Short answer: keep cats indoors on cold nights, bring guinea pigs inside, and winter-proof rabbit hutches. The RSPCA says cats should be kept inside overnight once temperatures fall below about 7–8°C (45–46°F), guinea pigs should move indoors below 15°C (59°F), and rabbits do best at 10–20°C (50–68°F) with a raised, dry hutch. Antifreeze and rock salt are the big winter poisons for all three.
Cats, rabbits, and guinea pigs face meaningfully different winter risks, and lumping them into one generic “keep pets warm” guide misses the specifics that actually matter for each.
Winter Temperature Guide at a Glance
| Cats | Rabbits | Guinea pigs | |
|---|---|---|---|
| Ideal range | 10–25°C (50–77°F) | 10–20°C (50–68°F) | 17–20°C (63–68°F) |
| Act when | Below 7–8°C: keep in overnight | Below freezing: consider moving indoors | Below 15°C (59°F): move indoors |
| Main cold-weather risks | Hypothermia, frostbite, antifreeze, cars | Frozen water, wet bedding, predators | Chilling, sudden temperature swings |
All figures from RSPCA winter and housing guidance.
What Do Cats Need in Winter?
Indoor cats face relatively low winter risk, but indoor heating can dry out their skin, and drafts near windows or doors can make certain spots noticeably colder. The RSPCA suggests warm, draft-free resting spots, regular brushing to help with dry skin, and continuing flea treatment, since fleas thrive in heated homes. Cold also makes arthritic joints stiffer — older cats benefit from soft bedding and ramps (see signs of hidden arthritis in cats).
Outdoor or outdoor-access cats face real risk, including hypothermia and frostbite on ears, paws, and tail. The RSPCA’s advice:
- Keep them inside overnight when it drops below about 7–8°C, and provide an indoor litter tray — one per cat plus one extra
- Tap the car bonnet (hood) and check wheel arches before driving, since cats shelter in and under cars
- Wipe paws and belly after time outside to remove antifreeze and rock salt, both poisonous to cats
- Dry a wet cat with a towel so it doesn’t become chilled
- Check that the cat flap hasn’t frozen shut
Signs of hypothermia include shivering that suddenly stops, low energy, confusion, pale gums and cold ears and paws. Get to a vet immediately, and warm the cat gradually with blankets — never place anything hot directly on the skin.
What Do Rabbits Need in Winter?
The RSPCA says rabbits cope with the colder months “pretty well” — they grow a thicker coat and huddle together for warmth, which is one more reason they should never live alone. But they only stay safe with the right setup:
- Position the hutch away from wind, rain, and snow, and raise it at least four inches off the ground to keep out damp and ground frost
- Add extra bedding — dust-free hay and straw over layers of newspaper provides insulation and absorbs moisture
- Check water at least twice a day, since bottles and bowls can freeze; the RSPCA notes a bowl is less likely to freeze than a bottle, and offering both helps
- Remove wet or moldy bedding daily, since wet bedding freezes on cold nights and can make rabbits ill
- Insulate from the outside. The RSPCA suggests insulating hutch walls with cardboard, blankets or boards while keeping ventilation; keep fabric where rabbits can’t chew it, and use hay or straw as bedding inside
- Reinforce against predators, since the RSPCA warns foxes get bolder in winter
If temperatures drop below freezing, moving the hutch into a shed, garage or indoors is safer than relying on outdoor insulation alone — as long as the rabbits still have room to exercise. Antifreeze and rodent poisons stored in sheds and garages are a real hazard, so clear them out first.
What Do Guinea Pigs Need in Winter?
Guinea pigs are considerably more cold-sensitive than rabbits. The RSPCA’s housing guidance says to move them indoors when temperatures fall below 15°C (59°F), that room temperatures of 17–20°C are ideal, and that they “don’t cope well with big changes in temperature.” That’s a correction to advice you may see elsewhere suggesting 10°C is the cut-off.
Indoors, choose a well-ventilated, dry room away from radiators, heaters and drafts — central heating can make some spots too hot. An unheated garage or shed may not stay above 15°C, so it isn’t a reliable substitute. When spring comes, wait for consistently suitable temperatures before moving them back outside. The same bedding, water and mold precautions that apply to rabbits apply here, with less margin for error. Keep up daily vitamin C through fresh vegetables too — see how much vitamin C guinea pigs need.
Which Winter Poisons Should You Watch For?
- Antifreeze (ethylene glycol). The Merck Veterinary Manual notes most poisonings in colder climates happen in fall, winter and early spring, and that cats are especially sensitive — the minimum lethal dose of undiluted ethylene glycol is about 1.4 mL per kg of body weight. US makers have added a bittering agent since 2012, but some animals still drink it. Store it sealed, and clean up drips.
- Rock salt and de-icers. The RSPCA warns ingestion can cause vomiting and, in severe cases, convulsions and kidney damage.
- Rodent poisons and plants. For rabbits, the RSPCA lists rodenticides, ivy and foxglove among common winter poisons.
If you suspect poisoning, don’t wait for symptoms: call your vet, ASPCA Animal Poison Control at (888) 426-4435, or Pet Poison Helpline at (855) 764-7661.
What’s a Shared Winter Checklist for Small Pets?
- Move any outdoor hutch or enclosure to a wind- and moisture-protected location, or indoors, before temperatures drop significantly — for guinea pigs, below 15°C
- Add and regularly refresh dry, mold-free bedding for insulation
- Check water at least twice a day for freezing, and replace immediately if frozen
- Provide fresh leafy greens and vegetables daily for rabbits and guinea pigs, since garden grazing disappears in winter
- Keep antifreeze, de-icers and rodent poisons sealed and out of reach
- Watch for lethargy, reduced appetite, or reluctance to move, which can signal a pet is too cold even with a reasonable setup in place — and see an exotics vet promptly, since small mammals hide illness (our guide to signs of illness in small mammals explains what to look for)
For dogs, see our separate winter safety guide for dogs.
This article is for informational purposes only and does not replace guidance from your veterinarian.
Sources
- RSPCA — How to help cats in cold weather
- RSPCA — Looking after your rabbit in winter
- RSPCA — Creating a good home for guinea pigs
- RSPCA — Keep pets safe in cold weather
- Merck Veterinary Manual — Ethylene glycol toxicosis in animals, updated September 2024
- ASPCA — Animal Poison Control
