First you must be a licensed Chiropractor of Vet. The course is 5 month and 215 hours with a board exam.
I teach at Options for Animals Chiropractic College and the course work is demanding.
There is a course out there called VOM which is a joke. The course is over a few weekends with next to no lab work [ hands on demo]. They also offer it online so you do not even have to go to a seminar. Would you like your doctor to have been trained in a few weekends without any board testing... probably not.
I am a certified animal chiropractor by the Amer Vet Chiropractic Assoc and as stated teach at the college. Please always ask about certification.