Canine leishmaniasis (Leishmania infantum) is one of the most serious health threats facing dogs in Spain. Spread by the bite of tiny sandflies, it is endemic across much of the Mediterranean and the Iberian Peninsula. This guide explains how it spreads, where and when the risk is highest, the symptoms to watch for, how it is diagnosed, the reality of treatment and lifelong management, how to protect your dog — and why ongoing conditions like this are exactly what pet insurance is designed to help with.
Canine leishmaniasis (also spelled leishmaniosis) is a chronic, potentially life-threatening parasitic disease caused by a single-celled parasite called Leishmania infantum. It is one of the most important vector-borne diseases affecting dogs in southern Europe, and Spain — along with the rest of the Iberian Peninsula — is considered an endemic region, meaning the parasite is well established and present year after year.
The disease has been part of life for dogs in the Mediterranean basin for a very long time, but for many expats moving to Spain with a pet, it comes as a genuine shock. In the UK, Ireland, northern Europe and much of North America, leishmaniasis is rare or essentially absent, so owners simply have not had to think about it. In Spain it is a mainstream veterinary concern that responsible owners plan for from the moment they arrive.
What makes leishmaniasis different from a one-off emergency — such as a snake bite or contact with a processionary caterpillar — is that it is a slow, insidious, long-term condition. A dog can be infected for months or even more than a year before obvious signs appear, and once the disease takes hold it typically requires ongoing veterinary care for the rest of the dog’s life. That is a crucial point for both your dog’s welfare and your finances, and it runs right through this guide.
Leishmaniasis is also a zoonotic disease, meaning the parasite can, in principle, affect people as well as dogs. However, people do not catch it directly from their dog — both dogs and humans are infected the same way, through a sandfly bite. Human cases in Spain are relatively uncommon and tend to affect people with weakened immune systems. The information in this guide is about protecting your dog; for any concern about human health, speak to your doctor.
Leishmaniasis is spread almost entirely by the bite of the phlebotomine sandfly — a tiny, delicate insect distantly related to mosquitoes and midges. Sandflies are only two to three millimetres long, roughly a third of the size of a mosquito, and they are silent fliers, so most owners never notice them. When an infected sandfly bites a dog, it injects the Leishmania parasite into the skin, where it can go on to spread through the body.
Understanding the sandfly’s behaviour is the single most useful thing you can do, because prevention is built entirely around avoiding its bite. A few key facts stand out:
Because there is no casual dog-to-dog spread, a diagnosis in one household pet is not a reason for panic about the others — but it is a strong signal that sandflies are active in your area and that every dog you own should be properly protected.
Leishmaniasis is present across large parts of mainland Spain, but the risk is not uniform. Historically the highest-prevalence areas have been the Mediterranean regions — the coastal strips and their hinterlands — along with central and southern Spain. The parasite thrives where the sandfly thrives: warm temperatures, mild winters and the right kind of humid, sheltered habitat.
Importantly, the picture is changing. Veterinary and parasitology bodies have flagged that warming temperatures are allowing sandflies to establish in areas further north where the disease was barely known a generation ago. In practical terms, that means no dog owner in Spain should assume they are completely outside the risk zone — the sensible default is to treat leishmaniasis as a nationwide concern and adjust the intensity of prevention to your local conditions with your vet’s advice.
| Factor | Higher risk | Lower risk |
|---|---|---|
| Region | Mediterranean coast, inland valleys, central & southern Spain; increasingly the north | High-altitude and colder inland areas (but not zero) |
| Season | Warm months — broadly spring to autumn, peaking in summer | Cold winter months when sandflies are inactive |
| Time of day | Dusk, night and dawn | Middle of a hot, bright day |
| Setting | Rural, garden, near vegetation, animal shelters, ruins & walls | Well-sealed indoor environment at peak biting times |
Because the timing of the season varies year to year and place to place, it is worth asking your local vet directly: “How active is leishmaniasis here, and what months should I be most careful?” A vet who works in your specific area will know the local pattern far better than any general rule of thumb, and their answer should shape your prevention plan.
One of the most difficult things about canine leishmaniasis is that it is a master of disguise. Signs can take months — sometimes more than a year — to appear after the bite, and they develop gradually rather than suddenly. Many infected dogs stay outwardly healthy for a long time, which is exactly why regular check-ups and, where advised, screening blood tests are so valuable in endemic areas.
When signs do appear, they usually fall into two broad groups: skin (cutaneous) changes and more general (systemic) illness. A dog may show a few of these or many, and the combination varies from dog to dog.
None of these signs is unique to leishmaniasis on its own — weight loss, skin problems and lethargy have many possible causes. That is the point: in an endemic country like Spain, leishmaniasis should be on the list of possibilities your vet considers, and only a vet can tell the difference through proper examination and testing.
Because the symptoms overlap with so many other conditions, leishmaniasis cannot be diagnosed by appearance alone. Your vet will combine a physical examination with laboratory testing to build a clear picture. There is no single “yes/no” test that answers every case, so vets often use more than one method.
