He will grow a little but he will always be a little smaller than the rest of the litter.
My Chihuahua Just Had A Litter Of Puppies. I Have One Runt In The Litter Will He Stay Small In Size?
The runt usually does stay smaller than the other pups but this does not mean that he is not healthy. Just make sure that the other pups let him eat.
Like stated above, the runt does not mean that the pup will always be smaller than the rest of the pups. Yes they are born smaller, but usually they catch up pretty quick. My sister used to breed rottweilers, and her neighbor got the runt from one of the litters, and named him tiny, but guess what he is not tiny by any means, he is a dog that is at least 100lbs if not more, he just got huge, so it is hard to say. But because it is a small breed he may stay small, but then again he may just be the same size as all the rest of the pups.