Small Cell Lymphoma in Cats: Treatment options, hospice/palliative care, and how to know when it’s time for euthanasia

Small cell lymphoma is a slow-growing but ultimately incurable cancer of the intestines involving lymphocytes (a type of white blood cell). The most common symptoms are weight loss, vomiting, and diarrhea.

Diagnosing small cell lymphoma can be challenging because its symptoms—chronic weight loss, vomiting, diarrhea, and decreased appetite—overlap with other conditions such as inflammatory bowel disease (IBD) and pancreatitis. Basic diagnostics including bloodwork and ultrasound can show evidence of thickening of the intestines suggestive of small cell lymphoma. A biopsy is required for definitive diagnosis and can be performed via endoscopy (using a flexible fiber-optic camera inserted into the mouth) or surgery (an incision in the belly).

Treatment Options for Small Cell Lymphoma

While there is no cure for SCL, treatment with oral medications can often provide a good quality of life for many months to even years. 

Option 1: Chemotherapy (Chlorambucil & Prednisolone)

The standard treatment for small cell lymphoma is an oral chemotherapy drug (chlorambucil, trade name: Leukeran) and a steroid (such as prednisolone). 

Veterinarians will often want the diagnosis confirmed by biopsy before starting chemotherapy, but sometimes they feel confident enough of the diagnosis based on ultrasound and symptoms that chemotherapy can be tried without a biopsy.  

Pros of chemotherapy: Chemotherapy is a scary word but oral chemotherapy with chlorambucil is not like other types of chemo because you give it at home!

• It can be easily given at home by YOU, the owner

• Side effects are uncommon

• Cats can sometimes live for years with this treatment. 

Cons of chemotherapy: There are some families, however, that this is not the best approach for.

• It does require you to be able to give your cat an oral medication (prednisolone is usually daily or every other day, and chlorambucil is usually given twice a week)

• Occasionally cats can experience side effects, and there may be conditions that make treatment with chemotherapy and steroids (diabetes, for example) very challenging

• Bloodwork monitoring is generally required to make sure your cat’s body is tolerating the medications

• If a pet parent has health issues that makes it risky for them to handle chemotherapeutic drugs. 

• Although chlorambucil is relatively inexpensive compared to other forms of chemotherapy, there are still some costs associated with medications and monitoring that may be prohibitive for some families. 

Option 2: Palliative care

If your family chooses to forego chemotherapy and focus on comfort care, below are some of the treatments that may help your cat be comfortable and happy for a period of time. 

• Steroids alone (Prednisolone): Can help reduce inflammation and improve appetite.

• Appetite stimulants: Such as mirtazapine or capromorelin to encourage eating.

• Anti-nausea medication: Cerenia (maropitant) or ondansetron can help with vomiting

• B12 injections: To support gut health and overall vitality.

• Diarrhea medications: sometimes certain antibiotics can help with diarrhea

• Probiotics: oral probiotics can be mixed with food to help support good bacteria in the gut

• Diet: A diet that is delicious and focused on getting high quality calories without upsetting your cat’s tummy is ideal. Every cat is different so talk to your veterinarian about dietary recommendations.

End of Life Care Planning and Decisions

It’s really scary to think about end of life, but REALLY important in my opinion. When we are brave and plan ahead – especially when we envision how we WANT our pet’s last days and weeks to look – we can make a big impact to ensure they have a peaceful rather than scary ending. 

Two things I recommend: 

1. Coming up with a set of objective criteria for euthanasia while we’re in a relatively calm state of mind. This can help us make decisions when it gets close to time and our emotions are very strong.

2. Keeping a daily diary of your cat’s quality of life. It doesn’t need to be complicated – just  a happy face for a good day and a frowny face for a bad day. You can write a couple notes too such as: “Chester enjoyed watching the birds today” or “Chester didn’t feel well and spent a lot of time in the closet lying on my shoes.” This diary can also be used to create memories – I recommend writing beautiful new memories you created with your pet and even sticking photos in the journal. 

Below are some criteria to consider when assessing your cat’s quality of life: 

• Appetite changes: A significant or persistent loss of interest in food no longer responding to medications. If your cat’s appetite is extremely poor or absent for a few days in a row, it might be time to consider euthanasia. 

• Weight loss and muscle wasting: Weight loss is common with this disease. We generally score body condition (BCS) from 1-9 (see this chart: Body Condition Score Chart.) If your cat is getting down to BCS of 1-2, it may be time to consider euthanasia or your cat’s organs may start to shut down. Note: some cats with lymphoma will actually be STARVING, eating massive amounts, and still losing weight rapidly. This is because their intestines can no longer absorb nutrition. If your cat with lymphoma is getting very thin despite a ravenous appetite, it can be hard to elect euthanasia, but these cats are truly starving and euthanasia should be considered. 

• Persistent vomiting or diarrhea: Some vomiting and diarrhea is probably okay with this disease. But if your cat is having constant vomiting and diarrhea that is making them feel very sick and no longer controlled by medications, it may be time to think about euthanasia. One exception: some cats with lymphoma have daily diarrhea but are maintaining their weight and otherwise seem quite well – it’s probably not time for euthanasia yet in these cats.  

• Lethargy and withdrawal: When a cat no longer engages in their routine activities, isolates, hides or spends time in unusual or hidden locations, they are likely experiencing pain or discomfort. 

• Difficulty grooming: Poor coat condition with matting or unkempt fur signals your cat is not feeling well enough to groom normally. 

• Pain or distress: We don’t see a lot of acute pain with small cell lymphoma, but if your cat is crying out or seems in pain or distress that cannot be controlled with medications, it may be time to consider euthanasia. 

• Postures: A comfortable cat might sleep or lie in a “croissant” or “loaf” position, with relaxed posture and face. Cats with belly pain often sit in a “sphynx” position – which looks like a loaf position but the body is stiff, the back and neck are often more hunched, and your cat’s face may look tense. 

Final Thoughts

Navigating small cell lymphoma in cats is an emotional journey, but prioritizing comfort and quality of life will help guide your decisions. Whether you choose treatment or palliative care, the most important thing is ensuring your beloved feline companion is not suffering. Remember, every moment you share is a testament to your love and devotion.

If you would like more guidance, schedule a 45 minute teleconsult with one of our compassionate veterinarians who can discuss your cat’s unique situation and help you formulate the most compassionate and loving plan.