swollen ears

A couple of different things could be going on with your dogs ears.  Dogs can react to bug bites in sensitive areas like the ear with swelling.  Allergies, either to a new food or something in the enviroment can cause ear irritations.  If he is shaking his head alot because of an infection, he could cause what is called and aural hematoma where the ear flap swells.  However this conditon usually does not resolve itself.  If you feel there is an ear infection, he should have a vet visit because they usually do not go away on thier own.

You can give him something to reduce the swelling if all else is well with him like he is eating and drinking, peeing and pooping and acting fine, with plenty of energy, you can try a little Benadryl.  Plain, nothing mixed in, capsule of Diphenhydramine (generic name for Benadryl).  It ususally comes is a 25 mg capsule.  The dose for dogs is 1/2 to 2 mg of the drug per pound of dog. Start with the low end of the dose and if no improvement, repeat in 8 hours and try increasing the dose to 1mg per pound of dog.  An example of the dose is if your dog weighs 50lbs, start with 1,  25 mg tablet and see if it helps the swelling go down.  100lb dog would get 2, 25mg capsules at the low end of the dose.  If you have any questions on dosing, check with your vet before giving the drug.