Black rhinos have a hard enough time in the wild. As they’re hunted to the verge of extinction, auctions for the right to gun one down can fetch as much as $350,000 from wealthy thrill-killers. A zoo, if not the ideal habitat, should at least be safer. But researchers are finding the sedentary lifestyle has its own dangers.

Ohio State University doctors have found that between the lack of movement and rich food, black rhinos in captivity are developing the same health problems plaguing their chubby caretakers. According to the research at least two health problems are appearing in black rhinos we don’t see in their wild counterparts: inflammation and insulin resistance.

That might sound like a small problem, but it’s rhinos we’re talking about here. Only about 5,000 black rhinos remain on the planet, and 73 percent of those born in captivity die without reproducing. Any health problem could mark the beginning of the end, which means across-the-board changes in how zoos feed the great mammals. Even if only one of the top 20 oil men in Texas can afford to shoot one legally.

Photos via Wikimedia