I'm not going to say that MJ is bad for dogs because I don't know the facts. However dogs (and some other animals) do not sweat, they pant to cool themselves. Sweat is one way (among others) that humans get rid of toxins. Some veterinary drugs are the same as human drugs and some are not. Aspirin for example does not do the same thing in humans and some animals. It is possible that some animals do not process and excrete`recreational drugs the same way we do.