Help! My Dog Has Plasma Cell Tumors! (Vet Answered)
This question has been answered by a vet
Veterinarian & Animal Behaviorist
With nearly two decades in veterinary medicine, Dr. Paola brings hands-on experience across multiple species. A graduate of the University of Guadalajara, she specializes in preventive care, animal welfare, and positive reinforcement training.
The Question
“Dear Dr. Paola,
Darby has been diagnosed with benign plasma cell tumors. For over a year now, each time we located one or more, our veterinarian has removed them and had them tested. She now has 5 more that have grown, and our vet no longer wants to risk surgery at her age. She will be 14 in July 2025.
The vet has been consulting with a specialist at Colorado, and they suggest we start Darby on prednisolone and melphalan instead of surgery. Other than these tumors, Darby seems healthy. She eats well, is interested in her surroundings, has healthy stools, and plays with us. We’re worried that steroids and chemotherapy will harm her and decrease her quality of life.
My daughter read an article that stated plasma cell tumors responded to CBD oil. Are you familiar with using CBD oil this way? Please share how you would treat these types of tumors. Thank you” – Vivian
Quick Info about Darby
Hello Vivian,
Thank you for sharing Darby’s story. It’s clear she’s deeply loved and well cared for, and I’m glad to hear that despite the plasma cell tumors, she’s still engaged, eating well, and enjoying life. At nearly 14, her comfort and well-being understandably take priority. The approach your veterinarian and the consulting specialist are recommending is a recognized palliative protocol in cases where surgical removal is no longer the safest option. Prednisolone can help reduce inflammation and may slow tumor progression, while melphalan, though a mild oral chemotherapy drug, can systemically target abnormal plasma cells. When used at the appropriate dose and with careful monitoring (prepare yourself for regular vet visits and bloodwork), this combination is often well tolerated in dogs and may offer you more good-quality time together. The key lies in balancing effectiveness with side effect management, and many dogs continue to enjoy their usual routines while on these medications.
Like you, many pet owners are interested in the potential benefits of CBD oil for pets with cancer. However, at this time, there is no strong scientific evidence confirming its effectiveness against plasma cell tumors specifically. Most of the available data is anecdotal or comes from early-stage studies in lab settings. Some pet parents have reported that CBD helps with pain relief or anxiety, which can indirectly support quality of life, but it is not considered a reliable stand-alone treatment for cancer.
Additionally, while CBD is not the same as THC, it’s important to be aware that its legal status varies. In some countries or states, possession or use may still be restricted, especially when administering it to animals. If you’re considering it, make sure you check your local regulations and always consult your veterinarian to avoid any unintended interactions with her prescribed medications. In these cases, a carefully guided palliative approach, supported by regular monitoring and adjustments, often gives the most compassionate and effective results.
Ultimately, every treatment plan should be guided by how the dog is feeling and what will give them the best quality of life.
– Dr. Paola