Babesiosis in Dogs: a Complete Guide to Symptoms and Treatment

If you’ve come across the intriguingly named condition ‘babesiosis’ in dogs and want to learn more about this infection, you’re in the right place. It’s a serious condition, but one that vets understand well and can treat, especially when it’s caught early.

Babesiosis is a tick-borne disease UK vets are now more aware of than ever before, particularly following localised outbreaks in areas such as Essex, Kent and parts of Devon in 2016. While it’s still relatively uncommon in the UK, it can progress quickly and make a dog very unwell. 

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The key is spotting the signs and acting fast. Understanding what to look for and getting veterinary advice promptly can make a big difference. Read on to find out more about babesiosis in dogs, how it affects them and what you can do to keep your dog safe.

What is babesiosis in dogs?

In the UK, babesiosis is an infection caused by a parasite called Babesia canis. It is most commonly spread through tick bites. Once inside your dog’s body, the parasite enters the red blood cells and multiplies, eventually causing those cells to burst.

Red blood cells are responsible for carrying oxygen around the body. If too many are destroyed faster than the body can replace them, your dog develops something called haemolytic anaemia. This means anaemia caused by red blood cell destruction. When this happens, the body’s tissues don’t receive enough oxygen, and dogs can become weak and unwell. In more serious cases, the illness can affect organs and interfere with normal blood clotting.

In simple terms, babesiosis is a tick-transmitted infection that damages your dog’s red blood cells. Without treatment, it can escalate quickly, but with early veterinary care, many dogs recover well.

Is babesiosis common in the UK?

The good news is that babesiosis is relatively uncommon in the UK. However, it is no longer considered an imported disease. Local transmission has been confirmed in parts of southern England and Wales.

In 2016, several dogs in Harlow, Essex, were diagnosed without any history of travel. According to the Animal and Plant Health Agency (APHA) and the UK Health Security Agency (UKHSA), these cases were linked to the tick species Dermacentor reticulatus.

This tick species is now known to exist in:

• Essex (including Harlow)

• Coastal Kent

• Parts of Devon

• Areas of Wales

While overall numbers remain low, the presence of Dermacentor reticulatus means babesiosis in dogs is a genuine, though still relatively rare, risk in specific regions. For most UK pet parents, the risk is small. For those in known tick areas, awareness is important.

How do dogs get babesiosis?

Dogs usually develop babesiosis after being bitten by an infected tick, most commonly Dermacentor reticulatus in the UK. The parasite enters the bloodstream during tick feeding.

Ticks attach and feed on blood. If the tick carries Babesia canis, it can transmit the parasite into your dog’s circulation. Transmission typically requires several hours of attachment.

High-risk environments include:

• long grass

• marshland and coastal paths

• woodland

• areas with deer or livestock

Babesiosis is not spread through normal dog-to-dog contact. It is a vector-borne disease, meaning the tick acts as the carrier.

In rare cases, infection can also occur through blood transfusions, dog bites involving blood-to-blood contact, or from an infected pregnant dog to her unborn puppies. The most effective way to reduce risk is through consistent use of a veterinary-recommended tick preventative and checking your dog carefully after walks, especially in high-risk areas. Early tick removal significantly lowers the chance of transmission.

Signs and symptoms of babesiosis in dogs

Babesiosis primarily causes anaemia by destroying red blood cells. The most common signs seen in dogs are linked to anaemia, as well as the inflammation and strain it places on the body and vital organs.

Early symptoms can look vague at first. Many pet parents describe their dog as being “just not themselves.”

Common early signs include:

• lethargy

• reduced appetite

• fever

• pale gums (this is a key early warning sign)

• weakness

As more red blood cells are destroyed, pet parents may notice:

• dark urine (red or tea-coloured urine)

• jaundice (yellowing of gums or eyes)

• rapid breathing

• collapse in severe cases

The breakdown of red blood cells releases a protein called haemoglobin, which contributes to dark urine and jaundice. Some dogs deteriorate rapidly and require emergency treatment. If a dog is seen to have any of the signs listed above, or there is any rapid change in their demeanour, particularly in areas where babesiosis is known to occur, it’s important to seek veterinary advice without delay.

Diagnosis and vet treatments for babesiosis

Early diagnosis is very important, as it can significantly improve survival and help prevent serious complications from developing.

If your vet suspects babesiosis, they will typically carry out the following:

• Full physical examination: this is to check your dog’s general condition, hydration status, and vital signs. 

