Genetic Welfare Problems of Companion Animals

An information resource for prospective pet owners

Peruvian Long Hair

Peruvian

Long Hair

Outline: The abnormally long fur of the Peruvian guinea pig is due to an autosomal recessive gene. Peruvian guinea pigs are unable to groom themselves adequately because of the length of their fur and their coats are prone to becoming matted which can lead to skin infections. Because the fur often becomes matted and soiled, they are at particular risk of fly strike. These conditions can adversely affect the animals’ welfare with effects ranging from discomfort to intense pain.


Summary of Information

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1. Brief description

The fur of the guinea pig varies between breeds. There are various long haired breeds, the best known of which is the Peruvian, which has long, silky hair growing all over its head and body, so that it is difficult to identify which end of the animal is which. The hair can grow up to 50 cms long (Alderton 2001; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian).

Normally, wild or short-haired guinea pigs are able to groom and care for their fur themselves but this is impossible for the Peruvian. The long coat is very vulnerable to matting, where the fur becomes tangled together in a dense, confused mass, and this occurs rapidly without regular grooming (Alderton 2001; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian).

A matted coat causes discomfort and, if severely matted, the skin underneath may become sore and infected. Large mats can physically affect the guinea pig’s ability to feed if, for example, the mats are below the chin, or can interfere with normal movement when the mats involve the limbs (RWF 2007).

As well as matting of the fur, Peruvians are predisposed to other problems because of their long coats. These include: difficulties in mating; difficulties in nursing - as the pups (baby guinea pigs) cannot easily find the nipples to feed; and fly strike (in which flies lay their eggs on the guinea pig and on hatching, the maggots feed on its body tissues – eating it alive). Fly-strike is a life-threatening, painful and distressing condition.

Although regular grooming or clipping/ trimming is recommended and will prevent the diseases associated with long hair, Guinea pigs may find these procedures uncomfortable and stressful. Peruvians are ‘high maintenance’ guinea pigs that need regular and prolonged attention from their owner to maintain their coat condition and avoid disease and discomfort.

2. Intensity of welfare impact

Peruvian guinea pig fur mats readily. Matted fur can be uncomfortable causing irritation, sore and infected skin and, if severe, can affect ability to feed and mobility. Regular grooming or trimming can be stressful and may be painful too. All these factors can compromise the quality of life for these guinea pigs.

The long coat and matting predisposes the breed to experiencing a life-threatening condition: fly strike. This condition causes significant pain, distress and suffering (Cousquer 2006).

Veterinary visits can cause significant stress in prey species (such as the guinea pig). They may show few obvious signs of pain so suffering may be underestimated and problems may be undetected until they are severe (Fawcett 2011).

As far as we are aware, the impact of the long fur on the guinea pigs ability to regulate their body temperature effectively has not been investigated but it seems likely that Peruvian guinea pigs may be at greater risk of thermal discomfort in warm environmental conditions than short-haired breeds.

3. Duration of welfare impact

The welfare risks of long fur are life-long, and can only be reduced by regular trimming and/or daily grooming.

Matting and fly strike can occur at any age. Matting can cause discomfort and irritation of days to weeks in duration and can cause pain if the skin beneath the matting becomes infected or ulcerated. Fly strike can lead to a painful death within days.

4. Number of animals affected

All Peruvians have the coat qualities that predispose them to matting and the secondary consequences of this. We are not aware of any data on the prevalence of the conditions described here (matting and fly strike) but they are considered to be common conditions (Cousquer 2006; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian).

5. Diagnosis

Coat mats and fly-strike are easy to detect on careful examination but determination of the extent of tissue damage caused by maggot infestation may need detailed veterinary examination under sedation or anaesthesia.

6. Genetics

The long coat of the Peruvian is due to an autosomal recessive gene. All Peruvians have a pair of these recessive genes and so have the coat that puts them at particular risk of the conditions described here.

7. How do you know if an animal is a carrier or likely to become affected?

All Peruvian guinea pigs are homozygous for the autosomal recessive gene that causes their long coats (ie both copies of this gene are of the abnormal form). Semi-long haired guinea pigs may produce fully long-haired offspring when mated together.

8. Methods and prospects for elimination of the problem

The risks of the welfare problems described here would be greatly reduced by selection for individuals with normal length coats, which would involve out-crossing affected individuals with other breeds.

Opinions differ as to whether it is ethically acceptable to breed animals whose welfare is at particular risk because of the abnormal characteristics for which they have been selected.


