Our correspondent
In early August 2025, Aalborg Zoo in Denmark ignited a firestorm of controversy with a social media post inviting the public to donate unwanted pets—not for display, but as food for its predators. The zoo’s call for chickens, rabbits, guinea pigs, and even small horses to be “gently euthanized” and fed to carnivores like European lynxes, Asiatic lions, and Sumatran tigers has divided opinions, highlighting stark differences in cultural attitudes toward animal welfare and zoo practices.
A Natural Diet for Predators
Aalborg Zoo, located in northern Denmark, defends its program as a means to replicate the natural food chain for its carnivores. “Chickens, rabbits, and guinea pigs form an important part of the diet of our predators, especially the European lynx, which needs whole prey that resembles what it would naturally hunt in the wild,” the zoo stated in a July 31, 2025, Facebook post. The initiative, which also accepts horses under strict health and size conditions, aims to ensure “natural behavior, nutrition, and well-being” for its animals while minimizing waste.
Deputy Director Pia Nielsen emphasized that the practice is longstanding and common in Denmark. “For many years, we have fed our carnivores with smaller livestock,” she told NPR. “When keeping carnivores, it is necessary to provide them with meat, preferably with fur, bones, etc., to give them as natural a diet as possible.” Donated animals are euthanized by trained staff, and horse donors may receive a tax deduction based on the animal’s value.
Backlash and Support
The zoo’s appeal triggered a heated online debate. Some commenters were outraged, particularly over the term “pets,” which evoked images of beloved animals being fed to predators. “This is a joke, right?” one Facebook user wrote. “No one would bring their healthy pet to a zoo so they can kill it and feed it to their animals.” Others criticized the program as callous, with one commenter calling it “a terrible trend of indifference with animals in Denmark.”
However, supporters argue the program is practical and ethical. One commenter praised their experience donating a rabbit, describing it as “super nice and professional.” Signe Flyvholm, a Danish resident, considered donating her horse, which needed to be euthanized due to a medical condition, but its size exceeded the zoo’s limits. She told The New York Times she appreciated the idea of her horse “making a difference” by feeding predators.
Expert Perspectives
Zoological experts highlight the nutritional benefits of feeding whole animals to captive carnivores. Stamos Tahas, a veterinarian at Copenhagen Zoo, explained to The Washington Post that whole prey provides essential nutrients, strengthens bones and teeth, and encourages natural feeding behaviors. “It’s a quieter death than going to a slaughterhouse,” he said, noting that the practice reduces waste from animals already slated for euthanasia.
In contrast, the Association of Zoos and Aquariums (AZA) in the United States clarified that its member zoos do not solicit pets for food, though feeding vertebrate carcasses is a recognized management tool to stimulate natural behaviors. Craig Packer, director of the Lion Center at the University of Minnesota, noted that offal—liver, heart, and other organs—offers critical nutrients absent in processed meat, making whole prey a healthier option for predators like lions.
A Cultural Divide
The controversy underscores a trans-Atlantic divide in zoo practices. European zoos, particularly in Denmark, often allow animals to breed naturally and euthanize surplus populations, viewing it as part of natural life cycles. American zoos, by contrast, prioritize contraception to manage populations, reflecting differing cultural attitudes toward death and animal management.
This isn’t Aalborg Zoo’s first brush with controversy. In 2014, Copenhagen Zoo sparked global outrage by euthanizing a healthy giraffe named Marius to prevent inbreeding, later feeding its remains to lions. A year later, Odense Zoo faced criticism for publicly dissecting a lion cub to control its population. These incidents highlight Denmark’s pragmatic approach to zoo management, which often clashes with international sensibilities.
Moving Forward
Aalborg Zoo has clarified that it excludes cats and dogs from its program, focusing on livestock like chickens, rabbits, guinea pigs, and horses. The zoo accepts small animals on weekdays between 10 a.m. and 1 p.m., with a limit of four at a time without an appointment, and maintains strict health requirements for horses, including a valid passport and no recent medical treatments.
While the zoo insists its program aligns with animal welfare and professional integrity, the backlash reveals a deep divide in public perceptions of ethical animal treatment. As the debate rages on, Aalborg Zoo’s initiative forces a broader reckoning with how zoos balance the needs of captive predators with societal values around pet ownership.
