Guinea pigs naturally live in large groups of 6-10 so, as with rabbits, it is best to keep more than one. Males do not always fight with each other, but it is safer to keep a male and female pair, or a male and several females. The male should be castrated if you don't want to breed from your pets. Boars mature between 3-5 weeks of age, and sows can breed from around 6 weeks, so neutering has to be carried out quite young.
Guinea pigs need plenty of raw fibre to avoid dental and digestive problems. They also require a source of vitamin C in their diet as, unlike most animals, they are unable to produce this vitamin for themselves. They need good quality hay, small amounts of fresh vegetables, grasses and wild plants, plus a high quality complementary feed such as Burgess Supa Guinea. Fresh, clean drinking water should always be available and treats should only be offered occasionally.
Guinea pigs are commonly presented at the clinic with 'itchy skin' due to mite infestations. Mites are usually present on the skin but do not tend to cause problems unless the guinea pig's immune system is compromised for some reason. Lice and ringworm are also seen, and other skin conditions include bacterial infections and alopecia.
Respiratory disease is relatively common, and may be caused by a variety of agents, many of which are bacterial. It is essential that you obtain veterinary advice and treatment for your guinea pig as soon as you notice any problems with breathing, including sneezing and nasal discharge.
Digestive disturbances can be due to stress or dietary changes but other causes of diarrhoea are also regularly seen. As with rabbits, it is important to arrange for your guinea pig to be examined by a vet since rapid deterioration is possible.
The teeth and claws of guinea pigs continue to grow throughout the life of your pet, so they should be regularly checked to ensure that they are not causing problems.