Dr. Heather O'Leary |  September 4, 2025

*NOTE: Email spam detectors and web servers flag the common name for what I am calling Cannabis in this blog. You may hear it called “weed,” “pot,” or “MJ.”

If you’ve ever felt confused by the words hemp, CBD, and cannabis, you’re in good company. Even veterinarians sometimes need to pause and make sure we’re speaking the same language when discussing this area of plant medicine!

These terms describe plants that belong to the same extended botanical family, but their chemistry, legality, and safety for pets vary in critical ways.

Hemp vs. Cannabis vs. CBD

• Industrial hemp is a variety of Cannabis sativa bred to contain less than 0.3% THC (by dry weight, as defined by U.S. law). It’s legal to grow, and it’s often used for fiber, food, and supplements. Hemp extracts are the main source of CBD products marketed for pets.
   
• “Cannabis” generally refers to Cannabis plants cultivated for human medical or recreational use. These plants are bred for much higher THC content — the compound responsible for the “high.”
   
• CBD (cannabidiol) is just one of more than a hundred cannabinoids found in hemp and cannabis. CBD itself is non-intoxicating, and when used properly, it has potential benefits for pets without producing a “stoned” effect.
   

So, hemp is the plant, CBD is one of its many chemical components, and cannabis is a THC-rich cousin that isn’t safe for dogs and cats in the same way it may be for humans.

Beyond CBD: The Full Spectrum of Cannabinoids and Terpenes

When you see “CBD oil” on a label, it’s easy to assume it’s one simple ingredient. In truth, hemp extracts contain a whole symphony of compounds:

• Major cannabinoids like CBD and THC (in trace amounts if from hemp).
   
• Minor cannabinoids such as CBG (cannabigerol), CBC (cannabichromene), and the acidic forms CBDA and THCA.
   
• Terpenes, the aromatic molecules that give cannabis (and lavender, pine needles, or citrus peel) their scent — and may also shape the therapeutic effect.
   

This mix is often called the entourage effect: the idea that cannabinoids and terpenes work better together than alone. It also explains why one pet may thrive on a particular hemp extract, while another sees no response. 

Not all CBD products are created equal — the cannabinoid profile, terpene content, and quality control matter a great deal.

You’ll see these terms describing medical CBD products: isolate, broad spectrum, and full spectrum. They refer to how many different cannabinoids are present, and whether there are terpenes, and possibly THC included in the mix.

Why THC Is a Problem for Pets

Here’s where things get serious. Both dogs and cats have an endocannabinoid system (ECS) — a network of receptors that interacts with plant cannabinoids. All mammals have an ECS, humans included! The ECS influences mood, appetite, pain perception, immunity, and more.

The key receptors, CB1 and CB2, are spread throughout the brain, nervous system, and immune tissues. THC binds strongly to CB1 receptors in the brain, which is what causes the “high” in humans.

Dogs in particular, however, have a higher density of CB1 receptors in certain parts of the brain compared to humans. This means THC affects them much more dramatically — and not in a good way. Clinical signs of cannabis toxicity in pets can include:

• Drunken-like incoordination
   
• Excessive drooling
   
• Dilated pupils and glassy eyes
   

• Urinary incontinence/dribbling urine

   

• Sensitivity to sound/light
   
• In severe cases, tremors, seizures, or coma

RESPIRATORY DEPRESSION is what can kill a dog or cat who ingests a large amount of THC, because at high doses, it suppresses their innate drive to breathe.

Cats may show less of the classic “ataxia” (wobbliness) but can still suffer significant neurologic and gastrointestinal signs. 

In summary: pets should never be given full-spectrum or THC-rich products outside of carefully guided veterinary supervision.

Where Does That Leave Us?

• Hemp-derived CBD, when well-sourced and tested, can be safe and beneficial for some pets.
   
• Cannabis (THC-dominant plant extract) can be dangerous for dogs and cats.
   
• The nuanced effects of CBD and other cannabinoids may depend on the entourage effect, which is why product quality, testing, and veterinary guidance matter so much.
   

As more research emerges (VCS, The Morris Animal Foundation and ACVBM are helping to lead the way), veterinarians are learning how to responsibly incorporate cannabis medicine into integrative care. The safest step for pet guardians is to work with a veterinarian trained in cannabis therapeutics — not to experiment on your own.

What to Do?

If you follow me on Facebook and Instagram, you may know that my delightful puppy, Oliver, recently suffered from cannabis intoxication. The beach had been crowded on a holiday weekend, and now that cannabis is legal in most states, it’s becoming more and more common for accidental pot intoxication to occur. 

If it wasn’t for his classic symptoms and my own knowledge of the most likely cause, his sudden collapse on the beach would have been terrifying! Even with that knowledge, I was pretty concerned about my little guy – as you can imagine.

I took him directly to the nearest veterinary ER clinic, where they checked his blood glucose, then gave him fluids and charcoal to support his metabolism of the drug. I kept him quiet in a darkened room until he began to perk up.

Remember that many prescription and over the counter drugs for humans can cause severe symptoms in dogs. Most cats are hard enough to pill when we want them to take medicine, and aren’t at as high a risk of accidental ingestion. 

An even bigger problem comes with flavored gummies and the classic “pot brownies,” because most pets love sugar! Weirdly, dogs seem to be attracted to the flavor of cannabis even in its unflavored state.

Small pets are at higher risk because the effects are dependent on both dose and weight. It doesn’t take much THC to intoxicate a seven pound puppy!

Accidental cannabis intoxication is very rarely life threatening, so above all, maintain your composure. A bit of nursing care is all that’s needed for the overwhelming majority of pets to recover safely, and I don’t think they remember their “bad trip” once back on their feet.

Take Home Message

Stay vigilant, and keep ALL medications, including cannabis, safely secured where your pet can’t reach them. 

Be extra observant when out in public places, and/or when at a gathering where guests may not be aware of the risks their medications can pose to pets. Keep your dog on a leash, or leave them home where they are safe.

Want to Learn More About Holistic Pet Care?

I talk about CBD, cannabis safety, and other integrative therapies all the time in my free Facebook group.

It’s a welcoming space to ask questions, share stories, and connect with fellow pet parents.

👉️Join us here

Woofs and Wiggles,