Furry Diary

Warm, smooth and smiley.

Skinny Pig

Cavia porcellus

Also called Skinny guinea pig, Hairless guinea pig, IAF hairless guinea pig (laboratory strain)

VarietyDeep profile

From Canada (Institut Armand-Frappier, Montreal, 1978)12

At a glance the quick version

Lifespan5 to 7 years1
Unique, velvety hairless look
No brushing needed
Warm, soft skin that many owners love to cuddle
13

Coat and looks how to spot one

Mostly hairless with short hair on muzzle, feet and legs

Skinny pigs are almost bare, with smooth, soft skin that gathers in gentle folds around the neck and legs. Small patches of short hair stay on the nose, feet and lower legs, and some individuals carry a faint fuzz along the back. Pups are born nearly bare. A so-called 'werewolf' type grows noticeably more hair over the face, neck and shoulders.13

ColoursSkin in many colours and patternsDutchBrindleHimalayan1

Personality what they are like

Skinny pigs share the gentle, sociable nature of guinea pigs in general: chatty, food-motivated animals that wheek, chirp and purr, and that do best in the company of other guinea pigs.45

Daily activity how busy a day looks

They need the same daily exercise as any guinea pig: a roomy, safe area with tunnels and hides to explore and space to run and popcorn, kept indoors at a comfortable temperature.64

Grooming and care the hands-on bits

With so little hair there is no brushing, but the bare skin needs a bit of thought: keep them indoors, out of direct sun and away from rough or scratchy surfaces, and give soft fleece or blanket-style bedding and nesting material so they can snuggle up warm.1

Home where they are happiest

Always house indoors. Wikipedia gives a comfortable range of roughly 20 to 26 C for skinny pigs, a little warmer than the 17 to 20 C the RSPCA suggests for haired guinea pigs. Provide a draught-free enclosure with plenty of soft bedding, hides and blankets to burrow into.16

Food basics what goes in the bowl

Standard guinea pig diet of unlimited hay, fresh leafy greens and vegetables, a vitamin-C-fortified pellet and fresh water. Because they lose more body heat without fur, skinny pigs tend to eat more than haired guinea pigs, so keep food and hay plentiful.137

Company who they like around

Very social herd animals that should live with at least one other guinea pig; a haired or hairless companion also shares body warmth.57

The story where it all began

The skinny pig traces back to 1978, when a hairless pup appeared by spontaneous mutation in a colony of Hartley laboratory guinea pigs at the Institut Armand-Frappier in Montreal. The trait turned out to be recessive. In 1982 the animals went to Charles River Laboratories, which developed them as a hairless research strain (still known as the IAF hairless guinea pig). Breeders later crossed the laboratory line with Teddy and other haired guinea pigs to build a sturdier pet population, and skinny pigs reached the pet trade in the mid-to-late 1990s. They are genetically separate from the Baldwin, another hairless guinea pig that arose from American Crested parents and loses its coat with age.1283

Fun facts for the dinner table

  1. 1

    The very first hairless guinea pig was spotted in 1978 at a research institute in Montreal, Canada.2

  2. 2

    Hairlessness is recessive, so two skinny pigs always produce hairless babies, while a skinny pig and a haired pig produce haired pups that carry the gene.1

  3. 3

    Skinny pigs eat more than their furry cousins to keep themselves warm.1

  4. 4

    Some skinny pigs, nicknamed 'werewolves', grow extra hair over the face, neck and shoulders.1

  5. 5

    The Baldwin looks similar but is a different hairless guinea pig: it is born with a full coat and sheds it as it grows.3

  6. 6

    In the laboratory world the strain is known by the code Crl:HA-Hrhr.8

  7. 7

    Hairless and skinny guinea pigs may not be entered at cavy shows in the United Kingdom.9

Recognised by the official bits

American Rabbit Breeders Association / ACBA
Not among the 13 cavy breeds recognised in the Standard of Perfection1
British Cavy Council
Hairless and 'Skinny' cavies may not be shown at UK cavy shows9

The care rhythm Furry Diary remembers it for you

A typical home-care rhythm for a Skinny Pig. It is our own starting plan, not a vet's advice, and you can change every line in the app.

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Where this comes from

Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.

  1. Wikipedia: Skinny pig en.wikipedia.orgused for origin, history, genetics, appearance, colours, lifespan, care, temperature
  2. PubMed: Temperature preference in IAF hairless and Hartley guinea pigs (2016) pubmed.ncbi.nlm.nih.govused for 1978 spontaneous recessive mutation at Institut Armand-Frappier
  3. Wikipedia: List of guinea pig breeds en.wikipedia.orgused for Teddy outcrossing, pups born nearly hairless, Baldwin comparison, higher food needs
  4. Merck Veterinary Manual: Guinea pig description merckvetmanual.comused for general weight, vocalisations, behaviour
  5. RSPCA: Guinea pigs rspca.org.ukused for companionship
  6. RSPCA: Guinea pig environment rspca.org.ukused for housing and temperature comparison
  7. Wikipedia: Guinea pig en.wikipedia.orgused for general weight, diet, social needs
  8. PubMed: Ocular wound chamber study (2018) pubmed.ncbi.nlm.nih.govused for laboratory strain designation Crl:HA-Hrhr
  9. British Cavy Council breed standards britishcavycouncil.org.ukused for skinny pigs not showable in UK

Checked 2026-09-30. Text is written in our own words from these sources.