The term "bird dog" originally referred to a hunting dog that was trained to retrieve birds. However, if we're looking for antonyms for this term, we can explore words that describe animals that are not typically used for hunting or retrieving birds. For instance, cats, which are known for catching birds, would be an antonym, as would a fish or an elephant. In general, we could also use terms that describe animals that are not related to hunting or the great outdoors, such as pets like hamsters, reptiles like snakes, or farm animals like cows. Ultimately, there are many potential antonyms for "bird dog," depending on the context and the desired effect.