Guinea pig teeth: they grow for life, and hay wears them down

According to the MSD Veterinary Manual, guinea pigs have 20 teeth: incisors at the front, and premolars and molars at the back of the mouth. All of them grow continuously, and it is chewing that keeps them the right length.

When the upper and lower teeth no longer meet properly (malocclusion), they overgrow, form sharp spurs that cut the tongue and cheeks, and make chewing painful. The MSD manual points out that the back teeth are often the problem, even when the incisors look normal.

Not enough hay

The main cause: without long periods of chewing, the teeth don’t wear properly. Too many pellets or muesli-style mixes increase the risk, according to the Royal Veterinary College.

A lack of vitamin C

Scurvy weakens the teeth and the tissues that hold them in place.

Genetics

Some guinea pigs inherit a tendency to misaligned teeth.

An injury or broken tooth

A broken incisor or a loose tooth should be checked by your vet.

• Unlimited good-quality hay, refreshed every day.
• Only a small portion of pellets, so they stay hungry for hay.
• Fresh vegetables rich in vitamin C every day.
• No sugary treats, such as honey sticks.
• Check their incisors every week, as the RSPCA advises: they shouldn’t be too long, broken or loose.

• Drooling, a wet chin or neck.
• Eating less, struggling to eat or seeming to be in pain when chewing.
• Weight loss, sometimes before any other visible sign.
• Discharge from the nose or eyes, a swelling under the jaw (a tooth root abscess), bleeding from the mouth.

A weekly weigh-in is a good way to pick up dental problems early: a guinea pig that can’t chew properly loses weight.

Your vet will examine the whole mouth, back teeth included, and may suggest skull X-rays. Overgrown teeth are shortened and filed down; in long-term cases this may need repeating regularly, sometimes every month according to the MSD manual.

A guinea pig that can’t chew properly loses weight, often before any other sign. Log the weekly weigh-in in MyArk: the chart shows the trend at a glance, for everyone in the household.

• A weight chart for each guinea pig, over time
• A weekly weigh-in reminder
• Dental treatment kept in the health record
• A dated note when you notice drooling or eating less