Milopoo, the fact that your dog is itchy all over his body and
that his ears are infected, leads me to believe that he likely has allergies.
Your best bet is to have the vet perform a allergy panel. Your vet may not be able to do it at their clinic, but will take a sample and can send it away.
Allergy testing may not be 100% accurate, but it is a good start. Take it from someone who has a dog that has suffered for allergies for years
. My dog was diagnosed with some sort of allergies when he was about 2, now finally at 7 I had an allergy test done. Do not wait that long, I tried shampoos, sprays, special diets, etc. with no luck. Your best bet is to have an allergy panel done, likely he is allergic to several things (most dogs are). For example, my dog is allergic to beef, chicken, and rice and several enviro allergens (weeds, alfalfa hay, etc.).
As Frenchy said, you should determine the cause first before taking action. Steroids are
an option to relieve allergies, but a poor one at that because of many side effects. They are alright to use for short amounts of time, but are not ideal to use on dogs for any extended period of time. If
your vet determines it is in fact allergies and you try several tools with no luck, you can look into a newer drug called Atopica for atopic dermatitis. I am currently trying it with my dog with allergies. There have been several threads on Atopica on here... http://www.pets.ca/forum/showthread.php?t=41296