I heard this relevant joke - we'll see how it goes over in print.
A guy comes in the house after working outside all day. Opens the fridge and grabs the first open can and eats it all. Asks the wife what is cause it sure was good. She's stunned and tells him it was dog food. He doesn't seem to care.
This happens several times over the next few days. The wife is getting worried and talks to a doctor. He says it's a little strange but it shouldn't kill him.
The wife sees the doctor on the street a couple of months later and he asks if the hubby is still eating dog food. She says no - he died. Worriedly, the doctor says the dog food shouldn't have killed him. She says, no it wasn't the dog food, he got hit by a car when he stopped in the middle of the road to lick himself.