Dog with skin rash surrounded by chemotherapy pills, representing Canine Lymphoma treatment.

Is Lomustine the Right Choice for Your Dog's Cutaneous Lymphoma? What You Need to Know

Beau Callahan in Health & Wellness August 2025 • 4 min read.

"A comprehensive look at the effectiveness and side effects of lomustine (CCNU) in treating canine cutaneous lymphoma, helping you make informed decisions about your pet's care."

Finding out your dog has cancer is devastating. Cutaneous lymphoma, a rare skin cancer in dogs, presents unique challenges. While various treatments exist, lomustine (CCNU) is a commonly used chemotherapy drug. This article explores a detailed study evaluating lomustine's effectiveness and potential side effects in treating canine cutaneous lymphoma.

Cutaneous lymphoma is a cancer that originates in the skin. It's characterized by the proliferation of neoplastic lymphocytes, which infiltrate the layers of the skin. While the exact cause is often unknown, factors like genetics, environmental exposures, and chronic skin inflammation may play a role. This type of cancer can manifest in various ways, from scaly, red patches to nodules and ulcers, making diagnosis challenging.

The aim of this article is to provide a clear, accessible overview of the research findings, empowering you to discuss treatment options with your veterinarian and make informed decisions aligned with your dog's well-being. We'll break down the study's methodology, results, and what they mean for the overall management of canine cutaneous lymphoma.

Lomustine (CCNU) for Canine Cutaneous Lymphoma: What the Research Reveals

Dog with skin rash surrounded by chemotherapy pills, representing Canine Lymphoma treatment.

A recent study investigated the clinical response of dogs with cutaneous lymphoma treated with lomustine and aimed to identify potential adverse effects. Fifteen dogs diagnosed with cutaneous lymphoma were treated with lomustine at a dose of 90 mg/m² every three weeks. Researchers closely monitored the dogs' hematology and serum chemistry throughout the treatment period to assess both the drug's effectiveness and its impact on the animals' health.

The results indicated that lomustine showed some efficacy, but also significant drawbacks:

Partial Response: 53.3% of the dogs showed a partial response to the treatment, meaning their tumors decreased in size.
No Complete Remission: None of the dogs experienced a complete remission, where the cancer completely disappeared.
Disease Progression: 46.6% of the dogs had progressive disease, meaning the cancer continued to worsen despite treatment.
Survival Time: The median survival time was only 22 days, indicating a limited impact on extending the dogs' lives.
Side Effects: Significant hematological and biochemical changes were observed, including leukopenia (low white blood cell count), thrombocytopenia (low platelet count), and anemia. Renal and liver toxicity were also noted in a considerable number of dogs.

These findings suggest that while lomustine can offer some benefit in managing canine cutaneous lymphoma, its adverse effects can significantly compromise the quality of life for affected dogs. It's crucial to carefully weigh the potential benefits against these risks when considering treatment options.

Making Informed Decisions About Your Dog's Cancer Care

The study underscores the complexity of treating canine cutaneous lymphoma. While lomustine may offer some benefits, its potential side effects warrant careful consideration. Talk to your veterinarian about all available treatment options, including alternative therapies or supportive care to manage symptoms and improve your dog's quality of life. Together, you can make the best decision for your furry friend.

About this Article -

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Everything You Need To Know

What is cutaneous lymphoma in dogs?

Cutaneous lymphoma is a rare form of cancer that originates in the skin of dogs. It is characterized by the uncontrolled proliferation of neoplastic lymphocytes within the layers of the skin. This can manifest as various skin abnormalities, such as scaly patches, red areas, nodules, and ulcers. The exact causes are not always clear, but factors like genetics, environmental exposures, and chronic skin inflammation may play a role in its development.

How is lomustine (CCNU) used to treat canine cutaneous lymphoma?

Lomustine (CCNU) is a chemotherapy drug used in the treatment of canine cutaneous lymphoma. The study mentioned in the text involved administering lomustine to dogs diagnosed with cutaneous lymphoma at a dose of 90 mg/m² every three weeks. The study's goal was to evaluate the drug's effectiveness and to monitor for any adverse side effects that might arise during treatment.

What were the main findings of the study on lomustine for canine cutaneous lymphoma?

The study revealed mixed results. While 53.3% of the dogs showed a partial response, with a reduction in tumor size, there was no complete remission, meaning the cancer did not disappear entirely in any dog. Furthermore, 46.6% of the dogs experienced disease progression, meaning the cancer worsened despite treatment. The median survival time was only 22 days. The study also noted significant side effects, including leukopenia (low white blood cell count), thrombocytopenia (low platelet count), and anemia, along with signs of renal and liver toxicity in many dogs.

What are the potential side effects of lomustine (CCNU) in dogs?

The study highlighted several concerning side effects associated with lomustine treatment. The most significant were hematological changes, including leukopenia, thrombocytopenia, and anemia. These conditions can compromise the dog's immune system and overall health. Furthermore, the study observed signs of both renal and liver toxicity in a considerable number of dogs, indicating that lomustine can negatively affect these vital organs. These side effects can significantly impact a dog's quality of life.

How should I make decisions about lomustine (CCNU) treatment for my dog's cutaneous lymphoma?

Making an informed decision requires a thorough discussion with your veterinarian. While lomustine (CCNU) may offer some benefits in managing canine cutaneous lymphoma, the study's findings highlight potential drawbacks, particularly the side effects. You should carefully weigh the potential benefits against the risks, considering your dog's overall health and quality of life. Discuss all available treatment options, including alternative therapies and supportive care to manage symptoms. Your veterinarian can help you make the best decision based on your dog's specific condition and needs.