Couple Leaves Dog with Vet for the Weekend; Vet Neuters Dog without Permission

Yesterday, my niece came over, and during her visit, she said something about dog sitting for one of her friends.  My sister said that she couldn’t imagine dog sitting and that if she was going to be gone for a day or two, she’d just leave her dog in the back yard.  She said she would be apprehensive about leaving her dog with a sitter business after what happened to our aunt and uncle.  I hhhaaaddd to ask what happened.

So, our aunt and uncle made plans to go out of town to celebrate their anniversary.  They took their dog to a vet, where they paid a fee for their dog to have proper care while they were away.  Sounds reasonable, right?

Well, when they returned from their trip (and you know how that goes… alone time, celebrating your marriage, you’re in a good mood), they went to get the dog, and their dog had been neutered!

WHO DOES THAT???

How do you take your dog to a facility for a weekend, come back, and he’s been surgically altered?  Of course, they’re talking about taking legal action.  What would make the vet think they wouldn’t want their dog to reproduce?

Is this commonplace?  Sounds illegal.  Has this happened to anyone else?