Puppies must be at least eight weeks old and have been weaned for at least five days for air travel, according to the U.S. Department of Transportation. If it's a small breed dog, there may be weight and age minimums, too. The CDC requires all dogs entering the United States to be immunized against rabies.

In 2026, the youngest age a dog can generally travel on a plane is 8 weeks old for most domestic flights and 12 to 16 weeks old for international travel. Airlines enforce these age limits because puppies under 8 weeks haven't fully developed their lungs or immune systems, making them highly vulnerable to the pressure changes and recycled air in a cabin or cargo hold. For international routes, the age is often dictated by rabies vaccination requirements; most countries require a pet to be at least 12 weeks old to receive the vaccine and then wait an additional 21 to 30 days before entry. Some high-standard carriers may even require a minimum age of 15 weeks to ensure the pup is stable enough for long-haul stress. Always verify with your specific airline, as "ultra-low-cost" carriers may have stricter 12-week minimums even for short hops to minimize health risks and liability during transit.