The pie charts compare the types of pet owned by households in one country in 2000 and 2020.
Overall, cats replaced dogs as the most popular pet, while fish and birds lost ground and small mammals gained popularity.
In 2000 dogs were the most common pet, owned by 38% of pet-owning households, followed by cats with 30%, fish with 16%, birds with 10% and small mammals with 6%. By 2020 the situation had reversed at the top of the ranking. Cats had risen to 42%, making them by far the most popular choice, while dogs had slipped to 34%.
The decline of the two smaller traditional pets was striking. The proportion keeping fish halved, from 16% to 8%, and birds fell from 10% to only 4%, the lowest figure in the 2020 chart. Together, fish and birds accounted for 26% of the total in 2000 but only 12% in 2020.
In contrast, the share of small mammals doubled from 6% to 12%, so that they overtook both fish and birds. Dogs and cats together represented 76% of pets in 2020, up from 68% in 2000.