Cavalier King Charles Spaniels grow a little larger than a Yorkshire Terrier, with the typical weight for this dog breed being around 13 to 18 pounds, according to Caughill.
Patrik Holmboe, a veterinarian with Cooper Pet Care, says that this breed only grows to a maximum size of 8 to 16 pounds, which helps to give it "that perpetual puppy look."
If you're looking for a puppy-like pet that packs a lot of intelligence and personality in a small frame, Caughill suggests a Toy Poodle.
Courtnye Jackson, veterinarian and founder of The Pets Digest, says you can also get the same puppy-like appearance from anything mixed with a Toy Poodle
The Maltese breed also belongs to the Toy group of dogs, Caughill tells Best Life. "So they only grow to about 7 lbs. when fully grown," he says.
Pomeranians weigh around just 3 to 7 pounds, and they don't really change their appearance as they get older, according to Caughill.
Chihuahuas are another breed that doesn't change much in appearance over time, and that means they'll be tiny forever.
The AKC describes the Bichon Frise as a "small but sturdy" dog. According to Holmboe, this breed only grows to a maximum size of 1o to 20 pounds.