can I still become a vet?Watch
If you email admissions teams you will be able to get a better idea. You may only have to retake one or two subjects in order to qualify (I *think* Harper/Keele will accept students who only have one science A Level, for example). Admissions will be able to advise you on what the best route to take is in your position.
Finally, there are other options such as the Access to HE Diploma, taking BTECs in science or animal-based subjects etc. which are also open to you, however, you may find that fewer vet schools accept these qualifications and that A Levels will leave your options more open.
I was in a similar situation to you, I finished sixth form with two irrelevant A Levels (with poor grades actually!) and then decided I wanted to try and become a vet. I went back to college to study an Access course and worked hard to gain work experience placements. I am now happily at vet school after completing my Prelim Year at Notts. So it is possible. Good luck.