Around 3.2 million households have acquired a pet since the start of the pandemic, figures show.
There are now an estimated 17 million pet-owning homes in the UK, according to the Pet Food Manufacturers’ Association.
Many people took in a furry friend for companionship while they were at home during lockdown.
Almost 60% of new pet owners are under 35, the PFMA said.
But deputy chief executive Nicole Paley added: “Introducing a pet to a household in Covid times can have repercussions or create unexpected difficulties.”
More than a third of new owners say having a pet is like having a baby, while around a fifth of families with children said training their new pet was challenging.
As a result, 5% of those who bought a pet during the pandemic have already given it up.
But 74% said their pet had helped to boost their mental health during periods of isolation.
Actress Emily Atack and former EastEnders star Jacqueline Jossa and hubby Dan Osborne are among those who have got new puppies.
But the “unprecedented rise” in the number of new owners has seen demand for pet food go through the roof.
On Wednesday, Sainsbury’s emailed customers to apologise for a “shortage of dog and cat food”.
Morrisons said it might not have “full availability for several months”, while Waitrose also reported running low on pet food and Tesco said it had seen strong demand.