For the first time, pet dogs have taken rides on the MTR's heavy rail line.

Many of the 1,200 owners who were allowed to bring their dogs on board on Sunday said they enjoyed the experience and called for more pet-friendly policies in future.

Each owner can bring one animal and use the last car of trains. Pets dogs must be placed in a fully enclosed carrier or backpack that complies with the MTR's size requirements for luggage, with no body parts exposed.

Pre-registration was required and there's no limit on the number of journeys.

Certain stations are off-limits, however, namely those on the Airport Express and at West Kowloon, Racecourse, Lo Wu and Lok Ma Chau.

Many pet owners said they enjoyed the experience.

They pointed out that the only public transportation option thus far has been taxis, which are expensive.

"The cost for riding taxis is usually over HK$100, while the cost for MTR is ranging between some HK$10 to HK$20, which is much more cheaper," one said.

Another owner noted that her dog remained calm during the journey thanks to prior training to stay in a carrier.

The MTR previously ran a pilot scheme for pet dogs on its LRT network.

And as the government proposes allowing dogs into restaurants, pet owners said the Hong Kong's environment is becoming more pet-friendly and society's acceptance is on the rise.

They anticipate more pet-friendly policies will be launched.

Sunday's campaign on the MTR was part of Dogathon 2026 organised by the Society for the Prevention of Cruelty to Animals.