Which one

[rebbonk]

The sheriff of a small town was also the town's veterinarian.

One night the phone rang, and his wife answered. An agitated voice inquired, "Is your husband there?"

"Do you require his services as a sheriff or as a vet," the wife asked?

"Both," the caller replied.

Spoiler:

"We can't get our dog's mouth open, and there's a burglar in it."