The pug comes first, which may not come as a surprise to most people. Due to the flatness of their features, these little, wrinkly-faced puppies are known to have difficulty breathing.
They can be taught to swim, although it won't seem very natural owing to their big bodies, barrel-shaped chests, and lengthy legs, which do not bode well for the water.
They have longer muzzles than brachycephalic breeds like the pug, so they won't have the same difficulty breathing in the water, but their short legs will prevent them from paddling for extended distances.
Don't be deceived by a boxer's big legs and muscular physique. As with the pug, they have a flat face and a short snout, and, you got it, they are classified as brachycephalic.
The tiny muzzles and small legs of Shih Tzus make it difficult for them to maintain their heads above water. In addition, they carry a thick coat, which may get wet, making it harder for them to breathe.
These short-legged hounds were originally designed for hunting, but you shouldn't expect your basset to continue a quest that goes to a body of water with a depth of more than a few feet.
They would struggle to acclimatise naturally if put in cold water and will likely be grateful that you choose to play on land instead.
Bull terriers are not natural swimmers; their deep chests and shorter legs make it more difficult for them to float. Despite being a fairly powerful and energetic breed of dog.