Miniature pig

From Wikipedia, the free encyclopedia
  (Redirected from Micro pigs)
Jump to: navigation, search
Miniature pig
Full-grown miniature pigs
  • Pig
  • Sus scrofa domesticus

A miniature pig (also mini pig) is a class of pig developed and used for medical research or as a pet. Miniature pigs weigh between 22.5 kilograms (50 lb) and over 68 kilograms (150 lb) when fully grown. 'Mini pig' has become an acceptable, if imprecise, term that is used to distinguish the difference between farm pigs and smaller breeds such as American Mini pigs, Pot-bellied pigs, Choctaw Hog, Kunekune (and specimens derived by cross breeding with these). There are no breeds called teacup, micro, micro mini. These are all adjectives and not breeds of pigs.[1]


In the 1960s, Chinese pigs that grew to be 150–200 pounds (68–91 kg) were sent to zoos in Western cities[2] and were used for medical research in the fields of toxicology, pharmacology, pulmonology, cardiology, aging, and as a source of organs for organ transplantation.[3] These comparatively smaller pigs were easier to work with than the larger farm pigs, which typically reach weights of 300-500 pounds.[4] Pot-bellied pigs also became a fixture in many zoological parks where their small stature, sway backs, and potbellies attracted the attention of visitors.[5] The purchase of a few potbellied pigs by wealthy pet owners helped start a new trend in pet pigs.

The popularity of miniature pigs grew in the 1980s, with pet potbellied pigs appearing everywhere from New York apartment complexes to small hobby farms. However, the trend was short-lived, mostly due to city ordinances forbidding raising farm animals within the city limits. Furthermore, many owners came to realize that even a 75 kilograms (165 lb) pig was difficult to handle in most housing situations.

The 1990s and 2000s saw a rising trend of marketing pet pigs that were supposed to be much smaller than even the potbellied pigs, and therefore suitable pets for house and apartment owners. While multiple animal protection groups and pig breeders question or deny the existence of true "miniature pigs",[6] there are currently breeders selling piglets claimed to be miniature pigs in North America and in the United Kingdom. The word "mini" or "miniature" has been accepted as a term to differentiate between farm pigs and potbellied pigs, but in no way describes the sizes of "mini" pigs.[7][8] Realistic sizes of pigs vary from pig to pig, genetics drives the growth along with appropriate nutrition and care.[9] The misleading terms have grown to include other adjectives to represent breeds that do not exist.[10]

In the mid-1980s, Keith Connell of the Bowmanville Zoo in Ontario imported breeding potbellied pigs to Canada, which became the foundation for the potbellied pig in North America.[11] Because of customs laws, only their offspring could be sold in the United States. US zoos were the main target for the piglets, but private owners soon began purchasing them as pets. Up to five additional imports were made in the following 10 years. To track the pedigrees, the Potbellied Pig Registry Service, Inc (PPRSI) was created to preserve these bloodlines and establish a breed registry in the United States. This registry was dissolved in the late 1990s.[11]

The Miniature Potbellied Pig Registry Service, Inc (MPPRSI) was established in 1993 to provide a registry for those pigs who were pedigreed in the PPRSI and met the breed standard, when fully grown not being more than[12] 37 centimetres (15 in) tall and weighing under 25 kilograms (55 lb).[13] All of the foundation pigs were dual registered in PPRSI and MPPRSI.[11]

Medical research[edit]

Miniature pigs have been used for medical research, including toxicology, pharmacology, experimental surgery, pulmonology, cardiology, xenotransplantation, and aging. Scientists genetically modified the pigs' genomes in order to create smaller pigs for medical research since pigs can be useful in studying human disease and due to their high intelligence, are easy to manage in a laboratory setting.[12] For example, scientists are working on studying the possibility of utilizing pig hearts for human heart organ transplant and work has been done to genetically modify the tissues of pigs to be accepted by the human immune system.[14]

The Göttingen minipig (or Göttinger or Goettingen Minipig) is a breed of miniature pig developed for use in biomedical research. Beginning in the late 1960s at the Institute of Animal Breeding and Genetics (Institut fϋr Tierzucht und Haustiergenetik) at the University of Göttingen, Germany, the breed was developed by crossbreeding the Minnesota minipig, the Vietnamese Potbelly Pig and the German Landrace pig.[15]

