But while it may seem harmless, there are concerns about the long-term effects of secondhand smoke on our furry friends. According to the ASPCA, dogs who are regularly exposed to marijuana smoke can suffer from lethargy, confusion, and even respiratory problems. But, they don’t really have any studies to back that one up. Most of the long term claims on pets are simply conjecture – there aren’t any real scientific papers on the subject matter. Irrespective, for pet owners who aren’t in the loop about cannabis – this shit petrifies them!