For further details about this condition, please click on the following:
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1. Clinical and pathological effects

The wild ancestors of domesticated guinea pig originated from the mountainous regions of South America. They were probably first domesticated by Andean Indians 3000 to 6000 years ago (Fawcett 2011), and were brought to Europe in the 1700s (Alderton 2001). Since this time many different breeds have been developed with a wide range of colours and fur characteristics.

The Peruvian appears to have been the first long-haired breed to have been specifically recognised and selected for. It has long silky hair which falls over the head and rear giving the animals a “mop-like” appearance (http://www.petplanet.co.uk/small_breed_profile.asp?sbid=21). The coat can grow up to 50 cms long (Alderton 2001; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian). All of the several species of wild guinea pigs in South America have short coats.

Short-haired wild guinea pigs and domesticated breeds groom and care for their fur themselves but this is impossible for the Peruvian. The long, silky coat is very vulnerable to matting, where the fur becomes tangled together in a dense, confused mass, and this occurs rapidly without daily grooming by the owner (Alderton 2001; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian). Unless Peruvians have their fur clipped regularly to keep it short, their coats need constant (daily) attention ( https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian).

A matted coat is uncomfortable for the guinea pig. The skin underneath severe mats may become sore and infected. Large mats can physically affect the animal's ability to feed, for example, if mats form below the chin, or they can prevent normal locomotion when the mats involve the limbs (RWF 2007). The long coat can impede normal movement even when not matted.

Peruvians may also be predisposed to other problems, listed below, because of their long coats.

  • Difficulties in mating and suckling young. Difficulties in mating due to excessive hair around the genitals have been reported in long-haired rabbits, and may occur also in Peruvian guinea pigs. It may be necessary to clip the sow to allow mating. The boar’s penis can also become enclosed in mats of hair which prevents mating (http://www.angorarabbit.com/angora/angora-rabbit-manual/index.htm). Pups (baby guinea pigs) can have difficulty sucking from their mothers because they cannot find the nipples. Clipping prior to giving birth may be required, as is the case with Angora rabbits (http://www.angorarabbit.com/angora/angora-rabbit-manual/index.htm).
  • Fly strike (myiasis). Some species of flies lay their eggs on live animals and their hatched larvae (maggots) feed on the living animal’s tissues. In the UK these species include the blowfly (Lucilia sericata), bluebottles (Calliphora species) and greenbottles (Lucilia species). Other species of flesh-eating flies are found around the world (Cousquer 2006).

    These flesh-eating flies are attracted to moist hair and skin soiled by urine and faeces. They lay their eggs in the soiled coat, and, on hatching, the larvae eat the living body tissues. Some maggots are capable of damaging intact healthy skin, others can reach living tissues only if the skin is already damaged. The larvae will eat through tissues under the skin and cause extensive damage (Cousquer 2006).

    Long-haired guinea pigs (like other long-haired animals eg rabbits) are prone to matting around the anus and perineum which the animal is unable to alleviate through self grooming, so soiling persists and they then become vulnerable to fly strike (Cousquer 2006, RWF 2005). The long hair and mats tend to hide sore skin and maggots so that detection of the disease can be delayed. Fly strike can develop rapidly. In warm conditions the time from laying eggs to development of second stage larvae, which are the most damaging, can be as little as 38 hours (Cousquer 2006).

    Cousquer (2006) described this as an extremely distressing condition for the animal and owner. Affected guinea pigs become depressed, stop eating and lose weight. There may be an unpleasant, fetid smell. On examination, fly eggs and larvae may be seen in the coat and wounds caused by the maggots may be apparent. The guinea pig may become dehydrated and collapse and die. There is significant pain associated with extensive tissue damage (Cousquer 2006). If caught early, treatment may be possible but guinea pigs with more advanced disease often have to be euthanased. Treatment involves fluid therapy for shock, pain relief, the removal of all eggs and larvae, and wound care and management, which may last for weeks.
  • As the Peruvian has hair growing over its face it seems likely that it’s vision is affected. Hairs touching the eyes cause irritation and can damage the surface of the eyeball at times.

Peruvians are ‘high maintenance’ guinea pigs that need regular and prolonged attention from their owner to maintain their coat condition and avoid disease and discomfort. This includes a programme of regular grooming (daily or several times a week) or regular clipping, and daily examinations to check for perineal soiling, particularly during warmer weather or in warmer climates. Unfortunately guinea pigs are excellent at masking signs of illness and pain so conditions may not be identified until severe, so owners need to be particularly vigilant (Fawcett 2011). Guinea pigs may find the necessary grooming procedures uncomfortable and stressful.