In May 2015, the China Academy of Agricultural Science announced that its research team had successfully produced F-25 (the 25th generation) of inbred Chinese Wuzhishan Mini Pig (WZSP), with an inbreeding coefficient of 0.99519. On June 23, 2017, the Academy of Military Medical Sciences of China and Grand Life Science Co. Ltd. jointly announced in "Study on Porcine endogenous retrovirus from Wuzhishan minipig inbred and establishment of a new population without infectious PERV" [16]that the PERV-pol gene-deficient WZSP have been identified and verified by systematic virology methods and whole genome sequencing, and Grand Life has succeed in reproducing F0/F1 PERV-noninfectious WZSP herd that available for advanced biomedical research purposes, including series of studies under the 2017-2020 National Primary Research Programs on Bio-material Development, Tissue-organ Repair and Xenotransplantation that commissioned by the Ministry of Science and Technology of China.

As pets[edit]

Young mini-pig on the streets of Condesa neighborhood (Cuauhtémoc borough, Mexico City) during an earthquake in May 2014

Miniature pigs can be pets. They are very intelligent animals,[17] or according to David DiSalvo writing in Forbes they are "widely considered the smartest domesticated animal in the world" -pigs ... can move a cursor on a video screen with their snouts and even... learn to distinguish between the scribbles they knew from those they saw for the first time...)[18][a] and can be easily house-trained.[22] They can also be taught how to go through a doggy door or ring a bell at a door to notify their owners if they need to go outside. They are supposedly hypoallergenic and often do well with people that have usual animal allergies as they have hair and not fur. (Some people have had allergy testing and are allergic to pigs though) They do, however, "blow their coat" meaning that they shed most of the longer hair once a year, usually in Spring or early summer to prepare for the warmer months ahead. Because pigs do not sweat (the often used term "I'm sweating like a pig" is a misnomer since pigs only sweat a small amount from their snouts), they shed to help keep cool in the warmer summer months. This can often be a hassle as they can shed a large amount of long, stiff hair that can pierce through the skin if stepped on or embedded in clothing. It is common for the pig to gain bald spots or be mostly bald through summer and fall, and most of the hair will grow back. Though the main assumption about pigs is that they are very dirty animals, in fact, they will usually only get muddy or dirty when provided with a much needed outside area to gain vitamin D from sun/rooting soil and grass for a diet, and use the mud as a sunscreen or cooling agent to keep their body temperature regulated. Wallowing, as it is referred to, is when a pig will root up a certain area of dirt and roll around in the mud to get a nice layer of mud on their skin to protect against the sun and as a bug repellent.[23]

'Teacup-sized' immature miniature piglet

Breeders claim that micro pigs can potentially make great pets, but that there are considerably more risks involved when buying a micro pig over other common pets, such as cats or dogs. The biggest concern is that, since there is no established breed of "teacup pig", there is no guarantee that the pig sold as such will actually stay small.[24] It may be possible to reduce the risk of ending up with a large pig by looking at the pig's parents and grandparents if possible.[25] However, since pigs can breed years before they fully mature, unscrupulous or ignorant breeders may show off parent pigs which are not fully grown themselves, so have not reached their full adult size.[26] Some breeders may falsely claim that a mini-pig is guaranteed to stay under a certain weight, and sometimes will recommend a diet regimen that starves the animal and unnaturally stunts its growth.[27] Pigs need enrichment activities to keep their intelligent minds occupied, if pigs get bored, they often get destructive.

Some towns and cities have ordinances disallowing farm animals within city limits; a pig is usually considered a farm animal regardless of their size. However, one can petition city councils and have outdated ordinances amended before a pig is introduced into a household, since many ordinances were put into place before the potbellied pig was even introduced to the US.[28] As many small animal vets will not treat pigs, a prospective owner will need to find a vet that is willing to see pigs before a pig is brought home. Many educational websites for pigs have collected and verified veterinarians that do.[29] Since these animals have a life span of 15 to 20 years, they require long term commitment. Due to their ability to bond, combined with their need for attention, people who have limited time for a pet may find a pig far more than they can handle. Additionally, if pet pigs are not properly trained when they are young, they can strive for dominance and become aggressive.[30] There are methods to retrain pigs that have not been trained properly though. Normally, there is a reason a pig acts out aggressively such as not being neutered, starved or abused.

There are multiple animal rescue organizations set up to find new homes for pet pigs which have grown too large or otherwise unmanageable for their owners.[31]

Other notable references[edit]

A Yucatan miniature pig is the unofficial mascot of the Animal Rescue League of Boston.[32]

The world's smallest wild pig species is believed to be the 71 centimetres (28 in) long wild pygmy hog which lives in Assam, India.[33] It is an endangered wild species, not appropriate for domestication.


