How long is vet school?

It takes around 8 years; however, it depends on you. You can shorten the time or linger it depending on your academic performance and work load. Check the link below.

http://study.com/how_to_become_a_veterinarian.html

Vet school itself is 4 years, which will qualify you to work in general practice. There are also options to do internships (1-2 years) and residencies (~2-4 more years) just like MDs to gain either more experience prior to going to private practice or to specialize in a specific field (eg. Internal medicine, neurology, oncology, dermatology, dentistry, surgery, anesthesia, pathology, lab animal medicine, etc). However these tend to be more competitive to get than in the MD field.