There is a feature in the system for Dog Sports catalogues that will allow you to easily bulk update the exhibitor numbers if you need to move dogs around. Often this is used to separate the same exhibitor so they don't have more than one dog running after the other.
After you have run the 'Generate Report Data' step, this will activate a button to the right 'Bulk Update Exhibitor Numbers'. This page will step you through the process, but the basics are you download the catalogue excel export file, edit the numbers and then upload the file again.
This will then renumber the dogs and move them around in the catalogue to where you want them to be. It's a quick and easy way to make many changes without having to individually edit and change each entry.