Swimming is an excellent exercise for your dog to participate in.
It works the heart and the lungs as well as stimulates the entire musculature system.
Unlike heavy running and darting through hard ground, this will not be hard on the hips and shoulders. This makes it perfect for puppies that are just developing and adult dogs that have any sort of structural defects.
Swimming is so good for tender joints or injuries that hydrotherapy is often used in rehabilitating dogs after surgery. The water takes the weight off legs and feet, yet allows them to move to gain strength.
If properly introduced to swimming, most dogs can learn to very well. Keep in mind that there are a few breeds that are just not built to swim so well.
One example is the bulldog. The bulldog has a wide torso and such short legs that it becomes difficult.
This also makes for tough breathing in the water for dogs with similar physical attributes, like brachycephalic breeds, with a short snout.
Dachshund and basset hounds also have a hard time in the water but it does not mean that they will not or cannot enjoy it .
Some dogs just plain hate the water and it usually is because of not being properly introduced to it.
The absolute worst thing you can do is just throwing your dog into water.
This is the biggest mistake that dog owners make when wanting to teach their dog how to swim.The best time to teach your dog to swim is on a super hot day. Even dogs that generally dislike water will enjoy getting cooled off in the creek or lake.
To be completely safe, fit your dog with a life jacket, with an attached handle to grab to pull them out if they get into trouble. This is especially important if you're out on a boat and away from shore.
Make sure to dry them off after they get out of the water, and watch for chiggers, which burrow in to the top layer of skin.
Also familiarize yourself with the correct doggie cpr techniques, as dogs can get out of their depth too, just like people.