Scientists devise new nutritional solution for cat hairballs

Sept. 30, 2003

by Madeline Fisher

It's a question most people wouldn't think - or want, really - to consider: What's in the average cat hairball besides hair?

A team of scientists did ponder that question, however, and their curiosity has produced a new nutritional solution for hairballs that may improve the lives of thousands of felines and their owners.

Mark Cook, animal scientist at the University of Wisconsin-Madison, and researchers at the Nestlé Purina PetCare Company have devised a way to help dissolve hairballs by using agents that break up, or emulsify, fats. Cook and his collaborators, Beth Drake, Leonard Girsch and Janet Jackson, conceived the idea after discovering that hairballs can contain up to 30 percent fat.

A patent on the technique was issued jointly to the Wisconsin Alumni Research Foundation, a non-profit agency that manages intellectual property for UW-Madison, and Nestlé Purina in May 2003. Nestlé Purina holds an exclusive license to the technology and has incorporated it into new hairball-control cat food formulas that arrived on store shelves earlier this summer.

Known scientifically by the more obscure term bezoars, hairballs are a natural, albeit unappealing, outcome of a cat's grooming rituals. They develop when hair swallowed by the cat enters the stomach and snares undigested fat, forming a tight association with it, says co-inventor Jackson, a Nestlé Purina scientist. Once a ball forms, it tends to stay trapped and growing in the stomach until coughed up, much to the dismay of cat owners.

During ongoing conversations with Nestlé Purina scientists about a variety of pet care issues, Cook says the subject of hairballs kept coming up.

"They kept asking me about them," he recalls. "So, I finally said, 'Well, what is a hairball?' They all laughed and said, 'It's hair.' So I said, 'Put 20 of them in a box and ship them to me.'"

After a simple analysis of the water, fat, protein and ash content of the hairballs revealed their fatty nature, the team quickly hit upon the idea of using a detergent to break up the fat and disintegrate the balls. Cook first tested a common dishwashing detergent. When that worked, he moved on to a food-grade fat emulsifier, a solution of which trimmed the size of hairballs by more than 50 percent.

In the new hairball formulas developed by Nestlé Purina, an edible emulsifier called soy lecithin helps break down existing hairballs, allowing them to pass more easily through a cat's digestive tract, and minimizes the formation of new ones. The technology's main advantage, says Jackson, is that it provides good hairball control with less fiber than traditional hairball formulas.

"High-fiber diets help to push hair through the digestive tract. But they also aren't as digestible, so cats need to eat more food for proper nutrition," she says. "Adding a fat emulsifier in conjunction with a lower fiber level addresses the hairball problem while allowing cats to absorb the nutrients they need."