Plus-Hex CLINICAL
Background
Originally a wild food source known as Cavia tschudii and more recently reclassified as Cavia porcellus, guinea pigs were domesticated some 3,000 years ago in South America as a food source and for religious sacrifice [ 1, 2 ]. A study by the Royal Belgian Institute of Natural Sciences documents their arrival in Europe in the 16th century, where they were bred and kept as pets [ 3 ]. Guinea pigs have since become globally popular pets, with veterinary involvement in their care and owner education [ 1, 4 – 7 ]. They are also used as laboratory animals and remain a source of food in parts of South America [ 8 ].
C. porcellus originates from the Andes mountains, where there is an average temperature of 18 ° C and mild humidity [ 9 ]. The species is now domesticated but guinea pigs are still sensitive to hot and damp conditions, which can cause heatstroke or respiratory illness [ 10 ]. Cavia aperea, their wild counterparts, choose to live in herds that eat and forage together for companionship, and avoid predation either by using tall and dense vegetation or by finding and claiming burrows [ 11, 12 ]. Despite morphological changes, the behavioural ethogram of the domesticated guinea pig is markedly similar to that of C. aperea, and failure to meet this ethogram in the domestic environment often results in negative clinical outcomes and negative effects on welfare [ 13 ].
The dominant cause of pet guinea pig morbidity and mortality is inadequate husbandry. Therefore, the primary care responsibilities of guinea pig owners must be to meet the most basic needs of housing and diet [ 14 ]. Guinea pigs are often hospitalised with preventable issues related to stress and husbandry [ 15 – 17 ].
Furthermore, guinea pigs are prey animals and so they expertly hide illness and often are presented for veterinary intervention only when critical or moribund; should death occur, owners may conclude that it was sudden and for no obvious reason [ 18 ]. Legally, owners must meet animal welfare needs such as protection from pain, suffering, injury and disease. As part of their duty of care, veterinary nurses( VNs) can help by educating owners [ 19, 20 ].
Commercially available pet guinea pig housing often falls below recommended sizing, resulting in many new owners immediately providing inadequate space to support natural behaviour [ 21 ]. Hutches alone are insufficient; guinea pigs should also have access to exercise runs large enough for free movement and space to mediate relationships with their companions, such as creating distance following a disagreement.
A major UK retailer of guinea pigs now states in its listings that a cage alone is insufficient and additional runs are required. However, one of the largest enclosures available is only 117 cm × 118 cm, which research from the Blue Cross suggests is still suboptimal [ 22 – 24 ]. Enclosures are often advertised as suitable for both guinea pigs and rabbits. Because pet shops sometimes house these species together in the store, prospective owners could misconstrue this to mean they are compatible companions, yet both should live only with conspecifics [ 23, 25 ]. Prey species require hides, ideally one each, to avoid territorial aggression and accommodate their natural instincts to escape [ 13 ]. Appropriate housing, substrate and companions help meet the need for a suitable environment, as does being housed with, or apart from, animals in the same enclosure or within the household [ 19, 20 ]( Figure 1).
Figure 1. A guinea pig enclosure with hides and suitable soft bedding, such as newspaper and hay.
Volume 40( 5) • October 2025
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