Leishmaniasis in dogs: what it is, symptoms, treatment and prevention

When we pack our bags or go out to enjoy the good weather with our furry friends, health and protection should always be in the carry-on luggage. Among all the diseases that can affect our pets, there is one that generates a lot of doubts and concerns among guardians: leishmaniasis.

Knowing well what leishmaniasis in dogs is, how it is transmitted, how to detect the first symptoms, and what measures to take to prevent it is the best tool to keep your companion healthy, strong, and ready for any adventure.

Leishmaniasis in dogs: what it is and why it is a serious disease

Canine leishmaniasis is a serious parasitic disease caused by a microscopic protozoan called Leishmania infantum. This parasite multiplies inside the cells of the dog's immune system and eventually spreads to various organs and tissues.

It is considered a serious pathology because it is chronic and systemic in nature. If not detected and treated in time, the parasite can cause irreversible damage to vital organs such as the kidneys, liver, or bone marrow. The good news is that, thanks to current veterinary advances, early diagnosis and appropriate treatment allow an infected dog to live a completely normal, happy, and long life.

How is leishmaniasis transmitted in dogs?

There is a widespread myth that leishmaniasis is transmitted through direct contact between dogs, through bites, or by sharing water bowls. This is completely false. Leishmaniasis is not transmitted directly from one dog to another.

The only culprit of transmission is a vector insect: the sandfly, a small mosquito barely a couple of millimeters in size that acts as an intermediary. The female sandfly bites an infected animal, absorbs the parasite, and when it bites another healthy dog to feed, it transmits the Leishmania. The period of greatest activity for this insect is from spring to autumn (coinciding with the warmer months), especially during dawn and dusk.

Symptoms of Leishmaniasis in Dogs

One of the biggest challenges of leishmaniasis is that it manifests in very varied ways. Some dogs show obvious skin symptoms, while in others the parasite directly attacks internal organs without giving striking external signs.

Among the most common warning signs are:

• Skin problems: Hair loss (especially around the eyes, ears, and muzzle), dandruff-like scaling, dry skin, and wounds or ulcers that do not heal well.

• Abnormal nail growth (onychogryphosis): Nails grow very quickly, taking on a curved and brittle shape.

• Progressive weight loss and lack of appetite: The dog appears apathetic, thin, and loses muscle mass even if it continues eating.

• Nosebleeds (epistaxis): Bleeding from one or both nostrils with no apparent reason.

• Intermittent lameness and joint inflammation.

• Kidney symptoms: If the disease affects the kidneys, the dog will drink a lot of water and urinate much more frequently than usual.

Stages of Canine Leishmaniasis

To determine the state of the disease and the best treatment, the veterinary community classifies leishmaniasis into four stages or phases based on the parasitic load and organic damage:

• Stage I (Mild): Mild clinical signs (generally some skin lesions or slightly inflamed lymph nodes) and very low antibody levels. Kidney function is intact.

• Stage II (Moderate): More widespread skin lesions, weight loss, apathy, and a medium or high antibody titer. Kidney tests still come out normal.

• Stage III (Severe): In addition to the previous symptoms, immune complex lesions appear (such as ocular inflammation or vasculitis) and the kidney begins to be affected (protein in urine).

• Stage IV (Very severe): The animal suffers from advanced kidney failure or serious complications requiring hospitalization and intensive care.

Diagnosis of Leishmaniasis in Dogs

Detecting the presence of the parasite before it causes havoc is the key to success. In veterinary routine, there are several ways to reach an accurate diagnosis.

Most Common Veterinary Tests

The veterinarian will combine a complete physical examination with rapid immunochromatography tests (the well-known in-clinic kits that give results in minutes) to check if the dog has been in contact with the parasite.

Blood Tests and Serology

To confirm the disease and know what stage it is in, it is essential to perform a complete blood test with serology (techniques such as ELISA or IFI that measure the exact level of antibodies), as well as protein electrophoresis and kidney and liver profiles.

Importance of Early Detection

A routine check-up once a year (especially at the end of mosquito season, towards late autumn) allows catching the infection in its early stages before it damages the kidneys. If you want to delve deeper into preventive health guidelines for your travels and daily life, we invite you to check our section on care and tips for your pet.

Treatment of Leishmaniasis in Dogs

Although the parasite is rarely eliminated 100% from the body, treatment manages to stop its multiplication, eliminate symptoms, and restore an excellent quality of life to the dog.

