Is Marijuana (THC) toxic to dogs?
Yes, all forms of marijuana, including plants, dried materials, and edibles, are toxic to dogs. The primary psychoactive component, tetrahydrocannabinol (THC), affects a dog's neurological system, and even small amounts can cause significant symptoms.
Dogs have a higher concentration of cannabinoid receptors in their brains compared to humans, making them more susceptible to the toxic effects of THC. Edibles are particularly dangerous as they may contain other ingredients toxic to dogs, such as chocolate or xylitol, and the butter or oil used can lead to pancreatitis. Due to the high variability of THC concentration in different products (from plant material to potent concentrates), any exposure warrants veterinary consultation.
Toxic dose by dog weight
There is no established safe dose of marijuana for dogs, as the concentration of THC varies significantly between products. Published data is limited and ranges vary, so veterinary toxicologists at the ASPCA Animal Poison Control Center (APCC) and Pet Poison Helpline recommend treating any exposure as potentially harmful.
| Dog Weight | Toxic Dose (Any Amount) |
|---|---|
| 10 lbs / 4.5 kg | Any amount is considered potentially toxic. |
| 25 lbs / 11.3 kg | Any amount is considered potentially toxic. |
| 50 lbs / 22.7 kg | Any amount is considered potentially toxic. |
| 75 lbs / 34 kg | Any amount is considered potentially toxic. |
| 100 lbs / 45.3 kg | Any amount is considered potentially toxic. |
Symptoms timeline
Symptoms of marijuana toxicity in dogs typically appear within 30 to 60 minutes of ingestion but can be delayed for hours, especially with edibles. The signs can last from 12 hours to several days depending on the dose consumed.
- 0-2 hours: Onset of ataxia (stumbling, wobbliness), lethargy, disorientation, dilated pupils. Some dogs may show agitation or vocalization initially.
- 2-6 hours: Symptoms peak. Classic signs include severe ataxia, dribbling urine (urinary incontinence), vomiting, slow heart rate (bradycardia), and hyperesthesia (exaggerated reaction to sounds or touch).
- 6-24 hours: Symptoms typically persist. Lethargy and depression are common, along with continued ataxia and urinary incontinence. The dog may be difficult to rouse.
- 24+ hours: In most cases, signs begin to gradually resolve. However, with very high doses, symptoms can persist for up to 72 hours and may require ongoing supportive veterinary care.
What to do right now
Dog poison control: phone numbers, fees and when to call. If you suspect your dog has ingested marijuana, immediately collect any remaining material and call your veterinarian or a pet poison control hotline. Do not induce vomiting unless specifically instructed by a veterinary professional, as this can be dangerous for sedated pets.
- Secure Your Dog: Confine your pet to a safe, quiet, and comfortable area to prevent injury from stumbling.
- Gather Information: Collect any packaging or remnants of the marijuana product to help experts determine the potential dose and ingredients. Note your dog's weight and the approximate time of ingestion.
- Call for Help: Contact your veterinarian, the ASPCA Animal Poison Control Center (APCC), or the Pet Poison Helpline immediately. These experts will provide guidance based on the specific situation.
- Do NOT Induce Vomiting: THC can cause rapid sedation and inhibit the gag reflex, which increases the risk of aspiration pneumonia if the dog vomits. Professional guidance is essential.
When to call a vet
You should call a veterinarian or poison control hotline immediately upon discovering or suspecting any marijuana ingestion, regardless of the amount. The variable potency of THC means any exposure is a potential emergency.
- If you see your dog eat any part of a marijuana plant, edible, or concentrate.
- If your dog exhibits classic signs like severe wobbliness (ataxia), dribbling urine, or extreme lethargy.
- If the dog becomes non-responsive, has a very slow heart rate, or experiences seizures (rare).
- If the ingested product also contained other known toxins like chocolate, raisins, or xylitol.
How Marijuana (THC) compares to other common toxins
Unlike toxins such as xylitol, where even a tiny amount can be life-threatening, the primary danger of THC is severe neurological impairment, with a high margin of safety before it becomes lethal. However, its effects can be more prolonged and dramatic than toxins like chocolate, often requiring veterinary monitoring for 24-48 hours.
THC is often compared to chocolate because both are found in edibles. While a large amount of milk chocolate might cause mild stomach upset, a similar-sized brownie containing potent THC can cause severe neurological signs requiring hospitalization. Compared to grapes, where toxicity is idiosyncratic (unpredictable), THC toxicity is dose-dependent, though the dose is hard to determine from packaging alone.