We know that eating one's poop is very unhealthy. What we do not know instead is whether cheetahs are aware of this, but they can die if they take up this "practice", as signaled by a new research published in the Proceedings of the National Academy of Sciences. In fact, they catch a disease similar to the mad cow disease and Alzheimer's, meaning, also characterized by malformed proteins.

Cheetahs represent an endangered species. 70% of the cheetahs kept in captivity die because of a disease called AA amyloidosis. The condition triggers normal proteins to form dangerous clumps due to misfolding. These insoluble fibrous proteins (amyloids) aggregate in Alzheimer's and mad cow disease in the brain, but in the case of AA amyloidosis, they emerge mainly in the spleen, liver and other organs.

"Severe deposition in the heart causes heart failure," said co-author Keiichi Higuchi, a pathobiologist at the Shinshu University in Asahi, Japan. It seems that the clumps turn normal proteins into amyloids resembling the prions that determine mad cow disease in cattle. The new research has shown that cheetahs seem to catch the disease from feces. Cheetah wastes were found to contain small, fragile amyloid fibers that proved highly infectious in mice, triggering AA amyloidosis. However, the cats may not willingly consume their excrements.

"We speculate this may occur during mutual grooming - licking of fur contaminated by fecal matter," Higuchi said. The amyloids may also contaminate the soil, from which they can easily enter both the food and the fur of the cheetahs. "We hope that we could suggest possible measures for rescuing cheetahs from extinction by preventing AA amyloidosis, such as removing feces as soon as possible," Higuchi said.

This disease could also be transmitted via saliva or urine. Unfortunately, Higuchi warns, this cat "is a fierce and protected animal and it is dangerous and difficult for us to collect urine and saliva samples."

In 2007, a team led by amyloidologist Alan Solomon from the University of Tennessee at Knoxville found that foie gras (made of goose or duck liver) containing amyloids can infect susceptible mice with AA amyloidosis. "So, a number of amyloid diseases may be very similar to prion diseases, where the abnormal form of protein can serve as a seed. One thing we're working on is a way to eliminate or prevent this disease process, an antibody that can recognize this amyloid and help destroy it." Solomon concluded by saying.