As legislation for medical and recreational marijuana sweeps the country, the application of cannabis for dogs and cats has become a point of focus for pet parents and the veterinary community. This article, will cover more detailed information about cannabis and it’s medicinal use in dogs and cats. For a more basic understanding of cannabis for pets, check out my articles for cats here and dogs here.

Endocannabinoid System

Are you ready to geek out? There is a whole system in both human and animal bodies known as the endocannabinoid system. This system is located in the nervous system (brain, spinal cord and nerves) and is made up of receptors. These receptors bind THC and CBD among other components of the cannabis plant. This system influences many processes related to pain, mood, immune function and much more. As this system is studied we will be able to understand why cannabis works so well for certain conditions. We may also expand the scope of what cannabis may treat.

There is still much to learn about the endocannabinoid system in people and pets. However, we do know that dogs have many more THC receptors (CB-1) in their brains compared with people. This is why they are more sensitive to effects of THC compared with their human counterpart. In other words, the amount needed for a person to become comfortably euphoric (high) can cause extreme high with negative effects of the nervous system in dogs.

As cannabis is bred to have more and more THC, veterinarians see more and more toxicity in dogs. Some of these cases can be deadly and cause much suffering for patients. If your veterinarian is not open to discuss cannabis (even without THC), this is most likely the reason. We all took an oath to first do no harm. As cannabis becomes legal across the US, veterinarians will have more opportunities to learn about the difference between hemp and marijuana.


You may have heard of the ‘entourage effect’ when it comes to medicinal marijuana. This simply refers to the synergistic effect of THC on CBD. In other words, the presence of THC is thought to increase the medicinal effect of CBD. Many experts in the field recommend only products with THC due to this concept.

While this synergy may be beneficial for people, it is important that we consider our animal’s comfort when using cannabis. When a person consumes cannabis, they can report how they feel and titrate the dose independently. Our animal companions don’t have this ability. THC can cause paranoia, hallucinations and anxiety in people. This most likely occurs in dogs as well.

While most focus lies on THC and CBD, cannabis contains other medicinal constituents like terpenes and flavanoids. Terpenes are the aromatic oils in the plant. These enhance the medicinal effects of both CBD and THC. Flavenoids are chemical compounds found in plants. These compounds also have medicinal effects such as anti-oxidant, anti-inflammatory, anti-cancer, anti-viral and anti-anxiety.

Conditions Benefited from CBD

The list of conditions that are improved by cannabis grows daily in my practice. Often I recommend cannabis to treat one ailment, only to find it has improved other symptoms. These are the best side effects! These are the conditions I have seen improved with cannabis:

  • Anxiety
  • Arthritis/Pain
  • Aggression
  • Seizures
  • Asthma
  • Allergies
  • Inflammatory Bowel Disease
  • Increased Immune Function
  • Appetite Stimulation

I also use cannabis for patients with cancer. Depending on the type of cancer, CBD may slow the progression and offer the pet an increased sense of well being. Each type of cancer has different properties and behavior and will respond differently to CBD.


Good news! Colorado State University is currently conducting clinical trials for the use of CBD in seizures and arthritis. As more research gets funded, we may begin to have a more information for the best dosing regimen. As it stands currently I use a wide dosing range of 0.1-3 mg/kg twice daily. My recommendations depend on the animal and the disease being treated.

Product Selection

As products flood the market, it is important that consumers make an educated purchases for themselves and their pet. My inbox is full of people asking about products they have purchased or considering purchasing. When I vet these products, I am looking for the following criteria.

  1. Farming practices. Has the plant been grown with the use of pesticides?
  2. Extraction method. Watch out for methods that use chemicals as these residues will be present in the final product.
  3. Concentration. Some products contain too little CBD to be effective.
  4. Guaranteed analysis. Does the company test their product for the constituents beyond THC and CBD? Does it look at the terpenes and flavonoids? Check out the HempRx guaranteed analysis here.
  5. Other ingredients. Make sure you know what other ingredients are present. I prefer HempRx because it only contains hemp. For my very sensitive patients introducing one ingredient at a time is beneficial.
  6. Terpene/Flavanoid. As discussed earlier, CBD and THC are not the only medicinal components of cannabis. I only use products that have the terpene and flavanoid profile analyzed as well.

My absolute favorite product line is HempRx by Rx Vitamins for Pets. This line is specifically made for cats and dogs. It comes in an oil and chewable form. The oil comes in two concentrations so that dosing large dogs can become more affordable. The HempRx Soft Chewz (Cats/Small Dogs & Larger Dogs) are very palatable for picky pets. For cats I recommend getting the regular strength HempRx and starting with 1-2 drops twice daily. This bottle will last approximately 2-3 months. For dogs greater than 20 lbs I recommend the HempRx Forte as it will be the most economical.

Sending love to you and your furry friends!