Rex

The Rex is a short-haired guinea pig, or cavy, breed defined by coat texture rather than colour. The hair sits dense and woolly, standing slightly proud of the body, and unlike most other guinea pigs the breed carries no stiff guard hairs. The result is a soft, springy feel and a faintly rumpled look. Adults reach a medium build and weigh roughly 700 to 1 200 grams, with boars usually heavier than sows.

Like all domestic cavies, the Rex is a social, ground-dwelling rodent that lives in a herd and communicates through squeaks, purrs and chutters. It is active by day and at first and last light, and shows little interest in climbing or jumping onto furniture. The temperament is even and people-focused, so the breed settles into handling once it knows its keeper.

The Rex is often mixed up with the Teddy guinea pig, since both carry short, plush coats. They are separate breeds with different genetic backgrounds, and Rex fur tends to feel a touch coarser and denser under the hand.

Who it suits

The Rex suits owners who want a calm, easy-to-handle small pet and who can commit to daily care. The short coat needs less brushing than long-haired breeds, so it works well for first-time cavy keepers and families with school-going children who can be supervised. Guinea pigs are deeply social and should never be kept singly, so the breed is a poor fit for anyone who can house only one animal.

All domestic guinea pigs (Cavia porcellus) trace back to the Andean highlands of South America. Peoples in present-day Peru, Bolivia, Ecuador and Colombia domesticated the wild cavy thousands of years ago, keeping the animals for food and for use in folk practice. The guinea pig held a place in household and ceremonial life across the region.

Spanish and other European traders carried guinea pigs to Europe in the 16th century, where they became fashionable pets among the wealthy before spreading more widely. Selective keeping over the centuries that followed produced the range of colours, coat types and sizes recognised today.

The rex coat comes from a recessive mutation that shortens the hair and removes the usual guard hairs, leaving a dense, woolly undercoat. The same rex mutation turns up independently in other species, including rabbits and cats, where it produces a similarly short, plush texture.

The Rex is now kept mainly as a companion animal and shown by hobbyists through cavy clubs, including local clubs in South Africa. Exact dates for the first standardised Rex lines are not well documented, and the breed continues to be bred chiefly for its distinctive coat and steady temperament.

The Rex has a compact, rounded body with a broad head and short, slightly drooping ears. The defining feature is the coat: hair is short, usually under about 1.5 cm, and stands away from the skin so the animal looks fuller than its actual frame. Because guard hairs are absent, the coat feels soft and springy and lacks the sleek shine of a smooth-coated guinea pig. The whiskers may be curled or kinked, which is normal and tied to the rex gene.

Coat and colours

Colour is independent of the rex texture, so the breed turns up in the full guinea pig palette. Common colours include black, chocolate, cream, white, red and agouti, and these can appear as a single self colour or in patched and roan patterns. Coat density stays even over the body, including the belly, with no part or rosette pattern. The plush texture holds throughout life, though hair length and thickness can shift slightly with age and season.

The Rex has a steady, affectionate temperament. Once it learns to trust its keeper, it tolerates handling well and often relaxes on a lap, sometimes purring softly when content. The breed is not prone to nipping and tends to stay calm during routine care, which suits gentle children under supervision.

With strangers, a guinea pig is naturally wary and may freeze or bolt for cover when startled. This is normal prey behaviour and eases as the animal grows used to a person's voice and scent. Slow, predictable movements and a quiet room help a new Rex settle in.

Guinea pigs are deeply social and do best with at least one companion of their own kind. A Rex housed with other cavies will form bonds, share food and communicate through squeaks and rumbles. The breed is generally peaceful, though same-sex groups can squabble a little over space, which good housing helps prevent.

Grooming

• Brush the coat once or twice a week with a soft brush to lift loose hair and check the skin.
• Check the dense coat for mats, debris, and signs of mites or lice, which can hide in thick fur.
• Trim nails every few weeks, since they grow continuously and do not wear down enough indoors.
• Bathe only when needed, using a small-animal shampoo, and dry the coat fully so the cavy does not catch a chill.

