Can Cats Eat Dog Food?

I'll spare you all the long story of what's behind the question, but I
called my Vet's office and got a less than satisfactory answer to the
question. The person who tried to answer went on about cats needing a
higher protien diet than dogs, since they were carnivors (and what,
praytell, are dogs?) etc., etc. I was told something about needing more
meat, and wondered to myself *whence commeth dry cat food, such as Meow
Mix?* Our ferals scarfed up Pedigree dog food, to the last trace in the
bowel. Regarding the need for more protien, if such is the case, why not
eat more of it?
So far, I think I've been getting the benefit of well intentioned, but
unsupported, conjecture. Anybody know the answer?
Cheers,
Jack