Chronic lymphocytic leukaemia in dogs: Symptoms, diagnosis & care

Chronic lymphocytic leukaemia (CLL) is a slowly progressing cancer of the lymphocytes, a type of white blood cell involved in the immune system. It is the most common form of leukaemia in dogs and predominantly affects mature, non-functional lymphocytes, usually from cytotoxic T cells (CD8+). Although rare compared to other cancers, CLL is serious and requires a long-term management approach to maintain quality of life.

The condition typically develops gradually, often without clear early symptoms, meaning it is commonly diagnosed in more advanced stages. This article provides a detailed guide to CLL in dogs, including what the disease is, risk factors, symptoms to watch for, diagnosis procedures, treatment options, and how to care for your dog if affected.

Understanding Chronic Lymphocytic Leukaemia in Dogs

CLL causes an abnormal accumulation of mature lymphocytes in the bone marrow and spleen, leading to high lymphocyte levels in the bloodstream. This results in enlarged lymph nodes and spleen, anaemia, and low platelet counts, which impair your dog's immune response and blood health.

German shepherd puppies have been observed to have a slightly higher prevalence of CLL, alongside various small and toy breeds. The exact cause of CLL is not fully understood but is believed to involve genetic mutations, as certain breeds are more commonly affected, though no definitive hereditary link has been confirmed.

Which Dogs Are Most at Risk?

CLL is generally diagnosed in older dogs, especially males. Small and toy breeds are at a higher risk, but the large German shepherd breed also shows a noticeable rate of cases. Regardless of breed, any dog can develop this disease, highlighting the importance of regular veterinary checks as dogs age.

Recognising the Symptoms of CLL

Spotting the early signs of CLL can be difficult due to its subtle onset. Many dogs show no symptoms until the disease progresses significantly. When symptoms do appear, they may include:

• Increased thirst and urination
• Enlarged lymph nodes and spleen
• Slightly raised temperature
• Easy bruising and slow healing of wounds
• Reduced appetite, low activity, and decreased alertness

Blood tests conducted by your vet may reveal lymphocytosis, anaemia, and low platelet counts, assisting in diagnosis alongside clinical signs.

Diagnosis and Monitoring

Diagnosis relies on comprehensive blood and urine analyses, bone marrow examination, and imaging techniques like X-rays or ultrasounds to assess organ involvement. Immunophenotyping through flow cytometry helps identify the lymphocyte subtype, crucial for prognosis and treatment planning.

Regular blood tests and physical examinations are essential, especially for senior dogs, to detect abnormalities early and monitor disease progression.

Treatment Options for Canine CLL

CLL is considered incurable but manageable. Treatment is often deferred until clinical signs emerge or lymphocyte counts rise above critical levels. When initiated, a combination of oral chemotherapy drugs such as chlorambucil and corticosteroids like prednisone is standard. These medications can be administered at home, reducing stress for your dog.

Additional chemotherapies such as vincristine or cyclophosphamide may be used if needed. In some cases, surgical removal of an enlarged spleen may be considered.

While chemotherapy does not cure CLL, it achieves remission and symptom control, often extending your dog's lifespan by years with good quality of life. Continuous monitoring allows your vet to adjust treatment based on your dog's response.

Supporting Your Dog With CLL

Providing supportive care is vital to help your dog maintain comfort. Ensure a balanced, nutritious diet suited to their needs, manage any infections promptly with veterinary guidance, and avoid unnecessary stress or strenuous exercise. Keep a close eye on any changes in symptoms and maintain regular veterinary visits.

Common Questions About CLL in Dogs

Is CLL hereditary in dogs?

No definitive hereditary cause has been confirmed, but certain breeds like German shepherds and small/toy breeds appear more frequently affected, suggesting a possible genetic predisposition yet to be clearly identified.

What is the prognosis for dogs with CLL?

With appropriate treatment and monitoring, many dogs live around two years post-diagnosis, sometimes longer, enjoying a reasonably good quality of life. The disease can remain stable for extended periods before advancing.

Can CLL be cured?

Currently, CLL is incurable, but long-term management with chemotherapy and supportive care can control the disease effectively.

Conclusion

Chronic lymphocytic leukaemia in dogs is a serious but slow-progressing cancer that primarily affects older dogs. Understanding the subtle symptoms, ensuring early veterinary detection, and following a consistent treatment and care regimen can greatly improve your dog's well-being and life expectancy. If you suspect your dog may have CLL or want to understand how to care for senior dogs better, consult your vet for personalised advice.

For those looking to add a new dog to the family, always seek reputable breeders or responsible adoption options to support ethical and healthy canine ownership.