In endemic areas, many vets recommend periodic screening of apparently healthy dogs — often as part of an annual check — precisely because early, symptom-free cases can be picked up before serious damage occurs. Whether that is right for your dog is a conversation to have with your vet, based on where you live and your dog’s lifestyle. If your dog is diagnosed, the results also give a baseline that future tests are measured against, which matters because leishmaniasis is managed over the long term rather than cured in a single course.
This is the part every owner needs to understand honestly. The good news is that leishmaniasis is treatable and many dogs, once diagnosed, go on to live good-quality, active lives for years. The harder truth is that it is very often not fully curable. Veterinary and parasitology sources are consistent on this point: no drug has been shown to reliably eliminate the parasite from the body altogether. Instead, treatment aims to control the parasite, calm the immune reaction, resolve the clinical signs and protect the organs — and that usually means ongoing care.
In practice, management of a diagnosed dog typically involves a combination of the following, always under veterinary direction:
Because management is ongoing, the costs are ongoing too. Diagnosis, initial treatment, repeat medication and the lifetime of monitoring blood tests all add up. We deliberately avoid quoting figures — they depend on your dog, your region, your vet and how the disease progresses — but it is realistic to expect that a leishmaniasis diagnosis means a recurring commitment rather than a single bill. That financial reality is exactly where pet insurance comes into the picture, and it is why when you insure matters so much.
Since leishmaniasis is difficult to cure but largely preventable, prevention is where you should focus your energy. The strategy is simple in principle — stop the sandfly biting your dog — and the most effective approach combines several layers rather than relying on any one measure. Veterinary bodies broadly agree that the strongest protection comes from combining a proven repellent with, where appropriate, vaccination and sensible avoidance. Always agree the exact products and schedule with your vet, as recommendations and licensed products vary.
The core of prevention is a veterinary product that repels and kills sandflies before they can bite. These commonly come as:
The active ingredients used against sandflies (of the pyrethroid family) are the same class veterinarians rely on for this purpose. Crucially, timing and consistency matter: protection needs to be in place before and throughout the sandfly season, and lapses leave a gap. Your vet will recommend the right product and re-application schedule for your dog and area.
Vaccines against canine leishmaniasis are available and can be a valuable part of prevention for at-risk dogs. A vaccine does not replace repellents — the most effective protection pairs vaccination with topical insecticides — and it is not suitable for every dog. Whether to vaccinate, and when, is a decision for your vet, who will usually test the dog first to confirm it is not already infected.
Leishmaniasis is close to the textbook example of why pet insurance exists. It is not a single emergency you pay for once; it is a long-term condition with diagnosis costs, treatment costs and — potentially for the rest of your dog’s life — the cost of repeat medication and monitoring blood tests. Faced with that kind of open-ended commitment, having cover in place can be the difference between choosing the best care for your dog and having to make decisions based purely on what you can afford that month.
Sanitas offers pet insurance in Spain through its Salud Mascotas product, and it is worth understanding how it works so you know what it can and cannot do for a condition like leishmaniasis:
If you are weighing up cover, our dedicated guides walk through the options: pet insurance in Spain for the overview, and dog insurance if you specifically own a dog. Cat owners can read about cat insurance too — while leishmaniasis is overwhelmingly a disease of dogs, cats living in Spain benefit from cover for the many other conditions they can face. If you would rather just talk it through, an English-speaking adviser can help you get a quote or answer questions via our contact page.
Leishmaniasis is the most significant long-term parasitic threat, but it is not the only seasonal hazard for pets in Spain. Building good habits around one risk makes it easier to stay on top of the others, and the same annual vet visit is a natural moment to review them all.
The pine processionary caterpillar is a sudden, acute emergency in late winter and spring — the opposite of leishmaniasis in timing and speed, but just as important to know about. And in the fierce Spanish summer, heatstroke is a genuine and rapid killer, especially for dogs walked in the heat of the day. Notice how the timings interlock: the same warm months that bring peak sandfly activity are also the peak heatstroke season, so summer is when your guard should be highest on several fronts at once.
A lifelong condition like leishmaniasis is exactly what cover is for — but only if it is in place before diagnosis. Tell us about your pet and an English-speaking adviser will find a Sanitas plan that reimburses your vet bills.
Get My Quote →This guide is general information for dog owners, not veterinary advice. Always consult your own vet about diagnosis, treatment and prevention for your dog. Key veterinary and parasitology sources include:
• ESCCAP — Guideline GL5: Control of Vector-Borne Diseases in Dogs and Cats: esccap.org/guidelines/gl5
• Companion Animal Parasite Council (CAPC) — Leishmaniasis: capcvet.org/guidelines/leishmaniasis
• LeishVet guidelines for the practical management of canine leishmaniosis: ncbi.nlm.nih.gov/pmc/articles/PMC3125381
• Canine Leishmaniasis: Update on Epidemiology, Diagnosis, Treatment, and Prevention (peer-reviewed review): ncbi.nlm.nih.gov/pmc/articles/PMC9416075