs already on prophylactic medication.

American Heartworm Society