With the increasing medical use for Cannabis and its legalization in many states, veterinarians are seeing more cases of toxicity in their pet patients. The Cannabis sativa plant contains over 400 chemical substances, including over 100 different cannabinoids, which are the main chemicals that interact with our nervous system and other organs. Of these, delta-9-tetrahydrocannabinol (THC) is what can be toxic to our pets. Dogs and cats are intoxicated when they ingest dried parts of the cannabis plant, THC products, or inhale second hand smoke. Baked goods are a common culprit as they are often quite enticing to eat. Additionally, if THC-infused butter is used, this will have a higher concentration than other forms of THC, meaning just a small amount can cause significant effects.
The main signs of intoxication include: dilated (large) pupils, stumbling/poor coordination, and dribbling urine. Some dogs can be very reactive to movement and light and act scared or panicked. Signs can occur within 30 minutes of ingestion and can last for hours to days depending on the quantity ingested. In most cases, pets will recover. In severe cases, the toxin can cause seizures, coma, or respiratory depression that can be so significant that dogs can stop breathing.
Diagnosis of intoxication is based mainly on clinical signs and history, as the urine test that humans use can produce inconsistent results.
Treatment is mainly focused on supportive care: oxygen supplementation, fluid therapy, and medications to control heart rate, respiratory rate, seizures and agitation. It is typically not recommended to induce vomiting as pets can aspirate due to their altered mental state. Cannabis can also inhibit vomiting, making it futile, unless it is done immediately after ingestion. Veterinarians will often also use intravenous lipid therapy to help bind the toxins.
Thankfully, prognosis is generally very good, although full recovery can often take several days depending on the dose. While THC toxicity is often curable, there are other toxicities and illnesses that can look similar with very different treatments and prognoses, so it is best to tell your veterinarian if you know your pet was exposed to THC.
When discussing THC, it is also common to discuss Cannabidiol (CBD). This is another cannabinoid that is widely used in human medicine and gaining traction in the veterinary world. It is mainly derived from hemp (the Cannabis plant containing less than 0.3% THC) and unlike THC; it does not have psychoactive properties. CBD is used to improve sleep, reduce stress/anxiety, and reduce inflammation. In veterinary medicine, there are unfortunately no regulations on CBD and no FDA approved veterinary CBD products. This means there can be contaminants and pesticides, and what is on the label is not necessarily what is in the bottle. Additionally, not all products are the same. It is based on the plant genetics, cultivation and processing. While there is no governing agency to regulate CBD, the National Animal Supplement Council has designated itself to aid in the regulation and evaluation of the various CBD products. While CBD is very well tolerated in dogs and cats, there can be some side effects and interactions with other medications, so it is important to discuss with your veterinarian before giving it to your pet.