One in three dogs develop some form of cancer in their lifetime and due to the the aggressive nature of most cancer treatments, pet owners are looking for a more holistic option to help their dogs. In this article, we will talk about the role of CBD oil in cancer treatment strategies.  

From tumor-shrinking properties through destruction of cancerous cells to pain and nausea alleviation – cannabinoids (CBDs) seem to benefit dogs with cancer on multiple levels.  

Keep reading to find out how CBD can make your dog's journey through cancer treatment a bit more comfortable and a lot more successful. 

Does CBD Oil Help With Cancer in Dogs?

CBD Oil for Dogs with Cancer

In dogs, CBD oil exerts its beneficial effects by interacting with the endocannabinoid system (ECS). The ECS is a complex regulatory system that modulates many bodily functions and processes to achieve a state of overall balance (homeostasis) and health.

CBD oil has been used to help pets mitigate symptoms of seizures, arthritis, and even anxiety in dogs. Now it is even being used to help mitigate symptoms of cancer in canines. While CBD oil for dogs is not a cure for cancer, it can benefit your canine and provide support.  

Common Types of Cancer in Dogs

Canine cancer comes in a variety of forms. Although each form is different and deserves attention, we will briefly describe the five most common types of cancer in dogs. 

Bone Cancer

Bone cancer or osteosarcoma, is a primary bone tumor usually linked with large and giant dog breeds. It generally affects the limb bones, but the skull, spine, and ribcage are also common locations. The treatment of choice is usually amputation of the affected limb. Without treatment, the average survival time is less than two months after the cancer diagnosis. 


Hemangiosarcoma is a malignant and metastasizing cancer attacking the lining of the blood vessels, particularly the vessels spleen (in over 50% of cases). Hemangiosarcoma is more common in elderly dogs of medium and large breeds. These tumors are prone to rupture, which can lead to life-threatening blood loss. 


Canine lymphoma stems from the lymphoid tissue and lymphocytes. Accounting for 15-20% of new cancer diagnoses, it is the third most common cancer type in dogs. There are several different forms of lymphoma, but sadly, none has a significantly good prognosis. 


Melanoma is an aggressive and fast-spreading cancer type affecting the melanocytes – the pigmented skin cells. It is one of the few canine skin cancer types visible from the outside (dark spots on the skin). Melanoma grows quickly, thus requiring fast and adequate treatment. 

Mast Cell Tumors

Mast cell tumors stem from abnormally formed and functioning mast cells – these cells are responsible for managing inflammation and allergic reactions. They are one of the most common malignant types of cancer in dogs. Mast cell tumors are challenging to treat because of two main reasons. First, they multiply really quickly, and second, they have high metastasizing rates. 

Using CBD Oil as Part of Your Dog's Cancer Treatment Plan

CBD oil Stimulates Appetite in dogs

CBD oil makes a great addition to the vet-approved, multimodal anti-cancer treatment. CBD oil fits in well with many canine cancer treatment plans by mitigating unpleasant side effects and enhancing the effectiveness of certain medications. Here are some benefits of CBD oil for dogs with cancer. 

CBD Oil for Dogs Mitigates Pain and Reduces Inflammation

Pain and inflammation are common companions of cancer. They are associated with both cancer diagnosis and cancer treatment. Pain decreases the quality of life and delays healing processes

Traditional anti-pain and inflammation medications like opioid drugs and non-steroid anti-inflammatory drugs (NSAIDs), although efficient, have significant side effects ranging from increased tolerance to liver issues. 

Cannabinoids are a natural alternative to pain relief and inflammation reduction. They are safer and come with fewer and lesser side effects than traditional medications. 

What is more, CBD use enhances the potency of traditional meds (opioids and NSAIDs), thus allowing decreased drug administration while achieving the same results.  

CBD Oil for Dogs Helps Support Anti-Tumor Medication

From leukemia to lung cancer and colon cancer, CBD has powerful anti-tumor properties in several cancer types. 

The ECS acts as a signaling system in cancer patients meaning cannabinoids are an excellent addition to your dog's cancer treatment plan

What can Shrink Tumors in Dogs?

In addition to having its own tumor-shrinking features, CBD oil is a promising anti-cancer drug that can enhance the effects of other treatments like radiation therapy and chemotherapy.  

CBD oil improves the radiation therapy effects in terms of shrinking the tumor without increasing the side effects of this brutal treatment. Basically, with CBD, your dog could potentially reduce the time spent in radiation treatment by optimizing the effects of the treatment on the tumor.

Because of its entourage effect, CBD decreases the reproduction of cancerous cells when combined with chemotherapy drugs. Also, when combined with chemotherapy, CBD use results in increased survival rates

CBD Improves Immune Health

The functioning of the immune system and endocannabinoid system is closely linked. In fact, this link is so close and strong that some scientists coined a new term – the immunocannabinoid system

CBD boosts your dog's immune system and reduces oxidative stress, thus helping the body effectively defend against foreign pathogens without damaging healthy tissues. 

Plus, CBD promotes gut health in dogs, and since a major portion of the immune system is located in the gut, it indirectly promotes healthy immunity. 

CBD Reduces Nausea and Stimulates Appetite

Sometimes handling the side effects of anti-cancer treatment is more challenging than handling cancer itself. Among the most common and concerning treatment side effects are nausea and appetite loss in dogs. 

Nausea is an uncomfortable and debilitating issue that, in the long run, affects the appetite. Together these symptoms can leave lasting damage on your pet by triggering metabolic disorders and conditions like cancer-induced cachexia and anorexia. 

