Leishmaniasis in Dogs: Symptoms, Diagnosis and Dietary Considerations
Leishmaniasis, more correctly called canine leishmaniosis when discussing the disease in dogs, is one of those conditions that many UK dog owners have never heard of until they adopt a dog from abroad, travel with their dog, or receive a worrying blood test result from their vet.
It is a serious parasitic disease caused most commonly by Leishmania infantum, a protozoal parasite. Dogs are considered the main reservoir host for L. infantum, and infection is usually associated with areas where infected sand flies are present, particularly parts of southern Europe, the Mediterranean, South America, Asia and Africa.
For UK dog owners, the key message is this: leishmaniasis is still uncommon in the general UK dog population, but it is increasingly relevant because of imported dogs and dogs travelling to endemic countries. It should not be a panic diagnosis, but it should be on the radar if your dog has lived in, travelled to, or been imported from an affected area.
What is leishmaniasis in dogs?
Leishmaniasis is caused by microscopic parasites from the Leishmania genus. In dogs, the most important species is usually Leishmania infantum. The parasite is most commonly transmitted through the bite of infected female phlebotomine sand flies. Once inside the body, the parasite lives within certain immune cells and can trigger a complex immune response.
This is one of the reasons leishmaniasis can be so challenging. It is not simply a tummy upset, skin problem or infection that disappears after a short course of treatment. In some dogs, infection may remain silent for months or even years. In others, it can lead to skin disease, weight loss, eye problems, joint pain, anaemia, enlarged lymph nodes and, importantly, kidney damage.
Treatment is available, but it does not always completely clear the parasite. Some dogs remain carriers and may relapse, meaning long-term monitoring is often needed.
How likely is leishmaniasis in dogs in the UK?
For a dog born and living in the UK with no travel history and no close contact with infected imported dogs, leishmaniasis remains unlikely. The UK is not currently considered an endemic country in the same way as many Mediterranean regions.
However, cases are being reported more often in the UK, mainly in dogs that have been imported, rescued from abroad, or travelled overseas. A BSAVA summary of a recent UK study reported that dogs infected with Leishmania infantum have been increasingly reported in the UK, predominantly in imported or travelled dogs. The same study reviewed data from diagnostic laboratories and veterinary practices and found that many UK cases were linked to dogs rescued/imported from, or having visited, countries such as Spain, Greece, Cyprus and other southern European countries.
There have also been rare reports of suspected non-traditional transmission in the UK. The Royal Veterinary College reported a case in a dog with no travel history where dog-to-dog transmission was suspected, and noted that transmission via dog bites and infected blood transfusion has been reported elsewhere.
That does not mean UK dog owners need to panic. It means context matters. A Labrador who has never left Leeds and has itchy paws is far more likely to have allergies, infection, parasites, endocrine disease or another common condition than leishmaniasis. A dog imported from Spain, Greece, Cyprus, Portugal, Romania, Italy or another endemic region who has unexplained weight loss, skin lesions and abnormal blood results should absolutely be tested.
Which dogs are most at risk?
A dog may be at increased risk if they:
were imported from an endemic country
lived abroad before coming to the UK
regularly travels to southern Europe or other endemic areas
has unknown travel history
has lived with or had close contact with an infected dog
received a blood transfusion in a region where screening may not have been robust
was born to an infected dam
Some imported diseases can remain silent for long periods, and for Leishmania infantum, only around half of dogs may have detectable antibodies five months after exposure, with some taking up to two years. This is why follow-up testing may be recommended depending on risk, clinical signs and travel history.
Symptoms of leishmaniasis in dogs
Leishmaniasis can be frustrating because symptoms are often vague and can mimic many other diseases. Some dogs show obvious signs; others may have subtle blood or urine changes before they look unwell.
