My 10-month-old dog has been shaking his ears a lot lately. I took a look inside them and didn't see any gunk. They're not bright pink or inflamed. They don't smell any worse than I would expect the inside of a dog's ear to smell. Slightly musty, perhaps, but not bad at all. He's part Basset, although his ears are not as long.

He doesn't exhibit any other symptoms ... just shaking his ears. He doesn't rub them against the ground, wince, etc.

Are there other possible problems outside of an infection? I thought infections typically created a residue inside the ear. Please help ... thanks!

There could be a few ear mites running around down there that you can't see.
Whatever, it is obviously causing the dog some distress so you need to take him to a vet to get the cause checked over.

Being the type of cross-breed he is, they do tend to have problems with air flow to the ears, although they don't have the hairy ears that cause problems in some breeds.