Dirofilaria immitis and D. repens in dog and cat: A questionnaire study in Italy

Dirofilaria immitis and D. repens are vector-borne parasites of dogs and cats, with zoonotic potential, endemic in many parts of Europe, including Italy. Control and prevention of dirofilariosis are essential points to reduce their diffusion in animals and humans and veterinarians are the main subjects involved in this battle. With the aim to better understand current practice by veterinarians, an online questionnaire on different aspects of D. immitis and D. repens was sent to companion animal veterinary facilities registered with the Italian Veterinary chamber. The overall response rate was 25%. Approximately 47% had diagnosed at least one case of Dirofilaria spp. in dogs in the last year and approximately 6% had diagnosed at least one case of Dirofilaria spp. in cats. Of the 662 facilities surveyed, 83.8% used serology to diagnose heartworm infection. For the diagnosis of D. repens infection in dogs and cats, a high percentage of facilities relied on an external laboratory. Most recommended beginning prevention of canine heartworm disease in April-May. Topical and injectable moxidectin and oral ivermectin were the two most commonly used preventives for D. immitis in dogs. The drug most commonly used for heartworm adulticide treatment in dogs was melarsomine. This study show that veterinary facilities ians working in an endemic area for D. immitis and D. repens are aware of recent developments in adulticide therapy. Results would suggest however that diagnosis is not always carried out according to what is currently recommended by international guidelines and that the timing for starting prevention may not be optimal.