Guide to Canine Leishmaniasis: What It Is, How It Works, and How to Protect Your Pet

08-06-2026

Guide to Canine Leishmaniasis: What It Is, How It Works, and How to Protect Your Pet

The health of our dogs and cats is our top priority. However, there are silent threats that every pet owner should be aware of. One of the most relevant is leishmaniasis, a condition that raises many questions.

In this guide, we explain clearly what it is, how it acts in the body, and how the combination of traditional prevention and advanced botanical science represents the best strategy to maintain your companion’s vitality.

What Is Leishmaniasis and How Is It Transmitted?

Canine leishmaniasis is a significant parasitic disease caused by a microscopic protozoan called Leishmania infantum. It is important for pet owners to know that it is not transmitted through casual day-to-day contact, such as playing, sharing a food bowl, licking, or living together. Therefore, there is no need to isolate a positive animal or change its coexistence with other pets or family members.

To go into a little more detail, it is a chronic and systemic disease. This means that once the parasite enters the body, it does not remain limited to one area. Instead, it travels through the circulatory and lymphatic systems, with the ability to affect multiple organs and tissues at the same time if the body does not control it.

Transmission Routes: Beyond the Mosquito

The main and most common route of transmission occurs through the bite of an insect vector: the sandfly, a very small flying insect that is mainly active during periods of heat and humidity. Contrary to what is often believed, the sandfly does not infest the animal like a flea or tick. Instead, it acts as a “transport” vehicle that directly inoculates the parasite while feeding.

However, current scientific research has shown that there are other secondary transmission routes that do not depend on the insect vector and are important in the clinical setting:

• • • Vertical transmission, from mother to offspring: an infected mother can transmit the parasite to her puppies during pregnancy or birth.
    • Venereal transmission: transmission through mating between breeding animals.
    • Direct blood transmission: through blood transfusions if the appropriate veterinary screening is not carried out.
    • What Does the Disease Cause? Symptoms and Clinical Signs

Leishmaniasis is known in veterinary medicine as “the disease of a thousand faces” because it can manifest in many different ways depending on which organs are most affected and on each patient’s immune response.

The incubation period may vary from a few months to several years, so symptoms can appear very gradually. The most common clinical signs that owners should monitor are divided into several categories:

1. Skin Signs: The Most Visible

These are usually the first warning signs and appear in the vast majority of clinical cases:

• • • Periocular alopecia: hair loss around the eyes, giving the animal a characteristic “spectacle-like” appearance.
    • Excessive scaling: dry skin, abundant dandruff, and skin thickening, especially on the head and limbs.
    • Skin ulcers: wounds that take a long time to heal, frequently located on the ears, elbows, paw pads, or nose.
    • Excessive nail growth, or onychogryphosis: the nails grow disproportionately, become fragile, and curve abnormally.

2. General and Visceral Signs: The Most Serious

These occur when the parasite has progressed toward the internal organs, compromising the pet’s overall health:

• • • Progressive weight loss: the animal loses weight and muscle mass noticeably, often despite maintaining the same appetite.
    • Lethargy and apathy: lack of energy, unjustified tiredness, and loss of interest in playing or going for usual walks.
    • Intermittent fever and lethargy: fever spikes that come and go without an apparent reason, accompanied by lack of energy, unjustified tiredness, and lack of interest in play.
    • Musculoskeletal signs: intermittent lameness, stiffness when walking, and joint inflammation, or polyarthritis, which may sometimes shift from one limb to another.
    • Kidney involvement: this is the most serious internal complication. It appears as an excessive increase in water consumption, known as polydipsia, and an increase in urine volume, known as polyuria.
    • Inflammation of lymph nodes and organs: the veterinarian may detect enlargement of the lymph nodes, liver, known as hepatomegaly, or spleen, known as splenomegaly, during the examination.

How Does It Act in the Body Once Infection Occurs?

• • • Parasite entry: the protozoan enters the animal’s body through inoculation from the bite, or through the secondary routes mentioned above.
    • Cell invasion: once inside, the parasite travels through the bloodstream and invades cells of the immune system, the macrophages.
    • Dissemination: instead of being destroyed, Leishmania has the ability to multiply inside these defensive cells and progressively spread throughout the body, potentially affecting vital organs such as the kidneys, liver, spleen, and skin.

The Impact of the Disease on the Immune System

The immune system is the body’s natural shield, keeping it protected against external threats. When leishmaniasis comes into play, this shield becomes the main target. The Leishmania parasite has a very specific destructive strategy: rather than directly attacking the organs in an initial phase, it hides and multiplies inside the very cells responsible for defending the animal, the macrophages.

Incidence: An Expanding Reality

Traditionally, leishmaniasis was considered a condition limited to warm areas of the Mediterranean basin during the summer months. However, the current situation has changed:

Non-endemic areas: due to climate change and the global rise in temperatures, the sandfly has colonised areas of northern Spain and western Europe where it previously could not survive, leading to local cases in places historically free from the parasite.

No seasonality: increasingly short and mild winters allow the vector to remain active for many more months of the year. In addition, the adaptation of the vector to new territories has disrupted the classic seasonal pattern. The risk is no longer only present in summer; for this reason, vigilance must be maintained throughout the year.

