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.
Even in breeds that were bred for swimming, such as Labrador Retrievers, you will occasionally find a dog who does not enjoy being in the water. You can try encouraging your dog to swim by going out and seeing if they will follow, and rewarding them with praise. Dogs who love to play fetch will often go out after tennis balls or other floating toys. You might get them swimming by getting them comfortable at a certain depth and then throwing a toy in water that is progressively deeper. Finally, many dogs will swim just to join in the fun if they are around other dogs who enjoy swimming.
Keep Your Non-Swimmer Comfortable
If your dog never comes to enjoy swimming, they can still enjoy going to the lake with you. Make sure they wear a life vest. Booties wouldn't hurt if the sand is sizzling. They must also have nonstop access to cool drinking water and must be able to get into the shade as often as they want. When they start to get hot, take a bucket and soak them frequently, especially the belly.
If your dog loves swimming or not, safety is still up to you. Make sure your dog does not 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.