Priska Kung offers a matchmaking service by renting guinea pigs to suddenly single pets to provide companionship, Der Spiegel reported Saturday.
Switzerland's animal welfare law forbids people from keeping single guinea pigs because the animals are sociable and need each other's company.
"Because they hardly ever die at the same time, even if they are exactly the same age, people who don't want a new guinea pig and lose one of their two animals need an interim solution," Kung said.
Kung, who has 80 guinea pigs, charges about $55 for a castrated male and $66 for a female and refunds half of the money when they're returned, Der Spiegel said. Some are returned after a few weeks, others after months, but some are leased for years.
"Sometimes people realize that they still get so much enjoyment from the guinea pigs that they want to go on keeping them and come back for another one once their supposed last pet has died," Kung said.