I'm not sure specifically as I haven't read it. But it might be about the adventures and experiences of the very first veterinarian in an imperial setting. It could involve treating the animals of the imperial court, dealing with diseases among imperial livestock, or perhaps having some sort of political or social influence within the empire because of this unique role.
I don't know the details of this 'the first veterinarian of the empire novel'. It may focus on how this first veterinarian overcame various difficulties in the empire. For example, there could be a lack of proper medical equipment or knowledge at that time. He or she might have to develop new treatment methods for the animals in the empire, while also facing challenges from other people in the imperial hierarchy who don't understand the importance of veterinary medicine.