I traumatized my son today

We went out after nap time to run some errands for church. We went down to the shopping center close to our house. I stopped at Staples for some labels, Michael's for some fabric and Bed, Bath & Beyond for a long-overdue wedding gift. While we were there Frances asked if we could go to the pet store. It is a fun place to visit and she likes to look at all the animals, so I said "sure." We went in and looked at the rodents first: mice, guinea pigs, gerbils, hamsters, and ferrets (which I know are not rodents, but whatever). Henry stayed in the stroller for a while, but then he started fussing. I thought he just wanted out of the stroller, so I leaned over to let him out and noticed that he has shaking. Everytime we would get close to a cage, he would hold tight to me and his lip would start to quiver. Same reaction for the frogs, toads, lizards, snakes, fish and birds. Poor kid was terrified of all of the animals. Even some dogs that walked by us make him jump, and he usually likes dogs. The nice customer associate assured me that he would grow out of it, so I am not too worried.