All 3 of mine have been in the pool several times- mostly as a result of chasing each other and falling in.
My daughter does take her dog, Spike in to swim with her but he's much happier on a raft. Truthfully, none of them are water dogs. It has never affected their hair although they do get baths after swimming. We don't have life jackets for them. We are just very careful to never let them out alone.
__________________
"If you have men who will exclude any of God’s creatures from the shelter of compassion and pity, you will have men who will deal likewise with their fellow men." — St. Francis of Assisi, 1181-1226