It is a common misconception that dogs are born knowing how to swim. Just because doggie paddling is based on the movement dogs use to propel themselves through water doesn’t mean the action is inherent to the species. And although certain breeds seem more comfortable in the water, you shouldn’t assume that your dog will inherently be a good swimmer (or even enjoy the water). However, if you know that your dog is going to be around water (i.e. you have a pool or access to a natural body of water), then you should certainly ensure that he is safe by teaching him to swim. And if your pet does enjoy the sport, then it can certainly be a way for both of you to have fun and get exercise together.
To start, you should take precautions to ensure your pet’s safety, especially if you’re not a strong swimmer yourself. Struggling with a panicking animal in deep water is not exactly easy, so you’ll want to avoid it even if you’re at lifeguard level. When you’re first teaching your dog to swim, go in the water with him and stay in the shallows, just in case he doesn’t take to it right away and you need to get him out quickly. Also, keep him on a leash. If he panics or gets in too deep, you can simply pull him out of harm’s way. You may even want to consider a doggie life vest in the beginning so that he can get used to being afloat in the water before he gets the sink-or-swim test. And you can always bring along another dog for him to follow as a method of teaching.
Once you’ve gotten him comfortable in the water, you can start to think about giving him a bit more reign while you train him on proper etiquette. Whether you’re in a pool or a lake, your dog needs to know the rules of conduct. He must come when you call him. This is imperative. If he’s out in the water and there is some sort of danger or you fear he’ll tire and be unable to return to shore, it pays to be able to call him back rather than having to swim out after him. To this effect, train him first with a long leash and then without any tether. Start in a small body of water where he can’t get into too much trouble (and if he does, you can help him). And never leave your dog unattended near water!
As for toys, some dogs love to play fetch in the water. This is fine as long as they return. If your pet is the type that likes to play keep-away, you should probably avoid playing the game near water (you don’t want him to get stuck out there because he’s too stubborn to bring you the toy. Also, avoid using balls or other round objects that can become lodged in his throat or cut off his air supply while he’s swimming back with them. As long as you take precautions and use common sense, there’s no reason you and your best friend can’t frolic and have fun in the water. Just ensure that he is properly trained to swim and that you keep a vigilant watch whenever he’s in or near a body of water.