CBD for Dogs with Cancer: A Comprehensive Guide - My Blissful Pet

CBD for Dogs with Cancer: A Comprehensive Guide

I have been a cancer researcher for the past 20 years, I still am, and there is no nice way of saying that "cancer sucks"!!! I have studied cancer in people, dogs, and rodents and, one thing is sure: even if no miracle treatment exists, you still want and need to do anything you can to make patients life better.

In this blog post, I will provide you with a factual summary of what cancer is in dogs, and, leveraging scientific studies, I will tell you what we know about alleviating some of the burdening side effects by giving CBD to your dog. Also, this blog post is not a substitute for your veterinarian's advice, but it is an educational resource to help you make informed decisions. 

Cancer vs. tumor

Technically, the term cancer refers more to the disease, while the term tumor indicates the actual mass present in an organ. That's the difference between saying "Jane has liver cancer" and saying "They found a tumor in Jane's liver". 

What is cancer in dogs?

But first...what is cancer in dogs? No matter the specie, cancer is always made by the same thing: a bunch of cells from an organ that decided to grow uncontrollably. These out-of-control cells will end up colonizing organs where they are not supposed to be, impairing that organ's functions and leading to a ton on downstream issues including organ failures and death. 

Dogs, like humans, can have different kind of cancers. The most common ones in dogs are, in no specific order:

  • Melanoma: this is a cancer of the skin, most commonly mouth and feet (well, paws). 
  • Osteosarcoma: aka bone cancer, it is a very painful form of cancer and some species like German Shepards, Goldens and Boxers are more likely than other breeds to get it.
  • Lymphoma: unluckily this is very a very common kind of blood cancer in dogs. There more than 20 type of lymphoma and the specific type can depend from your breed.
  • Lung cancer: just like human, they can get it too, it is more common in old dogs and signs can include problems breathing and lethargy.
  • Mast cell tumors: this is a cancer of the connective tissue on beneath the skin layer. Thankfully, most of the mast cell tumors are actually benign and do not represent a life/death danger for your dog.
  • Hemangiosarcoma: this is a very dangerous cancer that attacks the blood vessels, it compromises the heart and spleen, and it can spread very quickly. Retriever dogs and German Shepards seem to be more keen to get this kind of cancer. 

How to treat dogs with cancer?

Depending from the kind of cancer that your dog has, its age, the stage of the tumor and, yes, your budget, there area few options. This includes:

  • Chemotherapy: chemo is a very well established way of killing cancer cells by exposing them to chemicals that are cytotoxic (aka, they are toxic for cells), but, as you probably know, it has a lot of side effects. Hair loss, nausea and off-target effects are expected.
  • Radiotherapy: this is another way of exposing tumors to radiations that cause cancer death by breaking up their DNA so that cancer cells cannot recover anymore and they die. Here too, side effects are expected
  • Surgery: if your dog has a very well localized mass, your vet can remove it. This may or may not be followed by chemotherapy to make sure that he left nothing behind that could grow back
  • Immunotherapy: this is a new-ish frontier in treating cancer in dogs (and humans), and it basically works by activating your immune system to kill cancer. 
  • Other targeted drugs: this includes drugs that can target a specific protein known to drive cancer growth. By blocking it, the goal is to stop and kill tumor cells. 

Understanding CBD and its potential role in dogs with cancer.

CBD, or cannabidiol, is a compound found in hemp that has potential therapeutic benefits for a variety of health conditions. CBD works by interacting with the body's endocannabinoid system, which plays a role in regulating many physiological processes, including pain, inflammation, and immune function. CBD is often used to treat anxiety, stress  and joint issues *, and recent studies in cancer cells suggest that it may have an effect in killing cancer cell (Vet Comp Oncol. 2021 Jun;19(2):253-265, PLoS One. 2021 Aug 5;16(8)).

As a note of caution, these studies are done in vitro, aka in the lab using cancer cells. I can tell you from experience that obtaining results in the lab does not necessarily mean that you will see the same things in patients, in this case in you dog. Instead, you need randomized, blinded, placebo controlled trials in addition to the blessing from the FDA to say that something really works. 

Current studies on the role of CBD during dog cancer treatment

The University of Florida is running a pilot study on dogs with Lymphoma to understand the role of CBD in easing side effects from chemo treatment. The goal of this study is to see whether CBD changes the drug concentration in the blood (aka, can it block the effect of the treatment) and whether it can improve the quality of life of dogs that are undergoing chemotherapy. We don't have the results from this study yet, so it will be extremely interesting to see their findings. 

In parallel, there was a randomized double blind placebo controlled clinical trial (a mouthful to say that it was well planned) on dogs with osteoarthritis pain (Pain. 2020 Sep 1; 161(9): 2191–2202). This paper is relevant in this context because one of the major side effects of cancer therapy is pain. In this study, researchers gave CBD to dogs with osteoarthritis pain and saw that dogs who took 50mg/day of CBD improved their ability to sit, walk, and run. This suggests that CBD can be useful to help dogs overcome pain*.

In the context of cancer there are anecdotal evidences of dogs with cancer doing well while taking CBD during treatment, but there are no official clinical trials (yet). That said, given the evidence from scientific studies, it appears that CBD can help dogs with cancer overcome pain caused by the disease itself and by cancer treatment.


Cancer is a dreadful diagnosis for anyone, human or pet. While there are numerous treatments that can help your dog, there are side effects associated with them. Pain often co-occurs with cancer, and is a common side effect of chemo and other cancer treatments. CBD can help with a number of health conditions, but more studies are needed to precisely point out the mechanism by which this happens. Till then, dog parents should still do what they can to better the daily life of their dog with cancer, from supportive care to CBD, dogs are family and should be treated as such.


* These statements have not been evaluated by the Food and Drug Administration. Products mentioned here are not intended to diagnose, treat, cure or prevent any disease.

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