The Crucial Importance of the Immune System

Against leishmaniasis, the immune system is the real battlefield. Not all animals that receive the bite develop the condition in the same way. The key lies in how their defences react:

• • • Ineffective response: if the animal’s immune system is weakened or responds in an excessive and incorrect way, the parasite multiplies more rapidly, damaging tissues and disrupting the body.
    • Balanced response, or immunomodulation: if the immune system is strong and balanced, it is able to control and stop the replication of the parasite. The goal is not simply to “boost defences” in an uncontrolled way, but to modulate them so they act with precision and effectiveness without exhausting the animal.

Treatment and Comprehensive Management: A Chronic Condition

When an animal tests positive for leishmaniasis, it is essential to understand that this is a disease that currently has no definitive cure. Although conventional veterinary treatments, both leishmanicidal and leishmaniostatic, are excellent for controlling parasite replication, drastically reducing the parasitic load, and making clinical symptoms disappear, the protozoan remains latent in the animal’s body.

This involves two critical factors that every owner should know:

• • • Recurrences, or relapses: because the parasite is not completely eliminated, any drop in defences, stressful situation, or seasonal change can reactivate it, causing symptoms to reappear and showing an increase in analytical markers.
    • Reinfections: living in an endemic area, or continuous exposure to the vector due to climate change, means that a controlled dog may be bitten again by another infected sandfly, introducing a new parasitic load into its body.

For this reason, the modern approach to leishmaniasis is not limited to acting only during flare-ups. It requires continuous long-term support that keeps the immune system alert, strong, and balanced from within, minimising the risk of recurrences and helping the animal enjoy a full and happy quality of life.

Double-Layer Protection: The Comprehensive Shield

The best way to combat leishmaniasis is to combine protection from the outside and from the inside.

1. External Protection: Stopping the Vector

This consists of establishing a physical and chemical barrier to prevent the sandfly from biting the animal. Since no external tool is 100% infallible on its own, the ideal strategy is to combine several methods:

• • • Chemical repellents: constant use of repellent collars and spot-on pipettes to keep the insect away before it bites, adding sprays as reinforcement in high-risk areas.
    • Walking times: avoid walks or time in the garden at dawn and dusk, which are the periods of greatest vector activity and flight.
    • Environmental control: keep gardens clean, avoiding the accumulation of dry leaves or damp organic matter where the insect breeds, and avoid walking in wooded or riverside areas late in the day.
    • Home protection: install fine-mesh mosquito screens on doors and windows during the warmer months and prevent pets from sleeping outdoors.

2. Internal Protection: Preparing the Body with Artennua®

What happens if the mosquito has not bitten yet, or if it manages to bite despite external barriers? This is where the science of Artennua® and Artennua® XL comes into play. Our products contain Artemisia annua leaf optimised and standardised through patented biotechnology, achieving a high concentration of key phytocompounds such as artemisinin and flavonoids.

Their potential acts specifically depending on the situation your pet is in:

In Healthy Animals: Building a Proactive Shield

• Prior immunomodulation: regulates, trains, and strengthens the immune system continuously so that the defences are ready and alert against any possible infection.
• Cellular and antioxidant strength: protects cells against free radicals generated by stress or seasonal changes, keeping the body strong against external threats.

In Infected Animals: Defence, Control, and Stability

• • • Leishmanicidal effect: our published scientific study supports that Artennua® helps directly combat the protozoan.
    • Inflammation control: regulates the excessive inflammatory response caused by the disease, protecting vital target organs such as the kidneys, liver, and skin from deterioration.
    • Recovery of vitality: optimises the pet’s resources so that it no longer exhausts its energy solely on defending itself, resulting in better mood, improved physical appearance, and a greater desire to play.

What Is Artemisia annua and Why Does It Make a Difference?

Artemisia annua is a plant with a millennia-long history of use in traditional medicine, widely recognised by modern science thanks to its extraordinary biological properties. In fact, its scientific relevance is so significant that the discovery of artemisinin, its main active compound, was awarded the Nobel Prize in Medicine for its revolutionary efficacy in the treatment of malaria in humans and is widely recommended by the World Health Organization, WHO, for the treatment of that disease in humans.

What truly makes our botanical solutions different is that we grow and produce our own Artemisia annua. We do not buy common plant material from the market; we control the entire process from the seed and, through advanced patented biotechnology, optimise the crop to naturally maximise the concentration of its key phytocompounds. This allows us to standardise production to ensure that each batch always maintains the same concentration, efficacy, safety, and high quality. Artemisia annua acts by stimulating and modulating defence cells, while also offering a powerful antioxidant effect that combats free radicals and reduces inflammation at the cellular level.

It is very important to highlight that its benefits are by no means limited to dogs with leishmaniasis. This botanical compound is an excellent ally for dogs and cats of any age that need to strengthen their immune system against drops in defences, seasonal changes, periods of stress, or convalescence. In addition to its effects on the immune system, the plant has a proven natural antiparasitic action, making it a comprehensive tool to improve our pets’ quality of life in a completely safe way.

Conclusion: Living with Vitality

Leishmaniasis is a serious and expanding challenge, but today we have advanced scientific tools to address it. Whether to prepare your pet’s body against potential threats or to maintain the balance and energy of a dog living, or not living, with the parasite, the cutting-edge botanical support of Artennua® is your best ally. As it is a completely natural solution, it can be administered continuously and for life with complete safety, without risk of side effects to their health.

Because a strong internal response is the key to helping them continue enjoying life with the same joy as always.

👉 Would you like to learn more about how Artennua® biotechnology can protect your companion?

Contact us!