What’s cute, furry, and makes a horrible pet? It’s the Asian small-clawed otter, the latest pet craze in Japan. Some people have their own pet otters, while others play with them in so-called “otter cafes.” The animals are easily purchased online, but the trade comes at a terrible cost; otters are difficult to breed, so virtually all otters available for purchase are poached from the wild.

Even purchased legally, exotic pets are problematic. Biologist Clifford Warwick writes in in Journal of Animal Ethics that the keeping of exotic pets is immoral. He’s writing specifically about reptiles, but many of the same issues apply to exotic mammals and birds. Capturing the animals in the wild causes ecological harm, but even captive-bred animals rarely experience healthy and sanitary conditions. Transfer facilities for both wild and domestic reptiles tend to be cramped and stressful, followed by even worse conditions in transit, aboard aircraft or even on the back of a motorcycle. Many animals suffer injuries or death.

There are broader community concerns, as well. Many exotic animals harbor diseases that easily transfer to people. Pet turtles, for example, are a frequent source of salmonella infection. A variety of exotic mammals transmit monkeypox, among other zoonotic infections. Exotic animals may pose a risk of unusual injuries to owners or others through bites. Reptiles also pose a serious risk of biological invasion. For example, pythons that were formerly pets are now infesting Florida’s everglades.

Then there are practical concerns. In a free-ranging discussion between eight veterinarians published in The Journal of Avian Medicine and Surgery, a vet generally supportive of keeping exotic pets posited that only professional handlers should keep most species. The vets note that even for small exotic pets, like sugar gliders, providing proper care and feeding conditions is difficult for the average pet owner, especially those who acquire the animal without a lot of planning. Often the effort gets to be overwhelming and ex-pets are dumped on animal rescue organizations. Additionally most vets are ill-equipped to care for exotic animals—sometimes specialized equipment is required, and the vet will require the owner to provide it, making for expensive visits.

Providing for an exotic animal can be a great burden, and there are the ecological and moral concerns as well. As for otters, they are threatened by habitat loss, hunting, and now their very cuteness.