  1. ^ David DiSalvo's article in Forbes refers to via an article in Penn State Agricultural Magazine[19] referenced from 'Pork' by Catherine Becker at The Ohio State University[20] referencing work by Candace Croney, now head of Purdue center for animal welfare science[21]


  1. ^ "Mini Pig Info". Mini Pig Info. Retrieved 2016-10-21. 
  2. ^ John Pukite (1999). A field guide to pigs. ISBN 1-56044-877-6. 
  3. ^ Sachs, DH; Galli, C (2009). "Genetic Manipulation in Pigs". Current Opinion in Organ Transplantation. 14 (2): 148–153. PMC 2687522Freely accessible. PMID 19469029. doi:10.1097/mot.0b013e3283292549. 
  4. ^ "Ag Facts: Swine". 1985-03-05. Retrieved 2016-04-04. 
  5. ^ 'Mini-pigs' at Accessed 27 January 2017
  6. ^ what-is-a-mini at - Miniature Potbellied Pig Registry Service, Accessed 26 January 2017
  7. ^ "What is a "mini" pig?". 
  8. ^ "Mini Pig Breeds Typically Seen As Pets. pet pigs, miniature pig breeds, mini pig breeds, teacup pig, micro mini pig, royal dandie pig, is there such a thing as a teacup pig, teacup pig myth.". 
  9. ^ "Growth and mature sizes of real pigs, how big will a mini pig get, teacup pig sizes, micro mini pig, royal dandy pig, teacup pig lie". 
  10. ^ "Is there a "teacup" or "micro" pig?". Mini Pig Info. Retrieved 2016-10-21. 
  11. ^ a b c "History". Miniature Potbellied Pig Registry Service, Inc. Retrieved 4 February 2013. 
  12. ^ a b "Tea Cup Pigs, Yay or Nay? | SiOWfa15: Science in Our World: Certainty and Controversy". Retrieved 2017-03-08. 
  13. ^ "Breed Standard". 
  14. ^ Cooper, David K. C. (2017-03-08). "A brief history of cross-species organ transplantation". Proceedings (Baylor University. Medical Center). 25 (1): 49–57. ISSN 0899-8280. PMC 3246856Freely accessible. PMID 22275786. 
  15. ^ Bollen, PJA & Ellegaard, L.(1996). Developments in Breeding Göttingen Minipigs. In Tumbleson & Schook (eds.) Advances in Swine in Biomedical Research. New York: Plenum Press
  16. ^
  17. ^ "10 of the smartest animals on Earth". MNN - Mother Nature Network. Retrieved 2017-03-08. 
  18. ^ David Disalvo 2014/11/26 how-smart-was-that-turkey-and-ham-before-it-became-dinner at Accessed 27 January 2017
  19. ^ "In a Pig's Eye" - by Eston Martz Penn State Agricultural Magazine, Fall/ Winter 1997 Penn State College of Agricultural Sciences Accessed 27 January 2017
  20. ^ Catherine Becker: 'Pork' at Accessed 27 January 2017
  21. ^ 'Croney to head Purdue Center for Animal Welfare Science' Accessed 27 January 2017
  22. ^ "Pretty Little Porkers". 
  23. ^ "Mini Pig Spring and Summertime Concerns". 
  24. ^ You must have been told a porky: 'Micro' pig grows to 25 stone and takes over its owners' home By Daily Mail Reporter PUBLISHED: 12:51 EST, 27 July 2012 | UPDATED: 15:00 EST, 27 July 2012
  25. ^ Minimizing risk when buying a micro pig About Micro Pigs and their size - UK
  26. ^ Teacup Pigs All the Rage, But Animal Welfare Group Urges People to do Homework Before Taking One Home October 28, 2009
  27. ^ "This Vegan Digs On Swine » Yurtopian". 22 January 2013. Archived from the original on 22 January 2013. 
  28. ^ "Changing city ordinance information- pig ordinance, pig regulations, pig approved homes, changing the law to allow pigs.". 
  29. ^ "Mini Pig Veterinarians-find a pig vet near you". 
  30. ^ "Pot Bellied Pigs as Pets". 
  31. ^ "Sanctuary ... abandoned, ignored, hoarded or even outlawed" Accessed 27 January 2017
  32. ^ Meet Rosie a Yucatan miniature pig May 10, 2009
  33. ^ Mini pigs are big success on farm 15 October 2007 BBC News