CSU’s Vet Teaching Hospital sees rise in animals ingesting cannabis

highcat-1Veterinary hospitals in Colorado are seeing an increase in cannabis toxicity cases involving dogs and cats since the legalization of medical and recreational marijuana in the state, according to a Colorado State University study.

Animals that have accidentally ingested large amounts of tetrahydrocannabinol (THC), usually by eating baked goods containing THC-infused butter or oil, exhibit symptoms such as central nervous system depression, uncoordinated movement, dilated pupils and urinary incontinence.


“Basically, like humans, they become very tired and kind of not wanting to move very much,” said Christy Tomcik, veterinary technician work lead in the urgent care department of the Veterinary Teaching Hospital at CSU. “For those cases we really want to monitor them really closely, make sure they’re not choking, not vomiting, not having other complications.”

Trends in marijuana toxicosis in dogs living in a state with legalized cannabis were researched by CSU and the Journal of Veterinary Emergency and Critical Care, which evaluated 125 dogs with known or expected cannabis toxicity. The study found a four-fold increase in toxicity cases in the last five years.

Colorado voters approved medical cannabis in 2000 and dispensaries have been popping up since. Fort Collins currently has 11 dispensaries, none of which sell retail cannabis. Retail, or recreational, cannabis sales began Jan. 1 of this year in Colorado. As of this April, Larimer County has approved its first retail shop, Choice Organics.

The number of animal THC toxicosis cases at CSU increased from 0.16 cases per 1,000 visits in 2005 to 0.81 cases per 1,000 visits in 2010. CSU’s Veterinary Teaching Hospital sees a few cases a month and extreme cases just a few times a year, according to CSU Veterinary Hospital director Tim Hackett, who specializes in small animal emergency medicine.

Other facilities in the state have seen similar increases. The number of cases at the Wheat Ridge Animal Hospital and Veterinary Specialists, located west of Denver, increased from 1.5 cases per 1,000 visits in 2005 to 4.5 cases per 1,000 visits in 2010.

The Wheat Ridge hospital also experienced two THC toxicity-related deaths. These were likely because the dogs were so unconscious from the THC and nauseated from the baked goods that they aspirated their vomit, causing respiratory failure, according to Hackett.

“It’s just like the drummer from Led Zeppelin (John Bonham),” Hackett said. “The vodka didn’t kill him. He was unconscious and aspirated vomit.”

While there is no antidote for THC toxicity, a veterinary hospital can help remove THC from pets’ systems and possibly save their lives.

“We provide supportive care for them,” said Steve Sheldon, director at the Gypsum Animal Hospital. “That’s all we can do … We can treat the symptoms. If they have a seizure we can give them anti-seizure medication. If their heart rate gets really low we can give them low heart rate medication.”

Other methods used by Sheldon and Hackett’s hospitals include pumping stomachs and administering activated charcoal, which helps absorb the toxins. The cost of such an incident can range from $100 to $200 if it is an outpatient situation, to over $1,000 a day if the animal is admitted to the hospital and given an IV and a ventilator.


To avoid this, Sheldon and Hackett recommend that owners lock up their cannabis, no matter the form. Pets, especially dogs, will eat an entire pan of THC oil or an entire stick of THC infused butter, according to Hackett.

“I think (the cases are) going to continue to increase just because the product is likeable to dogs,” Sheldon said. “Dogs and cats like it …The more product there is, the more chance there is of exposure and toxicosis.”

Dogs metabolize THC differently than humans do, which makes it stay in their system longer, according to Hackett. This may cause a dog to appear higher the following day, which is what brings most owners to his hospital.

“You know, maybe their personal experience is you’re feeling pretty normal the next day so they see them getting more stoned and they think something is wrong,” Hackett said.

Medicinal and therapeutic benefits from cannabis are being looked into for animals, but it is still illegal for veterinarians to prescribe medicinal cannabis their patients. However, Sheldon said some of his colleagues are having patients tell them they are giving their pets medical cannabis to treat problems like pain, cancer, nausea, seizures and behavior disorders.

CSU and the VTH will host discussions concerning possible research regarding medicinal cannabis for animals in terms of proper dosage and therapeutic and pain relief benefits, according to Hackett.

“We’re just trying, as a University, to decide if this is something we want to be known for,” Hackett said. “I support research into understanding the metabolism of marijuana and possible medical benefits.”

Collegian Green Beat Reporter Laren Cyphers can be reached at news@collegian.com or on Twitter @larenwritesgood.