Diarrhoea and enteropathies in the guinea pig

Intestinal problems are fairly frequent in guinea pigs. They vary greatly in severity, but often the enteropathy is very severe and leads to death within a few hours. There are numerous causes, which are not always easy to identify. Diarrhoea may be the consequence of a primary disorder of the intestine or secondary to other conditions. Some of the primary disorders are listed below.

• Diet  This is a fairly common cause of diarrhoea. Diarrhoea can be caused by an abrupt change in diet (excessive amounts of fresh vegetables for animals not accustomed to eating them), administration of cold or perished vegetables or inappropriate foods (carbohydrates, dairy products).
• Bacteria. Salmonella spp. cause haemorrhagic diarrhoea and, sometimes, sudden death. The chronic form of salmonella infection causes progressive wasting; the guinea pigs that survive become chronic, intermittent excretors of the bacteria. The infection is generally transmitted by mice and rats. Yersinia pseudotuberculosis can cause generalised lymphadenopathy in addition to acute or chronic diarrhoea. It is worth remembering that both of these infections are zoonoses, even if they rarely affect the guinea pig. Clostridia spp., which are part of the normal bacterial flora, can cause an untreatable, fatal enteritis, particularly following antibiotic therapy. Clostridium piliforme (Tyzzer’s disease) and Campylobacter are rare in the guinea pig. Escherichia coli is not normally present in the bowel of the guinea pig and if isolated in cultures it probably has a pathogenic significance.
• Parasites. Parasitic infestation is a rare cause of diarrhoea in the guinea pig. The Paraspidodera uncinata nematode does not normally cause symptoms, but if large numbers are present, they may cause diarrhoea. Eimeria caviae is a coccidium that can be seen in recently acquired guinea pigs and causes diarrhoea and death. There are reports of infestation by Cryptosporidium wrairi, for which there is no treatment. Resistant subjects are cured in 4 weeks; the diagnosis is made from examination of the faeces. This is a potential zoonosis.
• ·Vitamin C deficiency. A lack of vitamin C causes degeneration of the intestinal mucosa, facilitating secondary bacterial infections, with consequent diarrhoea. The diagnosis is reached by exclusion of other causes and the response to treatment with vitamin C.
• Administration of antibiotics. The intestinal flora of the guinea pig is exceptionally sensitive to the administration of antibiotics which can, therefore, lead to excessive growth of pathogenic bacteria, in particular Clostridia spp. The normal, commensal bacteria of the guinea pig bowel are Gram-positive organisms, in particular Streptococcus spp. and Lactobacillus spp. The use of antibiotics with a narrow spectrum of action which affect the Gram-positive bacteria can lead to fatal enteritis. In theory, any antibiotic can have this effect, even those applied locally if they are licked. The most dangerous are those with a restricted spectrum of action. Subcutaneous and intramuscular routes of administration are preferable to the oral route. The safest antibiotics for use in the guinea pig are chloramphenicol, fluoroquinolones and trimethoprim/sulphonamides. Guinea pigs can also be given vitamins and probiotics together with antibiotic therapy, although their utility has yet to be demonstrated.

Diarrhoea may also be secondary to a variety of pathological conditions, malocclusion, stress and anaesthesia.

The diagnosis can be reached through an evaluation of the animal’s diet and housing conditions, a search for intestinal parasites (fresh or by the flotation technique) and culture of the faeces for bacteria. It is often not possible to identify the exact aetiological agent and symptomatic and support therapy is used, with subcutaneous administration of fluids, non-steroidal anti-inflammatory agents, prokinetics (clebopride), probiotics and vitamins, in particular vitamin C. If the animal is hypothermic, it should be warmed. In the case of bacterial enteritis or enteritis of suspected bacterial aetiology, antibiotics are administered parenterally, although in the case of infections by Salmonella spp. or Yersinia pseudotuberculosis it is better to euthanize the sick animal because of the zoonotic potential of these diseases. If the guinea pig continues to eat, all fresh vegetables should be removed and the animal left only hay and pellets. If the animal is anorexic, assisted or forced feeding should be used, since this can greatly increase the possibility of recovery. Minced fruit and vegetable, vegetable baby food, and blended pellets can be used for this purpose, although it is better to use a specific product (for example, CriticalCare® Oxbow), which is usually well accepted.

The animal should be kept clean, dry and warm; all therapeutic procedures should be carried out in a way that minimises the stress to the animal.