Common signs can include:
weight loss
lethargy or reduced stamina
poor appetite
skin lesions, scaling, crusting or hair loss
sores around the ears, eyes, nose, feet or pressure points
overgrown or abnormal nails
enlarged lymph nodes
eye inflammation or soreness
nose bleeds
lameness, joint pain or muscle pain
vomiting or diarrhoea
increased thirst and urination
pale gums or anaemia
kidney disease or protein loss through the urine
From a nutritionist’s perspective, the signs that often overlap with diet concerns include weight loss, poor condition, reduced appetite, diarrhoea, vomiting and changes in coat or skin. But this is exactly why guessing is risky. A dog with leishmaniasis does not need a random “immune boosting” diet from the internet. They need veterinary diagnosis, staging, treatment and then nutritional support based on what their body is actually dealing with.
How is leishmaniasis diagnosed?
Diagnosis is not usually based on one symptom or one quick look at the dog. It requires a combination of history, clinical signs, physical examination and laboratory testing.
Your vet may consider:
full travel and import history
clinical examination
blood tests, including haematology and biochemistry
urinalysis
urine protein:creatinine ratio, often called UPC or UPCR
serology, such as ELISA or IFAT antibody testing
PCR testing
cytology or biopsy in some cases
GOV.UK guidance explains that ELISA or IFAT serology can detect IgG antibodies and may support diagnosis when combined with clinical signs and travel history. However, not all dogs seroconvert quickly, so if leishmaniasis is still suspected despite negative serology, other diagnostic methods may be needed. PCR can be used on blood or tissue samples, and cytology or histopathology may directly visualise the organism.
This is also why a negative test soon after import does not always fully rule it out. In some cases, repeat testing is recommended.
Treatment: where diet fits and where it does not
Leishmaniasis is a veterinary condition. Diet cannot cure Leishmania. It cannot replace anti-parasitic medication, monitoring, kidney assessment or veterinary care.
Treatment commonly involves allopurinol alongside another medication such as miltefosine or meglumine antimoniate, depending on the case and what is available. GOV.UK guidance notes that dogs with active infection and clinical signs should be treated with allopurinol in combination with either meglumine or miltefosine.
MSD Veterinary Manual also notes that treatment may not provide a sterilising cure, meaning treated dogs may remain carriers and can relapse. Allopurinol can also be associated with xanthine crystalluria and urolithiasis, which is where diet becomes particularly relevant.
So, diet has three main roles:
Supporting the dog’s overall condition and body weight
Protecting or supporting kidney health where needed
Reducing dietary purines when a dog is on allopurinol, if advised by the vet
Dietary consideration 1: kidney support
Kidney involvement is one of the most important nutritional considerations in leishmaniasis. Leishmaniasis can cause immune-complex kidney disease and protein loss through the urine. MSD Veterinary Manual notes that renal pathological changes may be present in many dogs with leishmaniosis and that proteinuria should be evaluated using urine protein:creatinine ratio alongside other kidney markers.
This matters because “feed more protein to build them up” may be completely inappropriate in some dogs. Equally, automatically restricting protein in every dog with leishmaniasis may also be unnecessary and unhelpful.
The right diet depends on the dog’s staging:
Is there proteinuria?
Is there azotaemia?
Is phosphorus raised?
Is albumin low?
Is the dog losing weight?
Is appetite poor?
Is there concurrent gastrointestinal disease?
Is the dog on allopurinol?
In dogs with confirmed chronic kidney disease or significant renal involvement, a veterinary renal diet may be appropriate. These diets are typically controlled in phosphorus, modified in protein, adjusted in sodium and enriched with omega-3 fatty acids. But they should be used based on veterinary assessment, not because “leishmaniasis always needs a renal diet.”
Dietary consideration 2: low-purine feeding with allopurinol
Allopurinol changes purine metabolism. One known risk is the formation of xanthine crystals or stones. This is why vets may recommend a low-purine diet for dogs receiving long-term allopurinol.
Low-purine feeding usually means limiting foods naturally high in purines, such as:
organ meats, especially liver, kidney and spleen
oily fish such as sardines and anchovies
some seafood
game meats
yeast extracts
high quantities of certain legumes
high-meat, organ-heavy raw diets
This is where many well-meaning owners can accidentally create problems. A dog with leishmaniasis may be given extra liver, sardines, bone broth, “immune” powders, yeast-based supplements or raw organ mixes because the owner is trying to help or encourage an increased appetite. But if that dog is on allopurinol, those choices may not be suitable.
