Swimming is ideal exercise for humans -- and dogs -- but there are a few things to consider before allowing your pooch to take the plunge. The chlorine in your pool water can make your dog's skin dry and itchy. In some cases, it could even slightly bleach the color of his coat. Further, letting him swim in the pool regularly could cause some harm [source: Adamson].
Your dog's paws can scratch and tear a vinyl swimming pool liner, though a fiberglass shell will be unharmed. And, all that dog hair isn't so good for the filter system. Some say a single swim by a lone dog is comparable to 50 people in a pool. While this won't necessarily cause long-term damage, you'll want to clean the filter as soon as Fluffy's done getting wet [source: Sheridan]. Oh, he just may be taking a pee in that pool too.