Hamster care: cages, cage mates and signs of illness

Hamsters are small, cute and need little room, so they are often a child's first pet. Their needs are more complex than they look: they usually live about two to three years, hide pain well and can go downhill quickly when ill. Based on advice from the RSPCA, PDSA and the Merck Veterinary Manual, this guide covers housing, living together or alone, and the signs of illness that need a vet.

Buy or adopt from a place with clear origins, clean enclosures and no overcrowding. Ask which species it is (a Syrian hamster or a dwarf species such as Roborovski, Campbell's or winter white), plus its sex and age, because care differs by species. A healthy hamster usually has bright eyes, a dry nose, a smooth coat, a clean and dry rear end, and moves around actively. Avoid a hamster that is wet around the tail, has a runny nose or seems dull.

The RSPCA points out that an adult should always be responsible for a hamster's care, even when it is a child's pet. Children can help with feeding and play, but an adult should check the cage, food and health every day.

Wild hamsters dig deep burrows and travel far each night, which most small, multi-level shop cages cannot allow. PDSA cites the German Veterinary Association for Animal Welfare, which recommends a minimum floor area of 100 x 50 cm, and bigger is better. A wide single-level enclosure is better than a tall one, because hamsters have poor eyesight and can easily fall.

What the enclosure needs:

• A solid floor. Wire mesh floors can injure their feet.
• Bedding deep enough to burrow in. PDSA recommends at least about 25 cm.
• Paper-based bedding or shredded paper. Merck advises avoiding cedar and pine shavings.
• No cotton wool or fluffy bedding that pulls into strands, which can wrap around legs or cause harm if eaten.
• A dark nest box for sleeping, placed away from the water bottle so it stays dry.
• A wheel that is as large as possible with a solid running surface, so your hamster does not run with a curved back or catch a leg between bars.
• A secure lid and doors, because hamsters are excellent escape artists.

Merck recommends keeping the enclosure at about 18–26°C, while PDSA suggests a steady 18–21°C. Vietnamese summers are often much hotter. A closed enclosure near a window with afternoon sun or out on a balcony can cause heatstroke, and the hamster has nowhere to escape. Keep the enclosure in a cool room out of direct sun, with good airflow but no draughts. On very hot days, an air-conditioned room is safer.

Winters in northern Vietnam can be the opposite problem. PDSA explains that hamsters can slip into torpor, a hibernation-like state, when they get cold. If your hamster is unusually still, check whether the room has dropped below 20°C, warm the room gradually and call a vet.

The RSPCA notes that hamsters are sensitive to ultrasound from TVs, screens and vacuum cleaners, so keep the cage away from them and keep a regular lights-off time. Spot clean every few days and deep clean once or twice a month, while your hamster is awake rather than at midday when it sleeps.

Most hamsters prefer to live alone and can fight badly when housed together.

• Syrian and Chinese hamsters must live on their own, according to the RSPCA.
• For dwarf hamsters, the RSPCA says they can live together with the right care and conditions. PDSA is more cautious and advises against housing even Russian dwarf hamsters together, because dominance problems and fights are common.

The safest choice is one hamster per enclosure. If you still want to keep a pair of dwarf hamsters, use a much larger enclosure with plenty of hiding places (the RSPCA suggests at least one more hide than the number of hamsters), and separate food bowls and water bottles. If you see chasing, biting or wounds, separate them straight away. Bite wounds in hamsters often turn into abscesses, which need a vet.

The main food should be a complete pelleted food made for hamsters. Keep seeds limited, because hamsters may eat them instead of their balanced pellets. Vegetables and fruit are extras, and Merck advises keeping treats to no more than 10% of the diet. Give fresh water every day and check that the bottle spout is working.

Do not share human food such as sweets, salty or seasoned dishes, onion, garlic or chocolate. Many items in our article on foods that are dangerous for dogs and cats are unsuitable for small pets too. A hamster's front teeth never stop growing, so provide safe things to gnaw, such as untreated wood or plain cardboard.

Hamsters rarely show pain, so by the time you notice a problem, the illness may be advanced. Contact a vet promptly if you see:

• Wet fur around the tail or diarrhea, especially with low energy, poor appetite or weight loss. Merck notes that diarrhea in hamsters can be severe and can spread, so keep a sick hamster away from others.
• Wheezing, difficulty breathing, or discharge from the nose or eyes.
• Trouble eating, drooling, or front teeth that look too long or crooked.
• Limping or not wanting to move, especially after a leg got caught in a wheel or wire cage.
• A lump, a hot red swelling or a wound.
• Drinking or urinating much more, a rough coat, a hunched back, or a repetitive unusual behaviour such as constant bar chewing.

Never give your hamster human medicines or medicines meant for other animals. The RSPCA and Merck both warn that some antibiotics can cause severe diarrhea and death in hamsters. Hamsters can also catch colds from people, so wash your hands and handle your hamster less when you are unwell.

Not every clinic sees small pets, so find a vet experienced with exotic animals before you need one and call ahead. Use a small carrier with familiar bedding, and never leave it in the sun or a hot car.

Weigh your hamster regularly on a kitchen scale and keep a record of its weight, photos and vet visits. You can store these in the health profile in the PetID app and show them to the vet when needed, just like digital vaccine and health records for dogs and cats. If you have other small pets, see our guides to pet rabbits and healthy pet birds.

Sources: RSPCA – Hamsters, RSPCA – Hamster environment, PDSA – Hamsters as pets, Merck Veterinary Manual – Providing a home for a hamster, Merck Veterinary Manual – Disorders and diseases of hamsters.