Don't know if this would help, but I use a plastic spoon to get food out of the can.  No particular reason for doing this except that I just got into the habit of keeping some plastic spoons always available in the little drain cup on the sink and use them just for this purpose.  Maybe they would not scratch the can.  I haven't noticed any scratches in my cans before,  but have specifically checked since this thread was posted and haven't seen any.  I use FF and the can liner is white, but doesn't seem like it is plastic.   

karvskitties are you certain it is plastic?  I know it looks like plastic to me that's why I asked several times if it was made of plastic.  I only use the smaller cans 3 oz or 5.5 oz.  If I find out for sure they lied to me I will be furious

or punch holes in bottom of can with a bottle top remover and that will slide the contents out with the top open.
You know, what used to be called a "church key" bottle opener? Boy, am I dating myself ...

Fancy Feast Tender Liver & Chicken Feast
Best by: Jul 2010
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First spoonful I scooped I scratched the bottom of the can (white lining / silver scratch mark).  I knew I had seen this before but couldn't remember for sure which food it was as it happened quite awhile back. Made a point to note the product and lot numbers this time given this discussion. Opened another can, emptied (carefully) then tried actively to scratch it with no effect. Wonder what makes some cans more susceptible than others?

I really don't use a lot of canned dog food but there isn't much I trust about any commercial food these days, including the inside of the can.

I have several sizes of rubber spatulas that I use for many things around the kitchen & one is to remove food from cans, dog food or otherwise.  I don't think there's the possibility of scratching the interior of the can with rubber.

JJ also had a great idea:  to remove top/bottom lid & slide food out.  Works great. 

3cat:  We must be from the same generation........always called a can opener a church key.   That also works great to remove the contents of a can.

Using a regular spoon would make it way too easy to scratch the inside IMO.  Lord knows what may be in the liner.....yuk.....