Dogs joints much worse after sedation at vet?

I just had to take two of my dogs to the vet for an emergency porcupine quil removal! Not fun for me or puppies! They had mouths full of baby prcupine quills and needed to be sedated for about 30 minutes to get them all removed. My older dog, well 5, but is a large breed who has been hit by a car at age two and has since had joint problems in left shoulder and hips a little. He is on a new raw food diet and as long as we keep him lean, usually gets around quite well.
SInce we got back from the vet last night he has been so sore on his left hind leg that he will barely bear any weight on it. It's never been so bad and I wonder if there could be any connection between the sedative used and this issue. (I don't know exactly what they used). I have started giving him arnica, 5 pellets 3 times a day, but have only done two doses and so far no improvement. Vet suggested an asprin and a half every day to ease his Arthritis but at age 5 that seems like a lot of asprin he'd be getting over time! Any thoughts or suggestions? Sorry I always end up with more than one issue and question! Tweet