The CDC has been responsive to the input from many organizations and government and has relaxed and streamlined the process for crossing the border as of August 1. Dogs from low-risk rabies countries such as Canada, are now required to have proof of vaccination, be microchipped, and owners (consignors) are required to complete an online Dog Import form. The 6 month age limit is still in place, however organizations and government are still working to have that age limit reduced.
https://www.cdc.gov/importation/dogs/dog-import-form-instructions.html