Leishmania

What is leishmaniasis?

Leishmaniasis is an infectious disease caused by leishmania. These are unicellular organisms that belong to the protozoa. There are different types of leishmania, which can cause different clinical pictures. The most common form in dogs is visceral leishmaniasis, in which the internal organs such as the liver, spleen or kidneys are affected. Cutaneous leishmaniasis mainly manifests itself on the skin, where open wounds and ulcers can form.

Leishmania is transmitted through the bites of sand flies. These are small insects that are mainly found in warm and humid regions. They are mainly active at dusk and at night and prefer to bite in areas with thin hairs such as the ears, nose or stomach. The sand flies pick up the leishmania from an infected animal when sucking blood and pass it on to another animal or a person the next time they bite.

How do you recognize leishmaniasis?

Leishmaniasis is an insidious disease because it can remain undetected for a long time. The incubation period, i.e. the time between the bite and the outbreak of the disease, can vary from a few weeks to several years. This depends on various factors, such as the dog's immune system, the number of pathogens or the type of leishmania.

The symptoms of leishmaniasis are often non-specific and can easily be confused with other diseases. The most common signs include

• Fatigue and loss of appetite
• Weight loss and muscle atrophy
• Fever and swelling of the lymph nodes
• Skin changes such as dandruff, hair loss or wound healing disorders
• Excessive claw growth
• Anemia or a tendency to bleed
• Kidney failure or liver inflammation

If you notice one or more of these symptoms in your dog, you should definitely consult a vet. Only a blood test can provide a reliable diagnosis and rule out other diseases.

How can leishmaniasis be prevented?

The best way to prevent leishmaniasis is to protect your dog from sand flies. This is especially true if you are traveling to or living in a risk area with your dog. Risk areas include countries around the Mediterranean, but also parts of South America and Asia.

You can take the following measures to protect your dog from sand flies:

• Avoid walks at dusk or at night when sand flies are most active.
• Keep your dog away from damp places such as bodies of water or garbage dumps where sand flies breed.
• Protect your dog with a suitable repellent against insect bites. This can be a collar, a spot-on or a spray. Make sure that the product is suitable for dogs and contains the active ingredients permethrin or deltamethrin. If in doubt, ask your vet for a suitable product.
• Let your dog sleep in a closed room or under a mosquito net to protect it from sand flies.
• Have your dog tested regularly for leishmaniasis, especially after a trip to a risk area or if you adopt a dog from abroad.

There is also a vaccination against leishmaniasis, but this does not offer 100% protection. The vaccination can reduce the likelihood of infection or mitigate the course of the disease, but not prevent it. The vaccination is only suitable for healthy dogs that are not yet infected with leishmania. The vaccination must be boostered annually. You should discuss with your vet whether a vaccination makes sense for your dog.

How is leishmaniasis treated?

Unfortunately, there is currently no medication that can completely remove the leishmania from the dog's body. The treatment of leishmaniasis therefore aims to inhibit the multiplication of the pathogens and alleviate the symptoms. Treatment is usually lengthy and often has to be continued for life.

The most common drugs used to treat leishmaniasis are

• Allopurinol: This drug inhibits the production of uric acid, which the leishmania need to survive. Allopurinol is usually administered as a tablet and must be given daily. Possible side effects include gastrointestinal complaints or skin rashes.
• Miltefosine: This medication attacks the cell membrane of the leishmania and thus prevents them from multiplying. Miltefosine is administered as a capsule and must be given for several weeks. Possible side effects include vomiting, diarrhea or loss of appetite.
• Glucantime: This medication blocks the metabolism of the leishmania and thus leads to their death. Glucantime is administered as an injection and must be given for several weeks. Possible side effects include pain at the injection site, kidney damage or cardiac arrhythmia.

The choice of medication depends on various factors, such as the stage of the disease, the general condition of the dog or the presence of other diseases. Your vet will recommend the right medication for your dog.

In addition to drug therapy, it is important to support your dog with a special diet. The diet should be easy to digest and low in protein to protect the kidneys. There are special diets for dogs with leishmaniasis that you can feed in consultation with your vet.

What is the life expectancy of dogs with leishmaniasis?

The life expectancy of dogs with leishmaniasis depends on various factors, such as the time of diagnosis, the severity of the disease or the response to treatment. With early and consistent treatment, many dogs with leishmaniasis can lead a normal and happy life. However, they must be regularly examined and treated by a vet to prevent a relapse.

Unfortunately, there are also cases where treatment does not work or is started too late. Leishmaniasis can then lead to severe organ damage or death. In such cases, it is sometimes necessary to make the difficult decision to put the dog out of its misery.