Old guy walks out on his porch early one morning on the farm, and tells his old hound to get up, let's go. Dog just lays there, doesn't even raise an eye to him. Tells him again, nudges him with his foot, nothing. Now he's worried.
Calls the vet, who tells him he just happens to be heading out that way to check on a horse, he'll stop by.
Vet gets there, walks up on the porch, doesn't like what he's seeing. Tells the Old guy he can run a quick test.
Goes out to the car where he has a big yellow tomcat in a carrier. Reaches in, grabs the tabby by the scruff of the neck and they walk back up on the porch. Bends over, holds the now hissing and squirming cat right in the dog's face. Nothing. 'I'm sorry, he's gone.' Puts the cat back in the car.
Old guy says he hates to lose him, but thanks the vet and asks him how much he owes him.
'525 dollars.'
'WHAT??? How on EARTH do I owe you $525?'
'Well, the House Call is $25, and the Cat Scan is $500.'