CBD Oil for Cats with Cancer: Top Products Reviews

Illustration for a Cat with Cancer being surrounded by CBD Oil Bottles.
Written by Nina Julia | Last updated: November 7, 2023

Cancer is one of the most dangerous diseases, and although cats are less likely to suffer from it than dogs, it still affects many of our feline friends. Cats with cancer usually experience persistent sores, lumps that can grow or change shape, unexplained bleeding, loss of appetite, and lameness.

Although there’s no established cure for cancer, many medications are available to alleviate the clinical symptoms of feline tumors. However, conventional treatments also entail the risk of dangerous adverse reactions — not to mention harmful side effects that come with long-term use.

CBD has recently come sparked the attention of medical researchers due to CBD’s potential anti-cancer benefits. CBD is a naturally occurring, non-intoxicating cannabinoid found in hemp plants.

A growing number of pet owners are using CBD-based products to ease pain, inflammation, and other conditions in their pets. Although there is no hard data on the efficacy of CBD for cats with cancer, there are studies that highlight its therapeutic potential and safety in small animals.

Today, we explore the potential benefits of CBD for cats with cancer, covering the current scientific literature and outlining the available forms of CBD for your feline friend.

CBD for Pets: A Brief Overview

A 2018 study showed promising results on the effects of hemp-derived CBD and terpenes on dogs with osteoarthritis. Most of the dogs that consumed CBD oil during the study experienced significantly reduced pain and better mobility in general.

The same study also showed that there were no side effects reported by the dog owners — and that the dogs could tolerate a dose of 2 mg of CBD oil per kilogram twice a day. These results may indicate that hemp-based phytonutrients are safe for animals.

A study on the endocannabinoid system (ECS) has revealed that all mammals, except for some insects and protozoans, share the same ECS in their bodies. The ECS is responsible for maintaining homeostasis throughout the body and for regulating the functions of the brain, endocrine, nervous, and immune systems through a set of CB1 and CB2 cannabinoid receptors.

Since animals and humans have the same receptors, it means that cats can naturally interact with the cannabinoids present in CBD oil. This research on the ECS proves why the dogs in the aforementioned study didn’t experience any adverse effects after taking CBD oil for dogs.

CBD Products for Cats with Cancer

Before we elaborate on the benefits of CBD for cats with cancer, let’s take a look at different product types — and what purpose they serve best.

CBD Oils

Cats Lying besides a Hemp Oil

CBD oil is the most popular form when it comes to giving CBD to cats with cancer. When people mention the best CBD oil for cats, they typically refer to using tinctures to alleviate certain symptoms.

CBD oil is administered with a dropper, which allows for an easy application in the mouth. You can choose from various flavors, from natural to pet-appealing flavors like bacon or cheese.

CBD Capsules

CBD capsules are a good alternative to use in cats because they provide a fixed amount of CBD in each serving. Each capsule can be administered once or twice a day, depending on your veterinarian’s recommendation.

CBD capsules contain between 5 and 20 mg of CBD, so make sure to consult your vet before application. You can mix these pills into your pet’s food to make them easier to consume.

CBD Treats

cat looking at cbd treats

Similar to capsules, CBD pet treats contain a premeasured dose of CBD per piece. They come in appealing shapes and textures; you can choose from flavors like bacon, cheese, salmon, catmint, or peanut butter. Just keep in mind that the dosage in CBD treats and capsules may not be as accurate as with oils, so again, you should talk to a holistic veterinarian to estimate the proper dosage for your cat.

CBD Topicals

Topical formulations include products such as lotions, creams, balms, and ointments. They are used to address localized discomfort, such as pain, redness, swelling, and irritation. For cats with cancer, CBD topicals can provide pain relief from stiff and inflamed joints, as well as from abdominal issues. Topicals are often infused with other supportive ingredients that enhance the therapeutic properties of CBD (e.g. herbal extracts, fruit oils, plant-based oils, and butter).

Can CBD Oil Treat Cancer in Cats?

Several clinical trials have suggested that CBD can cause programmed death of cancer cells in cats and contribute to the inhibition of tumor growth. Here we elaborate on both of these properties.

CBD for Cancer Cell Death

In a 2011 study, researchers examined the effects of CBD on breast cancer cells. Although the study was conducted in vitro, meaning it used a sample dish or test tube instead of a living organism, the results were quite promising.

The authors found that CBD could help speed up programmed death on the cancer cells without damaging the healthy ones. The mechanism behind this action is relatively unclear, but the cannabinoid was able to destroy malignant cells, and cause apoptosis (the said programmed cell death).

Since cancer is triggered by the abnormal growth of malignant cells, their elimination proves that CBD is involved in regulating cell growth.

CBD for Tumor Growth

In the same year, the Breast Cancer Research and Treatment journal posted a similar study on breast cancer cells.

This time, the study was conducted on mice and found that CBD can inhibit the growth of breast cancer in the subjects. Moreover, researchers also learned that it could reduce metastasis — a scientific name for the development of secondary cancer growths.

In another study — this time from 2003 — the authors revealed that cannabinoid receptors exist in both healthy and cancerous skin cells of mice. The researchers found that by targeting these receptors with cannabinoids, the compounds induced cell death while slowing down the growth of skin cancer.

Several studies also link CBD with slowed angiogenesis. Angiogenesis is the process that spurs tumor growth by forming new blood vessels.

What Side Effects of Cancer May CBD Alleviate?

