Cavies' physiology is very similar to humans, that's why they are used in medical experimentation. That also means we suffer similar rates and causes of diabetes and heart disease. Part of the puzzle in preventing those illnesses is exercise, and another part diet. Now, my girls eat well. They eat more hay than anything else, which is just what they need. They only drink dechlorinated, flouride-free filtered water. Organic, freshly-washed and rinsed, dark leafy greens are the fresh food in their daily diet, plus treats of low-sugar veggies and very, very, occasionally a nibble of fruit. We even grow a garden for them, with wheatgrass, clover and lemon balm, an herb that helps Ash deal with her grouchies. Because they are caged, I can control their diet.
But, because they are caged, they get less exercise than if they were "free range" cavies. Those little hamster balls are very bad for guinea pigs and can cause permanent spinal injury and death, so that option is most definitely out. I can't force them to exercise, but in an effort to encourage it, I have designed the girls a figure-friendly cage.
The whole thing is made from those snap-together grid and connector things. I used the snap connectors to maintain even distances between the grids, but I also used plastic zip ties from the hardware store because those little connectors can fall off and make the whole thing very unstable.
The first story is three grids wide by four grids long and has lots of hiding places, room to be separate, play or snooze. The front left grid is a "door," attached with zip ties at the bottom and grid connectors at the top. We can swing the door down and invite cavies out for a snuggle if they want. This reduces their anxiety about being chased around and picked up when they don't want to be.
Each ramp was made by bending grid squares in half and attaching them to the sides of the enclosure with zip connectors. The second story is one by three grids and each ramp is two grids long, providing a gentle enough angle for easy climbing.
Now, it's not good for tender little cavy feet to be walking around on cage floors or grids, so inside both stories and the ramps is a piece of folded coroplast. Coroplast is corrugated plastic used for making signs. I bought my coroplast from a sign making shop. But, coroplast is pretty slippery if you have long nails, so I made a little blanket carpet.
I used waterproof mattress pads sewn to leftover pieces of colorful fleece for the "carpet." I left one edge unsewn from each piece so any dust or hay that gets between the layers can be shaken out. The bottom floor will eventually be one large piece and the second story and ramps will be a second piece all sewn together. Since this photo was taken I've already made an improvement: I added ties to the sides of the "carpet" to tie on the outside of the grids, much like a crib bumper would, just to stabilize the flooring a little more even during the girls' most rambunctious run.
As for the exercise encouragement? While the girls' favorite toys, snuggle spots and water bottle are on the bottom floor, the top floor is where the food is! Their hay, daily greens and occasional treats are all served "upstairs." No matter how lazy they are feeling, if they want food, they gotta go up, and if they want water, they gotta go back down.
Twice a day, usually around 7AM and 7PM, the girls zoom up and down the ramps and around the second story so fast they are almost a blur! The hay basket (made from a bent grid square) hangs over their potty corner (yes, one is potty trained, and the other isn't), and since cavies usually poop and pee where they eat, I rarely have to stand on my head to sweep up beans (beans are what we cavy slaves call the poops because they are hard and small, much like dried beans.)
The cavies live in my schoolroom/office, and have a very small space for themselves. Making the most of the available space, simplifying cleaning as much as possible and providing a healthy environment were the motivating factors in my design. It took me a long time to think this through, and I'm very proud of it!