How are Guinea Pigs Kept ?

Should Guinea Pigs be kept in groups or single ?

Guinea Pigs are social animals usually mix well with other animals - even members of other species such as rabbits. However, some authorities and authors do not advise keeping guinea pigs with rabbits, because there have been reports of guinea pigs being injured (and even killed) by rabbits, which have a powerful kick.  On the other hand, many Guinea Pigs are kept in isolation and do not seem to mind a solitary life-style. It is usual to separate pregnant females from others to reduce stress and protect the young until they are weaned. Mixing sexes together of course increases the number of offspring produced !

Guinea Pigs have excellent teeth for gnawing and they can easily chew their way out of cardboard or wooden accommodation. Nevertheless, commercially available housing usually consists of a hutch made of wooden construction with wire mesh runs.

A Guinea Pig will be happy in it's home if it :

• Is dry 
• Is drought-free
• It is warm
• Is kept clean
• Allows in day light during the day
• Is dark during the night
• Has a private, secluded nest area for sleeping . This can be a screened off area - or a separate section of the hutch.
• Has a separate area for use as a toilet
• Has an exercise area.
• It has no materials that will easily splinter when gnawed.
• Some hutches/runs have mesh floors - but these should be avoided as they can cut their feet on the wire.

Guinea Pigs will usually use one area of their home as a toilet - but sometimes that can be a large area of the floor. Because they are rodents - if you don't clean them out regularly their home will develop an unpleasant, pungent musty smell…which the Guinea Pig will happily live with - but you, your family or your friends may not !

Absorbent material (paper, sawdust) can be used on the floor of the home to soak up urine - BUT this does not mean that the mess can be left on the floor for a long time. Guinea Pigs s should be cleaned out every few days otherwise they may urinate and pass droppings in their nest area - which can lead to contamination of food stores and so create a health risk. Mastitis is often seen in guinea pigs kept in dirty conditions.

Bedding materials should be provided (cellulose wadding, hay, straw, shredded paper or woodchips) for the guinea pig to construct it's nest with. Nylon fibre wool and cotton wool should be avoided as bedding materials because they have been associated with obstruction of the intestine and injury to toes and limbs if the fibres wrap tightly around them cutting off the blood supply.

Guinea Pigs are not very active creatures but they do like to lie in the sun and run around an exercise area. They are deceptively fast for a small creature - especially if they are frightened and you must be careful to restrict them to a confined area if you are trying to pick them up - or they might escape.  

Guinea Pigs can tolerate a wide range of environmental temperature but it is recommended that they be kept at a temperature of between 12^o-20^o C and temperatures in excess of 27^oC can lead to heatstroke - especially in obese or pregnant individuals. In reality most Guinea Pigs are kept at the ambient temperature of general household gardens or garages in the UK and they do very well without the need to maintain a constant environmental temperature. However, when Guinea Pigs are kept in countries where they could be subjected to extremes of hot or cold temperatures, control of environmental temperature may be needed.

In countries where extremes of humidity occur some environmental control may be needed. 

Guinea Pigs are usually placid though they can get very frightened by sudden movements or loud noises, in which case they can be difficult to catch Guinea pigs should be picked up by placing one hand over the shoulders and the other under the hind legs  but they do not like rough handling, being squeezed or being swung about. Contrary to popular belief a Guinea Pigs eyes will not "pop out" when handled properly

Breeding

Guinea Pigs are very easy to breed. Youngsters are sexually active from as early as 4-6 weeks (females - are called sows) and 9-10 weeks of age (males - are called boars) but mating should be delayed until females are 12 weeks of age. Females come into oestrus (commonly called being "on heat") and are receptive to males every 15-17 days. Oestrus itself only lasts for about 8 hours. "On heat" females are easy to recognise because they arch their backs and hold their rear end in the air. The vagina is usually closed off with a membrane except during oestrus when they initially develop a clear mucous discharge from the vulva. Following mating, a plug of material forms in the vagina and this dries and falls off a few days later.

Sexing can be very difficult if you haven't got one of each sex available to compare. Basically if you examine the undersurface females have an anus near the tail base, and the vaginal opening lies a short distance in front of it. In the male the penis can be exposed by retracting the foreskin with the fingers. 

Guinea Pigs are pregnant (called the gestation period) for 59-72 days and they usually have a litter of 1-6 young. Body weight can increase greatly - sometimes females double their weight - and this needs to be differentiated from pregnancy. Pregnant females should be separated from other animals until weaning.

24-48 hours after giving birth the female will come into oestrus again.

Guinea Pigs are covered with hair at birth and are born with their eyes open. They start to eat solid food in the environment within the first day of life and the young can be weaned at 21 days of age - which means that they should be totally separated from their mother.

Injury to young Guinea Pigs is common if they are not kept separate until weaning.

If a mother rejects her offspring or dies during a difficult birth (which can occur if there are complications) hand rearing by feeding a mixture of diluted cow's milk and commercial pellets can be successful. Alternatively they can be fostered by other lactating sows.

1. Dental disease Teeth-related problems  are common in Guinea Pigs 
2. Diarrhoea Diarrhoea is very common in Guinea Pigs and there are many causes - some of which can be fatal

• Campylobacter  is a rare cause of disease in Guinea Pigs
• Coccidiosis 
• Salmonella 
• Tyzzer's disease  is a rare cause of disease in Guinea Pigs
• Yersiniosis or pseudotuberculosis 
• Antibiotic-related enteritis
• Non-specific diarrhoea - associated with stress or changes in food. To avoid this always introduce new foods gradually.

