A summer of lake swims and paddling-pool chaos is exactly what a dog is for — right up until the head-shaking starts. Ear infections are among the most common things a vet treats, and the ones that follow swimming are also among the most preventable. The fix is a two-minute habit, not a product you spray in.

Just how common is it?

Very. A large UK primary-care study of over 22,000 dogs put the one-year prevalence of otitis externa — inflammation of the outer ear canal — at 7.30%, or roughly one dog in fourteen every year (O'Neill et al., 2021). That makes sore ears one of the single most frequent reasons dogs end up at the clinic. It's common enough that "my dog just gets ear infections" starts to sound normal — but for most dogs it's preventable, not inevitable.

Why some dogs are sitting ducks

The same study found that breed and ear carriage were the top-ranked risk factors — Basset Hounds carried almost six times the odds of crossbreds (O'Neill et al., 2021). The reason is plumbing. A floppy ear flap seals warm air over the canal; hair inside traps moisture; and the dog's L-shaped ear canal doesn't drain well to begin with. Add water and you've built the perfect incubator: warm, dark and damp is precisely what yeast and bacteria want (VCA). Swimmers with heavy, hairy ears are the classic case.

The habit that prevents most of them

You can't change your dog's ear shape, but you can remove the one variable that tips a healthy ear into an infected one: trapped water. After every swim or bath, dry the ears — gently blot the flap and the opening of the canal, don't jam anything deep inside (AKC). For dogs with a lot of fur around the canal opening, keeping it trimmed helps air circulate. That's genuinely most of the prevention.

Prevention starts before the water, too. A dog that tires mid-swim gulps, panics and goes under — and a fatigued swimmer is a soggy-eared one. Flotation keeps a weaker or older swimmer higher and calmer in the water, which is a safety point in its own right; our guide to dogs and water covers when a life jacket earns its keep.

Know when it's already an infection

Prevention is for healthy ears. If your dog is shaking its head, scratching or rubbing an ear, or you notice redness, an unpleasant smell, or dark discharge, that's an infection that needs a vet — not a home flush (VCA, AKC). Ear infections are painful and get worse untreated, and the right cleaner and medication depend on what's actually growing in there, which only an exam can tell you. Book the appointment; save the drying routine for after they're better.

You can't redesign a floppy ear, but you can dry it. Two minutes with a towel after every swim is the cheapest ear medicine there is.