An outbreak of the disease affecting some dogs in Essex has vets, pet owners and the government very concerned

What is babesiosis?

A malaria-like disease resulting in anaemia in dogs which is caused by single-celled babesia parasites spread by ticks.

Tick-borne disease that can kill dogs will spread in UK, experts warn Read more

What’s happened?

For the first time, an outbreak of babesiosis has occurred in dogs in the UK. At least four dogs in Harlow, Essex, with no history of foreign travel contracted the disease in the past three months. One of the dogs died.

Can humans get babesiosis?

Yes. But the human strain, which is caught by bites from infected ticks, is rare and mainly confined to the US and parts of Europe. The dog strain of the disease caused by Babesia canis is not thought to present a risk to human health. Other pet species such as cats are not thought to be at risk from this species of the babesia parasite.

What is the government doing?

Monitoring the situation. A tick removed from one of the dogs was examined by the Animal and Plant Health Agency. It was identified as Dermacentor reticulatus a tick found in wooded areas of western Europe. It confirmed the presence of the Babesia canis parasite. Government inspectors have examined a field where the infected dogs exercised. In a statement, Public Health England said: “The tick concerned, Dermacentor reticulatus is not a common tick in England, and PHE are monitoring the distribution of this tick across England.”

Is the babesiosis in dogs likely to spread in the UK?

Yes. Experts regard the spread as inevitable and are alarmed at the implications for animal health. Prof Richard Wall, of Bristol University’s biological sciences school, who is leading the largest UK veterinary study of tick-borne disease, said the outbreak was of “huge significance” and a “major concern for animal health”. Clive Swainsbury, a partner at Forest Veterinary Centre in Harlow, which treated three of the infected dogs, said: “The problem in the future is that every female tick will lay a couple of thousand eggs and all those offspring will carry the disease. Even if you do all you can, you are not going to stop the spread of the disease.”

How did the disease spread to the UK?

None of the dogs that contracted the disease had travelled out of the UK. But a relaxation in pet travel restrictions could be why the disease has spread to the UK. It used to be compulsory for imported dogs to be treated for ticks before entering the UK and Ireland. This requirement was dropped in 2012 to comply with EU regulations. Swainsbury, the Harlow vet who first identified the disease in the UK, told the Vet Record: “There has been a marked increase in the number of dogs being rescued from abroad into the area but we are at a loss to know why the requirement to treat dogs for ticks upon entry to the UK was relaxed.” Sean Wensley, president of the British Veterinary Association, said: “The BVA lobbied hard against the relaxing of controls under the EU Pet Travel Scheme, which included removing the requirement for tick treatment to prevent diseases such as babesiosis being introduced into the country, and it is disappointing to see our concerns potentially becoming a reality.”

How are dogs infected?



Bites from ticks carrying babesia parasites infect red blood cells, damaging the cells directly, but also cause the dog’s immune system to attack its red blood cells. This leads to an anaemia which can be life-threatening. A tick typically needs to be attached to a dog for 24-48 hours to successfully transmit the disease.

What are the symptoms of babesiosis in dogs?

They vary, but the main symptoms are: lethargy, weakness, pale gums, jaundice, red/brown urine and fever. Diagnosis is made by examining the blood under the microscope or using specialised genetic tests to detect the parasite’s presence.

How can it be treated?

Treatment is focused on killing the parasite and stopping the dog’s immune system from destroying more red blood cells. In severe cases, dogs may need blood transfusions in animal hospitals.

How can it be prevented?



There are no vaccines for babesia available in the UK. Anti-tick medication can stop the spread of the ticks, and if ticks are physically removed from animals as soon as they are seen then transmission of the parasite can be prevented.

What’s the advice to dog owners?

The BVA recommends that they check pets for ticks after walks. If one is found on the body it should be removed completely using a tick-remover or fine-pointed tweezers, it said. If owners spot suspect symptoms in the dogs, such as weakness, pale gums or “coffee-coloured” urine then they should contact their vet immediately.