On the heels of the legalization of marijuana for recreational use in Colorado and Washington, last week the Justice Department effectively announced it won’t challenge other states’ attempts to legalize the drug for medical or recreational use. While marijuana is still classified as illegal, eight new federal enforcement priorities were issued that essentially discourage federal prosecutors from pursuing non-violent marijuana users and focusing efforts on marijuana sales linked to criminal activity. Many believe these policy changes lay the groundwork for more states to legalize marijuana, especially for medicinal use in humans. Meanwhile, debates about whether or not medical marijuana is beneficial for ailing pets are becoming more frequent. While the jury remains out regarding the benefits of medical marijuana for pets, recent news coverage and an increase in the number of pets being treated for accidental marijuana poisonings are raising questions about the safety of marijuana, especially in dogs.

A veterinary study from Colorado published recently by the Journal of Veterinary Emergency and Critical Care reported a four-fold increase in the number of dogs treated for marijuana intoxication between 2005 and  2010, following the legalization of medical marijuana in that state. Similarly, over the past five years Pet Poison Helpline® has experienced a 200 percent increase in the number of cases for pets that have ingested marijuana.

“The trend we’ve seen in recent years involving pets and marijuana is significant,” said Ahna Brutlag, DVM, MS, DABT, DABVT and associate director of veterinary services at Pet Poison Helpline®. “Of all illicit drugs, marijuana has always been responsible for the most calls to Pet Poison Helpline®, but this recent increase is the sharpest we have ever seen.”

In an effort to help pet owners and veterinarians better understand how marijuana affects pets, the veterinary and toxicology experts at Pet Poison Helpline® provide these answers to some of the more frequently asked questions.

Q. Can pets die from marijuana poisoning?

A. Yes, but thankfully this is rare. Speaking in terms of drugs, marijuana has a “wide margin of safety,” meaning that the lethal dose is extremely high as compared to the lower dose necessary to result in therapeutic effect (or in this case, toxic effect). Therefore, it’s extremely rare for pets to ingest enough marijuana to cause death, although they may still need medical treatment to recover from poisoning. In the recent Colorado study, two small dogs died, both of which had ingested baked goods made with highly concentrated medical grade marijuana butter. Over the past five years, no marijuana-related deaths in pets have been reported to Pet Poison Helpline®.

Q. How do pets get exposed?

A. Poisoning in pets can occur following inhalation of the smoke, ingestion of the dried plant, ingestion of foods laced with marijuana (e.g., brownies, cookies, butter), or products made with hashish. Most commonly, dogs eat the dried plant directly from their owner’s stash, or eat foods made to contain marijuana. When those foods also contain chocolate, the risk of additional poisoning is increased.

Q. What are the signs of marijuana poisoning in pets?

A. Signs of marijuana poisoning in dogs and cats include glassy-eyes, stumbling/incoordination, dilated pupils, vomiting, coma, and in about 25 percent of dogs, agitation and excitement. Urinary incontinence or urine dribbling is also very common, especially in dogs. Serious effects include changes in heart rate, coma, tremors, and seizures. The signs typically begin 30 to 60 minutes after ingestion, or sooner if inhaled.

Q. What are the treatments for marijuana poisoning?

A. Treatment for marijuana poisoning includes IV fluids, anti-vomiting medication, oxygen, blood pressure monitoring, thermoregulation, and in severe cases, ventilator/respirator support. Decontamination (including inducing vomiting and giving charcoal to bind up the poison) may be performed if the ingestion was recent or large, but should never be done without consulting a veterinarian or Pet Poison Helpline®. However, inducing vomiting may be difficult due to the properties of marijuana. It can take pets 18 to 36 hours to recover.

Q. Can my veterinarian use an over-the-counter drug test (for humans) to test if my dog was poisoned with marijuana?

A. Over-the-counter human urine drug screening tests have been used to help diagnose dogs with marijuana exposure; however, the success rate is highly inconsistent and false negatives occur. With these drug screening tests, a positive THC result is consistent with marijuana poisoning, while a negative result does not conclusively rule out poisoning.

Q. Will Pet Poison Helpline® report pet owners to the police if his/her dog ingests marijuana?

A. No. The veterinary staff at Pet Poison Helpline® is primarily concerned about the wellbeing of the pet. They ask only that pet owners are truthful and communicate exactly what the pet was exposed to, so they can quickly identify the poisoning and treat it as soon as possible.