It was all smiles for cat and dog owners on Thursday as they took their furry companions for a ride on the light rail under a pilot scheme by the MTR Corporation.

Under the two-month trial, each passenger can bring one cat or dog aboard the light rail on weekends and public holidays.

The pets must remain in a carrier of specific dimensions during the trip, and owners must get on and off from the last door and stay at the back of the train compartment.

Ms Wong brought along her cat for a trip from Tuen Mun to Yuen Long. She praised the arrangement, saying it has made travelling with her furry companion convenient.

"I rarely take my cat out on a cage because we need to ride on cars. We must drive ourselves...[meaning] I have to wait until my children are free," she said.

"But now with this scheme, I can bring my pet out to meet friends during holidays."

Owners must also purchase a monthly pet pass for HK$99. Mr Cheng, who owns a dog, felt the price was reasonable.

He explained the only alternatives would be taxis or ride-hailing services, and they cost at least HK$50 per trip.

That said, he hoped the MTR could relax the rules so pets could ride in strollers.

It could be difficult for people to carry their pets in a bag for a long period of time, he said, especially if the animals were heavy.

Cheris Lee, the MTR's Chief of Operating and Metro Segment, noted the trial was smooth on the first day.

But as a precaution, around 70 extra staff members were deployed to different stations to provide assistance.

She also offered tips to travellers who may be allergic to cats and dogs, or are simply scared of them.

"If passengers want to keep a distance with the animals, they can board the train from the first door and remain in the front of the compartment," she said.

Citing expert comments from the Society for the Prevention of Cruelty to Animals, Lee insisted that allergic reactions will only occur upon direct contact with the allergen.

She did not rule out the possibility of extending the pilot scheme, saying a decision will be made after a review.