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Home > Guinea Pigs > Rex Guinea Pig Info: Pictures, Personality & Traits

Rex Guinea Pig Info: Pictures, Personality & Traits

rex guinea pig

Guinea pigs have a look about them that instantly makes you want to pick them up and cuddle them. Those big, brown eyes, tousled hairdos, and adorable expressions give them an air of harmless innocence. None is more cuddlesome than the Rex guinea pig. There is more to love about this larger-than-average cavy. The Rex is irresistible with its fuzzy cuteness and appealing personality.

However, just because a cavy looks friendly doesn’t mean you should dive in and pick it up without ensuring it is appropriate. Situations vary, as do guinea pig personalities. Any animal that feels threatened or scared might nip you to warn you off. Rex piggies are known to be laid back and are unlikely to sink their gnashers into your digits.

Size: 8 to 15 inches (up to 18 inches)
Weight: 1 to 3 lbs
Lifespan: 4–8 years
Similar Breeds: Teddy, Tissilar
Suitable for: First-time pet owners, children (supervised)
Temperament: Calm, sociable, friendly

“Rex” translates to “king,” and this little piggie is known as the king of guinea pigs due to its size and, subjectively, its exceptional temperament. The Rex is so-named due to the breed’s rex gene mutation. The mutation results in their trademark rough and bristly coat.

Rex guinea pigs can attain huge sizes, up to 18 inches long, and are the largest of any domestic cavy.

Rex Guinea Pig Breed Characteristics


How Much Do Rex Guinea Pigs Cost?

Guinea pigs originated in the Andes of South America. It is believed that native South Americans began domesticating guinea pigs around 5,000 years ago, both as pets and livestock (for food). Guinea pigs are not pigs at all; they are members of the rodent family.

From 1200 AD to about 1500 AD, the Peruvians undertook selective breeding of guinea pigs to create more exotic varieties. After the Spanish colonization of South America, the little rodents were exported to Europe as popular exotic pets, particularly favored among the royals.

Today, Rex guinea pigs are widespread pets and easy to source. They generally cost $10 to $40 from a shelter and $25 to $50 from a breeder. As well as the purchase price, don’t forget to figure in the costs of setting up your cavy’s enclosure, their maintenance, and any veterinary costs that may come up.

Temperament & Intelligence of the Rex Guinea Pig

Rex guinea pigs are renowned for being particularly laid back. Their very relaxed attitude gives the impression that they are not as intelligent as other breeds, but that is not necessarily true. Rex piggies can learn their names and some basic tricks. They also have good long-term memories.

Do These Guinea Pigs Make Good Pets? 👪

Their easy-going personality, sincere friendliness, and a high degree of sociability mean that Rex piggies make lovely pets. Due to their natural amiability, they are exceptionally great pets for children and those looking for a pet that will provide uncomplicated affection. They love to be petted and brushed and being around their humans.

Children over 9 years old are usually astute enough to understand that Rex guineas are relatively delicate and need to be handled gently. Younger children should be supervised when handling their piggies.

They are not the lowest maintenance pets, but their care regime is straightforward. This is another reason they are a good choice for kids who can learn about the responsibilities of owning a pet. Additionally, their unique coats make them particularly suitable for people with allergies. Although not strictly classified as hypoallergenic, it has been noted that Rex piggies are less likely to trigger allergies than other pets.

rex guinea pig
Image By: Jolly-Sunshine, Pixabay

Does This Guinea Pig Get Along with Other Pets?

As a prey animal, it is a guinea pig’s instinct to fear other pets, such as cats and dogs. These different species can, however, be taught to coexist peacefully if they are introduced to one another early on when both are young.

While the “predator” may be able to relax in the cavy’s company, it’s questionable whether a guinea pig will ever really be genuinely at ease around a cat or dog, even though they may appear so. It is best only to keep Rex guinea pigs with other guinea pigs.


Things to Know When Owning a Rex Guinea Pig:

If you have newly acquired an adorable Rex guinea pig or are thinking of getting one, there are a few healthcare basics to be aware of. A general understanding of these will enable you to make the right decisions to provide your new cavy with the best possible care.

