Question for business owners with credit card fees

Just had an 800$ vet visit but was charged 3% of the total bill to use a credit card. I recall (and understand) credit card fees but I always thought these were like 3$ not 3%. 3% seems nuts when you have a thousand or two thousand dollar vet bill. Just curious if this is normal, the vet is taking advantage or if this is a standard fee being passed on. The vets here are already insanely expensive and this just seemed abnormal but since I don’t own a business or need to deal with payment processing I didn’t want to jump to conclusions.

Anyone have experience with cc payments and the fees that can illuminate?