Guinea pigs are adorable creatures that make great household pets. If you have a guinea pig, you probably already know how to take care of it. But what do you know about your furry friend’s anatomy and physiology?
In this guide, learn all the information you’ll need about guinea pig anatomy, from the tip of its nose to the end of its tail!
Table of Contents
Guinea Pig Ears
Guinea pigs’ ears are on either side of their head. They have excellent hearing, able to detect frequencies that are inaudible to humans. Guinea pigs can develop health problems in their ears, including mites, fungus, or wax buildup. Ears are a delicate part of the guinea pig’s physiology, and so should be checked and cleaned regularly.
Guinea pigs can have too much wax in their ears if they go for too long without a cleaning, so you should do it a few times per month. The amount of wax that accumulates depends on your guinea pig – some have a lot and others don’t. Generally, long-haired cavies tend to get wax buildup more quickly than short-haired ones.

Guinea Pig Eyes
A guinea pig’s big, round eyes allow it a wide field of vision, to detect predators. They can’t see directly in front of their noses, though. The eyes are almost always open, too, even when they’re asleep. Although their field of vision is wide, guinea pigs don’t have very clear eyesight.
Like all of the guinea pig’s physiology, the eyes can have health problems. Normal, healthy cavy eyes should be clear and bright. Signs of an eye infection are eye cloudiness, redness, keeping an eye closed, eye inflammation or discharge, and frequent pawing at the eye. If you notice any of these symptoms, your guinea pig’s eye might need a veterinarian’s attention.
Guinea Pig Nose
A guinea pig’s nose is essential – it helps them eat! Smell is one of their most sensitive senses, as are the whiskers around their nose, eyes, and mouth. Because these animals can’t see directly in front of their nose, guinea pigs use their highly developed sense of smell to detect what they’re about to eat.
Guinea pigs also use their noses to communicate with each other. Two cavies will rub noses together to show their affection. Sometimes, they might touch noses to apologize for acting out. They also use nose touching to establish dominance.
Guinea Pig Teeth
Another vital part of a guinea pig’s anatomy is the teeth. They have 20 total, with four incisors at the front and 16 molars in the back. Their incisors are the most visible, with two on the top of their mouth and two on the bottom. The guinea pig’s incisors are for biting and the molars for chewing.
Guinea pig teeth are constantly growing. To keep them filed down, a cavy chews on fibrous foods. If, despite the chewing, your guinea pig’s teeth get too long, you’ll have to take it to the vet to have them trimmed down. You shouldn’t try to trim their teeth yourself at home.
Guinea Pig Tail
Do guinea pigs have a tail? Technically, they have seven tail bones. But the bones are fused to the cavy’s rear end (pelvis) so you can’t see their “tail” from the outside. A guinea pig’s tail is more like a human’s tailbone than other rodents’ tails.
Guinea Pig Digestion
Guinea pig digestion is a complex process that is essential to their health. They eat mostly seeds, vegetables, occasional fruits, and fibrous materials. After eating, their stomachs process the food and their intestines absorb fats and sugars.
Any unprocessed food goes to the cecum, a fermentation cavity. Guinea pigs leave two kinds of droppings. The first are hard droppings that you clean up, and the second are softer, known as cecotropes. Cecotropes are packed with proteins and vitamins, so the guinea pig will consume them directly from its bottom.
Skeleton of a Guinea Pig
A guinea pig’s skeleton consists of 258 bones. They have a spinal cord, front legs, back legs, skull, ribs, and breastbone. Specifically, guinea pigs have an axial skeleton, which includes the skull, hyoid apparatus, vertebrae, ribs, and sternum. The appendicular skeleton includes pectoral and pelvic girdle and limbs. Guinea pig bones are fragile and can easily break if they’re not careful. Always hold and carry your cavy carefully and gently, ensuring you don’t drop it.

Conclusion – Guinea Pig Anatomy
For such a small animal, guinea pigs have an impressive anatomy and physiology. As a guinea pig owner, it’s your job to know as much as you can about your cavy, so you know how best to take care of it.