Balantidiasis

Introduction

Balantidiasis is caused by Balantidium coli, which is a commensal in the large intestine of the pig. It cannot penetrate the mucosa without primary inflammatory damage, but when does so causes enlargement of a lesion due to the production of hyaluronidase. It is a ciliated protozoan parasite, which is usually transmitted faeco-orally in pigs.

Balantidium is a zoonotic parasite causing explosive and bloody diarrhoea in humans.

Clinical Signs

Usually none as it is a commensal in the large colon.

When opportunistic infection occurs, dysentry and general malaise and depression will be the main clinical signs.

Diagnosis

On post mortem, the colon will appear ulcerated and inflammed.

Demonstration of cysts and trophozoites on the mucosal surface will provide a definitive diagnosis.

Presence of cysts in the faeces does not lead to a diagnosis as this protozoa is a commensal organism of the pig and is therefore often found in faecal samples.

Treatment and Control

Nitrimidazole drugs cure the infection, but as they are category 4 drugs they cannot be used in food producing animals, meaning palliative treatment such as rehydration solutions are the only feasible option in all farmed pigs.

References

Fox, M and Jacobs, D. (2007) Parasitology Study Guide Part 1: Ectoparasites Royal Veterinary College

Straw, B.E. and Taylor, D.J. (2006) Disease of Swine Wiley-Blackwell

Taylor, D.J. (2006) Pig Diseases (Eighth edition) St Edmunsdbury Press ltd