Chinchilla wheels: size and safety

What size wheel does a chinchilla need?

At least 38 cm (15 in) across. That is the size VCA, PetMD and the MSD Veterinary Manual all give, and it is the one number about wheels that every vet source agrees on. Bigger is fine if you find one and it fits the cage; smaller is not.

The reason is the shape of a chinchilla. The MSD Veterinary Manual gives an adult body length of up to 25 cm (10 in), plus a tail of about 15 cm (6 in). On a small wheel, the curve of the track is tighter than the curve of the animal, so the back has to bend upwards with every stride. A simple check, reasoned from that: when your chinchilla runs, its back should stay flat or very slightly curved. If it arches, the wheel is too small.

What makes a chinchilla wheel safe?

A solid, smooth track, strong materials, and nothing that can trap a foot, leg or tail. The MSD Veterinary Manual says to avoid wheels with holes or rough surfaces, which can injure feet or legs, and PDSA and Burgess both ask for a solid base rather than rungs. Woodgreen warns against any toy that can trap a chinchilla's legs. Put together, a safe wheel has:

• A diameter of 38 cm (15 in) or more.
• A solid running track, with no rungs, bars, mesh or holes.
• A smooth surface that is easy to wipe and won't wear feet.
• A chew-proof body, ideally metal, with no soft plastic in reach.
• A solid back, so there are no spokes for a tail or foot to catch on.
• No gap between the wheel and its stand or cage fixing where a foot could slip in.
• A sturdy stand or a bolt-on fixing that stops it wobbling or tipping.
• Quiet bearings, since chinchillas run at night.

Metal wheels with a solid, flat track are the usual choice for chinchillas. They don't get chewed, they don't hold urine, and they last for years. Wooden wheels look nice, but the ones sold for small pets are mostly too small and soak up urine. Soft plastic wheels are a poor choice because chinchillas chew plastic, and swallowed pieces can block the gut.

Do chinchillas need a wheel?

Not always, but most chinchillas use one happily and it helps burn off night-time energy. The sources take different views. PDSA recommends "a large exercise wheel with a good solid base". VCA, PetMD and the MSD Veterinary Manual include a 15-inch wheel in their housing advice. The RSPCA and Woodgreen don't mention wheels at all, and focus instead on space to run and jump, solid shelves at different heights and daily exercise.

We would offer a correctly sized, safe wheel to a pair in a big cage, and treat it as one extra, not the main source of exercise. The MSD Veterinary Manual suggests about two hours of supervised time out of the cage every day in a chinchilla-proofed room. A wheel does not replace that, or a cage tall enough to jump in. Our guide to chinchilla cage size covers the room they need, and chinchilla enrichment has more ways to keep them busy.

Where to put a wheel in the cage

Low enough to be safe and high enough to stay clean. A wheel needs a lot of room: at 38 cm (15 in) across, plus the stand, it takes up a good part of one level in many cages.

1. Choose a level. Fit the wheel on a lower or middle level with a solid floor, not on a narrow shelf. The RSPCA says no open drop in the cage should be over 60 cm (2 ft), and that matters even more next to a fast-moving wheel.
2. Bolt it or stand it. If it bolts to the cage side, tighten it so it cannot swing. If it is free-standing, put it on a flat, solid floor where it cannot rock.
3. Leave clear space around it. Keep at least a hand's width between the wheel and shelves, bowls and the cage bars so nothing catches a foot or tail as it spins.
4. Keep it away from food and water. Droppings fly out of a busy wheel. Place hay racks, bowls and bottles on another side.
5. Check the run. Watch your chinchilla on it the first few nights. Its back should stay fairly flat and it should get on and off easily.

If your cage is too small for a wheel, set one up in the play area during time out instead. Our chinchilla cage setup guide shows how to lay out levels so everything fits.

Wheels to avoid, and exercise balls

• Hamster and rat wheels: usually 20 to 30 cm (8 to 12 in), far too small.
• Wire, rung or mesh wheels: feet and legs slip through. The MSD Veterinary Manual warns against wheels with holes.
• Soft plastic wheels: chewed and swallowed.
• Wheels with open spokes on the back: a tail or foot can catch as it turns.
• Flying saucers and tilted discs: made for smaller rodents; we would skip them, as a fast, heavy chinchilla has little to grip on a tilted spinning plate.
• Exercise balls: never. The MSD Veterinary Manual says plastic exercise balls are too small for chinchillas and can cause injuries.

Exercise balls are a particular worry because chinchillas overheat easily. VCA says they should never be kept anywhere as warm as 27°C (80°F), and a closed plastic ball with a running animal inside warms up quickly. Our chinchilla temperature guide explains why heat is so dangerous.

Wheel safety: what to watch for

Once a wheel is in, a quick look each week keeps it safe:

• Bolts tight, stand steady, no wobble.
• Track clean and dry; wipe off urine and droppings.
• No cracks, sharp edges or loose parts.
• Quiet bearings; a new squeak or grind can mean wear.
• Feet healthy: check the soles for redness or sores, and the toes for injuries.

Sore, red or swollen foot pads can come from rough or wire surfaces as well as from cage floors. If you see them, or a limp, take the wheel out and see a vet. A leg caught in rungs or a gap is exactly the injury the MSD Veterinary Manual's advice on wheels is meant to prevent. Our chinchilla health guide lists other signs to watch for, and our best chinchilla toys page includes wheels we would look at. For everything else your chinchillas need, see our complete chinchilla care guide.