Understanding Physical Characteristics of Guinea Pigs

While guinea pigs appear small, there are many areas to their bodies. Each area has its own set of characteristics and hallmarks. Using these physical characteristics as a guideline, you can determine when your guinea pig needs a vet and when they need some TLC.

The Head

The head of a guinea pig is one of its defining physical characteristics. Additionally, you may notice more about it since you want to interact with your guinea pig. Those cute facial expressions just draw you in.


A guinea pig’s mouth is essential since that’s where all nutrition goes in. Inside, there are a tongue and twenty teeth. Most people focus on the incisors when they look since those teeth are much bigger than the others. There are also premolars and actual molars, but no canines. All those teeth are necessary to break down grasses into digestible pieces.

The critical thing with guinea pig teeth is that they never stop growing. That’s why guinea pigs chew on everything. This action helps them keep their teeth at the right length. If your guinea pig’s teeth grow too far or they are experiencing trouble eating, seek veterinarian attention to correct those teeth.


Most guinea pigs have dark eyes, though some do have ruby or pink variations. Guinea pig eyes have poor depth perception but are great at spotting fast-moving objects. As prey animals, their eyes sit slightly raised from their faces to give them a wider field of vision.

This useful physical characteristic is routinely washed and lubricated by your guinea pigs. Your guinea pig will excrete a milky white fluid from the eye area. Then they will take their paws and make grooming motions. Typically, your guinea pig will do this several times a day.

Like humans, guinea pigs can get eye infections. If you see abnormal excretions, extended periods of crusty eyes, or any other eye changes, it’s time to seek vet help. Changes in the eyes can also mean underlying conditions, not just infection.


Guinea pig ears are covered in fine hair and very sensitive. All the same, you will need to check on these regularly. When you do, you’re looking for smooth skin free of cuts, white marks, and deposits that resemble dirt. White streaks or deposits which resemble dirt should be taken to a vet. They may be fungal infections or mite infestations.

Cleaning guinea pig ears is straightforward. At no point should anything go in your guinea pig’s ear canal, as these are easily damaged. You simply require a few cotton swabs and a little mineral oil. First, moisten each swab. Then, run it over your guinea pig’s ear skin. You will see wax and other materials collected on the cotton swab. Feel free to use more than one, just avoid going near the ear canal.

If you are uncomfortable or feel your guinea pig may have excessive buildups, you can ask your local small animal vet for assistance. They can safely perform deep cleanings, help with parasites, and teach you in a hands-on manner how to clean up guinea pig ears.

Guinea pig yawning to display the physical characteristics of its teeth

The Body

The majority of your guinea pig’s weight is in their body, making this physical characteristic important. As such, you should always support through their spine when you pick up guinea pigs. While guinea pigs may self-regulate their weight, guinea pigs can become overweight.


Guinea pig hair varies wildly based on breed, and these physical characteristics are actually what defines breeds. The key is understanding your guinea pig will do most of the work. Most guinea pigs are fastidious, and you can watch them groom themselves throughout the day.

If you have a long-haired guinea pig, you may need to help a bit. Long-haired guinea pigs either need daily brushing or monthly hair clipping. This care prevents your guinea pig’s hair from matting and picking up debris from the cage floor.


Sexing guinea pigs correctly is vital, especially if your guinea pigs live together. No one wants unexpected guinea pig pups. If you do not feel comfortable, your local vet should be able to reliably sex guinea pigs.

Guinea pig genitals are located on their underside, so you will need to be careful. Guinea pigs are prey animals, so being on their back is incredibly stressful. You’ll notice a button looking structure once you flip the guinea pig. The portion towards the head is what you look at for sexing. the difference between male and female physical characteristics should be readily apparent.

Guinea pig on books

Waste Disposal

Guinea pigs release waste like other mammals. A guinea pig only has a moderate amount of control as to when they release this waste, so practices like litterbox training are not practical. Guinea pigs are not in danger from their waste, and they generally do not consume it. However, regular removal is advisable for health reasons.

Gastrointestinal issues may manifest in the form of diarrhea or constipation. If you notice these issues, seek veterinary care.

The Feet

Guinea pigs have four feet. The front feet have four toes, and the back feet have three toes. Each toe has a nail, which continues to grow. Each foot also has pads as well. Guinea pigs can have issues with their pads, and your vet may advise you on what to do. At Guinea Pig Center, sometimes the pads grew weirdly and required trimming as well.

Guinea pigs should have their nails trimmed every couple of weeks. You can do this on your own, provided you have styptic powder just in case you miss a cut. On lighter colored guinea pigs, you will be able to see the quick in the nail and avoid it. Darker colored guinea pigs may require an educated guess since their nails will be black. Your vet can also provide this service.

Pair of guinea pigs on grass

This article is not a substitute for veterinary advice. Please consult a licensed veterinarian about ongoing symptoms.

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