Leishmaniosis In Dogs
Written by Shula Berg BVSc CertAVP(GSAS) GPAdvCert(SASTS) MRCVS
Clinically reviewed by Elizabeth McLennan-Green BVM&S CertAVP(SAM) MRCVS
Table of Contents
- Introduction
- Symptoms
- Diagnosis
- Treatment
- Prevention
Leishmaniosis is an infection caused by the protozoal parasite, Leishmania. Leishmaniosis is a zoonotic infection, which means it can be transferred to humans as well as other mammals. Although human infection is very rare, it is potentially serious.
The parasite which causes Leishmaniosis is spread by sand-flies. Due to our climate, the species of sand-fly known to spread Leishmania is not found in the UK. Cases of Leishmaniosis were considered very rare in the UK. However, in recent years, cases have increased significantly. This is due to the increase in pet travel and importation of foreign dogs; in countries where the sand-fly is common, up to 60% of dogs can carry the Leishmania parasite. Almost all reported cases of canine Leishmaniosis in the UK have been in dogs who have travelled. However, there have been cases of infection in non-travelled dogs thought to be transmitted within the UK via dog bite.
European countries in which canine Leishmaniosis is endemic (known to exist within the population) include the following:
- France
- Spain
- Portugal
- Italy
- Greece
- Cyprus
- Malta
- Bulgaria
- Romania
- Ukraine
Leishmaniosis is also found widely across Africa, Asia, and South and Central America.
What are the symptoms of Leishmaniosis?
Leishmaniosis can cause a wide variety of symptoms, and not every infected dog will show clinical disease. Symptoms include skin lesions, eye problems, nosebleeds, weight loss, lethargy, swollen lymph nodes, abnormal nail growth, kidney failure, increased thirst and urination, vomiting, diarrhoea, lameness and anaemia.
Due to the variety of possible symptoms, there is no single typical presentation of Leishmaniosis, though 80-90% of affected dogs will experience skin lesions. Skin lesions can vary in appearance but often affect the face, especially the skin surrounding the eyes. Other symptoms are often present in combination.
Which tests are used to diagnose Leishmaniosis?
Testing for Leishmania is not a requirement to import dogs to the UK, and most cases become unwell months or even years after travel. Due to the wide variety of symptoms, even if Leishmaniosis is suspected at initial presentation, the first step in diagnosis is general blood tests to look for other (more common) causes of clinical signs, as well as to assess general systemic health. In Leishmaniosis, general blood tests will often show very high protein levels as well as elevation in kidney markers. Anaemia (low red blood cell count) may be present, sometimes in combination with thrombocytopenia (low platelet count).
Due to the prevalence of kidney disease caused by Leishmaniosis, a urine sample is often checked to better assess kidney function.
Specific tests must be performed to identify the Leishmania parasite. These can be performed on blood tests, or on samples from the organs, lymph nodes or skin lesions. Identification of the parasite provides a definitive diagnosis.
How is Leishmaniosis treated?
Unfortunately, it is extremely rare to eliminate Leishmania infection in dogs. Medication can be used to manage the symptoms, but it is very likely that dogs will remain infected. The aim of treatment is to resolve clinical signs, although relapses may occur. Usually, two different medications are used in combination, and may be given short or long term. As Leishmaniosis is not common in the UK, there are no licensed veterinary treatments. This means that human medications are used and sometimes the correct drugs need to be imported. This can make treatment very expensive.
Many dogs will respond well to treatment, and can be managed successfully for many years. Treatment is rarely administered for life to prevent drug resistance occuring, and is typically stopped when blood tests show good control. Due to persistent infection, relapses can happen and will require treatment to be resumed. In cases where the parasite has damaged kidney function, this is likely to be progressive and not reversed by medication.
How can Leishmaniosis be prevented?
The best prevention is avoidance – dogs who do not leave the UK have minimal risk of contracting Leishmaniosis. If travel cannot be avoided, parasite products are available that repel the sand-flies that spread Leishmania. These include spot-on treatment and collars, but are usually different to the products used routinely in the UK. If you are planning on travelling with your dog, speak to the practice about the best products to use.
Two Leishmaniosis vaccines are licensed in the UK. These do not prevent infection completely, but can reduce the likelihood of infected dogs becoming unwell. They are only suitable for dogs who are not already infected. Vaccines are only recommended for dogs spending a significant amount of time in affected areas, and should be used in combination with a product to repel sand-flies.
Disclaimer
Please note that the content made available on this webpage is for general information purposes only. Whilst we try to ensure that at the time of writing all material is up to date and reflects industry standards, we make no representation, warranties or guarantees that the information made available is up to date, accurate or complete. Any reliance placed by yourselves is done so at your own risk.
Page last reviewed: 19th April 2024
Next review due: 19th April 2026