Leishmaniasis is one of the most serious diseases a dog can contract in Spain. It is not transmitted by the common mosquito: it is transmitted by the Phlebotomus, or sandfly, a tiny insect barely visible to the naked eye whose bite goes unnoticed. What is visible — and often only when it is too late — are the consequences.
Summer is the period of greatest risk: the sandfly is most active between May and October, especially in rural, humid areas with dense vegetation, though it also appears in urban environments.
What is leishmaniasis?
It is a parasitic disease caused by the protozoan Leishmania infantum, which the sandfly transmits to the dog through its bite. The parasite establishes itself in the immune system and internal organs — primarily the spleen, liver, kidneys, and bone marrow — and causes progressive deterioration if left untreated.
The dog is the main reservoir of the disease, but humans can also become infected (visceral leishmaniasis or kala-azar), particularly immunocompromised individuals.
Where is it most common in Spain?
Leishmaniasis is endemic throughout most of Spain, with higher prevalence in:
- Community of Madrid and surrounding areas
- Mediterranean coast (Valencia, Catalonia, Murcia)
- Andalusia and Extremadura
- Castilla-La Mancha and Aragon
- Coastal areas and islands (Balearic Islands)
Mountain areas above 1,000 metres have a lower incidence, although climate change is expanding the distribution range of the vector.
Symptoms of leishmaniasis in dogs
The disease can take months or even years to manifest. The most common symptoms are:
Skin symptoms (the most visible)
- Flaking skin, particularly around the eyes and muzzle
- Hair loss with areas of thickened skin
- Ulcers on the paw pads, ears, or muzzle
- Excessive nail growth (onychogryphosis)
General symptoms
- Progressive weight loss
- Lethargy and low energy
- Enlarged lymph nodes
- Eye discharge or conjunctivitis
- Nosebleeds
- Kidney problems (in advanced stages)
At any of these signs — especially if the dog lives in or has travelled to endemic areas — it is essential to consult a vet.
Diagnosis
Diagnosis is carried out via blood tests (serology) to detect antibodies against Leishmania. In uncertain cases, more specific tests such as PCR or bone marrow aspiration may be performed. Many vets include the leishmaniasis test in the annual health check for dogs in at-risk areas.
Treatment
Leishmaniasis has no definitive cure: current treatments (mainly antimonials, allopurinol, and miltefosine) control the disease and improve the dog's quality of life, but the parasite can remain latent. Periodic veterinary follow-up is essential.
Prevention: how to protect your dog
Antiparasitic products
Repellent collars (such as Scalibor), spot-on pipettes, and some tablets provide protection against the sandfly. It is important to consult your vet about which option is most suitable for your dog and to maintain protection throughout the entire risk season.
Leishmaniasis vaccine
A vaccine is available in Spain (CaniLeish / LetiFend) that reduces the risk of infection and, above all, of developing clinical disease. It is particularly recommended in endemic areas. It requires an initial vaccination course followed by an annual booster dose.
Environmental measures
- Avoid walks at dawn and dusk, when the sandfly is most active.
- Use mosquito nets on windows and doors.
- Keep your dog indoors at sunset in high-risk areas.
- Eliminate potential breeding sites (humid areas with dense vegetation).
Nutrition and immunity
A well-nourished dog with a strong immune system has a greater capacity to resist or limit the progression of the disease. Balanced diets rich in quality protein, essential fatty acids, and antioxidants support immune wellbeing.
At OnlyFresh you will find options from brands such as Amanova, Harper and Bone, and TrovetPlus, formulated with high-quality natural ingredients and without unnecessary additives, which support your dog's general wellbeing — including their immune defences.
