What is Cannabidiol?

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Plants make many different chemicals called phytochemicals, many of which have positive medical benefits. Cannabis sativa, commonly known as marijuana, produces over 500 other phytochemicals. The most recognized is tetrahydrocannabinol, also known as THC.

Drugs that affect the mind are called psychoactive, and THC is one of these. This is one reason marijuana is used recreationally by humans. It is also why marijuana is a Schedule I controlled substance in the United States and many other countries. THC is not the only phytochemical made by the marijuana plant.  Of the over 500 phytochemicals that can be made, at least 100 are other phytocannabinoids.

Cannabidiol, or CBD, is another commonly recognized cannabinoid produced by Cannabis sativa. However, unlike THC, CBD is not psychoactive. The United States Congress recently passed a law allowing industrial hemp to be grown. Hemp is a strain of Cannabis sativa that still has CBD but has very little THC. Cannabidiol derived from hemp is not a controlled substance.

Cannabis is a Schedule I substance in the US, which means it has a high chance of abuse (due to the THC, which is the psychoactive substance in marijuana) and has no currently accepted medical use. Nevertheless, research is showing that THC may help many diseases.

Some synthetic versions of THC for humans are approved as drugs and are federally legal, but none are currently approved for pets. However, CBD is approved in humans as a drug, so your veterinarian may be able to prescribe it if considered necessary for treating your pet.

How Cannabinoids Work

One of the many systems working to keep the body healthy is the endocannabinoid system in the brain. This system is made of naturally produced chemical compounds produced by neurons (cells that make up nerves) that are then sent on to direct many other cells.

The endocannabinoid system includes receptors located on different body cells, especially the nervous system. Phytocannabinoids may work at receptors like endocannabinoids.

The endocannabinoid system includes receptors located on different body cells, especially the nervous system. Phytocannabinoids may work at receptors like endocannabinoids. A common endocannabinoid, anandamide (AEA), is called the “bliss” endocannabinoid because it helps relieve stress.

THC interacts with cannabinoid receptors like AEA does, causing the same positive psychoactive effects in most people. CBD also interacts with the endocannabinoid system, but not at the same sites that THC works, which is why it does not affect the brain the same way THC does. 

Both THC and CBD can potentially interact with other receptors in the body. Because CBD may have many of the medical benefits of marijuana but does not have psychoactive effects, CBD is emerging as the cannabinoid most used medicinally in animals.

CBD as a Potential Treatment for Some Diseases

Because cannabinoids are mainly present in the brain, diseases involving the nervous system have been the focus of study for positive benefits. Some studies in humans have not found a clinical effect of CBD, but that does not mean that CBD does not work.

CBD appears to help other drugs control pain in humans, especially if it is chronic. Studies have shown that pain associated with osteoarthritis in dogs may be better controlled if CBD is added to drugs such as nonsteroidal anti-inflammatories (e.g., carprofen, robenicoxib, grapiprant, etc.).

Another potential indication for CBD is epilepsy, or seizures, that have not responded sufficiently to other antiseizure medications.

The use of CBD in treating diseases involving the nervous system, such as anxiety and pruritis (itchy skin), needs further research but may be promising. Studies involving cancer are also underway. CBD for treating various cat diseases has not yet been studied. 

CBD as a Supplement  

Animals must receive CBD orally. It is commonly given to pets as a treat, in oil, or as a capsule supplement. In the last decade, many supplements containing CBD have been marketed for use to treat a wide variety of diseases in animals. While CBD may prove to help treat some of these diseases, using these supplements to treat a pet can be a problem for several reasons.

It is important to understand that supplements are not like drugs approved by the Food and Drug Administration (FDA). Approved drugs have undergone a rigorous assessment to ensure that the drug is safe and effective for the disease being treated. The label guarantees the product contains the correct medication in listed amounts, strength, and quality. Any additional ingredients are clearly listed.

Supplements, including those containing CBD, are not held to the FDA standard. There is no guarantee that what is listed on the label is correct.

CBD products can be inconsistently labeled. Hemp oil is not the same as hemp extract, and the amount of CBD in the product can vary.

Labels can list the amount of CBD in ounces, by ml, in the total container, per dose, or per serving. This can make it difficult to ensure you give your pet the correct amount of CBD needed.

Another issue with CBD supplements is that they may contain other compounds added by the manufacturer. The compound might be a drug or, worse, a synthetic cannabinoid. Added synthetic cannabinoids are also Schedule I products and are illegal but hard to identify. This includes metabolites of THC. They are much more likely to be toxic compared to phytocannabinoids.

Yet another concern is how the CBD is “delivered” to your pet. Some manufacturers are trying to increase CBD absorption by changing what it is in. However, CBD may be absorbed differently if mixed in hemp oil, sesame seed oil, or other fats or added to a cookie or biscuit.

A final consideration is to be aware of the cost of CBD in these supplements, which can vary greatly. Higher cost does not equate to a better product.

One of the ways to avoid most of these concerns is to ask your veterinarian to prescribe a CBD that has been approved by the FDA for human use. Because it is approved, your veterinarian is legally allowed to prescribe it.

Is Cannabidiol Safe for Your Pet?

CBD appears very safe in dogs and is not likely to cause behavior changes. Studies have shown that CBD in oil, even at very high doses, does not cause any more side effects than oil alone in dogs or cats.

However, longer-term studies need to be done because there is some suggestion that the liver might be affected. This may be more likely if CBD is combined with other drugs.

Another safety consideration is whether CBD might change how other drugs work in the body. Some drugs inhibit the metabolism (or processing) of other medications, making it possible for other medications to become toxic.

In most cases, studies show that the effects of CBD are seen around two weeks after beginning treatment at the dose recommended by your veterinarian. However, the body often develops a tolerance for drugs used in treating the nervous system.

If tolerance develops, a higher dose may be necessary to control the clinical signs.

You must discuss with your veterinarian any other drug or supplement your pet may be receiving and make sure you know the potential benefits, dosing suggestions, and any cautions to look for when giving CBD to your pet.

Pegi Webster, Content Editor, VP, CDP, VetzInsight, contributed to this article.