I don't know how the clinics work, but the PetAid cover is supposed to work on the theory that you pay a set amount and that covers you for the year unless you can give a donation. (Which I try to, as a rule.)
However, recently when I've been in I've been "chased up" for a donation, which makes me more reluctant to give money. Reason being, these practices are supposed to understand that people that go for help to the PDSA aren't always going to be in the position financially to give anything.
I agree though, Lisa. Some people will be embarrassed they only have a couple of pounds to give - which is a shame. It's kind of undoing some of the good work that's been done.