How to take your pets on Amtrak from the Boston area

Headed out on Amtrak from the Boston region and don’t want to leave your pet behind? You might be in luck.

Amtrak since February 2016 has allowed cats and dogs up to a certain weight to accompany their owners on trips of up to seven hours on most routes.

That duration pretty much covers Boston-to-New York runs on both regional and Acela trains as well as runs up to Portland and the wilds of Vermont from Boston. Down to Philadelphia or D.C.—and points in between—might be a stretch.

There are some caveats to the carry-on. A couple of major bits:

• Amtrak’s pet fare is $25 per travel segment.
• Only one pet per rider.
• There’s a maximum of five pets per train; and reservations are on a first-come, first-serve basis, so book early.
• Pets are only permitted in coach class.
• And here’s probably the biggest caveat: Pets—and the container they must stay inside of during the wait at the station and the trip on the train—may not exceed 20 pounds altogether.

There are more details here. One last thing: None of this applies to service animals, which Amtrak says it welcomes throughout its system.