Hello! I'm assuming you're in Year 10? And you want to apply for veterinary medicine?
GCSE's: As
@ReadingMum has said, have a look at all the different vet unis. They will have their GCSE and A-level requirements clearly set out. Luckily, there are only 10 veterinary schools so it's really easy to gather all the info you need. The schools are: Edinburgh, Glasgow, Nottingham, RCV, Bristol, Liverpool, Surrey, Cambridge, Harper & Keele (not accredited by the RCVS yet as it's a new school, with the first cohort starting Sept 2020), and Aberystwyth (joint with RVC, once again a new vet school so not accredited yet, first cohort starting September 2021).
GCSE's themselves aren't overly important - as long as you meet the minimum requirements then it's fine, you won't really get much of an advantage with all 9's compared to someone who just got the requirement. I'm not actually familiar with what the GCSE requirements are (so check on the vet school websites), but personally I would suggest to aim for at least 7's in your science and maths subjects, and then 6/7 in others.
In terms of revision for science, the best thing to do is make sure you have a good understanding, and then revise by doing lots of past papers and practice questions - especially for chemistry, as this will help you to familiarise yourself with the mark scheme. I used the CPG revision guides to make sure I understood all the topics, and then just did practice papers.
Work Experience: Definitely more important than GCSE's! Your grades will only get you as far as being eligible for the course, while your work experience can be big factor in whether or not you get an offer (obvs A-level grades are important but that's kind of the last hurdle). Once again, each vet school has different requirements for how much work experience they want you to do, so have a look at their requirements on the websites. In general, most schools will require you to have work experience both in vet practices, and animal husbandry experience. If you don't have the minimum work experience requirements, it's unlikely you will be offered an interview - when you apply, most unis will send you a separate form to fill out your work experience. Furthermore, work experience really helps you gain an insight into the profession so you can be sure that it is the career for you, and will also give you valuable things to talk about at interview. The work experience I did was: 1 week each at 3 different first opinion vet practices, 1 week at an equine referral hospital, 3 years volunteering for the RDA, lambing, 1 week on a dairy farm, 2 weeks at an animal shelter (which had both small and large animals), and volunteering at a wildlife rescue (I think I had done about 50 hours there when I applied). Aim to get experience with small animals, horses, cows and sheep, and then you can look for any extra interesting things.
In terms of interview, we cannot disclose any information about specific interviews or questions. In general, when preparing for an interview you want to think about the key skills and qualities a good vet should have, and examples of either how you demonstrated those, or a vet demonstrating them on your work experience. Think about interesting things you saw at work experience and do some extra research to gain a better understanding of them. Keep up to date with current topical issues in the profession so you can talk about them if asked, and think about whether you saw any of these issues on work experience.
You can apply to four vet schools. I was accepted into Nottingham, Bristol and Surrey, and was waitlisted for Edinburgh. In terms of grades, at GCSE I got 9's in English Lit, Biology, RE and Drama, a 7 in Spanish, and then 8's in my other six subjects. For my A-levels, my predicted grades that went on my UCAS application were A* in English Lit and Biology, and A in Chemistry (I am in Yr 13 so my A-levels have obviously been cancelled and I haven't received my 'grades' yet).
Hope that helps! If you are in year 10, then it's great that you are starting to think about applying now, as it means you have plenty of time to do work experience. I only really decided on vet med when I was in yr 12, so ended up having to do all of my work experience (except the RDA volunteering) from January-October last year, which was very stressful, as places get booked up quickly!