Many of the common health problems seen in pet guinea pigs are often preventable by good husbandry and good feeding practices.

Some of the most common health problems include:

Vitamin C deficiency
Like humans, guinea pigs cannot synthesise vitamin C (ascorbic acid ) from other food substances so they require a direct dietary source of vitamin C. This is usually supplied sufficiently by feeding fresh leafy green vegetables. It is safer, however, to supplement this with small quantities of vitamin C rich food such as citrus or kiwi fruit. Vitamin C must be provided directly from food materials. Vitamin C liquid supplements (added to their drinking water) or processed vitamin C added to commercial feeds are not reliable sources.

Vitamin C deficiency related disease usually involves swollen joints and haemorrhaging (bleeding) into skeletal muscle, the intestines and other tissues. Affected guinea pigs may be anorexic, lethargic, weak; move with difficulty and appear painful when moving. They may also have diarrhoea and a rough coat, among other symptoms. Vitamin C deficiency causes the guinea pig severe pain and discomfort and is a preventable condition. 

Ulcerative pododermatitis (ulcerated and swollen footpads)
In the wild, guinea pigs generally live on grassed areas or other types of natural material which provide some measure of cushioning for their feet. Swollen and ulcerated footpads are a common problem when guinea pigs are kept on hard surfaces and/or uncovered wire mesh floors. The lack of any cushioning effect creates pressure sores. These pressure sores cause severe discomfort and pain. In some cases inflammation may spread to the bone tissue of the feet. 

Domesticated guinea pigs should be kept on soft floor material and soft bedding material to help prevent ulcerative pododermatitis. Suitable materials include grass hay including Timothy, Oaten, Wheaten, Pasture, Paddock, Meadow or Rye grass hays (they should not be fed or provided with Lucerne (alfalfa) or Clover hays as floor/bedding material as these are too high in calcium and protein). Other suitable materials include straw or shredded paper. Uncovered wire mesh floors should be avoided as these are too hard on the guinea pigs' footpads.

Mites
Guinea pigs are susceptible to mite infestation. Symptoms include hair loss and intense itchiness and scratching. Mite infestations can severely compromise a guinea pig's well-being (in some cases the itchy sensations can severely disrupt the ability of the guinea pig to sleep properly). Fortunately, mite infestation is easily treatable by your local vet. Should a mite infestation be diagnosed, please thoroughly clean out the guinea pig hutch/housing.

Dental problems
Guinea pigs fed an inappropriate diet are highly susceptible to dental problems. The fact that their teeth grow continuously also makes them more susceptible to dental problems. They need to chew on fibrous material for long periods throughout the day to wear down their teeth. Dental disease causes severe pain and discomfort to the guinea pig and is best prevented by feeding an appropriate diet.

Guinea pigs have evolved over thousands of years to eat a high fibre diet. In their natural environment wild guinea pigs eat predominantly grass throughout the day. Pet guinea pigs should be fed in much the same way. Feed predominantly grass and/or grass hay (Timothy, Oaten, see above) and fresh leafy green vegetables. Please see the article below titled " What should I feed my guinea pig?" for more detailed information.

If you suspect your guinea pig is suffering from any of the above mentioned diseases and/or you notice any other abnormalities or problems please consult your vet immediately.

You should regularly check your guinea pig to ensure he/she is eating well, urinating, defecating normal droppings (normal droppings are formed and shaped like elongated baked beans) and walking around easily.  Also check the guinea pig has a healthy coat,  clear eyes, a nose free of any discharges, normal length nails (that are not too long) and normal healthy footpads.