I've noticed my animal trainers seem to hoarde food. For training dogs they will take very large stacks (20+) of meat and walk around for days with that in their pockets. In addition I'm guessing there is some kind of "minimum" amount of food in a stack an animal trainer must have to train because over time they accumulate a lot of 1 and 2 stacks of different kinds of meat. Because of the variety, I had an animal trainer walking around with 50! pieces of meat (one large stack of 20 and then about 5-10 little stacks of 1-2 pieces each).
I have 2 wargs and 1 retriever. My other animal trainer was in the same position with stacks upon stacks of meat just sitting in his pockets...
I had the same bug: https://ludeon.com/forums/index.php?topic=15720.0
This will be fixed in the next release. Thanks.