Alderton (2001) recommended that Peruvians should not be housed using hay as bedding material as it can easily become entangled in the coat and worsen matting. It would seem likely that this is also true for other commonly used bedding materials such as wood shavings.

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2. Intensity of welfare impact

Pervian guinea pig fur mats readily. Matted fur can be uncomfortable causing irritation, sore and infected skin and, if severe, can affect ability to feed and mobility. Regular grooming or trimming can be stressful and may be painful too. All these factors can compromise the quality of life for these guinea pigs.

The long coat and matting predisposes the breed to experiencing a life-threatening condition: fly strike. This condition causes significant pain, distress and suffering (Cousquer 2006).

Veterinary visits can cause significant stress in prey species (such as the guinea pig). They may show few obvious signs of pain so suffering may be underestimated and problems may be undetected until they are severe (Fawcett 2011).

As far as we are aware, the impact of the long fur on the guinea pigs ability to regulate their body temperature effectively has not been investigated but it seems likely that Peruvian guinea pigs may be at greater risk of thermal discomfort in warm environmental conditions than short-haired breeds.

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3. Duration of welfare impact

The welfare risks associated with long fur are life-long, and can only be reduced by regular clipping and/or daily grooming.

Matting and fly strike can occur at any age. Matting can cause discomfort and irritation lasting from days to weeks and can cause pain if the skin beneath the matting becomes infected or ulcerated. Fly strike can lead to a painful death within days.

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4. Number of animals affected

All Peruvians have the long coat that predisposes them to matting and the secondary consequences of this. We are not aware of any data on the prevalence of the conditions described here (matting and fly strike) but they are considered to occur commonly (Cousquer 2006; https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian).

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5. Diagnosis

Coat mats and fly-strike are easy to detect on careful examination but determination of the extent of damage caused by maggot infestation may need detailed veterinary examination under sedation or anaesthesia.

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6. Genetics

The coat characteristics of guinea pigs are controlled by a number of genes. One affects coat length. Guinea pigs which are homozygous for the dominant form of this gene (ie which have a pair of dominant genes) have short hair. Peruvians (and other long-haired breeds) are homogygous for the recessive form of the gene which causes the abnormally long hair growth. Heterozygous individuals (with one dominant and one recessive gene) are semi-long haired (Warren et al 2008). The recessive gene is autosomal, that is it is located on one of the autosomal chromosomes rather than on those (the x and y) that determine sex.

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7. How do you know if an animal is a carrier or likely to become affected?

All Peruvian guinea pigs are homozygous for the abnormal, autosomal recessive gene that causes the long coat (ie both copies of this gene are of the abnormal form). There are no unaffected carriers within the Peruvian breed. However, the breeding of semi-longed guinea pigs together may produce long-haired offspring.

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8. Methods and prospects for elimination of the problem

The risks of the welfare problems described here would be greatly reduced by selection for individuals with normal length coats, which would involve out-crossing affected individuals with other breeds.

Opinions differ as to whether it is ethically acceptable to breed animals whose welfare is at particular risk because of the abnormal characteristics for which they have been selected. Pairing semi-longhaired guinea pigs should also be avoided as there is a one in four chance that offspring they produce will be long haired.

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9. Acknowledgements

UFAW is grateful to Rosie Godfrey BVetMed MRCVS and David Godfrey BVetMed FRCVS for their work in compiling this section and to Nina Taylor for her contribution to it.

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10. References

Alderton D (2001) The ultimate encyclopedia of small pets and pet care. Lorenz books: London

Cousquer G (2006) Veterinary care of rabbits with myiasis. In Practice 28: 342-349

Fawcett A (2011) Management of husbandry-related problems in guinea pigs. In Practice 33: 163-171

Rabbit Welfare Fund (RWF) (2005) Flystrike: Is your rabbit at risk. Owner information leaflet. Horsham, UK: RWF

Rabbit Welfare Fund (RWF) (2007) The long and the short of it. Caring for long-haired pet rabbits. Owner information leaflet. Horsham, UK: RWF

Warren N, Mayoh B and Neeson S (2008) Cavy Genetics: An Exploration. On-line http://www.britishcavycouncil.org.uk/Information/. Accessed 9.9.11

http://www.angorarabbit.com/angora/angora-rabbit-manual/index.htm

https://www.omlet.co.uk/breeds/breeds.php?breed_type=Guinea+Pigs&breed=Peruvian

http://www.petplanet.co.uk/small_breed_profile.asp?sbid=21

© UFAW 2011


Credit for main photo above:

http://depositphotos.com/38878731/stock-photo-peruvian-guinea-pig.html ©Depositphotos.com/cynoclub