Pet Threats and Animal Dangers

Insects, snakes and other things may threaten the health of dogs in Portugal - understand what to do about the dangers of processionary caterpillars and leishmaniasis...


Leishmaniasis is a disease that mainly affects domestic dogs. In humans, it is called Kala-Azar which is the Indian for black fever. It is carried by a small, yellow sand fly that resembles a mosquito and is around two to three millimetres long. Southern European countries with a Mediterranean climate are severely affected by the disease. It is said that the fly carrying the disease does not bite at sea level, only at altitude - but the altitude at which they bite is not high. A local vet should be able to answer any questions about the area.

Typically the fly bites the dog's exposed skin (nose and ears). Dogs can incubate Leishmaniasis for over a year before displaying symptoms, which vary from dog to dog. One clue is when the hair around a dog's eyes drops out and claws grow abnormally. Infected animals will lose weight, become anaemic and often display symptoms of renal failure. If medical help is not sought, the dog will die after several months.

There are products (available from vets) that can protect against the bite if applied regularly and should be used to protect against this disease from spring to autumn when the risk is highest. Also, cattle pest control badges are said to protect against bites, but the best protection is to keep a dog inside from before dusk until after dawn, the time when the flies are most active.

Processionary Caterpillars

The processionary pine caterpillar (Thaumetopoea pityocampa) is usually three to four centimetres long, brown and hairy. The Portuguese for caterpillar is lagarta. At the start of spring the caterpillars come out of round, white, fuzzy nests built in pine trees (normally property owners will burn these nests if they see them) and travel down the tree and across the ground in single file, sometimes stopping in writhing circles. This phenomenon will continue well into the summer.

These caterpillars are extremely dangerous as they "burn" the flesh of any animal, child or person that touches them. A small animal can die from the burn on contact. If a pet comes in to contact with these caterpillars it is advisable to seek veterinary assistance immediately.

The caterpillars are often found on sports pitches and courses, many Portuguese golf clubs have exceptional rules in case a ball has touched a procession of caterpillars. Consult the club for more details.


Heartworm disease (Dirofilaria immitis) is a caused by a parasite carried and transmitted in its larvae stage by mosquitoes. Once the larvae matures the adult worms reside in the pulmonary arteries (blood vessels in the lungs), and cause blockages, inflammation and damage to blood vessels. While most commonly found in cats and dogs, other species can be infected.

The infection can not be detected during the six first months with no signs of infection usually apparent until the worms mature.

Symptoms include coughing, exhaustion, severe weight loss and fainting. Cats may also get pneumonia-like symptoms, diarrhoea and may vomit.

The disease is not easy to treat and can be fatal; however early diagnosis may result in full recovery. Prevention is preferable and a pet can be protected from infection with the use of anti-mosquito drops and collar treatments.

The parasite is common in the south of France, in Spain and Portugal, and Italy.

Dangerous Ticks in Portugal

As in most hot countries ticks can be a serious problem for cats and dogs and not only do they spread disease but they can cause serious discomfort to the animal. Two of the most common diseases are Babesiosis and Ehrlichiosis. Take advice from the local vet in order to ensure that the pet is adequately protected. Drops and collars are available.

Note: if tick bite disease is ignored it can be fatal.

Poisonous Snakes in Portugal

There are some poisonous snakes that can cause death if they bite an animal.

For more information on poisonous snakes, see:

Further Information