Thinkstock Some breeds, such as Labradors, are better suited for the water than others. Do you think this cute fur ball is enjoying her first swim?

Q. Do dogs know how to swim naturally? If not, how can I teach my dog? She's a Border Collie mix, and she gets very hot when I take her to the lake with us.

A. Dogs will naturally start “dog paddling” when they find themselves in water, but that doesn’t mean that they can stay afloat for any length of time, that they like being in the water, or that they can safely swim.

Dogs who can’t swim — though they may try their best — are typically those with large, heavy chests in relation to their hindquarters, and they often have short muzzles. These dogs may swim well enough to splash about a little under supervision while wearing a life vest, but that’s about it. The most extreme example of these breeds, the Bulldog, is so poorly built for water survival that breeders and rescue groups often require a home check to ensure that a pool is safely fenced off, and that an emergency monitor is used to alert those inside the house when something, such as a child or dog, breaks the surface of the water. Bulldogs typically sink like rocks.

How to Teach Your Dog to Swim

There aren't any physical reasons why your Border Collie can’t swim, but she may nonetheless be reluctant to do so. Even in breeds that were bred for swimming — such as Labrador Retrievers — you’ll occasionally find a dog who doesn’t enjoy being in the water. You can try encouraging your dog to swim by going out and seeing if she’ll follow, and rewarding her with praise. Dogs who love to play fetch will often go out after tennis balls or other floating toys. You might get her swimming by letting her get comfortable at a certain depth and then throwing the toy in water that’s progressively deeper. Finally, many dogs will swim just to join in the fun if they are around other dogs who enjoy swimming.

But again, even if your dog comes to love swimming, safety is still up to you. Make sure your dog doesn’t get overly tired, and be aware that puppies and older dogs tire more easily and seem less aware of their fatigue until it’s too late. Stay away from strong currents and areas with underwater debris that can entangle a dog.

Keep Your Non-Swimmer Comfortable

If your dog never comes to enjoy swimming, she can still enjoy going to the lake with you. Make sure she wears a life vest. Booties wouldn't hurt if the sand is sizzling. She also must have nonstop access to cool drinking water and must be able to get into the shade as often as she wants. When she starts to get hot, take a bucket and soak her frequently, especially her belly. Be aware, always, of signs of heat stress.

If you’re able to keep her cool, she’ll be able to enjoy her lake time with you safely, even if she never does learn to like swimming all that much.