No, your dog can't give you leishmaniasis no matter how much you hug him and live with him. Why? Because the culprit that transmits the disease does not have four legs (but six) and does not wag its tail when it sees you.
Our dogs can transmit some diseases to us, but this is not the case with leishmaniasis. This potentially lethal disease is caused by a parasitic protozoan called Leishmania, to which both humans and dogs are exposed. So, your faithful companion cannot infect you directly, although it can play an important role in the transmission and spread of the parasite. Therefore, in order to prevent the spread, we need to know how diseases are transmitted from animals to humans.
What are zoonoses?
Zoonoses are diseases that can be transmitted from animals to humans and vice-versa. In the case of dogs, this includes rabies, tuberculosis and ringworm, among others. COVID-19, although now affecting humans, probably started when the coronavirus "jumped" from an animal to a person.
As they are specific to other species, humans do not usually have natural defences against them, so they are often serious, which is why zoonoses deserve our full attention. Moreover, since many of them subsist in wild animals, they are very difficult to control and almost impossible to eradicate.
How are zoonoses transmitted?
Zoonotic diseases are transmitted by direct contact, where one infected animal is enough to infect a person. For example, the bite of a rabid dog is more than sufficient for a person to contract rabies.
In the case of canine leishmaniasis, you can rest assured: this disease cannot be transmitted directly; even if your dog has it, you will not catch it from them if you hug them, they lick your hand, or simply by living with them.
Many zoonoses have an indirect cycle, i.e., they need an intermediate host to infect a person. The vector (that transmits it) is usually an insect. For example, the tsetse fly is the vector for sleeping sickness, and the sand fly is the vector for leishmaniasis.
People are usually incidental hosts of zoonoses. These diseases subsist in other species called reservoirs. For example, deer and wolves are the main reservoirs of Lyme disease and the tick is its vector. In the case of leishmaniasis, stray dogs are the main reservoir in Europe.
Leishmaniasis transmission is a major public health problem, partly because the vector has expanded its geographical distribution due to rising temperatures linked to climate change.
The bite of a small insect can give you leishmaniasis
The vector for leishmaniasis is a tiny, elusive insect known as aphlebotomine sandfly. When it bites an infected dog, it also sucks in the parasite, which continues to multiply inside the sand fly, so that its bite becomes contagious. The female insect feeds on the blood of mammals, which is how it spreads the disease.
Leishmaniasis can only be transmitted to humans by a sand fly that has previously bitten an infected animal. Therefore, avoiding their bite is the best strategy for preventing leishmaniasis in dogs and humans. This is mainly achieved with insecticides and repellents, but don't put all your eggs in one basket: vaccination, hygiene and cleanliness also play an important role.
The sand fly is nocturnal and is very active at dawn and dusk. It loves to hide in cracks, holes and burrows, and thrives in places where rubbish or organic matter accumulates. This insect can be found almost everywhere in Spain, although the Mediterranean basin is the most favourable area for its reproduction and, therefore, the areas with the highest risk of leishmaniasis are found in this region.
Put a stop to leishmaniasis
Although the fact that our beloved pet cannot infect us through direct contact is excellent news, we should not drop our guard. Our friend must be prevented from becoming a factor in the spread of Leishmania, otherwise it can have very serious consequences for humans, especially in people with compromised immune systems and in children.
A quality repellent collar protects our faithful companion from sand fly bites for several months. It is a simple and affordable way to protect our dogs from leishmaniasis, and at the same time take care of our own health, and that of our family and our community.
Together we can help prevent leishmaniasis in dogs and people!