My cat Ted sprained his ankle yesterday.

Didn't know it at the time, I brought him in to get his vaccinations, and have his bloodwork done. Mentioned that he'd been limping on his hind leg.
Doc x-rayed it, found nothing wrong with the hip - where we assumed the injury was, and sent him home with an opioid pain injection.
Turns out - Ted didn't react well to the injection, and spent the entire night and day rushing about the house totally stoned. I came home - because of his injection he didn't feel pain and sprained his ankle and spent the entire day running around on it. I noticed the huge swelling on his ankle, took him back - assuming he broke it, doc x-rayed it and pronounced him fine except for a sprained ankle and bad arthritis.
So now he's stewing at the vets for 2 or so days to keep him immobile.
That cat finds any number of ways to break my heart and ramp up my stress levels.