Uncle Lu in The Secret Life of Pets 2 is a Bernese Mountain Dog. They are large dog breeds and are representatives of long legs. They are divided into long-haired and short-haired varieties. Uncle Lu in The Secret Life of Pets 2 is a short-haired dog. Hairy Bernese Mountain Dog, this kind of dog has a high IQ, can be trained and can be done well. They have good personalities and are suitable for home breeding and can also be used as working dogs.