Before Zhong Ze'an, a 32-year-old migrant worker in Beijing, left for his hometown to celebrate Spring Festival, he needed to help his pet settle down.

The distance to his hometown in East China's Jiangxi province is about 1,400 kilometers, too far for Zhong to take his cat with him. Asking someone to take care of it was his only choice.

Rather than sending the little creature to the pet shop, which charged dozens of yuan each day, Zhong found a cheaper option, a door-to-door pet service.

The service provider would come to his home once every few days, feeding his pet and cleaning up after it. Each service costs 70 yuan ($10.5), says Zhong.

Besides saving money, his cat has also benefited from the service. Staying at home in familiar surroundings minimizes the stress for the feline.

Since 2018, Zhong has used this service three times, and he had no worries about letting strangers into his room. "The business is built on trust, and people who love pets are decent," says Zhong, who leaves his keys to a stranger every time.

Data from a 2021 white paper on China's pet industry shows the number of pet cats and dogs in urban areas in China exceeded 100 million in 2021, and the industry's market reached 249 billion yuan in size.

As the market has expanded, providing door-to-door pet services has evolved into a profession for many.

Chen Xi, a financial freelancer and a pet keeper in Beijing, spotted the niche when she found herself in need.

"Once I left my cat at my friend's house during a business trip. Unable to adapt to the new environment, my cat got diarrhea. I realized door-to-door pet care could be a need," says Chen, who opened an online shop on e-commerce platform Taobao.

Most of her clients are young white-collar workers and are often away on business trips or holidays. The price for each service is normally within 100 yuan and varies according to the distance and the number of pets.

By offering door-to-door pet care services, Chen has earned about 20,000 yuan in total since 2020, a good income for a part-time job. Orders sharply increased during this year's Spring Festival. "I went to eight or nine houses each day to feed their pets," Chen recalls.

Unlike Zhong's unconditional faith in pet lovers, there are still many consumers who worry about safety, whether it is the safety of their property, or indeed that of their pets.

To alleviate their worries, Chen records videos of the service process and sends them to consumers, and also makes video calls to pet owners during the service.

Some service providers even have professional certifications from Alipay. Another part-time service provider Zhao Xintong recently acquired the certification, which can be shown on Xianyu, a consumer-to-consumer marketplace spun from Alibaba's Taobao.

"The certification will improve my credit rating, which will win me more customers," says Zhao, who now has 15 regular clients.

Chen has great faith in this fledgling business. "I hope door-to-door pet care services can become more regulated in the future to better meet the huge market demand."

Xinhua