PremiumBreed retains detailed logs of changes that occur to information in the database. Some information is directly available to users depending on the permissions granted to you by your Breed Society.
If you have a serious concern regarding the data in the system, the first port of call should be your registrar. They may have additional detail regarding why data was changed. If they are unable to help, they may follow up the issue with PremiumBreed support. PremiumBreed support can investigate detailed server logs to find the exact time, and user that adjusted the data.