• Blood tests: this gives important information about the severity of anaemia and how well the liver, kidneys and other organs are functioning. 

• Blood smear: this involves looking at a small sample of red blood cells under a microscope to see if the parasites are present. 

• PCR test: this is used to confirm the presence of Babesia DNA, providing a highly sensitive and specific diagnosis that can guide treatment decisions. The Vet Times reports that PCR testing is the most sensitive way of diagnosing the infection.

By combining the steps above, vets can identify babesiosis early, monitor how it is affecting the body, and start treatment as soon as possible, giving your dog the best chance of a full recovery.

Babesiosis treatment

In the UK, treatment typically involves imidocarb dipropionate, given by injection. As outlined by the Veterinary Medicines Directorate (GOV.UK), this medication is often prescribed under the Cascade system, which allows vets to use appropriate medications when no specific UK-licensed product exists for that exact condition.

Supportive care is also very important and usually includes:

• Intravenous fluids.

• Pain relief.

• Monitoring clotting function.

• Hospitalisation in more severe cases.

If anaemia is severe, a blood transfusion may be necessary to stabilise oxygen delivery. Many dogs respond well to treatment when started early. Prognosis depends on how quickly therapy begins and whether complications such as kidney injury or clotting disorders develop.

How to prevent babesiosis in dogs

The best way to prevent babesiosis is to focus on reducing tick exposure and using effective tick control products.

If you live in or travel to areas where Dermacentor reticulatus is present, year-round tick prevention is advisable.

Prevention steps include:

• Using a vet-recommended tick preventative.

• Checking your dog thoroughly after walks.

• Removing ticks promptly with a tick twister tool.

• Avoiding high-risk habitats when possible.

Managing tick exposure in known regions is currently the most effective strategy for reducing local transmission. It is important for pet parents to remember that prevention is far easier and far less stressful than treating the infection in the advanced stages.

Bottom line: babesiosis in dogs

Babesiosis in dogs is a serious tick-borne disease, but the good news is that it can be treated. Pet parents, particularly in southern England and Wales, should be aware of the warning signs. If you notice pale gums, yellowing of the eyes or gums, or dark-coloured urine, it’s important to seek veterinary care straight away. With early diagnosis and treatment, many dogs make a full recovery. Staying vigilant, preventing tick bites, and acting quickly if something seems wrong are the best ways to keep your dog safe

Frequently asked questions: babesiosis

If you’re worried about babesiosis, these are some of the most common questions pet parents ask.

Can humans get babesiosis from dogs?

No, dogs cannot pass babesiosis directly to people. The species of Babesia that infects dogs is different from those that cause the disease in humans, so there’s no direct risk of catching it from your pet. That said, ticks can bite humans as well as dogs, which means good tick prevention is important not just for your dog’s health, but also for the safety of everyone in your home. Protecting your dog with regular tick checks, appropriate repellents, and preventive treatments helps reduce the risk of tick-borne infections for the whole family.

Will my dog fully recover?

Many dogs make a full recovery from babesiosis, particularly when treatment is started early. The overall prognosis depends on how severely the parasite has affected the red blood cells and whether any complications, such as organ stress or secondary infections, have developed. Even dogs that are very unwell or require a blood transfusion can still recover well, provided they receive prompt and appropriate veterinary care. Close monitoring, supportive treatment, and following your vet’s advice can make a big difference, giving your dog the best chance to return to their normal, happy self. 

References

Tappin, Simon, ‘Tackle Ticks: Babesiosis’. Vet Times, vettimes.co.uk, 2016.

Animal and Plant Health Agency, and Department for Environment, Food & Rural Affairs. “Babesia Canis.” Defra, gov.uk, 16 Apr. 2016, www.gov.uk/government/publications/babesia-canis.

de Marco, Maria del Mar Fernández, et al. “Emergence of Babesia Canis in Southern England.” Parasites & Vectors, vol. 10, no. 1, May 2017, https://doi.org/10.1186/s13071-017-2178-5.

Hall, Gavin. ‘Imidocarb: Summary of Product Characteristics’. Defra, gov.uk, 20 May 2025. Accessed 26 Feb. 2026.

Marshall, Claire, ‘Dog owners warned about new tick disease.’ BBC News, bbc.co.uk, 16 March 2016.

Veterinary Medicines Directorate. “Treatments for Babesiosis in Dogs.” gov.uk, 13 May 2016. Accessed 26 Feb. 2026.

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