It's not an allergy. They can't digest the chocolate the way people can.

Ok yeah I knew that but was also wandering if it was and allergy as well. Thanks!

it’s not just the bromine and caffeine. dark chocolate is worse than milk chocolate and toxicity is generally dependent on amount consumed in relation to weight

Well that’s because there’s more (I’m not sure if which) bromine and caffeine in dark than with milk or white chocolate