Is Weed Smoke Bad for Dogs? A Veterinarian‘s Perspective

As a veterinarian and lifelong dog lover, my pups‘ health and happiness is always my top priority. Like any devoted pet parent, I want to protect them from anything that could cause them harm — including substances that may seem innocuous, like marijuana smoke.

In recent years, as cannabis laws have relaxed and smoking weed has become more socially acceptable, veterinarians like myself have seen a concerning uptick in the number of dogs exposed to marijuana. In fact, the Pet Poison Helpline saw a 448% increase in marijuana-related calls over the past 6 years.

I‘ve personally treated numerous dogs in my veterinary ER for marijuana toxicity. I‘ve seen firsthand how distressing and dangerous it can be — from dogs so lethargic they couldn‘t lift their heads, to pups hallucinating and crying out in fear. In severe cases, I‘ve witnessed dogs experience seizures and come close to death. It‘s heartbreaking to see.

While most of these cases involve dogs eating marijuana edibles or plant material directly, secondhand smoke is an often overlooked route of exposure that can also make dogs sick. Many well-intentioned owners simply don‘t realize that the weed smoke they exhale poses a risk to their beloved pups.

As a vet, I feel it‘s my duty to spread awareness and educate pet parents about this issue. If you‘re a dog owner who smokes weed (or even if you don‘t), it‘s essential to understand how marijuana affects our canine companions and how you can keep them safe.

Why Is Weed Toxic to Dogs?

The cannabis plant contains over 100 chemical compounds called cannabinoids. The two main active ingredients are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD).

THC is the psychoactive compound that produces the "high" associated with marijuana use in humans. It interacts with the endocannabinoid system, which helps regulate various functions like mood, memory, appetite, and pain sensation.

While humans and dogs both have endocannabinoid systems, dogs actually have a much higher concentration of cannabinoid receptors in their brains. This means they are exquisitely sensitive to the effects of THC — much more so than people.

In fact, dogs are estimated to be 10 times more sensitive to the behavioral effects of THC and 4 times more sensitive to its medical effects compared to humans, according to a study published in the Journal of Veterinary Emergency and Critical Care.

So while people may enjoy the mind-altering effects of THC, for dogs it is a powerful toxin that profoundly alters their mental state and bodily functions. Some key differences in how dogs metabolize THC include:

Put simply, THC overwhelms a dog‘s system with potent effects that can last for an uncomfortably long time. What‘s a mellow 2-hour buzz for a human turns into a 12-hour bad trip for a pup.

To make matters worse, dogs also have more cannabinoid receptors in areas like the brainstem that control vital functions like heart rate and breathing. This means THC doesn‘t just make them feel disoriented and distressed mentally — it can cause serious physical illness and even death in high enough doses.

The Dangers of Secondhand Marijuana Smoke for Dogs

Many people understand that it‘s dangerous for dogs to directly ingest marijuana by eating edibles, flower, or other concentrated products. But unfortunately, few realize that secondhand exposure to weed smoke can also cause significant adverse effects.

A 2016 study in the Journal of Veterinary Emergency and Critical Care found that dogs can inhale enough secondhand smoke in an unventilated room to test positive for THC in blood and urine for up to 3 days after exposure. So that bong rip or joint you exhale doesn‘t just vanish into thin air — it lingers and makes its way into your dog‘s lungs.

Dogs also have a much stronger sense of smell than humans, so they can detect marijuana smoke at much smaller concentrations. Those supersensitive noses mean they inhale far more smoke than their owners realize.

The most common signs of marijuana intoxication in dogs exposed to secondhand smoke are lethargy, sedation, disorientation, low blood pressure, and slowed heart rate. Dogs may have trouble walking normally or seem confused and out of it. Some pups become agitated, vocalize excessively, and seem disturbed by bright lights and loud sounds. Vomiting, drooling, tremors, and urinary incontinence can also occur.

In serious cases, usually involving very heavy smoke exposure in an enclosed space, dogs may suffer seizures. This is a medical emergency that requires immediate treatment. While fatalities are rare, a few tragic cases of dogs dying from severe marijuana toxicity have been reported.

Weed smoke can also irritate dogs‘ sensitive lungs and exacerbate pre-existing respiratory conditions like asthma, bronchitis, or collapsing trachea. Coughing, wheezing and shortness of breath may occur in these pups.

Beyond the acute risks of toxicity, vets are also concerned about the potential long-term effects of chronic secondhand smoke exposure, especially in young puppies or dogs frequently in the presence of heavy smokers. One alarming study found that dogs living in a home with marijuana smokers had trace amounts of THC in their hair, blood and urine months after initial exposure.

Keeping Your Dog Safe: Preventing Weed Smoke Exposure

As a vet, my professional and personal recommendation is that dog owners refrain from smoking weed around their pets. Avoiding exposure entirely is the absolute best way to protect your pup from potential harm.

However, I understand that some people rely on medical marijuana for health reasons or simply enjoy using cannabis recreationally. If you do choose to smoke weed at home, please take the following precautions to minimize your dog‘s risk:

• Always smoke outside if possible, or in a well-ventilated room away from your dog. Open windows, turn on a fan, or use an air purifier to dissipate the smoke.

• Never smoke in confined, poorly ventilated spaces with your dog, like a small bathroom, closet, or car.

• Don‘t allow your dog access to areas where you regularly smoke until the air has fully cleared.

• Change clothes after smoking and wash your hands before interacting with your dog. THC residue can easily transfer from your skin or clothing.

• Safely dispose of roaches, ash, pipes, vape pens, and other smoking paraphernalia where your dog can‘t reach.

• If you grow your own cannabis, ensure your plants are completely inaccessible to your dog. Make sure to lock up or properly dispose of all leaves, buds and stems.

• Keep all cannabis edibles and THC-infused products well out of paw‘s reach, ideally in a locking cabinet or childproof container. Never underestimate a determined dog‘s ability to sniff out a "special brownie"!

• Talk to your veterinarian about whether CBD products may help manage your dog‘s health issues with less risk compared to THC.

• If you notice your dog showing any signs of marijuana intoxication, contact a veterinarian right away for guidance.

While I hope all dog owners will take this issue seriously, accidents and unexpected exposures can happen to even the most conscientious pet parent. If your dog is exposed to marijuana smoke or ingests cannabis despite your best efforts, try not to panic.

Most dogs who receive prompt and appropriate veterinary care will survive and fully recover. Be upfront with your vet about what happened — we are not here to judge, only to provide the best possible care for your beloved companion.

The Bottom Line

As cannabis becomes increasingly mainstream and accessible, it‘s more important than ever for dog owners to educate themselves about marijuana‘s effects on our four-legged friends. Exposure to weed smoke may seem harmless to some, but it absolutely has the potential to cause toxicity and serious illness for our precious pups.

No caring dog parent wants to see their fur baby afraid, disoriented, vomiting, or struggling to breathe — all because of a substance they deliberately brought into their home. We owe it to our dogs to be responsible, informed pet owners and do everything in our power to keep them safe.

So I urge you, for the love of your loyal canine companion, avoid exposing them to weed smoke. Take precautions, educate others, and keep those pups protected. Trust me — your best friend will thank you with endless sloppy kisses and joyful tail wags!