Food & Diet Requirements 🥕

Rex guinea pigs thrive on a varied and interesting diet, including plenty of fresh hay, fruit and vegetables, and a good-quality commercial pellet. Cavies are strict herbivores, and their diet should ideally comprise mostly hay—around 80%. The remaining 20% of their diet can be comprised of pellets and fresh produce.

These two types of food are an essential source of vitamin C, so it’s important to ensure that they are high in it and other necessary nutrients such as calcium. Rex guinea pigs are prone to Vitamin C deficiency, which can result in scurvy. This could affect their skin, joints, and immune system if allowed to persist.

Guinea pigs’ teeth grow continuously for their entire life. Including hay and other fruits and vegetables ensures that their teeth are correctly worn down and are not impacted. Don’t forget to ensure that your cavy always has abundant fresh water to drink. This is preferably supplied from a drip-feed water bottle.

Habitat & Enclosure Requirements 🏠

Rex guinea pigs are social animals; keeping them in pairs or larger groups is preferable, but the minimum cage size for one is 7.5 square feet. The minimum enclosure size for a pair would be 10.5 square feet, but this size is preferable even if there is only one. Bigger is always better—the more space they have to explore, the happier and healthier they will be.

Depending on where your Rex piggies enclosure is placed, it should be safe from predators and weather-proof. It should have a good flow of fresh air. Glass tanks/aquariums are not suitable at all. If their enclosure has multiple levels, access between the levels must be safe and stable so that they can’t fall.

Smooth wood floors are the best; wire should never be used for the floor of their enclosure. Guinea pigs do not have foot pads, and wire flooring can damage their sensitive feet and cause an unpleasant condition called bumblefoot. They could also catch their feet or toes in the wire and cut or break them.

All male groups or pairs of piggies need a slightly larger enclosure. It is best to use guinea pig-specific bedding and avoid pine or cedar shavings, which could cause skin irritation. Their enclosure and all its contents—bedding, toys, bowls, bottles—must be regularly cleaned.

Exercise & Sleeping Needs 🐹

Rex guinea pigs sleep in short spurts throughout the day, never for more than 10 minutes or so at a time. Depending on the time of day, they nap in different spots, but they appreciate a guinea pig house to go into when they want some quiet time or a darker space.

They are very active little critters, keeping themselves busy throughout the day foraging, socializing, and generally being inquisitive about their environment. Even if they have an enclosure that is the minimum recommended size, it’s still a good idea to have a run for them to utilize daily to get adequate exercise. Hutch and run combos are a great choice.

Guinea pigs should never be put in a rodent exercise ball, which could damage their backs.


Rex piggies are intelligent and obliging rodents. Ordinarily, there is little need to train them, but it can be quite fun to teach them a few tricks or for them to learn their name. They’re not the most athletic of fur babies, so they won’t be able to perform tricks like cats and dogs.

At the very least, it is usually easy to train piggies that haven’t been handled much to enjoy human companionship and cuddles. Of course, every guinea pig is different, and you may encounter an odd individual who is aloof and anti-social.

Grooming ✂️

Due to their coarser, shorter coats, the Rex piggie’s coat does not require much attention to stay in good condition. They do, however, love being brushed and caressed, so even though they don’t necessarily need it, you can do it out of love!  Regularly grooming your piggies will alert you to any changes to their general well-being early on and enable you to seek immediate veterinary attention if necessary.

They rarely require a bath since they are generally clean creatures. Should it be necessary to bathe them, try to complete the process as quickly as possible so as not to cause undue stress. This is best done by thoroughly preparing beforehand.  Have everything you need to complete the bath lined up and ready to use.

Guinea pigs’ toenails need regular trimming as they are fast-growing. Trimming intervals will depend on the kind and size of the enclosure and how much natural wearing down of the toenails takes place. If they are not cut properly, they might grow around and into their feet, which is, at the very least, uncomfortable but usually rather painful. It might also result in a condition known as bumblefoot (pododermatitis).

