The moment you add a required field to the 'animal form' it must also be filled in for animals that are already known in the system. If they haven't done so in the past they get an error message when booking (which is logical) but we find that customers don't understand what to do then. They think it has to do with the booking when in fact it has to do with the animal itself. --------- what we can do is a short explanation so they know why it is asked and why they have to fill it in.