Image of cat looking at a hemp leaf

Although CBD hemp oil for cats isn’t an approved cancer treatment for cats, it is capable of providing relief from many of the side effects associated with conventional cancer treatments.

Three main options for treating cancer in cats include chemotherapy, radiation therapy, and surgery. Although these methods can effectively manage cancer cells in felines, they also have a lot of long-term side effects, such as vomiting, nausea, loss of appetite, inflammation, pain, and insomnia.

Below we explain how CBD may help alleviate these symptoms in cats with cancer.

Chronic Pain

Cats with cancer experience mild to severe pain. Treatments such as chemotherapy, radiotherapy, and surgery, can also lead to problems with pain management.

Veterinarians usually prescribe Tramadol, which is a popular analgesic for cancer pain. However, its effectiveness in treating acute or traumatic pain is questionable, and its non-opioid mechanism may not provide relief for felines.

The aforementioned study on dogs with osteoarthritis showed that dogs given CBD oil products experience significantly less pain than their counterparts treated with conventional methods. On top of that, the dogs became more active after the study after using CBD oil for dogs with arthritis.

This clinical study also noted that CBD oil didn’t produce any side effects despite a relatively high dosage of 2 mg of CBD per kilo of body weight every 12 hours for one month.


Squamous cell carcinoma in cats begins as a small patch of sore skin and oral tumors, which, if not taken care of, could herald the growth of cancerous cells in the body. Inflammation is the most common contributor to the symptoms of squamous cell carcinoma in cats.

A study conducted in 2000 revealed that whole-plant CBD extracts possess remarkable anti-inflammatory properties. The study also investigated the efficacy of cannabinoids on mice with collagen-induced arthritis and concluded that CBD was able to improve both conditions on these subjects.

A follow-up experiment from 2004 that used a novel synthetic cannabinoid acid on mice with arthritis yielded the same results. The compound was found to have suppressive effects on the immune cells while also producing pro-inflammatory mediators, an indicator that it’s a novel, anti-inflammatory molecule.

Nausea and Vomiting

Nausea is a common side effect in cats that are treated with radiotherapy or chemotherapy to control the growth of cancer. Such treatments affect the lining of the intestines and stomach, leading to nausea and vomiting.

The modulation of the ECS is associated with reduced nausea. A 2011 study showed that a wide range of animals can benefit from the anti-emetic properties of CBD. Additional evidence also points to CBD as a potential antiemetic agent for the side effects of chemotherapy.

Causes of Cancer in Cats

Several factors can trigger or speed up the growth of cancer in a cat, including:


Aging is inevitable for all animals; it’s also one of the main reasons behind cancers in many cats. Aging can speed up cancer growth for several reasons.

According to one theory, the mutations in aging cells accumulate over the years, which increases the chances of cancerous cell division. Degeneration of the cat’s body is another possible cause.

For example, chronic inflammation experienced by cats over the years may wreak havoc on their DNA and compromise the immune system. This, in turn, may lead to the uncontrolled growth of malignant cells.


Fibrosarcoma is a type of feline cancer that occurs in the cat’s soft tissue. It is caused by a combination of genetic and environmental factors. Although fibrosarcoma doesn’t have an identified specific cause, most cats with this cancer developed it at a prior injection site.

Intact Reproductive Organs

If your cat isn’t neutered or spayed, they are at a higher risk of developing cancer in their bodies. Unspayed female cats can develop breast and ovarian cancer, while unneutered males may suffer from prostate cancer.

Cats that have undergone spaying or neutering can also live longer and healthier lives.


Carcinogens are the substances that cause cancer through mutations in the genes that eventually turn into cancerous cells in your cat’s body. Cats can be exposed to the same carcinogens as humans, including food additives, tobacco smoke, asbestos, radiation, benzene, and x-ray.

Is CBD Safe for Cats with Cancer?

Image of cat looking at hemp leaf and bud

Before you give CBD oil to your cat with cancer, you should be aware of the possible side effects.

CBD is generally considered safe and well-tolerated in both humans and animals — even in high doses administered over several weeks.

That being said, giving your cat too much CBD can result in:

  • Dry mouth
  • Dizziness
  • Sedation
  • Changes in appetite
  • Diarrhea

CBD is also known to compromise the liver’s ability to metabolize pharmaceutical compounds in most medications. If your cat is on any medication, consult your veterinarian before incorporating CBD into their routine. Doing so will help you establish the right dosage and avoid potential negative interactions between CBD and your cat’s meds.

Key Takeaways on CBD and Cats with Cancer

While cancer isn’t as common in cats as it is in dogs, the symptoms of feline cancer can significantly worsen the quality of their life. Some of the cancer signs in cats include lumps, persistent sores, loss of appetite, unexplained bleeding, and lameness.

Conventional medications, while effective, can also bring undesired side effects, some of which can have a particularly negative outcome on your cat’s health.

CBD is a promising solution for cats with cancer. Studies have shown that it can induce apoptosis and slow down the growth of cancerous cells. Moreover, you can give your cat CBD oil to help them cope with the side effects of radiation therapy, chemotherapy, and surgery; these include pain, inflammation, nausea, and loss of appetite.

Although we still lack sufficient clinical evidence to support the use of CBD as monotherapy for cancer, current findings are very promising, to say the least.

Do you have any experience in using CBD oil in cats with cancer? Share your stories in the comment section!


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Nina created CFAH.org following the birth of her second child. She was a science and math teacher for 6 years prior to becoming a parent — teaching in schools in White Plains, New York and later in Paterson, New Jersey.

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