Not sure about Liverpool, but I believe the only 'exit' degree out of all the vet schools is Nottingham's BVMedSci which ALL students get in their third year, regardless of if they are leaving the course or continuing to get their vet degree.
Other universities don't allow you to pick up a degree in this way, with the exception of intercalation as mentioned in the above post. However, if a student expresses desire to leave the course, they can usually do a research project or some work to turn what they've studied so far into a degree. I know for a fact this can happen at RVC. I believe the degree name is BSc Public Health or something? I'm not 100% but I know a girl who is considering doing this.