It’s possible. I never had a 2.5, but I had below a 3.0 until my second semester sophomore year. You’re going to want to put as much distance between your bad grades and your good ones as possible. Also look at how many pre-reqs you’ve already taken and now you did in them. If they’re B’s, it’s not worth retaking them. If it’s only one or two C’s/C+’s, it’s probably not worth retaking them. But if it’s bio 1/2, chem 1/2, and anything else for example, you may want to retake them. Your cumulative GPA will not do you any favors by the time you apply in your senior year if you go that route. Even if you get a 4.0 every single semester (so this one and the next two) until you apply, that still only puts you at a 3.25 if every semester has the same number of credits.
Your last-45 will be your best GPA, which is good for showing a trend. Your science/pre-req GPA will depend on what I said above. If you retake pre-reqs you did poorly in (if any), you’ll have a higher pre-req GPA, especially in schools that do grade replacement. But it’s difficult to retake courses if you’re going to be applying in your senior year. You’ll also want to boost your application by having good experiences. This goes for anyone, but especially applicants with mediocre academics. Varied experience in lots of fields is best, plus lots of hours to show you have really gotten your feet wet. That’s how I did it. Everyone has their own way of getting in, but as someone who had mediocre academics including a mediocre science GPA, but still got in on my first try, this is the route I took. I crushed my last 45 hours, got my cumulative GPA to place that wouldn’t disqualify me (and was okay with grade replacement), had tons of hours, and knew a lot of clinical things which seemed to impress interviewers. Not everyone does this, and people will say you don’t need to do this. You might not. I felt that I did.
Don’t be set on applying in your senior year either. If you want to retake courses, get lots of experience, study for the GRE, and not have all of that impact doing well in school, taking a gap year can be beneficial. I personally would recommend that over applying with mediocre stats all around, getting rejected, and having to apply again anyway. Not to mention, vet school applications take a lot of time and energy, which can impact your ability to well in school, which can impact your ability to get in the next year. It’s a vicious cycle.
And remember, this is just my experience. I’m anticipating people quoting parts of this and saying “well I didn’t do that and I got in” or “you really don’t need to do that if you bla bla bla.” Sure, whatever. This is what I did to get in.