Rex Guinea Pig Breed Profile: Info, Pictures, Care, Facts

The Rex guinea pig is easily recognizable because of its unique coat. The Rex has a short and dense coat that grows from the back to the front. Their short and dense coat gives them a very unique appearance. Furthermore, they’re also quite big. The Rex is the largest of all the guinea pig breeds. This breed is also known for its calm and docile temperament.

When you decide that you want to get a guinea pig as a pet it can often be difficult to know what breed to go for. There are over a dozen different breeds, all with their own personality, appearance, and history. To help remedy this, we’re going to take a closer look at the Rex breed in particular. I will give you all the necessary information about their history, temperament, appearance, care, and much more to give you the most complete overview possible of this beautiful breed.

Rex guinea pig history

The name “guinea pig” is quite deceptive. Guinea pigs are neither from Guinea nor are they closely related to pigs. Instead, these rodents are native to the Andes mountains where they roam on grassy plains and forest edges in large herds.

Humans and guinea pigs have a long history. Native tribes first started domesticating these animals as early as 5000 BC as a source of food. Gradually, we stopped eating them and instead domesticated them as pets. Once guinea pigs became our pets instead of our food, a lot of breeding programs came into being because we wanted to create guinea pigs with specific traits and attributes. It is because of these breeding programs that we have such a large variety of different guinea pig breeds today, including the Rex breed.


The Rex guinea pig is a short-haired breed with hairs that are no longer than one centimeter. They have a very dense and rough coat with no guard hairs, meaning that they only have one layer of fur. Because they have no guard hairs, their fur stands up straight on their skin, giving it a spiky appearance. It kind of makes them look like a little hedgehog.

The Rex breed is also very big, especially for a guinea pig! Whereas the average breed is around 10 to 12 inches, the Rex has an average length of up to 17 inches. This means that they’re up to 50% bigger than your average guinea pig.

rex guinea pig
Rex guinea pig on the left, regular-sized guinea pig on the right – as you can see, the rex is quite a big cavy!

The ears of this breed are droopy, their whiskers curly, and they have a broad head. The Rex comes in many different colors and patterns, ranging from white to brown, but their most common color is Agouti.

To get a better idea of what the breed looks like I’ve included many pictures in the post, as well as a picture gallery at the end. However, in my opinion, a video does a better job of capturing what the breed looks like, so take a look at this video to get a good idea of what to expect from a Rex guinea pig’s appearance:


The Rex guinea pig is a gentle giant. This breed is known for its calm, docile, and friendly temperament, making them an ideal pet. They’re easy to handle and love attention and affection. Because they’re so calm and friendly, they’re quite easy to train and make a great pet for families with children.

Furthermore, they’re also quite an intelligent and curious breed making them very receptive to learning tricks, as long as they’re properly motivated with treats of course.

They also get along well with other guinea pigs and other pets. It’s important that you make sure that you get at least a pair of guinea pigs instead of keeping them alone. Guinea pigs are highly social animals so they desire the company of other guinea pigs. They do not do well when kept alone. They need a friend to keep them company, keeping them in solitude is inhumane. Do make sure that you keep a same-sex pair, otherwise, you might end up with unwanted pups.


The lifespan of the Rex guinea pig is about the same as that of other breeds. The Rex has a lifespan of around 4 to 8 years.

Of course, you should keep in mind that any animal’s lifespan highly depends on the quality of care they receive and their genetics. If you have a healthy guinea pig that you give good care it’s very possible that they become much older than 8 years. In fact, the oldest guinea pig to have ever lived, Snowball, was almost 15 years old.


The Rex Guinea pig is not a breed that you will often encounter in a pet store because they’re relatively rare. It’s recommended to buy one from a reputable breeder. The price you pay depends highly on your location, in some areas the breed is cheaper than in others.

On average, expect to pay around $50.

Here are some websites that might have Rex guinea pigs for sale:


The Rex guinea pig is not all that hard to care for. Because they are a short-haired breed grooming them is much easier than some other breeds. Much of the grooming of short-haired guinea pigs such as the Rex is done by themselves or by their cagemates. The only thing you need to do is clean their grease gland, brush them once or twice a week, and give them the occasional bath.

One thing that you do need to be aware of is that the Rex guinea pig’s toenails grow faster than those of other breeds. Because of this, you will need to clip their nails more often.


The diet of the Rex guinea pig is the same as that of other guinea pig breeds. However, because of their larger size, they need to eat slightly more. Here’s what you need to feed your Rex guinea pig:

  • An unlimited supply of Timothy hay.
    Timothy hay is very important for your guinea pig. It lets them grind down their teeth and because it contains so much fiber it helps them digest their food. Make sure that they always have access to enough Timothy Hay so that they can feed on it whenever they need it.
  • Fresh vegetables.
    According to the veterinarians at the Small Animal Hospital, around 20% of your guinea pig’s daily food intake (by weight) should consist of fresh veggies. This comes down to about a cup of fresh veggies per guinea pig per day. The majority of these veggies should be leafy greens (kale, cabbage, romaine lettuce, etc) with a smaller amount being colored vegetables such as carrots.
  • Fruits & treats.
    Fruits are good for your Rex guinea pig in small quantities. Fruits should not be a large part of their diet because they’re quite high in sugar, so they should be considered a treat, not a staple of their diet. Make sure that no more than 10% of their food intake consists of fruits or treats.
  • Water.
    In order to stay healthy, you have to make sure that your piggy has access to plenty of fresh water from their water bottle at all times. Make sure to clean their bottle and replace the water often.


The Rex guinea pig is overall a healthy breed. They do not suffer from any breed-specific diseases. However, they can of course still fall ill. The main thing that you have to look out for when it comes to guinea pigs is that they get enough vitamin C. Just like you and me, guinea pigs are incapable of creating their own vitamin C which means that they need to get it from dietary sources.

If your guinea pig does not get enough vitamin C in their diet it can lead to lethargy, diarrhea, rough coat, sores, swelling, and even scurvy. To prevent this, many guinea pig owners opt to supplement their cavy’s diet with additional vitamin C. The NC State Veterinary Hospital recommends that you feed your guinea pig small quantities of bell peppers every day to add additional vitamin C to their diet.


You have to make sure that the cage for your Rex guinea pig is large enough. Because the Rex is such a large breed, they need enough space to walk around and live their life. When in doubt, a large cage is always better. The absolute minimum size that their cage can be is 7.5 square feet (minimum), but 10.5 square feet is preferred; generally, 30 inches x 50 inches is a good size, but as I’ve said, the bigger the cage the better.

Furthermore, their cage needs to have bedding, toys, water bottles, food bowls, and a sheltered area where they can sleep.

Cedar and pine bedding should be avoided because it can cause irritation to your cavy’s skin. It’s best to go with specialized guinea pig bedding like this. Make sure to change the bedding often. Make sure that you get at least two water bottles and food bowls so that they do not get into fights when they want to drink at the same time.

Final words

I hope this overview was helpful and informative. Now you know everything there’s to know about the Rex guinea pig and are properly informed on whether or not this breed is right for you. On the whole, this large, short-haired guinea pig is very sweet and kind, which makes it a great fit for many families.

To close it off, I’ll leave you with a gallery of some Rex guinea pig pictures.

You might also be interested in learning more about some other guinea pig breeds such as the:

ThePetFaq Team