Dogs coming in from other countries will be required to be microchipped and vaccinated in an effort to prevent the reintroduction of rabies into the U.S., the Centers for Disease Control announced Wednesday.

The new rules go into effect Aug. 1, and will also require dogs entering or returning to the U.S. to be at least six months of age with a healthy appearance, accompanied by the agency's dog import form receipt.

Dogs that don't meet the requirements will be sent back to their country of origin at the owner's expense.

"This new regulation is going to address the current challenges that we're facing," Emily Pieracci, a rabies expert at the CDC said, according to ABC News.

The U.S. eliminated dog rabies in 2007.

The updated regulations address recent challenges the nation has faced with dogs entering from other countries, including fraudulent paperwork.

Based on where the dog has been in the last six months and whether or not the dog was vaccinated in the U.S., there may be additional requirements.