This is your dog on drugs: Marijuana proves perilous for pets

It was obvious that Maizey, a brown-and-white pit bull mix, wasn't feeling well. She confined herself to her bed, where she lay shaking and confused.

When she tried to get up she stumbled, but on the way to the vet she started leaping like a puppy chasing imaginary balls. After a battery of tests, it was determined that Maizey was in no immediate danger, but was likely high on marijuana.

"Dogs will get into anything and everything," said Dr. Dorrie Black of the San Francisco-based veterinary clinic Animal Internal Medicine and Specialty Services.

Thirty-three states and the District of Columbia have legalized pot in some form. And since Colorado ushered in recreational marijuana in 2014, nine more states and D.C. have followed. As weed has become easier for people to get, it has also become a greater hazard for dogs.

Dogs ingest marijuana by eating the remainder of a joint, or getting into someone's edible marijuana, either at home, on the street or in parks, Black said. Another unsavory source in cities with high numbers of people living on the streets? Human feces tainted with marijuana.

But while it can be easy for dogs to find marijuana, it's not always easy to determine if a dog has ingested it.

Dr. Benjamin Otten of allCREATURES veterinary clinic in El Cerrito, Calif., said he looks for these telltale symptoms when identifying marijuana toxicity in a dog:

• Dribbling urine.

• A dazed or glazed look in their eyes.

• Low temperature.

• Nervousness.

Dogs exhibit these symptoms because THC, the psychoactive element in marijuana, is poisonous to them.

What can happen is that the drug can sedate a dog so fully that it can inhale its own vomit, which can be lethal. For that reason, Black cautions pet owners to play it safe.

"If you do not know the quantity that they got into, I'm always going to recommend that you go to your vet," she said.

Cannabidiol, or CBD, on the other hand, is actively being marketed to pet owners for a variety of pet ailments. But the research is incomplete about its efficacy for treating such things as animal anxiety and seizures, and veterinarians are not allowed to recommend CBD to patients.

It's not known how many dogs have died as the result of ingesting THC. A Colorado study found that two dogs that had eaten chocolate baked goods made with marijuana-infused butter died, but it's unclear if this was from the marijuana, the chocolate or the combination of those components. (Butter and dark chocolate, common ingredients in edible marijuana products, can be highly toxic to dogs.)

But calls to the ASPCA's Animal Poison Control Center about dogs eating weed have increased sevenfold since last year, and calls to the Pet Poison Helpline have quadrupled in the past five years. A 2012 study conducted in Colorado found a significant correlation between the number of medical marijuana licenses and marijuana toxicosis cases in dogs.

"In those states that have legalized marijuana, we are seeing an increased incidence of marijuana toxicity in pets, especially in dogs," he said.

Recreational marijuana is legal in 10 states and the District of Columbia, and many more states allow medical marijuana.

In California, Black and Otten said the changes to marijuana's legality have not significantly increased the number of visits they get from blitzed dogs. Black said she sees up to three affected dogs a week in the summer.

What Black and Otten said has changed, however, is the potency of the drugs the dogs are consuming.

Black said that at the start of her career in emergency veterinary medicine, marijuana toxicity consisted of a dog eating the end of a joint with fairly low amounts of THC. But, she said, "we got heavier and heavier toxicities over time because of medical grade marijuana and because of edibles."

On average, it typically takes about 24 hours for a dog to return to normal, but that can vary depending on the strength and amount of marijuana the dog has eaten. The cost of treatment can vary widely. De Jong said cases that require interventions such as blood work and IV fluids could cost up to $1,000.

It's rarer for cats to ingest marijuana. Black said she's seen only one case involving a cat in her 17 years in emergency veterinary medicine. De Jong hasn't had any high cats come through his practice, but he said some cats do like to chew on plants, which could be an issue if someone is growing marijuana at home.