Guinea pigs holding their head to one side sometimes have foreign material such a seeds from bedding in their outer ear canal. They also often have infection of the middle ear. The infection can be caused by a variety of bacterial organisms including Actinobacillus, Bordatella, Pasteurella,  and Streptococci. Affected animals may not recover, but antibiotic treatment is needed.

Soreness of the eyes (conjunctivitis) is a common problem - particularly when bedding materials are very dusty. There is a white, yellow, green or brown-red discharge from the eyes, and sometimes local irritation. Conjunctivitis can also be a feature of some respiratory infections eg Chlamydia. Antibiotics may be needed and veterinary advice should be sought.

Guinea pigs like to rummage under bedding materials and as a result they sometimes scratch the surface of their eyes against the sharp ends of dry straw or hay. This can cause local irritation, closing of the eye lead to the introduction of infection and result in conjunctivitis. Antibiotic treatment may be needed to prevent secondary infection  If a corneal ulcer forms the situation can become quite serious so early examination and treatment by a veterinarian is needed.

A hormonal basis is suspected (but not proved) for the bilateral hair loss (alopecia) that occurs in some females during late pregnancy. The hair grows back after they have given birth to their offspring..

Liver disease is the sequel to infection with Salmonella and Tyzzer's disease

Vitamin C deficiency (scurvy) If vitamin C is absent from the diet for only a couple of weeks serious illness can result with swelling and pain in the joints, depression, weight loss and even death. It is so painful to walk that affected guinea pigs refuse to move, and sometimes appear paralysed. Guinea pig rations should contain adequate available vitamin C. Vitamin C supplementation can be given - 100mg/day - usually in a solution formulation by mouth

Soluble Vitamin C tablets can be dissolved in drinking water once or twice weekly.

Spinal Injury Spinal injury is seen occasionally  following falls or after being trodden on.by humans. Paresis or paralysis may result, and these signs need to differentiated from other causes of inactivity such as nutritional scurvy (vitamin C deficiency) which is so painful that affected animals refuse to move.

Long Bone Fractures Fractures are common following trauma. They heal quite well with external support - unless they are compound when the wound needs to be closed under sterile conditions to avoid infection.

Mastitis Affected guinea pigs develop hard, swollen, hot and painful mammary glands. Sometimes pus will discharge form the teats. Good hygiene is important to avoid this - so bedding should be cleaned out regularly

Milk fever (also called pregnancy toxaemia) Occurs in late pregnancy or soon after the young are born. The cause is inadequate blood calcium concentrations which causes depression, inappetance and death. Overweight females are more likely to develop the disorder so overfeeding must be avoided. Stress is also thought to be an important factor so pregnant and nursing females should be kept quiet and undisturbed.

Respiratory infections are common in Guinea Pigs. Difficulty breathing (dyspnoea), increased rate of breathing, coughing, sneezing, discharges form the nose and eyes, weight loss are all signs. The animal is usually off it's food, and in the most severe cases death can result.

There are a variety of infectious agents that may be involved, and sometimes more than one organism is present at the same time :

1. Viral causes  eg adenovirus pneumonia in stressed individuals
2. Bacterial causes notably bordatella spp  and streptococcus pneumoniae and klebsiella. Affected animals often die despite treatment with antibiotics. For prevention of spread an autogenous vaccine has been used successfully in some guinea pigs colonies, but again these individuals become carriers of the disease.
3. Mycoplasma causes 

Respiratory infections are often associated with poor housing conditions, poor nutrition (vitamin C deficiency) and overcrowding. Even if treatment helps an individual recover from the disease it may carry the organisms for a long time, and so act as a reservoir of infection for other guinea pigs.

Itchiness

Guinea pigs are frequently presented with hair loss, scratching and flaky skin. In many cases the cause is likely to be due to the fungal infection ringworm  or to parasitic infestation particularly mites  called Trixacarus caviae which causes extreme irritation and itchiness. This irritation can be so severe that the patient appears to have a  nervous disorder. Lice  are also sometimes seen in the coat or when samples are taken for examination under a microscope - but they rarely cause irritation and scratching.

Hairloss (alopecia)

Bilaterally symmetrical hair loss (alopecia) is occasionally due to hormonal changes in pregnant animals.

Hairloss is often due to excessive grooming or even chewing by other guinea pigs. If mothers excessively groom their young they should be weaned as early as possible. If an animal is biting or pulling it's own hair (self-trauma) an underlying cause such as the sarcoptic mite should be sought. Otherwise excessive grooming can be abnormal behaviour due to stress or boredom. Changing the guinea pigs bedding and daily routine might help to alter it's behaviour pattern. If it is kept in isolation introducing a companion animal (another guinea pig or rabbit) might help.

Skin infections

Feet infection with reddness, swelling and ulcers (called pododermatitis) is quite common in guinea pigs kept on unsuitably rough flooring. It is caused by a bacterium Staphylococcus aureus and antibiotic treatment is needed.

Skin wounds in guinea pigs often get infected and puncture wounds may form abscesses which may need to be drained and cleaned under sedation or an anaesthetic. Infection with a bacterium, called staphylococcus zooepidemicus often spreads to local lymph nodes which swell forming hard lumps containing pus. These can burst and discharge white-yellow pus. Occasionally the infection gets into the guinea pigs bloodstream (called septicaemia) which can be fatal..