I think what I'd first do is put him on a better food. He could be allergic to something in the Pedigree which is not a very good food to begin with.
When is the last time he was at the vets? I think I would take him in again, and ask for a skin scraping to test for mites/ but it sounds like your vet thinks it's allergies of some sort?
At this age he could be having arthritis issues, with that, there are many good supplements that you could give him for those issues.
Is he a chewer? He maybe losing his teeth from chewing on 'things' or himself..
They do shed alot, and usually lose some bit of fur year round. Can you take him to a groomer and have them give him a medicated bath??
Danger Danger vom Kleinen Hain aka Masi
"Angel" Jakoda's Bewitchen Sami CD OA OAJ OAC NGC OJC RS-O GS-N JS-O TT HIC CGC
"Angel" Steinwald's Four x Four CGC HIC TT
Harmonyhill's Hy Jynx NA NAJ NAC NJC RS-N JS-N HIC
Jakoda's Jagged Edge