With proper care, guinea pigs live an average of five to seven years. But, just like humans, they experience many changes to their bodies and lifestyles as they age. According to the SmallAnimalChannel, you can determine the age of a guinea pig by looking at its toes. If they are thick and slightly twisted, you are looking at a senior guinea pig.
After a guinea pig reaches the age of 4, physical changes might start to occur. For example, its eyes might become cloudy from cataracts, or hearing loss might cause it to be less responsive to sound. Some guinea pigs also get more grey or white hairs.
Elderly guinea pigs spend more time lounging around than jumping around, as arthritis begins to hamper movement. They also might eat and drink less. They sleep more soundly and are often quieter, making fewer high-pitched squeaking noises than they did when they were younger.
Unfortunately, elderly guinea pigs are susceptible to several health ailments, including heart attacks, kidney and liver disease, stroke and an increasing incidence of cancer, most commonly lymphosarcoma. Another issue facing senior guinea pigs is bumblefoot, an infection of the pads of the feet. According to GuineaLynx.com, this condition can be caused by lack of activity or by circulation problems.