Parsons, more commonly known as Parson Russells or Parson Russell terriers, are closely related to Jack Russell terriers recognized as a separate breed. The American Kennel Club registers only Parson Russells. Parson Russells can have three different types of coat: smooth, rough or broken. You'll need to know how to determine the difference between them just weeks if not days after birth if you're looking for a puppy with a particular coat type.
Before you can determine coat types in newborn pups, you need to know the three types of coat a Parson Russell can have. Smooth coats are short, and they lie flat against the puppy's skin, with some extra hair around the whiskers or legs. Rough coats can be up to a couple of inches long, although they should still lie flat against the skin. They have lots of extra hair around the whiskers -- forming a small beard, eyebrows, ears and legs. Broken coats are somewhere between smooth and rough, with slightly longer hair and a small amount of whiskers.
Find out what types of coat the parents of the puppy in question have. If the parents, for instance, both have smooth coats, it's more than likely that the puppy will, too. If the parents have different coat types, a mixture of broken, rough and smooth puppies is likely.
Inspect the puppies carefully, looking at the length of the coat. Look for a telltale beard or whiskers that would indicate a rough-coated puppy. It may be hard to tell the difference in very young puppies, as their coats won't yet have grown much. By the age of six weeks, you should be able to determine coat type easily. A reputable breeder should be able to tell you the coat type of your prospective pup.