I was going to suggest the anal gland thing. If even a tiny drop leaks out it smells like death in the entire house. Sounds like you already checked that tho. My Schnauzer is almost 10 and she stinks too. I think it is just the elderly... 
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We give dogs time we can spare, space we can spare and love we can spare. And in return, dogs give us their all. It's the best deal man has ever made. -M. Acklam |