When a mosquito carrying heartworm bites a dog, it can leave microscopic larvae in its body. These larvae then develop and migrate to the dog's pulmonary artery, near the heart. Once adult, the worm can measure up to 30 centimeters and live in the body for 5 to 7 years, without any clinical signs. However, the presence of this adult parasite is not harmless for the dog's health. Without protection, the worms accumulate "silently" inside the body and when they are present in too large quantities, they prevent the normal functioning of the heart. In the advanced stages of the disease, affected dogs sometimes suffer from heart failure which can lead to death. In rare cases, heartworm disease can also affect humans and manifest itself as subcutaneous nodules or pulmonary nodules. 

Heartworm disease has been spreading in Central and Eastern Europe for several years. Its rapid spread is due to several factors: global warming², new species of mosquitoes that are competent vectors of transmission³, and the growth of reservoirs of infection such as jackals and foxes⁴. Controlling heartworm disease in the area is made particularly difficult by its rapid spread, with veterinarians having little knowledge of its diagnosis and management. 

One motto: prevention
Worldwide, treatments to eliminate adult worms exist, but they are not always available in some European countries. Moreover, the protocols for their use are complex and certain risks exist (allergic reaction, thrombosis in particular). Prevention remains the best solution, by destroying the larvae before they develop and, if possible, by reducing the risk of being bitten with mosquito repellents. 

To date, there are various repellent products (sprays, pipettes or collars) or larvicides. This therapeutic arsenal is generally administered monthly during the warm season, which is the most risky period for mosquitoes (generally from May to September). However, this period can be longer depending on the weather and compliance with monthly treatments can be difficult for the owner. In addition, the European Society of Dirofilariasis and Angiostrongylosis (ESDA) now recommends annual protection against heartworm disease due to the increasing persistence of mosquitoes in winter and larviciding solutions⁵. This is why our teams are now providing a new larvicidal prevention solution, which protects dogs all year round with a single injection. Available since 2021 in France and Slovenia, it is now available to veterinarians and owners in Hungary, Bulgaria, Czech Republic, Slovakia, Croatia and Romania.

<sub>1. Ciuca et al. 2022
2. Genchi et al. 2001; Sassnau et al. 2014.
3. Madon et al. 2002; Cancrini et al. 2003; Roiz et al. 2007
4. Tolnai et al. 2014
5. European Society of Dirofilariosis and Angiostrongylosis. Guidelines; ESDA: Las Palmas de Gran Canaria, Spain. Available online (accessed December 2022).</sub>