<p>Although you are only in high school, it is important to already begin working or shadowing a vet. A large portion of an application to vet school (aside from very high GPA in required coursework) is the demonstration of >1000 hours of documented work with animal health care. Online listings usually only require a few hundred hours, however, you are competing with applicants who began to show demonstrated interest in high school as evidenced by volunteer work at that time.</p>
<p>When in college, I recommend you concentrate on maintaining a high (higher than pre-med) GPA in required science courses and continued involvement at an animal hospital or vet office.</p>