Physical Features- Adult guinea pigs will weigh in around 1.5 to 2.5 lbs. This variety a little based on their age. There are currently 13 recognized breeds of guinea pigs with some more common than others. Guinea pigs typically have four toes on each foot as well as a life span from 6 to 8 years but that can vary based on lifestyle and other factors. Guinea pigs have 20 teeth but only 4 are mainly seen by humans.
Eyes, Ears, and nose- Guinea pigs eyes should be slightly pushed out, not flush with the rest of their head. There should be no mucus in or around the eyes of your guinea pig. Eyes being flush can be an alarming sign of an unhealthy guinea pig. Their ears should be soft to the touch and slightly standing up. Guinea pigs ears are extremely sensitive to sound and you can see their ears move if loud noises are heard. If you watch, whenever they week their ears should slightly move as well. Their noses are petite and rounded at the tip. Whiskers are around the nose area and are very important for them like most animals. Curled whiskers can be an alarming sign of an unhealthy guinea pig.
Nails and Teeth- The teeth of guinea pigs are open rooted, meaning that they continually grow. Chewing on things like hay and wood help guinea pigs file their teeth down to prevent injury. Guinea pigs teeth and nails can become overgrown quickly and can make them extremely uncomfortable if not taken care of properly.
Skin and Fur- Guinea pigs can have various types of skin and fur. This is the main thing about a guinea pig that sets them apart from others. Some things that can vary from guinea pigs are the pigment of skin, birth marks, color of hair, length of hair, and texture of hair. There are also guinea pigs that have little to no hair! Like most animals, they can develop skin conditions such as dry skin or ringworm.