I am not sure how a dog's metabolism works compared to a human's . We obviously have a different layout so i am not sure if cannabis works the same for us . Possibly his nausea maybe a sign of ' Herxheimer Effect" suggesting the cannabis is working . Also are you sure the Cannabis oil is of High Grade? there is alot of Snake oil salesmen out there. If you reside in Canada i would have no problem mailing you some high grade cannabis oil made from high grade outdoor organic medicine, Free of charge. Does your oil have a Amber tint to it, or is it black?