Guinea pig health: signs of illness to watch for

What does a healthy guinea pig look like?

A healthy guinea pig is alert, eats almost constantly and passes plenty of firm, dry droppings. PDSA's daily check and PetMD's care sheet describe what to look for:

• Bright, open, clear eyes (a little milky-white fluid at the eyes is normal, says the RSPCA)
• A clean, dry nose with no discharge
• Mouth closed, with front teeth white and not poking out
• Clean ears with no wax build-up, redness or smell
• A clean, glossy coat with no bald patches, tangles or lumps
• A clean, dry bottom with no droppings stuck to it
• Nails that are not too long or curling under
• Feet with no sores, and walking without stiffness or limping
• Firm, oval droppings, yellow-brown to dark brown, never soft
• Steady weight from week to week

Signs of illness in guinea pigs

The RSPCA warns that guinea pigs feel pain but show few outward signs, so they may be suffering before you notice. Its three key warnings are not eating, being quieter than normal and hiding more than usual. PDSA and PetMD add these:

• Eating less, or not at all, or dropping food
• Fewer, smaller or no droppings, or diarrhoea
• Weight loss or gain, especially over a short time
• Drooling or a wet chin
• Teeth grinding, sitting hunched or not wanting to be touched
• Fast, noisy or laboured breathing, wheezing or sneezing with discharge
• Runny, red, cloudy or crusty eyes
• Drinking or weeing more than usual
• Hair loss, scabs, flaky skin or constant scratching
• Lumps or swellings anywhere, including the jaw
• Limping, red or swollen feet
• Head tilt, circling or loss of balance
• Blood in the urine, or straining or squeaking when weeing

When to see a vet, and how fast

Guinea pigs can go downhill quickly. The Humane World for Animals notes that they can develop life-threatening gut problems relatively quickly, and the MSD Vet Manual says some with gut illness decline rapidly. Use this as a guide, and if in doubt, ring:

PDSA says eye problems can progress very quickly and that stomach upsets can quickly become very serious, which is why they sit high on the list.

Common guinea pig health problems

Most guinea pig illness comes down to diet, teeth, gut, airways and skin. The University of Florida's vets say most problems stem from nutrition, digestion, teeth or obesity. Here are the common ones, what they look like and what vets commonly do:

Scurvy is entirely preventable with daily vitamin C, and PetMD says signs can appear after only 2 to 3 weeks of a poor diet. Our guide to vitamin C for guinea pigs covers how much they need and where to get it. Dental disease and gut trouble are prevented mostly by unlimited hay; see our guinea pig diet guide.

Mites, lice and fleas

Mites are one of the most common guinea pig problems, says the Humane World for Animals, and PDSA lists them first among causes of skin trouble. They cause intense itching, hair loss, scabs and sore skin, and skin problems tend to get worse over time, so PDSA advises getting help even when signs seem mild.

While treatment works, deep clean the enclosure and replace bedding, as described in our guinea pig cage cleaning guide.

Heatstroke and cold

Guinea pigs cope badly with heat. The RSPCA says 17 to 20°C (63 to 68°F) is ideal indoors, that temperatures above 26°C (79°F) can cause heatstroke and that below 15°C (59°F) they can get chilled. PDSA says above 24°C (75°F) can be uncomfortable and above 27°C (81°F) can lead to heatstroke. PetMD puts the safe range at 65 to 75°F (18 to 24°C), never above 80°F (27°C).

Purdue's vets list the signs of heatstroke as listlessness, raising the head and shallow, rapid breathing. Move the guinea pig somewhere cool and shaded at once, cool it gently with a damp towel, offer water and ring your vet immediately. Our guinea pig temperature guide covers keeping them safe in summer and winter.

Weekly health check you can do at home

A five-minute weekly check catches most problems early. Do it on a towel in your lap, sitting down.

1. Weigh. Use kitchen scales in grams and write the number down. PDSA says large changes in weight, especially over a short time, are a warning sign.
2. Look at the face. Check eyes are bright and clear, the nose is dry and there is no wet fur on the chin. Lift each ear flap and look inside, as PDSA suggests.
3. Check the front teeth. The RSPCA says to check them weekly. They should be white, even and meet neatly. Only a vet should correct overgrown teeth.
4. Feel the body. Run your fingers over the whole body, under long fur too, feeling for lumps, scabs or thin patches.
5. Check feet and nails. Look for red or swollen pads. Trim nails about monthly, as the University of Florida and PetMD advise, or every 2 to 4 weeks per PetMD's bumblefoot guidance.
6. Check the bottom. It should be clean and dry. In warm weather, the RSPCA says check twice a day for flystrike.
7. Groom. Brush short coats once or twice a week and long coats daily, as PDSA recommends.

How to keep a guinea pig healthy

• Unlimited grass hay, every day, to wear teeth and keep the gut moving
• Daily vitamin C from fresh pellets and veg such as bell pepper
• A solid floor with deep, soft bedding, never wire, to protect their feet
• Daily spot cleans and a full bedding change at least weekly, so urine does not burn skin or feet
• Dust-free hay and bedding to protect their airways; see our guinea pig bedding guide
• A room kept at a steady, comfortable temperature, away from draughts and sunny windows
• A guinea pig companion, as stress makes illness more likely, says the RSPCA
• A yearly check-up with a vet who sees guinea pigs often
• Pet insurance, which the RSPCA recommends for unexpected bills

Finding a vet for guinea pigs

Look for a vet with experience of guinea pigs and other small plant-eaters, often listed as an exotics or rabbit-savvy practice. PetMD advises finding an exotic vet who specialises in guinea pigs, and the RSPCA recommends a check-up at least once a year. Register before you need one, and know where your nearest out-of-hours vet that sees guinea pigs is, because their emergencies cannot wait until morning. The Purdue vets also warn never to give a guinea pig antibiotics on your own, as some cause life-threatening diarrhoea.

Guinea pigs usually live around 5 to 7 years; our guinea pig lifespan guide covers how care changes as they age, and our complete guinea pig care guide covers the rest.