Common Guinea Pig Health Problems

Quick answer

The most common guinea pig health problems are respiratory infections, dental disease, vitamin C deficiency, bladder stones, skin parasites and digestive upsets. Guinea pigs hide illness, so the earliest clues are often small: eating less, weight loss, fewer droppings or sitting hunched. A guinea pig that stops eating needs a vet the same day.

Why guinea pigs need watching closely

Guinea pigs are prey animals. In the wild, looking weak attracts predators, so they keep going as normal for as long as they can. By the time a guinea pig looks obviously ill, the problem has often been building for a while. Daily checks at feeding time and a weekly weigh-in catch most problems early. The everyday basics are covered in Guinea Pig Care for Beginners.

Vitamin C deficiency (scurvy)

Guinea pigs, like people, cannot make their own vitamin C. Without enough in their diet they develop scurvy, and low levels also weaken the immune system and the teeth.

Signs: a rough coat, reluctance to move, limping or swollen joints, poor appetite, weight loss, sore gums, slow healing and getting ill more often.

Prevention: feed a fresh guinea pig pellet (vitamin C breaks down over time, so check the date and store it sealed), plus vitamin C-rich vegetables every day, such as bell peppers, kale and parsley in sensible amounts. Adding vitamin C to drinking water is not reliable, because it breaks down quickly and can put guinea pigs off drinking. If you suspect a deficiency, a vet can advise on supplements; follow your vet's dosing.

Respiratory infections

Breathing infections are one of the most serious problems in guinea pigs and can turn into pneumonia quickly. Several bacteria are involved, and some guinea pigs carry them without symptoms until stress, poor housing or low vitamin C lets the infection take hold. Rabbits can carry respiratory bacteria that affect guinea pigs, which is one reason the two shouldn't be housed together.

Signs: sneezing, discharge or crust around the eyes or nose, noisy, wheezy or fast breathing, a hunched posture, weight loss and not eating.

What to do: see a vet the same day if breathing looks laboured. Treatment usually involves antibiotics chosen for guinea pigs, supportive care and assisted feeding. Damp, draughty or dusty housing and ammonia from dirty bedding make things worse.

Dental problems

Guinea pig teeth grow continuously. Hay and grass, chewed for hours a day, keep them worn evenly. With too little hay, an inherited bad bite or vitamin C deficiency, the back teeth can overgrow, form spurs or trap the tongue, even while the front teeth look normal.

Signs: drooling or a wet chin, dropping food, eating slowly, wanting only soft food, weight loss and fewer droppings.

What the vet does: examines the mouth (often under sedation), may take X-rays, and trims or files teeth back to shape. Some guinea pigs need regular dental care for life. Never clip teeth at home.

Bladder stones and urinary problems

Guinea pigs are prone to bladder sludge and stones. A diet very high in calcium is thought to contribute, along with not drinking enough and genetics.

Signs: blood in the urine, straining or squeaking when passing urine, a hunched posture, a wet rear end and weight loss.

What to do: see a vet promptly. A stone that blocks the urinary tract is an emergency. X-rays confirm the problem, and many stones need surgery. Keep high-calcium foods (such as large amounts of spinach, kale or alfalfa hay for adults) moderate rather than daily staples, and encourage drinking with fresh water and plenty of wet greens.

Skin problems: mites, lice and ringworm

Mites are common and can be very itchy. Severe mite infestations cause hair loss, scabs, sores and frantic scratching; some guinea pigs scratch so hard they appear to have fits. Lice are visible as tiny moving specks or eggs on the hair. Ringworm is a fungal infection that causes round, crusty bald patches, often on the face and ears, and it can spread to people.

What to do: see a vet for a diagnosis. Treatment depends on the cause, and guinea pigs living together are usually all treated. Don't use flea or mite products made for other species, which can be harmful. Wash your hands after handling a guinea pig with skin lesions.

Diarrhoea and gut problems

Guinea pigs rely on a steady flow of fibre to keep their gut working, much like rabbits. A sudden diet change, too little hay, too many pellets or sugary treats, stress or infection can upset the balance. Like rabbits, they can also develop a dangerous gut slowdown, where a guinea pig that eats less gets worse quickly and needs urgent help.

Many antibiotics that are safe for dogs and cats can cause fatal gut upsets in guinea pigs. Never give any medicine that hasn't been prescribed for your guinea pig by a vet.

Other problems to know about

• Bumblefoot (pododermatitis): sore, swollen or scabbed feet, linked to wire floors, rough or dirty bedding, obesity and overgrown nails.
• Ovarian cysts: common in older females. Signs include hair loss along the sides, a smaller appetite and low energy. Spaying is the usual treatment.
• Heatstroke: guinea pigs cope poorly with heat. Keep them cool and shaded and see Keeping Pets Safe in a Heatwave.
• Lumps: abscesses and tumours both occur. Any new lump is worth a vet check.
• Eye injuries: hay and seed heads can poke eyes. A cloudy, half-closed or weeping eye needs attention.

When to see a vet

Go the same day if your guinea pig:

• has stopped eating, or is passing few or no droppings;
• is breathing fast, noisily or with effort;
• is straining to urinate or has blood in its urine;
• has diarrhoea, especially if it seems dull;
• is cold, weak, hunched or collapsed.

If your guinea pig is panting, limp or overheated, treat it as an emergency: move it somewhere cool, dampen its ears and feet with cool (not cold) water and call a vet straight away.

Book an appointment within a day or two for weight loss, drooling, sneezing with discharge, scratching and hair loss, a limp, sore feet, a new lump or a cloudy eye. Find a vet with guinea pig experience before you need one.

Looking for guinea pigs? Healthy ones are alert, plump, clean around the eyes, nose and rear, and eager to eat; you can find small-pet listings on Paalo.