At the vet's

A man comes hurrying into a vet office, carrying his dog in his arms.
Help me! he shouts. The vet comes out of his office, and looks at the dog in the man's arms. Give him to me said the vet, I'll do some tests on him. Do them all the man says.

He put the dog on an examining table, and opened the door to admit a cat. The cat sat still, looked up and down the dog. and she made a mournful cry, and left. As the cat left, a lab retriever entered. He took a look at the man's dog and barked.

A half-hour passed and the vet appears in the waiting room. Sir,
I'm sorry we could not save your dog. So we have to settle up. now.

Here's your invoice says the vet. $1200 for my dog to be examined? How is that? the dog's owner cried out.

Sir, the vet said, you did order a cat scan and a lab report...