The usual protocol combines two types of drugs:

1. Leishmanicides: Medications (such as meglumine antimoniate or miltefosine) that drastically reduce the number of parasites in the body over a few weeks.

2. Leishmaniostatics: Maintenance drugs (such as allopurinol) that prevent the parasite from reproducing rapidly again, often supplemented with immunomodulators that boost the animal's defenses.

Prevention of leishmaniasis in dogs

Since transmission depends on the bite of the sandfly, prevention is the best armor for our furry friend. The ideal approach is to apply multimodal protection by combining different barriers.

Repellent collars and pipettes

They are the first line of defense. It is essential to use collars or pipettes containing repellent active ingredients (such as deltamethrin, flumethrin, or permethrin) with proven effectiveness to repel sandflies. Always check the exact duration of the effect on the package insert to avoid leaving the dog unprotected.

Leishmaniasis vaccine

The vaccine does not prevent mosquito bites, but it trains the dog's immune system so that, in case of being bitten by an infected insect, its body can control the parasite and not develop the severe form of the disease.

Avoiding mosquito bites

During warm months, try not to leave your pet sleeping outside (gardens, terraces, or porches) from dusk onwards, which is when sandflies come out to feed.

Measures at home and during nighttime walks

Use mosquito nets on house windows, use anti-mosquito diffusers in rooms, and avoid walking near stagnant water areas or riverbanks late in the afternoon. At Viajes4patas, we love seeing you enjoy routes and getaways, so equipping your dog with its repellent collar before heading out into nature is a golden rule.

Leishmaniasis in dogs in Spain: risk areas

Spain is an endemic country for leishmaniasis due to its temperate and Mediterranean climate, favorable for the survival of the sandfly.

Mediterranean and coastal areas

The Mediterranean basin (Andalusia, Valencian Community, Catalonia, Region of Murcia, and Balearic Islands) has a high prevalence of the disease almost all year round due to its mild winters and warm, humid summers.

Cities like Barcelona, Valencia, or Malaga

Thinking that leishmaniasis is exclusive to the countryside is a mistake. Urban parks, gardens, and green areas in large cities like Barcelona, Valencia, or Malaga harbor sandfly populations perfectly adapted to the urban environment.

Risk in rural and urban areas

Areas with orchards, riverbanks, housing developments with pools, and rural plots concentrate a high number of mosquitoes, although the risk exists in practically the entire Iberian Peninsula (with lower incidence in the Cantabrian coast).

Is leishmaniasis in dogs curable?

Talking about a cure for leishmaniasis requires distinguishing between clinical cure and biological cure:

• Clinical cure (Yes): With appropriate treatment, symptoms disappear completely, organs function perfectly, and the dog regains its energy and normal health.

• Biological cure (Rarely): The parasite usually remains latent in small amounts within the body. Therefore, it is considered a chronic disease that requires monitoring, even if the dog appears perfectly healthy.

Tips for Living with a Dog with Leishmaniasis

If your companion has been diagnosed with leishmaniasis, don't panic. By following simple guidelines, they will live a full life by your side:

Diet and Daily Care

A high-quality, highly digestible diet is key. If the dog is taking allopurinol as maintenance treatment, the vet usually recommends low-purine foods or diets to prevent the formation of xanthine stones in the kidneys.

Frequent Veterinary Check-ups

Visiting the vet every 6 months for follow-up blood tests ensures the parasite remains dormant and that kidney and liver values are impeccable.

Lifestyle Adjustments

Keep your dog protected with repellents to prevent further bites, reduce their stress levels, and don't give up traveling and walking together as usual.

Frequently Asked Questions about Leishmaniasis in Dogs

Can leishmaniasis be transmitted to humans?

It is a zoonotic disease (it can affect people), but it NEVER spreads directly from dog to human. For a person to become infected, they must be directly bitten by a sandfly carrying the parasite. Having a dog with leishmaniasis at home does not pose a direct risk of infection to the family.

How do I know if my dog is at risk?

Any dog that lives in or travels to Mediterranean, temperate, or warm climates without adequate protection from mosquito repellents is at risk of infection.

Can it be 100% prevented?

No single measure is 100% foolproof, but if you combine the use of repellent collars/pipettes with vaccination and avoid nighttime exposure during warm seasons, the level of protection is nearly maximum.

What should I do if I suspect my dog is infected?

If you notice weight loss, dandruff on the ears, overly long nails, or unusual tiredness, go to your vet immediately for a rapid blood test. The earlier it is detected, the easier and more effective the treatment will be.