Rex

Guinea pig breeds are usually sorted by coat, and the Rex is defined by texture rather than colour. Its hair is short, dense, and woolly, standing slightly off the body instead of lying flat, and unlike most other guinea pigs it has no stiff guard hairs at all. The effect is a soft, springy coat with a faintly rumpled look rather than a sleek one. A full-grown Rex is medium-sized, typically 700 to 1,200 grams, and boars tend to outweigh sows.

As with every domestic guinea pig, the Rex is a social, ground-dwelling rodent that lives in a herd and keeps in touch through squeaks, purrs, and chutters. It is most active by day and around dawn and dusk, and it has little interest in climbing or jumping, staying close to the floor of its enclosure. The temperament runs calm and people-oriented, so once a Rex settles into a household it is straightforward to handle.

Owners often mix the Rex up with the Teddy guinea pig, since both carry a short, plush coat. They are separate breeds with different genetic backgrounds, however, and a Rex coat is usually a touch coarser and denser under the hand than a Teddy's.

Who it suits

The Rex works well for an owner who wants a calm, easily handled small pet and can keep up with daily care. Because the short coat needs less grooming than a long-haired breed, it is a reasonable pick for a first-time guinea pig keeper or a family with school-age kids, provided an adult supervises handling. Guinea pigs are herd animals by nature and need at least one companion of their own kind, so the Rex is not a fit for anyone planning to keep just a single pig.

Every domestic guinea pig (Cavia porcellus) traces its ancestry to the Andean highlands of South America. Communities in what are now Peru, Bolivia, Ecuador, and Colombia domesticated the wild cavy thousands of years ago, raising the animals for food and for use in traditional and ceremonial practices, and the guinea pig held a settled place in household life across the region long before Europeans arrived.

Spanish traders and other Europeans brought guinea pigs across the Atlantic in the 16th century, where they first caught on as kept animals among wealthier households before becoming more broadly popular. Selective keeping over the following centuries, carried on by fanciers in Europe and later North America, produced the wide range of colours, coat types, and sizes recognized today.

The rex coat itself comes from a recessive mutation that shortens the hair and removes the normal guard hairs, leaving only the dense, woolly undercoat. This same category of rex mutation shows up independently in other species too, including rabbits and cats, each time producing a comparable short, plush texture.

Today the Rex is kept mainly as a companion animal, and it is also shown by hobbyists through cavy clubs, including groups affiliated with the American Cavy Breeders Association (ACBA) and local Canadian cavy clubs. Precise dates for the earliest standardized Rex lines are not well documented, and breeders continue to select mainly for the distinctive coat and steady disposition rather than for any single fixed lineage.

The Rex carries a compact, rounded body, a broad head, and short ears that droop slightly. What sets the breed apart is the coat: hair is short, generally under about 1.5 cm, and stands away from the skin so the animal looks a bit fuller than its actual frame. With no guard hairs to weigh it down, the coat feels soft and springy to the touch and lacks the glossy sheen seen on a smooth-coated guinea pig. Whiskers may come in curled or kinked, which is a normal feature that travels along with the rex coat gene.

Coat and colours

Colour has nothing to do with the rex texture, so the breed turns up across the full guinea pig palette. Black, chocolate, cream, white, red, and agouti are all common, and any of these can appear as a single self colour or in patched and roan patterns. Coat density stays even everywhere, including on the belly, with no part line or rosette. The plush texture holds up for life, though hair length and thickness can shift a little with age and the season.

Once a Rex trusts its keeper, its temperament runs steady and affectionate. It tolerates handling well and often goes still on a lap, sometimes giving off a soft purr when it's content. Nipping is rare in this breed, and it usually stays calm through routine handling, which makes it a reasonable match for a gentle, supervised child.

With unfamiliar people, a guinea pig's first instinct is caution, and it may freeze in place or dash for cover if startled. That reaction is normal prey-animal behaviour and eases off as the pig grows used to a person's voice and scent. Slow, predictable movement and a quiet room go a long way toward helping a new Rex settle in.

Guinea pigs are strongly social and do best with at least one companion of their own species. Housed with other guinea pigs, a Rex will form real bonds, share food, and keep up a running conversation of squeaks and low rumbles. The breed is generally peaceable, though a same-sex group can have minor spats over space, which roomy housing tends to head off.

