For the welfare of our pets, THC toxicity is not to be taken lightly and can both be fatal and have long-term effects on a dog. My family’s accidental weed brownie incident put our dog Millie in the emergency hospital for seven days and cost almost $6,700 to save her life. The vets were seriously worried that she might not survive, especially after complications developed. Mille finally came home, but never fully recovered from THC-induced ataxia (imbalance and poor coordination). If we had not had pet insurance, we would have lost Millie.