Pets/Dogs: How much crude fat should be in can dog food? I own 7 yr old Boxer.?

I'm not a big fan of canned dog food, so I wouldn't really know the fat content, but I'm sure if can vary from brand to brand.  If you're dog is eating dry kibble, I would just stick to that.  If your dog has bad teeth and you feel it needs to eat softer food, soak the kibble in warm water to soften it.  Most canned dog foods are 80% moisture, so that doesn't leave very much actual nutrition left and I'm sure your dog does drink water so therefore is getting moisture/staying hydrated.  Just feed a high quality kibble and if you feel that you MUST add a little bit of canned food, it should be just a little bit so the fat content shouldn't really matter that much.

Canned/wet dog food is not the best for your dog as it is deceptively low in nutrition. I never order canned dog food from pet stores or online stores like Petcarerx. Instead, I use some milk suitable for dogs to make the kibble wet whenever required. Please note that dry kibble is also beneficial for dogs oral hygiene.

Boxer had some teeth extracted a yr ago. Thought I'd switch to can dog food. I'll go back to kibble TOTW and mix in w canned food.

In all honesty i really dont know.

So i suggest you consult a vet or an animal nutritionist they specializing in such subjects.

Canned food aint at all good for dogs though imho because its main content is Water.

"Should be" is to general.  I'd be asking my VET for his/her recommendation.