DENVER (CBS4) – The popularity of medical marijuana in Colorado has had an unintended side effect — dogs getting stoned, sometimes with deadly results.

Some people firmly believe that if medical marijuana helps people, it also helps their pets, but that’s not always the case. Marijuana can be harmful and sometimes toxic for dogs. New research shows that with medical marijuana, the number of dogs getting sick from pot is spiking.

“They basically have lost a lot of their fine motor control, they have a wide-based stance and they are not sure on their feet,” said Dr. Debbie Van Pelt of VRCC, the Veterinary Specialty and Emergency Hospital in Englewood.

Vets say they used to see dogs high on marijuana just a few times a year. Now pet owners bring in doped-up dogs as many as five times a week.

“There are huge spikes in the frequency of marijuana ingestion in places where it’s become legal,” Van Pelt said.

Colorado is one of those places.

Most of the time veterinarians say dogs get the medical marijuana by eating their owners food products that are laced with marijuana that were left out in the open. More and more dispensaries sell those kinds of products.

“I just want dogs, kids to be safe. It needs to be treated like any other drug. If you came home with a prescription of vicodin from your doctor you wouldn’t just leave it sitting there,” veterinarian Dr. Stacy Meola said.

Meola is a veterinarian at a Wheat Ridge clinic. She coordinated a five-year study that shows the number of dogs sickened by marijuana has quadrupled in Colorado since medical marijuana was legalized. Most dogs survive, but not all.

“Two dogs, however, got into baked goods with medical grade marijuana butter in it, which presumably seems to be more toxic to the dogs, so we did have two deaths,” Meola said.

That’s the exception. Most of the time the dogs will end up showing symptoms such as staggering, acting lethargic, vomiting, and being overly sensitive to sound and light. Sometimes they fall into a coma. It’s the doggie equivalent of a “bad trip.” After treatment most are back to normal within 24 hours.

While many dog owners think it’s funny to get their dogs stoned and have posted videos of their stoned dogs, Colorado veterinarians say there’s nothing funny about dogs on dope.

“We need people to realize it is potentially toxic and potentially fatal to their pets,” Van Pelt said.

Veterinarians say frequently when the sick dogs come in, their owners are reluctant to admit medical marijuana might have been the cause. They say if that’s a possible factor, tell the vet right away and they can more quickly treat the dog.