The information below was kindly supplied by Ian Wright BVMS, MSc, MRCVS

Babesia canis Background

Babesia canis is a parasite of canine red blood cells and a cause of potentially fatal haemolytic anaemia in dogs. Babesia canis canis is the most pathogenic sub species with Babesia canis vogeli causing less severe disease and currently limited to Southern Europe. B.canis canis infection occurs when the parasite is transmitted in the saliva of feeding Dermacentor reticulatus ticks, and occurs a few days after infected ticks bite. Infection has been acquired through blood transfusions but tick bites remain the source of infection in the vast majority of cases. The distribution of Babesia canis canis is therefore closely linked with its vector, D.reticulatus. Although until this year, the UK was thought to be free of B.canis canis, D.reticulatus is present in pockets across the South of England including Wales, Devon and Essex and this has raised concerns about the possibility of B.canis canis being introduced to the UK. There is potential for this to occur when infected dogs arrive in the UK from abroad or carry infected Dermacentor ticks from countries where the infection is already present. The increasing spread of D.reticulatus across Europe and increasing numbers in France, where many UK residents take their pets on holiday, combined with the increasing numbers of people taking their dogs on holiday year on year, means that the risk of B.canis canis establishing in the UK has been growing. These concerns were realised in February 2016 when B.canis canis was reported in three dogs from Harlow, Essex, with a fourth rapidly following in March. The dogs had not travelled abroad and testing confirmed ticks found on the infected dogs to be Dermacentor reticulatus infected with B. canis canis. This suggests that B.canis canis is now established in Essex and this pocket of infection is likely to spread. Dog owners in Essex therefore, particularly in Harlow, as well as in adjoining counties and counties known to have populations of D.reticulatus, need to be aware of the potential for B.canis canis transmission and the clinical signs of disease.

It takes at least 24 hours for B canis to be transmitted, so owners should check their dogs daily for ticks and remove any with a tick hook.

Babesia canis Clinical signs

Infection can lead to red cell destruction and immune mediated disease, resulting in anaemia, jaundice, enlarged lymph nodes, potential secondary organ failure and in severe cases, death. It takes at least 24 hours for B canis to be transmitted, so owners should check their dogs daily for ticks and remove any with a tick hook.

Babesia canis diagnosis

Diagnosis can be achieved by demonstration of the parasite in peripheral blood smears stained with Giemsa or Diffquick®. The parasite presents as piriform (pear shaped) organisms, often paired, in the red blood cell. PCR on blood is a sensitive alternative and allows speciation of the parasite but can take up to 7 days for completion. Serology can indicate current or recent infection but there can be cross reactivity with other closely related protozoa such as Toxoplasma gondii and Neospora caninum.

Dermacentor reticulatus tick

Babesia canis Treatment

Treatment consists of supportive treatment for anaemia and treatment for the parasite. Blood transfusion may be required if PCV drops below 15% and steroids may be used if PCV is slow to respond to treatment. An anti-parasite treatment (Imidocarb) given by 2 intramuscular injections given 2 weeks apart is considered the most effective treatment for infection but high strength oral antibiotics (clindamycin) also has some effect. The injection is painful and may lead to vomiting. Anticholinesterase effects such as increased tear production, salivation and restlessness may also be seen but these can be counteracted with atropine. Chances of recovery are improved if clinical cases are detected early and prognosis depends on the severity and duration of the clinical signs.

Treatment rarely completely eliminates the parasite, leaving infected dogs as low level sub clinical carriers. This needs to be born in mind as infected dogs may have subsequent relapses and act as potential reservoirs of infection. Preventative products on dogs that have had previous infection and monitoring for ticks is important to reduce the risk of spread of further infection.

Babesia canis Prevention

Tick treatment products that rapidly kill or repel and kill ticks will reduce the risk of transmission of babesiosis. No tick preventative product is 100% however, so it is important for pet owners to be vigilant and check for ticks on their pets every day, removing any ticks with a tick hook such as the tick twister remover. It is important to remove ticks without stressing them and without leaving the mouthparts in situ. A simple “twist and pull action” is required. This can also be performed with tweezers but with a straight pull upwards as rotation with tweezers may break off mouthparts. They should be fine pointed and not blunt as crushing will stress the tick, causing it to regurgitate and increase the risk of disease transmission. Traditional techniques to loosen the tick such as the application of petroleum jellies, freezing or burning will also increase this likelihood and are contra indicated. It takes at least 24 hours for B canis to be transmitted, so owners should check their dogs daily for ticks and remove any with a tick hook.

Dermacentor reticulatus tick
Courtesy of
John McGarry, University of Liverpool

What to do with ticks once removed

Removed ticks should either be killed or sent for identification. If killed, they should not be crushed as release of stomach contents into the environment may spread pathogens. Identification and recording of ticks across the country is important to map their distribution, and in identifying potential tick borne diseases that may be passed to dogs or owners.

If sending for identification:

Please carefully package live ticks so that there is no danger of them escaping or posing any risk to mail handling staff if the package becomes damaged during transit.

When posting ticks, please make sure that you:

  • Use a crush-proof, plastic container (eg, an old camera film case) that is securely fastened with tape; alternatively, a screw-top plastic vial can be supplied on request to the address below
  • Post the container in a padded envelope with a visible return address
  • Mark the package as ‘urgent – live creatures’
  • Include a completed recording form (see The Gov.UK website)

Send to:

Tick surveillance scheme
Public Health England
Porton Down

Wiltshire
Salisbury
SP4 0JG

PHE provide identification of specimens within 2 weeks of receipt (during exceptionally busy times, this may be longer). We will notify you of the identification results if you provide your email address.

Samples should ideally be unfed or only partially fed as features on the scutum and festoons may be partially obscured by engorgement. Tick surveillance forms and further information can be obtained from The Gov.UK website

Dermacentor reticulatus tick
Courtesy of
John McGarry, University of Liverpool