Exercise

• Give daily out-of-cage floor time in a safe, enclosed area for at least an hour where possible.
• Offer tunnels and low hides for movement and foraging; guinea pigs do not climb or use wheels.
• Keep play areas at floor level, since the breed can be hurt by a fall from height.

Environment

Keep the Rex indoors or in a sheltered spot at a steady 18 to 24 C, away from direct sun and drafts. South Africa's climate shifts sharply by region and altitude: Highveld towns such as Johannesburg and Bloemfontein bring cold, dry winter nights, while the KwaZulu-Natal coast and the Lowveld stay warm and humid for much of the year. Guinea pigs are sensitive to heat above about 26 to 28 C and to sudden swings in temperature, so a hutch on an open stoep or in an unshaded garden needs extra thought in both seasons. House the animals on soft, absorbent bedding such as paper-based material or fleece, and keep the enclosure clean and dry to protect the skin and feet.

Guinea pigs are herbivores with a constant need for fibre. Grass hay such as timothy should be available at all times and makes up the bulk of the diet. It keeps the gut moving and wears down teeth that never stop growing. Fresh vegetables supply vitamin C, which guinea pigs cannot make on their own and must get from food every day. A measured amount of plain, guinea-pig-specific pellets rounds out the diet, but pellets should never replace hay.

Treats and supplements

Offer fruit only in small amounts as an occasional treat, given its sugar content. Good daily vegetables include bell pepper, leafy greens and small portions of herbs, all of which support vitamin C intake. Provide clean water at all times in a bottle or a heavy bowl. Routine vitamin C supplements are usually unnecessary when the diet includes fresh vegetables, but a vet may advise them in specific cases.

The Rex is a generally hardy breed with a typical lifespan of 5 to 7 years when housed and fed well. Most health problems are shared across guinea pigs rather than specific to the rex coat, and many trace back to diet, hygiene or delayed treatment. Because guinea pigs mask illness, weight and appetite should be checked regularly so problems are caught early.

Preventive care

• Feed unlimited grass hay and daily vitamin C vegetables to prevent scurvy and dental disease.
• Keep bedding clean and dry to protect the feet and skin.
• Weigh the animal weekly to catch weight loss early.
• Quarantine new animals and treat parasites promptly.
• Find an exotics or small-animal vet before problems arise.

Guinea pigs need far more floor space than many small pets. A single-level enclosure with a large open floor area suits the breed better than a tall cage, since guinea pigs run rather than climb. A pair needs a minimum of about 0.7 square metres of floor space, and more is always better. The Rex coat does not change these needs, but its exposed skin makes clean, dry bedding especially important.

Setup checklist

• Solid-floored enclosure sized for two or more guinea pigs.
• Deep, dry, absorbent bedding changed regularly.
• One hide per animal plus tunnels for cover.
• Constant hay supply in a rack or pile.
• Water bottle or heavy bowl and a food dish.
• A calm spot away from drafts, direct sun and loud noise.

Guinea pigs reach sexual maturity young, with sows fertile from around 4 to 6 weeks and boars from about 3 to 5 weeks, so the sexes need separating early to avoid unplanned litters. Responsible breeders wait until a sow is mature and in good condition before any first mating. The rex coat is recessive, so two Rex parents produce Rex young, while crossing to a smooth coat can carry the trait without it showing.

Gestation runs long for such a small rodent, lasting roughly 59 to 72 days. Litters are small, usually 2 to 4 pups, and the young are precocial: born fully furred, with eyes open and able to move and nibble solid food within hours. Pups still nurse for the first weeks and should stay with the sow until weaning at about 3 weeks.

First-time breeding of a sow older than around 6 to 7 months carries serious risk, because the pelvic bones fuse and can prevent normal birth. For this reason breeding is best left to experienced keepers working alongside a vet.