people, Guinea Pigs can get scurvy from vitamin C deficiency. Guinea
Pigs with plenty of fresh grass and other plants to eat will be all
right, but if they get much of their food in the form of hay etc. they need a vitamin C supplement. The vitamin C content of some vegetables can drop incredibly quickly after harvest. Fresh lettuce contains a useful amount of Vitamin C, but this can halve within a few hours of picking. Lettuce from a supermarket is unlikely to be fresh enough for you or your pet.
A Guinea Pig that is kept in a clean hutch with a healthy diet will usually be in balance with its intestinal worms.
Many people never worm their Guinea Pigs while others recommend that it be done on a strict schedule, once every three months.
one of the many brands of wormer suitable for Guinea Pigs.
Guinea Pig Parasites
as internal parasites, practically all mammals, including Guinea Pigs, get
external ones. Two which can get onto Guinea Pigs are Lice and Mites. Lice are
insects, and have 6 legs while mites are related to spiders and have 8 legs.
Both are very small.
If your pets get external parasites, they need to be treated, not only for their own sake, but also because the parasites can get onto people or other animals. Get advice from a vet or pet shop keeper about what to use.
Here is a picture of a Guinea Pig Louse taken through a microscope., magnified 400 times.
Lice on Guinea Pigs can be controlled by sprays, dusts and spot ons. Guinea Pigs lick
themselves clean like a cat, so only use treatments recommended for Guinea
Mange is a serious condition caused by certain types of mites so small that a magnifying glass is generally used to see them. Guinea Pigs with it will lose their hair, at first in patches.
Here is a bad case at Los Angeles Guinea Pig Rescue.
Mange is curable and your local vet should be able to advise on a treatment available in your area.
Guinea Pigs can get urinary stones. One of the causes is bladder infection which is more common in female Guinea Pigs than in males. A vet can prescribe antibiotics for treating this condition. Keeping the hutch clean will help to prevent it.
Another cause of kidney and bladder stones in both in Guinea Pigs, and in some other animals, is excessive Vitamin C supplementation. If you cannot give your pets a diet with enough genuinely fresh food and need to give extra Vitamin C, remember that they are small animals. I recommend only using a vitamin C supplement intended for Guinea Pigs, and giving enough without overdosing.
The photomicrograph of a Guinea Pig louse is by Joel Mills (http://creativecommons.org/licenses/by-sa/3.0/) via Wikimedia Commons.