I have a cat; a very old cat. 
She is relatively good shape, bright-eyed and bushy-tailed, ready to chase even the lowly house-fly, or venture out on foggy mornings. She’s eaten dry cat food all of her sixteen years….until now.
Because she has only 3 teeth left, we switched her to fancy wet food a month ago: grilled seafood feast, chopped grill feast, tender beef and liver feast—-in gravy. 
She’s in heaven. But her personality has been altered. 
No longer is she the mellow go-ahead-and-make a move-toward the-laundry-room-I-don’t-care feline. She is manic-cat. Every time anyone gets within 3o feet of her food dish she becomes a needy mess, begging for just one more spoonful of anything with “feast” in it’s title.
Canned kitty heroine? Feline meth, anyone?
She’s a 2-can-a-day cat. She’s gained 20 percent of her body weight (1 lb) in a month. 
She purrs relentlessly–even on rainy, fly-less days. Her eyes are glazed even when she’s staring down the dog.
Don’ get me wrong. I’m happy she’s happy. And the pet food stock in my portfolio is on the rise. 
But I become increasingly convinced that there’s more to the feast than meets the eye….never mind the cans that I bought on special last week came with a free bong.