You can create Birth Records records from it's tab or the dog's record (Breeder record types only) using related lists. Filling it out from the Dame's or Sire's record will auto-fill the Dame or Sire field.
Below are the fields included on the Birth Records records.
From Birth Records Tab
You can enter a new record from the Birth Records Tab.
Only use this field if you are trying to link this record to an existing Dog record, otherwise use the Create Dog Record button after saving this record.