The first one probably won't shock you: it's the pug. The flat faces of these little wrinkled puppies make it difficult for them to breathe.
While corgis were originally developed for herding in Wales, United Kingdom, they aren't very strong or athletic swimmers.
Dachshunds, like corgis, have difficulty swimming due to their large body and short legs.
Boxers may seem intimidating because of their muscular build and lengthy legs, but don't be deceived.
Because of their small muzzles and tiny legs, Shih Tzus have a hard time swimming. Its thick coat may weigh them down and make breathing difficult.
Although the basset hound was initially developed for hunting, don't count on him to keep going if the trail takes him into some deep water.
Lightweight and with a full nose, these sociable canines are yet very sensitive to temperature swings.
Due to their deep chests and shorter legs, bull terriers are not built for swimming and will have a harder time maintaining their buoyancy.