Under the category of "things we wish manufacturers and pet stores would stop peddling to guinea pig owners," we'd like to add these exercise balls. We wish manufacturers would remove pictures of and text references to guinea pigs from the product packaging and the product pages on their Web sites. We wish pet supply retailers would stop filing these products under the "guinea pigs" category in their online catalogs. As long as they continue to do so, they perpetuate the myth that these balls are safe, appropriate, and acceptable toys.
Originally created for ferrets, hamsters, mice, gerbils, and rats -- animals with different body types than guinea pigs -- the marketing of these "exercise balls" was expanded at some point to include guinea pigs...even though their bodies just aren't built for these toys.
There's a variety of models, from balls that enclose animals (like the one shown here) to balls that have three open holes cut into them. They bear names like "krawler," "run-about ball," and "roll-about ball."
Stated simply, these balls are unsuitable for guinea pigs. In the balls with open cutouts, we've heard of (and seen) guinea pigs whose legs or feet were injured as a result of being put in these things. In the balls that completely enclose the guinea pig inside, the guinea pig is absolutely terrified by the environment.
We know folks want to keep their guinea pigs entertained and engaged. And that's good. But rather than invest in these balls, we suggest other toys -- tunnels, PVC pipe, paper bags, Chubes, and fleece sacks -- to give your guinea pigs the opportunity to tunnel, hide, run mazes, and play hide-n-seek with each other. Your investment in these objects will last much longer and will give your guinea pigs hours of fun in a safe environment.