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.