In Switzerland it’s illegal to own just one Guinea pig
The Swiss are known for their historic commitment to neutrality, but they’ve taken a firm stand on one of the most important issues of our time: guinea pigs. Because guinea pigs are social creatures who grow lonesome without a friend, it’s illegal to own just one of them in Switzerland. The law was introduced in 2008 as part of a legislative effort to grant social rights to pets. Should one guinea pig depart this mortal coil and leave its companion alone — and its owner in potential legal trouble — rent-a-guinea-pig services have emerged as a temporary solution.
Guinea pigs aren’t the only pets afforded special status in Switzerland. Goldfish are also prohibited from being kept alone, cats must at least have access to a window where they can see their fellow felines prowling around, and, for a time, dog owners were required to take an obligatory training course with their pooch, although that law was repealed in 2016. For all this, Switzerland doesn’t have an official national animal — though both the country and the Alps in general are strongly associated with cows and Saint Bernards.
I used to live in Switzerland (Bern) and never heard of guinea pigs needing companions. I actually had one guinea pig by itself, and no one said I needed to get another. I guess maybe a vet would have said something if it was really an issue to only have one.