First UK case of dog-to-dog leishmaniosis transmission

Leishmaniosis (also known as leishmaniasis) is an infectious disease caused by the parasite Leishmania infantum, primarily transmitted by sand flies. In the UK, it remains a rare disease because sand flies are not native, but recent cases linked to imported dogs have raised awareness among dog owners and veterinary professionals.

Historically, UK cases have involved dogs infected abroad or through rare incidents such as sand fly larvae hitching a ride on luggage. However, the Royal Veterinary College recently diagnosed the first confirmed case of dog-to-dog transmission within the UK in a dog with no travel history, marking a significant development in understanding disease spread.

What is leishmaniosis in dogs?

This disease can cause a range of immune responses in dogs. Some develop skin reactions while others suffer from a systemic illness affecting organs like the kidneys and spleen, known as black fever. The disease can be difficult to diagnose due to its rarity and variable incubation period, which can extend to several years.

Systemic disease is severe, often leading to kidney failure and organ shutdown, which can be fatal. Skin symptoms may or may not progress to systemic illness.

How is leishmaniosis transmitted in the UK?

While sand fly bites are the primary vector globally, recent veterinary consensus for the UK acknowledges alternative transmission routes:

• Direct dog-to-dog transmission (likely via bites or close contact).
• Sexual (venereal) transmission between infected dogs.
• Vertical transmission from mother to puppy.
• Blood transfusions with infected blood (rare).

This first confirmed UK case of dog-to-dog transmission was unusual, as typical triggers like blood transfusion or bite wounds were not evident. This emphasises the need for vigilance among dog owners, particularly for animals that have travelled abroad or been in contact with such dogs.

It's important to note leishmaniosis is zoonotic, but transmission to humans is extremely rare in the UK due to the absence of sand fly vectors. Prompt veterinary care usually ensures good management for infected dogs.

Recognising leishmaniosis symptoms in dogs

Dog owners should be aware of symptoms to seek early veterinary advice. Signs can include:

• Changes in skin texture and appearance, including sores or lesions.
• Unexplained weight loss and decreased condition.
• Lethargy and reduced activity.
• Increased thirst and urination.
• Vomiting or diarrhoea.
• Nosebleeds or eye inflammation.
• Lameness or discomfort when moving.

Since these symptoms overlap with many other conditions, a prompt vet consultation is crucial to obtain an accurate diagnosis, typically involving blood tests and history regarding travel or contact with other dogs.

Responsible dog ownership and leishmaniosis prevention

Given the emerging transmission potential, these steps can help minimise risks:

• Inform your vet about any foreign travel or contact with travelled dogs.
• Avoid blood transfusions from unknown or untested donors.
• Implement general good hygiene and wound care for your dog.
• If travelling to endemic areas where sand flies are present, use veterinary-recommended insect repellents and consider vaccination as advised by your vet.
• Regular veterinary check-ups help early detection and management.

Responsible ownership also means supporting ethical breeding and sourcing puppies from reputable breeders who perform health checks and screen for infectious diseases.

Next steps for dog owners in the UK

Although leishmaniosis remains uncommon in the UK, this first confirmed dog-to-dog transmission highlights the evolving epidemiology of the disease. Dog owners should:

• Stay informed about leishmaniosis and be vigilant for symptoms.
• Discuss risks with your veterinary surgeon, especially if your dog travels abroad.
• Ensure regular preventative healthcare and parasite control.

This knowledge supports a proactive approach to safeguarding canine health and limits disease spread within the UK.