What is Babesia Canis? Risks, Symptoms & Treatment Guide

Babesia Canis is a protozoan parasite that causes a serious disease primarily affecting dogs. Traditionally observed in mainland Europe, Babesia Canis has now been identified in the UK, with cases in dogs that have not travelled abroad, suggesting local transmission is occurring. This article explains what Babesia Canis is, its symptoms, diagnosis, treatment options, and how to manage the risk to your dog here in the UK.

How is Babesia Canis transmitted to dogs?

Babesia Canis is spread mainly through tick bites, with the tick species Dermacentor reticulatus, known as the marsh tick, being the principal carrier in Europe and likely in parts of the UK. Ticks feed on infected dogs and can transmit the parasite to other dogs when they feed for several days. Importantly, ticks do not suffer from the disease themselves, but they act as vectors, passing the parasite along. Recent research has also looked into wild animals like deer and foxes as potential reservoirs carrying infected ticks in the UK.

Transmission occurs when an infected tick attaches to a dog for around three to seven days, during which the parasite enters the bloodstream. Prompt removal of ticks within three days can significantly reduce the risk of infection.

What are the signs and symptoms of Babesia Canis in dogs?

Babesia Canis attacks and destroys red blood cells, leading to anaemia. The severity of symptoms depends on factors such as the dog's age and immune system health. Young dogs seem more susceptible. Some dogs may have no obvious signs, but typical symptoms resulting from anaemia include:

• Very pale gums
• General lethargy and sickness
• Increased respiratory rate
• Loss of appetite
• Blood-tinged urine, causing it to appear red

When examined by a vet, dogs may also have elevated heart rates and body temperatures. Some severe cases can cause the destruction of red blood cells to outpace bone marrow production, worsening the anaemia.

How is Babesia Canis diagnosed by a vet?

Diagnosis primarily involves blood tests. A blood smear examined under a microscope may reveal the parasite inside red blood cells. However, low parasite numbers can make detection challenging. Therefore, polymerase chain reaction (PCR) tests, which detect Babesia DNA, provide a more sensitive diagnostic tool, especially for chronic or mild cases.

Blood tests also assess the degree of anaemia and can detect antibodies indicating past exposure. A positive PCR test combined with clinical signs and history, especially in UK-based dogs without travel history, strengthens the diagnosis.

What treatments are available for Babesia Canis?

Currently, there is no definitive cure preventing Babesia Canis from persisting for life in infected dogs. Treatment aims to reduce the parasite load and manage clinical symptoms. The standard therapy involves two doses of imidocarb dipropionate injections, given two weeks apart. In severe cases, supportive care such as intravenous fluids or blood transfusions may be necessary. About 90% of dogs respond well to treatment, though some may suffer relapses if their immune system becomes compromised.

How can I protect my dog from Babesia Canis?

Prevention focuses on effective tick control. Prescription-strength tick treatments from your vet provide the best protection, especially for dogs travelling abroad or those living in tick-prone areas. Early detection and removal of ticks within three days can dramatically reduce transmission risks.

The UK veterinary community endorses regular tick surveillance and public awareness initiatives to help manage tick-borne diseases effectively. Routine veterinary check-ups and professional advice on tick prevention products are vital components of responsible pet ownership.

Final thoughts

Babesia Canis is an emerging concern for dog owners in the UK due to the arrival of infected ticks and possible wild reservoirs. Recognising the signs early, seeking prompt veterinary care, and maintaining regular tick prevention can minimise risks to your dog. Be vigilant, especially if your dog visits marshy or rural areas, and always consult your vet with any health concerns.