Here's a lovely breakdown of the paws as many artists aren't aware of how the paw should be structured. Remember, a cat's claws are retractable, therefore, they are hidden within the paw, with only the tip of it seeping out, unlike a dog, where their nails are constantly revealed. If you're going for a realistic approach on drawing canines, it would be wise to reference various types of paws at Google Images. An artist's greatest weapon is reference!