Ihave been surprised at what I have found out on my annual visits with my herps/small animals. My rabbit had a mass remved that I hadn't known about because my VET found it. It was cancerous, but because we caught it so early it didn't spread. I was also able to treat a lizard for coccidia because of my annual vet visit. Had I waited until symptoms had manifested, it would most likely have been too late.