A low-purine diet does not mean a poor-quality diet. It means choosing protein sources and formulations that reduce purine load while still meeting the dog’s essential nutrient needs.
Dietary consideration 3: maintaining weight and muscle
Some dogs with leishmaniasis lose weight or muscle. This may be due to reduced appetite, kidney disease, gastrointestinal signs, medication side effects or feeling generally unwell.
The goal is not simply to “feed more.” The goal is to feed appropriately.
Useful strategies may include:
feeding smaller, more frequent meals
choosing a complete food for lifestage with suitable calorie density
warming food to improve aroma
using veterinary-approved toppers if appetite is poor
monitoring body weight weekly during unstable periods
assessing muscle condition, not just body weight
avoiding excessive treats that unbalance the diet
checking whether nausea, pain or kidney disease is affecting appetite
If the dog has diarrhoea or vomiting, a highly digestible gastrointestinal diet may be needed temporarily. If there is kidney disease, renal support may take priority. If allopurinol is being used, purine control may be important. This is why leishmaniasis nutrition is rarely a one-size-fits-all plan.
What about “immune-boosting detox” diets and supplements?
This is where I would be very careful.
Leishmaniasis is heavily influenced by the immune system, but that does not mean owners should throw every immune supplement, mushroom blend, herbal detox or homemade recipe at the dog.
The immune system does not need to be randomly “boosted.” It needs appropriate veterinary management, adequate nutrition, controlled inflammation where possible and careful monitoring. Some supplements may interact with medication, affect the kidneys, add unnecessary purines or simply waste money.
A good diet for a dog with leishmaniasis should be:
complete and balanced
appropriate for kidney status
suitable for medication use
digestible
realistic for the owner
monitored alongside blood and urine results
Can leishmaniasis be prevented?
For dogs travelling to endemic areas, prevention focuses mainly on reducing sand fly bites. GOV.UK advises that sand fly repellent is very important for dogs travelling to endemic areas, and vaccination to reduce clinical disease can be considered, although vaccines do not prevent infection and vaccinated dogs may test positive on serology.
Preventive steps may include speaking to your vet about:
licensed sand fly repellent products
avoiding outdoor sleeping in endemic areas
keeping dogs indoors from dusk to dawn where sand flies are active
travel-related disease screening
testing before and after travel
vaccination where appropriate
ESCCAP also highlights the importance of sand fly repellents for travelling pets to reduce Leishmania transmission risk.
When should you speak to your vet?
Speak to your vet if your dog has lived in or travelled to an endemic area and develops unexplained:
weight loss
skin lesions
persistent lethargy
enlarged lymph nodes
eye problems
nose bleeds
lameness
increased thirst or urination
abnormal blood or urine results
Also speak to your vet if you are adopting or have recently adopted a dog from abroad. Testing immediately after import may be useful, but repeat testing may also be required because antibody responses can take months or even longer to become detectable.
Final thoughts from The Canine Dietitian
Leishmaniasis in dogs is not something to ignore, but it is also not something UK owners need to panic about without context. In the UK, it is mainly a concern for imported dogs, travelled dogs, and dogs with relevant exposure history.
The most important thing is proper diagnosis. Skin problems, weight loss, diarrhoea and poor condition can have many causes. Diet can support a dog with leishmaniasis, but it cannot replace veterinary treatment.
The right nutritional plan depends on the individual dog: their kidney values, urine protein levels, medication, appetite, body condition and clinical signs. Some dogs may need renal support. Some may need low-purine feeding because of allopurinol. Some may need help maintaining weight. Some may simply need a complete, consistent, digestible diet while their vet manages the disease.
Balanced nutrition matters, but with leishmaniasis, it must sit alongside veterinary diagnosis, treatment and monitoring — not in place of it.
Reference links
BSAVA: recent trends in canine leishmaniosis in the UK
GOV.UK: imported disease summaries for dogs and cats, including diagnosis, treatment and prevention
MSD Veterinary Manual: leishmaniosis in dogs
Langford Vets: recommended testing for imported dogs
Royal Veterinary College: UK case and transmission discussion
