Researchers have found that whether or not cannabis is legal does not affect the rate at which dogs are hospitalized for exposure to tetrahydrocannabinol (THC), the psychoactive ingredient in cannabis. While cannabidiol (CBD) can positively affect dogs, THC is known to cause depression, vomiting, and tremors. High doses of the compound are even known to cause tachycardia, hyperexcitability, and seizures.
For the study, researchers examined data from the 12 months before cannabis became legal in Canada in October 2018, and the 12 months afterward. The researchers noted that while the number of Canadians using cannabis before legalization was 4.5 million, it increased to 5.1 million after legalization.
From the data, the researchers found that there was no significant difference in the number of dogs hospitalized for THC toxicity between the 12 months following legalization and the 12 months prior. They also noted no link between cannabis legalization and whether or not presented toxicities were deemed ‘confirmed’ or ‘suspected’.
In fact, in real terms, the number of dogs hospitalized for THC intoxication decreased over the period. While in the 12 months before legalization, there were 39 total cases of cannabis toxicity among dogs; afterward, there were only 35.
The researchers did find, however, that among the cases, puppies- or dogs under one year of age- were disproportionately affected, making up a third of all cases after legalization. The researchers say that this may have happened as puppies are more likely than adult dogs to explore their environments by taste, making them more vulnerable to accidentally consuming THC-consuming cannabis.
While in many cases, owners did not see their dogs ingest cannabis, diagnoses made by looking at their symptoms suggested that 66% of cases occurred due to the ingestion of edibles.