Have they rolled in fox poo in the day or two prior, though, and not been bathed since? Do they have a foot long string of drool hanging from their chops? I've got a dog and I love her. I'd get in water with her, except she hates swimming. But a pool full of many dogs? No.
Those saying 'you don't realise how gross humans are' need to bathe a dog in a white bath. Humans are gross, but dogs are worse, and if you're not convinced by that, just the amount of hair is enough to be off putting. Imagine gagging on mixed dog hair whilst swimming. Eugh.