If your dog bites a toad, the first thing you should do is check to see if the toad is poisonous. If it is, then you will need to take your dog to the vet immediately. If the toad is not poisonous, then you can try washing the area where your dog was bitten with soap and water. You may also want to give your dog a bath if he or she has been rolling around in the mud or grass where the toad was found.