Grooming

• Brush the coat once or twice a week with a soft brush to clear loose hair and get a look at the skin underneath.
• Check the dense coat regularly for mats, debris, and signs of mites or lice, which can hide easily in the thick fur.
• Trim nails every few weeks, since they grow continuously and rarely wear down enough on their own indoors.
• Bathe only when it's actually needed, using a shampoo made for small animals, and dry the coat completely afterward so the pig doesn't chill.

Exercise

• Give the pig daily time out of the cage on a safe, enclosed floor area, an hour or more when it's possible.
• Set out tunnels and low hides for movement and foraging; guinea pigs don't climb and have no use for a wheel.
• Keep any play area at floor level, since a fall from height can injure this breed.

Environment

Keep the Rex indoors or in a sheltered space held at a steady 18 to 24 C (about 64 to 75 F), out of direct sun and away from drafts. Guinea pigs struggle in heat above roughly 26 to 28 C (79 to 82 F) and are sensitive to sudden temperature swings, which matters through a Canadian summer as much as a winter with the furnace running. Bed the enclosure with something soft and absorbent, such as paper-based bedding or fleece, and keep it clean and dry to protect the skin and feet.

Guinea pigs are herbivores, and their gut runs on a constant supply of fibre. Grass hay, timothy in particular, should be on hand at all times and makes up the bulk of a healthy diet: it keeps digestion moving and wears down teeth that never stop growing. Fresh vegetables carry the vitamin C a guinea pig cannot manufacture on its own and must therefore get from food every single day. A measured helping of plain, guinea-pig-formulated pellets rounds things out, but pellets are a supplement to hay, never a replacement for it.

Treats and supplements

Fruit is fine only in small, occasional amounts given its sugar content. Good vegetables for daily feeding include bell pepper, leafy greens, and small portions of fresh herbs, all of which help cover vitamin C needs. Fresh water should be available around the clock, in a bottle or a heavy bowl that won't tip. Routine vitamin C supplements are usually unnecessary if the diet already includes fresh vegetables, though a veterinarian may recommend them in specific cases.

The Rex is a generally hardy breed, typically living 5 to 7 years when housed and fed properly. Most of the health problems it faces are shared across all guinea pigs rather than tied to the rex coat specifically, and many trace back to diet, hygiene, or care that came too late. Because guinea pigs are prey animals that mask illness, weight and appetite are worth checking often so a problem gets caught early rather than after it has taken hold.

Preventive care

• Keep grass hay unlimited and vitamin C vegetables on the daily menu to head off scurvy and dental disease.
• Keep bedding clean and dry to protect feet and skin.
• Weigh the pig weekly so any drop shows up early.
• Quarantine new animals and deal with parasites right away.
• Line up an exotic or small-animal vet before a problem ever comes up.

Guinea pigs need a lot more floor space than many other small pets get by on. A single-level enclosure with a wide open floor suits the Rex far better than a tall multi-storey cage, since guinea pigs run rather than climb. A pair needs at least about 0.7 square metres of floor space, and more is always an improvement. The rex coat doesn't change these baseline needs, but the exposed skin underneath it makes clean, dry bedding especially important.

Setup checklist

• A solid-floored enclosure sized for two or more guinea pigs.
• Deep, dry, absorbent bedding, changed on a regular schedule.
• One hide per animal, plus tunnels for extra cover.
• A constant hay supply in a rack or a loose pile.
• A water bottle or heavy bowl, and a separate food dish.
• A quiet spot away from drafts, direct sun, and loud noise.

Guinea pigs reach sexual maturity early, sows from around 4 to 6 weeks and boars from about 3 to 5 weeks, so littermates need to be separated by sex early on to avoid an unplanned litter. A responsible breeder waits until a sow is fully mature and in solid condition before any first mating. The rex coat gene is recessive, so two Rex parents will produce Rex young every time, while crossing a Rex to a smooth-coated pig can carry the trait forward without it showing.

Gestation runs unusually long for such a small rodent, roughly 59 to 72 days. Litters stay small, usually 2 to 4 pups, and the young arrive precocial: fully furred, eyes open, and able to move around and nibble solid food within hours of birth. Pups keep nursing for the first few weeks and should stay with the sow until weaning at about 3 weeks.

Breeding a sow for the first time past roughly 6 to 7 months of age carries real risk, since the pelvic bones fuse by that point and can block a normal birth. For that reason, breeding is best left to an experienced keeper working alongside a veterinarian.