In simple words, something as being as nausea and loss of appetite can quickly become life-threatening for dogs with cancer when it escalates to anorexia. In fact, cancer-induced cachexia accounts for up to 20% of deaths among cancer patients. 

CBD can treat nausea and stimulate normal appetite because the ECS with which CBD interacts is responsible for managing metabolism, promoting gut health, and modulating the brain-gut pathways

As a result, your dog will continue to consume all the nutrients for normal functioning and receive the energy necessary to fight off the cancer ailment.  

CBD Acts as a Sleep Aid

The average dog needs between nine and fourteen hours of sleep broken up into several irregularly scheduled naps. Cancer makes sleeping difficult, and sleep deprivation leads to increased anxiety and decreased energy and appetite. 

CBD modulates sleep and promotes proper wake time during the day, meaning cannabidiol tends to be a more wakeful substance rather than a sedative (unless taken in high doses). However, quality wake time ensures better sleep during the night.  

How Much CBD Oil Should I Give My Dog for Cancer?

dog with cbd oil

As far as the dose of CBD oil for your dog goes – start low and gradually increase the dose to find the right amount for your pet. A general guideline is to fall within the range of 1-5 mg of CBD per 10lbs of body weight. 

At Honest Paws, we have a CBD oil for dogs dose calculator that factors in your dog's size and weight for the perfect dosage amount.

When starting your dog on CBD, observe your pet and write down any changes in its appetite, mood, demeanor, sleep patterns, and more. 

This will help you to keep track of the doses over time and gradually find the one that seems to keep your dog most comfortable, happy, and content.

The Side Effects of CBD Oil for Dogs with Cancer 

While cannabidiol is helpful to the treatment of dogs with cancer, it also has some side effects that are important to acknowledge. 

On a mild note, it can reduce saliva, leading to dry mouth in dogs. If your dog seems to drink excessively, it may be thirsty due to a dry mouth from the oil. CBD oil can also lower your pet's blood pressure temporarily, leading to lightheadedness. 

The last major side effect has to do with CBD oil's popular calming, anti-anxiety properties for dogs. This means that sometimes CBD can make dogs drowsy or sluggish. 

The good news is these side effects are rare, and even if they occur, a simple dosage modification will help eliminate them. 

How Safe is CBD Oil for Dogs with Cancer? 

As a natural herbal supplement, CBD oil is safe for dogs with cancer. The FDA "recognizes the potential opportunities that cannabis or cannabis-derived compounds may offer."

However, as with any other medicine or supplement, it is important to discuss its use with your trusted veterinarian and find a high-quality product with proven benefits. 

Finding the Right CBD Oil for Dogs with Cancer

Giving the vast array of options, choosing the right dog CBD oil for cancer patients can be challenging. Here are some considerations that will help narrow the list and find the ideal CBD product (CBD oil, CBD dog treats, or capsules). 

Full-Spectrum CBD Hemp Product  

Make sure the product contains the words full-spectrum somewhere on the label. Broad-spectrum and isolate products contain cannabinoids, but they lack additional compounds (terpenes, flavonoids), which act synergistically with the CBDs. On the other hand, products like hemp seed oil are healthy, but they do not contain cannabinoids. 

Hemp-Derived CBD Oil 

Only hemp CBD oil is safe for pets. This is because oils derived from marijuana contain high levels of THC (the psychoactive compound responsible for making users "high"), which is toxic to pets. CBD products formulated for pets are made from hemp and contain less than 0.3% of THC. 

Organic Hemp and No Harmful Compounds 

Hemp grown for commercial purposes is loaded with harmful chemicals and pesticides. Organic hemp production ensures a purer and healthier product. Even the additional ingredients and carriers (for example, coconut oil) should be organic. Additionally, make sure the CBD product you are purchasing is free from allergens like soy, dairy, corn, and gluten. 

Reputable Brand 

Before buying the CBD product, check its manufacturer's reputability. A reputable brand will provide a Certificate of Analysis for its products and reviews of satisfied customers. 

The certificate of analysis is a document (provided by a third-party lab) confirming the product's quality and verifying the label statements as true. 

Do Vets Recommend CBD Oil for Dogs with Cancer?

CBD oil for dogs is legal, available in stores, and can be purchased over the counter. Despite this, working with your pet's veterinarian or veterinary oncologist and getting their recommendation before pursuing this option for your canine is essential. 

According to a recent survey, 63% of the veterinarians reported that they are being asked about CBD oil for pets at least once per month. However, depending on where you are in the country, the best CBD oil for dogs with cancer may have a different reception in the veterinary community. 

For example, there is a law preventing state regulators from penalizing vets for discussing cannabis use with their clients in California. 

Be sure to find a vet who has not closed off on this idea of CBD altogether so that you can get a sense of whether CBD may be worth a try to give your dog. With the right strategy, CBD will offer your dog significant help, vital relief, and a little boost to its health during cancer treatment

Involving your vet in your pet's CBD use is critical as this supplement has several drug interactions. In dogs with cancer, some of the potential drug interactions are, in fact, seen as benefits. 

CBD Oil for Dogs with Cancer: Our Final Thoughts

woman walking her dog

The takeaway message would be that CBD oil is not a cure for cancer or a surgery substitute. However, there is plenty of research-backed reasons why CBD oil makes an excellent addition to the multimodal cancer treatment strategy for your dog – from mitigating the negative symptoms to improving the general health of canines with cancer. 

For more information about Honest Paws CBD for pets, browse the topics on our Honest Paws website. We want you to be informed and confident in the CBD products you choose for your pets. Make sure to also check for CBD for dogs reviews!