Ear infections

If your cat has an ear infection, the first sign you'll probably see is scratching—a whole lot of scratching. Ear infections make skin incredibly itchy.

Your kitty may also shake his head in an attempt to throw lose whatever is making his ears so darn uncomfortable.

Inside your cat's ears, you may also notice that the skin is red and that there's black, brown, yellow, or green discharge. And that funky smell? It's a sure sign of infection.

Ear infections always need to be treated by a veterinarian, says Grant. Left alone they can spread to the inner ear. If unchecked, ear infections can lead to scarring, narrowing of the ear canal, and sometimes deafness.

Regular cleaning of the ears and keeping your cat indoors are the best strategies for preventing ear infections.

If your cat gets a second ear infection though, it's time to consider allergy testing. Discovering what's at the root of chronic ear infections can help you get rid of them once and for all.