The pug is the first, and it probably won't come as a surprise to most people. These tiny, wrinkled-faced puppies are notorious for having respiratory problems because of their flat features.
Although corgis were originally developed in Wales, United Kingdom, for herding, where they aren't as strong and athletic in the water.
Dachshunds have comparable swimming issues to corgis because of their large bodies and short legs.
Don't be deceived by a boxer's big legs and athletic frame. They belong to the brachycephalic type and, like the pug, have a flat face and a short muzzle.
Shih Tzus struggle to maintain their head above water due to their short muzzles and small legs.
You shouldn't anticipate your basset to continue a hunt that takes him to any deep bodies of water because these short-legged hounds were initially intended for hunting.
These adorable little puppies are very light and have full muzzles, but they are also quite sensitive to sudden changes in temperature.
Bull terriers are not naturally good swimmers; because of their short legs and thick chests, it will be harder for them to stay afloat.