Doubling of the weight of a guinea pig occurs approximately 13-17 days after birth. At the age of four to eight weeks, they weigh 250-400 g.

Guinea pigs grow up to 15 months. Their growth is gradually slowing down. Then males begin to weigh 1000-1800 g, females from 700 to 1000 g. The greater weight in some cases is due to significant body fat.

Guinea pigs live from five to eight years, in rare cases up to 15.

Aging guinea pigs often lose weight. They are no longer able to optimally assimilate the feed offered to them. Then, along with a sufficient amount of hay and green fodder, an increase in the diet of such nutritious fodders as carrots, concentrates and additionally multivitamins is recommended. In addition, you should pay attention to the sufficient supply of the body with minerals and trace elements.

But special importance should be given to a sufficient supply of vitamin C to the body, which must be given at least 30 mg per kilogram of animal weight. Older guinea pigs, who may have trouble with their teeth, are less likely to turn to solid foods, often happily eat cucumbers or melons cut into pieces.

Having lost its luster, in some places even thin fur also indicates the age of the animal. At the same time, elderly guinea pigs, often already with a weakened general body resistance, are very susceptible to skin diseases. Then fungi, as well as lice and other ectoparasites appear in them much more often than among guinea pigs, which are not yet listed as pensioners.

A guinea pig from about six, rarely from seven years is considered an “old lady”.