Dew Claws

All dogs have five digits on their front feet. Four are equivalent to our fingers and the fifth is a smaller digit equivalent to our thumbs which doesn't connect with the ground known as the front dew claw. On the hind feet all have four digits equivalent to toes 2 to 5 but some may have a residual big toe known as the hind dew claw. Occasionally is duplicated so they have double hind dew claws.

In the beagle most people will remove the dew claws when the puppies are very young, legally it must be done before their eyes open in the nest so mostly this is done at three to four days of age. The main reason for removal is that they are quite loosely attached and prone to catching and tearing when the dog is older. It may be done by a lay person but must be done quickly and neatly. Usually a quick snip and then apply ferric chloride or potassium permanganate to the wound.

The Kennel Club standard requires hind dew claw removal and most breeders remove front as well.
Hind dew claws are inherited as a dominant trait with incomplete penetrance. This means generally at least one parent has to have had one or more for the puppies to have them. However occasionally you find neither parent did but grand parents had them and the gene is passed that way.