Do not get stuck with your little fuzzy loved one on the other side of the border!. Veterinarian Warns About New Puppy Border Regulations. Starting August 1st, 2024, new regulations from the CDC will significantly impact travelers crossing the U.S. border with dogs, according to a recent warning by a Spokane veterinarian. They posted the warning on Reddit after learning of the changes coming this August to the border which could greatly impact animal owners trying to cross to and from Canada. The changes are aimed at tightening security and closing loopholes at the border, especially when talking about the entry of puppies or the verification of rabies vaccinations.