Nov 23 (Reuters) - British retailer Pets At Home (PETSP.L) said the number of households taking on new pets, which surged last year during COVID-19 lockdowns, is continuing to grow, driving up membership numbers and sparking a 77% jump in half-year earnings. The UK"s largest pet care retailer, which has 453 stores, said membership numbers of its puppy and kitten club more than doubled, with members typically spending a third more per annum than non-members. Active VIP members rose 13% to 6.8 million. Shares in Pets At Home, which said that fiscal 2022 earnings will be at the top end of market estimates, climbed 7%, and were among top midcap gainers by 1450 GMT. Lockdowns and work from home policies due to the spread of COVID-19 over the past two years have been accompanied by a surge in pet sales, making companies that operate in the animal care market among winners of the pandemic. 3.2 million UK households have brought a pet home since the start of the pandemic, as per the latest report from the Pet Food Manufacturers" Association (PFMA), a trade body representing the pet food industry. "Conditions don"t get much better for a pet superstore," Hargreaves Lansdown analyst Sophie Lund-Yates said. "It seems ongoing flexible working, and perhaps the renewed popularity of rural living, have culminated in the trend having more room to run than initially thought." The PFMA also estimates that around 17 million households were responsible for a pet"s welfare, meaning roughly one in four British households owned a pet compared to one in five American households. Pets At Home, which kept its stores, website and veterinary practices open for much of the pandemic, said new registrations at its high-margin veterinary practices business averaged at about 10,000 per week for the six months to Oct. 7. Half-year profits rose to 70.2 million pounds. Reporting by Muvija M and Chris Peters in Bengaluru; Editing by Jan Harvey