The Blog

Canine Babesia Infection Spreads: How Concerned Should UK Dog Owners be?

Matilda Delves via Getty Images

Babesia canis is a protozoan parasite that lives inside certain species of ticks and can infect a dog when the tick bites. This leads to the clinical signs of 'babesiosis': lethargy, anaemia (pale gums), fever, very dark urine and even death.

In March, five cases of Babesia canis were reported in dogs living around Harlow in Essex. This created a media storm and as a vet myself, I saw a surge in worried dog owners with questions regarding ticks.

Last week, two new cases of Babesia canis were reported in Romford, also in Essex. Surprisingly, this seems to have fallen slightly 'under the radar'.

In the UK, canine babesiosis has been confirmed in the past. Whilst concerning, those cases have been isolated to dogs that have travelled abroad (babesiosis is endemic in many overseas countries). Therefore, until now, we have assumed the UK itself is relatively 'Babesia free'. However, the concern specifically with the dogs in Essex is that they have never travelled abroad.

In the majority of cases, babesiosis is contracted via a tick bite. Other routes of transmission are possible, for example through the placenta from mother to unborn puppy or through direct blood contamination from fight wounds.

However, in dogs that have never travelled, it makes sense to assume that the most likely route of transmission must have been via a tick bite.

And so here lies the concern.

Public Health England and the APHA, alongside various veterinary tick specialists, have isolated the protozoan parasite Babesia canis within the species of tick Dermacentor reticulatus on UK soil.

Where are these ticks coming from?

The 'Big Tick Project' was conducted in response to the changing distribution of tick vectors and the incidence of tick borne diseases. The results have now been published and it makes for some interesting reading.

Ixodes ricinus is still the most common tick species in the UK, accounting for nearly 90% of the ticks found. However, interestingly 10 dogs (0.17%) were found with Dermacentor reticularis (the species of tick that could potentially carry Babesia canis).

There is no doubt that the distribution of these tick vectors has moved. Many factors play a part in the changing global distribution of these ticks, for example climate change.

However, another important factor is the huge increase in the movement of animals between the UK and overseas under The Pet Travel Scheme.

What may surprise a lot of pet owners is that the Pet Travel Scheme protects human health, not the health or wellbeing of the pet.

Take for example, the current outbreak of Babesia canis. The parasite can only survive in dogs and therefore poses zero risk to humans. The Pet Travel Scheme, in this respect, has fulfilled its duty (despite being partly to blame for the introduction of this canine disease).

The rules to travel under the Pet Travel Scheme have also become increasingly relaxed and the previously compulsory tick treatment required to re-enter the UK was abolished in 2012.

Interestingly, there has been a report this week that a dog has entered the UK from Portugal with a species of tick attached, Hyalomma lusitanicum. The major concern is that this tick has the potential to carry a fatal human disease called Crimean-Congo haemorrhagic fever virus (CCHFV). This specific tick was tested and found to be disease free. But this is the first known record of this tick in the UK. Perhaps the Pet Travel Scheme is not quite so protective of human health after all?

It probably isn't fair to blame the outbreak of Babesia canis entirely on the Pet Travel Scheme or the relaxation of the rules (dogs ideally need to be protected against ticks before, during and post travel and not just on their return).

However, according to Professor Richard Wall, deputy head of The School of Biological Sciences at the University of Bristol 'the relaxation (of The Pet Travel Scheme) has increased the rate of entry of exotic ticks'.

The risk of travelling abroad with your pet does not stop with ticks. This week The Veterinary Times has reported that UK 'vets are seeing an increasing number' of cases of the disease Leishmania infantum in dogs that have travelled to countries where the vector, a species of sandfly, is present. The disease is not endemic in our country. However, the increased number of cases reflects the increased movement and vulnerability of pets travelling under The Pet Travel Scheme.

So what is the real time risk of Babesia canis to you and your dog? We know the risk to human health is zero. The same applies for our cats. Babesia canis is species specific and so will only survive in dogs.

The risk to your dog, however, is harder to pinpoint. The conclusion of the Big Tick Project is that Babesia canis is now 'well established in the UK' and according to Professor Richard Wall, Babesia canis is 'very likely to spread further'.

Geographic location will impact but as a general rule the risk of contracting Babesia canis from a tick bite is still probably 'quite low'. However that is not much consolation if your dog contracts babesiosis.

The advice from top veterinarians is that prevention of babesiosis in the UK is currently better than cure.

The year round use of a veterinary licensed, anti-parasite product to repel and kill ticks combined with the prompt, appropriate removal of any attached ticks will reduce the risk of disease in our own dogs.

There are currently no compulsory diagnostic tests for leishmaniasis prior to entry to the UK. The onset of clinical signs can be delayed, leaving owners unaware their travelled pet or imported rescue dog has contracted the disease until after they have returned home.

In all cases, owners planning to travel abroad with their dog should pay serious consideration to the risks, referring to ESCAPP for advice and taking relevant anti-parasite precaution beyond the regulations of the Pet Travel Scheme.

As a dog owner and vet, my concern is that this is just the 'tip of the iceberg' for Babesia canis cases in the UK. However, through continued investigation into the ecology and behaviour of the tick vector, and with owner education on tick prevention, we can help protect against the further spread of this potentially fatal canine disease.