Binary, my rescue Basenji mix, loves all people and other dogs, and I even have a picture of her curled up with the cat. (Although the cat insists it's photoshopped.) At the dog park, she will run and romp and roll around with whatever dogs are there. However, she has never been around really tiny dogs in the 3 years I've had her. Two weeks ago I boarded her with a family while I was out of town. Binary attacked the owner's Chihuahua, leaving a wound that required a couple of stitches. Then last weekend at the dog park she attacked a tiny dog, I think a Maltese, weighing about 15 pounds. We rushed the little guy to the urgent care vet who found two wounds, one of which needed a drain. I am baffled. I don't know if she's completely flipped, or if something is wrong with her health. I have an appointment for a health checkup, and I've been keeping her away from other dogs, but I would sure appreciate any insight any members might have. Binary has an extremely high prey drive. I live in the country, and no rodent of any sort will survive long on my property. Given her usually friendly nature, is it possible that she mistook those tiny dogs for rodents? Surely her sense of smell would tell her the difference, wouldn't it?