In Switzerland it is an offence to keep a single goldfish, guinea pig or budgerigar.
(Switzerland has adopted new animal protection legislation which specifies in great detail how fish and animals are to be treated — including how to dispose of unwanted goldfish, it is no longer legal to flush a goldfish down the loo — they must be knocked out and killed first. Which I'm sure is a great relief to them.
From guinea-pigs to budgerigars, any animal classified as a "social species" will be a victim of abuse if it does not cohabit, or at least have contact, with others of its own kind.
In addition, aquariums for pet fish should not be transparent on all sides and owners must make sure that the natural cycle of day and night is maintained in terms of light.
Anglers also have to take lessons in compassion, catch-and-release fishing and the use of live fish bait is banned.
Additionally, dog owners will require a qualification, they must take classes on how to properly raise their canine companions and how to minimize their risk of biting. Most cosmetic procedures such as cropping tails and ears and surgically making ears droopy are now illegal. Basically they should just pass a law that says owners should be at least as intelligent as their dogs.)