Contrac is lethal to mammals, birds and fish also. Although Contrac is not as lethal to other animals as Ditrac, it should still be kept out of reach of other animals. CAUTION: Be aware as pets may be exposed to secondary poisoning via contamination from a deceased rodent, that has consumed the poison. (Should this situation arise, take your pet straight to the vet). Vitamin K1 is the antidote.