Our cat Gogo was nursed by a mommy chihuahua from newborn age. She doesn’t like cats, but she loves dogs. Gogo will hop right in with a new mom Chihuahua and newborns,which I discourage. I had to put tops on the playpens to stop her from doing this. Every once in a blue moon I leave the playpen top open while I clean and replace food and then I catch GoGo in sitting next to a new mom with nursing puppies.Thank goodness my Chihuahua moms are so good natured and always have put up with this and never tried to harm GoGo.