Tiger mosquito eggs | Míkel Bengoa Paulis


A warning has been issued in Majorca about a significant rise in Dirofilaria immitis, or heartworm diagnosis in dogs.

It’s a parasitic disease that’s transmitted by tiger mosquitos, is endemic in the Ebro basin and in Eivissa and was first found in dogs that had never left Majorca, 7 years ago.

Pet owners in Pollença, Albufera and Alcúdia are already on alert and Marcos Makowski who’s a vet at the Moixica Clinic is warning that tiger mosquitos have now spread Dirofilaria immitis across almost all of Majorca.

Heartworm disease mostly affects dogs, but can also be transmitted to cats and people, although it is less harmful in humans.

The mosquito bite transmits a parasite which lodges in the pulmonary arteries and if it is not controlled it can also reach the heart.

“The biggest problem is that an animal might not show symptoms for a long time, but could still be a carrier of the infection,” said Mr Makowski.

By the time fatigue, coughs, swollen abdomen and renal failure are noticeable, the disease is serious and "long and complex" treatment is needed.

Specialists are urging all pet owners and especially those who live in the wetlands, to apply preventive treatments, with either injections or pills as soon as possible.

There is no official case register for heartworm in Majorca but Mr Makowski warns that "the presence of the parasite has been confirmed in animals from a number of municipalities, including Alcúdia, Pollença, Can Picafort, Sa Pobla, and Palma.”

The Aedes albopictus, or tiger mosquito, was first detected in the Bunyola area of Majorca by the Zoological Laboratory of the UIB and according to Míkel Bengoa, who’s one of the biggest specialists in tiger mosquitos it is "one of the 100 species with the greatest invasive potential in the world."

In 2012, the Environment Ministry put together a work team to study the expansion of the tiger mosquito in Majorca.

"The presence of the tiger mosquito was detected in Palma, Bunyola, Marratxí, Calvià and Esporles 8 years ago, which suggests that it had settled on the island long before that," says Míkel, who completed his doctoral thesis on the tiger mosquito and has studied its progression.

“Tiger mosquitos can transmit dirofilaria so it is not surprising that veterinarians have issued a warning about heartworm,” he says. “The bigger the mosquito population the more chance there is of infection, it’s a matter of probability, just like the lottery.”

Heat and humidity fosters diseases such as Dengue, Zika or Chikungunya, which makes the Balearic Islands a paradise for the tiger mosquito.

There are a few things that residents can do to stop the spread of tiger mosquitos.

Don’t allow water to accumulate in pots or bottles in the garden or on the patio; keep domestic water tanks covered; avoid having empty containers out in the rain; make sure that animal drinking troughs are washed regularly and keep grilles and gutters clean.

Tiger mosquitos usually fly at a low level, so most bites occur in the legs and its only the females that bite because they need the protein that’s in human blood to develop their eggs.