Both male and female guinea pigs have a grease gland at the base of their spine, in more or less the spot that their tail might be if they had one. This gland secretes a thick, oily substance, which they use to mark their territory. It can get messy if it’s not cleaned regularly in piggies with a particularly active gland.

Although the cavies clean themselves quite well, they sometimes need a helping hand in this department. You can use coconut oil to loosen grease build-up and wipe away the grease and oil with a warm cloth. Sometimes, it helps to clip the hair around the area a bit.

Lifespan and Health Conditions 🏥

The expected lifespan of a Rex guinea pig is between 4 and 8 years. Keeping your guinea pig in optimal environmental conditions, providing a healthy diet, and maintaining veterinary appointments can help them live long lives. Bear in mind, however, that some individuals do not have longevity in their genes, and no matter how well they are looked after, they may live happy but short lives. However, it’s not unheard of for them to reach the ripe old age of 10 years.

Like all animals, guinea pigs are susceptible to specific health conditions. The likelihood of health issues increases with age. Here are some health conditions to be aware of:

Minor Conditions
  • Vitamin C deficiency
  • Dental disease
  • Tumors
  • Skin disease
  • Flystrike
  • Heatstroke
Serious Conditions
  • Respiratory Infections
  • Inner Ear Infections
  • Gastrointestinal diseases
  • Reproductive diseases
  • Urinary problems
  • Abscesses


Male vs Female

The male Rex guinea pig, known as a boar, is typically larger than the female sow. Sows weigh between 1 ½ and 2 ¼ pounds, whereas boars can weigh anything from 2 to 3 pounds. Besides their size and primary sexual characteristic differences, boars and sows are similar in appearance.

Boars tend to be a little more confident than sows, and that may make them more curious about their surroundings and more amenable to being handled. They might even be more obliging when it comes to training. There is a misconception that boars can be more aggressive than sows. This is not true and can unfairly result in them sometimes proving more difficult to home.

It has been established that females tend to coexist more peacefully if you have, or want to establish, a larger herd of more than three piggies. There will still be a reasonable amount of social bickering that is normal and healthy. On the other hand, if you plan to keep just two or three cavies, then males form happy pairs or trios. Boars seem to not settle very well in larger herds.

As they age, the two sexes experience different health concerns. Health conditions may also be more common in unsterilized cavies. It’s worth chatting with your veterinarian about the health benefits of neutering or spaying your male or female piggie, respectively.

3 Little-Known Facts About Rex Guinea Pigs

1. Their Coats Have No Guard Hairs

Due to a gene mutation, Rex guineas’ coats lack guard hairs. Guard hairs are longer hairs that help protect the piggie from scrapes and provide extra water resistance to their coat. Several shorter hairs surround the guard hairs. Sometimes, the mutation results in curly hair and whiskers. The rex mutation affects many species of mammals.

2. When They’re Happy Rex Guinea Pigs Popcorn

When a cavy is overcome with joy, it will suddenly and explosively jump in the air in a movement that has affectionately been called popcorning! It can be alarming when a new guinea pig owner first observes it, but it is entirely normal and healthy. Although most frequently demonstrated by younger animals, older piggies will still sometimes enjoy the odd popcorn!

3. They Don’t Sleep Very Much

In every 24-hour cycle, a guinea pig only sleeps about 4 to 6 hours. This is not in one continuous block but comprises many little “power naps.” Older piggies might rest for up to 30 minutes at a time.


Final Thoughts

What’s not to love about Rex guinea pigs? They are lovable and rewarding pets that burrow their way into their owner’s hearts and become fond of their humans. Their laid-back personalities and friendliness endear them even more, making them perfect for first-time pet owners or children.

Rex guinea pigs are unique in the cavy world due to their large size (in some) and fuzzy coats that give them an almost hedgehog-like appearance. They are not difficult pets to look after, but their care can be time-intensive. In our opinion, it is time well spent. Those special Rex cuddles are a fitting reward for keeping them clean, healthy, and happy.

For more about Guinea pig breeds, check out these posts:

Featured Image Credit: Jolly-Sunshine, Pixabay

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