Cannabis, or marijuana, is not safe for dogs. Tetrahydrocannabinol (THC), one of a group of compounds called cannabinoids and the psychoactive ingredient in marijuana, is toxic to dogs. It can cause adverse effects and, in very, very rare cases, even death. Dogs are much more sensitive to the effects of THC than people, so much less cannabis is needed for your dog to start showing signs of toxicity.
The signs of marijuana poisoning in pets can vary depending on the amount ingested and the form it was taken in. Common symptoms include lethargy, dilated pupils, vomiting, excessive drooling, and changes in heart rate. If your pet has ingested marijuana, it is important to seek veterinary care immediately. Treatments for severe THC poisoning include intravenous fluids, medications, fluids, and possibly induced vomiting.
There may be some situations where THC products are appropriate for dogs, generally when the benefits outweigh the risks. However, it is important to consult with your veterinarian before giving your pet any type of cannabis product. Over-the-counter human urine drug testing has been used to help diagnose exposure to marijuana in dogs; however, the success rate is highly inconsistent and false negatives occur. With these drug tests, a positive THC result is consistent with marijuana poisoning, while a negative result does not conclusively rule out poisoning. The veterinary staff at Pet Poison Helpline is primarily concerned with the well-being of the pet and they only ask that pet owners be sincere and communicate exactly what the pet was exposed to. THC percentages vary between different strains, so you should be even more careful if you have marijuana that contains more than 20% THC.
On the other hand, a 150-pound dog would need 1023 grams of marijuana flower or 256 grams of THC concentrate for a possible lethal dose. They also show that CBD for dogs has more potential benefits than THC in treating several different ailments. For example, ingesting a “potted brownie” requires a different treatment than inhalation, since eating the brownie requires treatment for the toxicity of cannabis and chocolate, while inhalation may require additional treatment for respiratory irritation.