Antibiotic Responsive Diarrhoea

Signalment

• Common in young German Shepherd Dogs

Description

Antibiotic responsive diarrhoea (ARD) used to be termed as small intestinal bacterial overgrowth (SIBO). It is a sign of an underlying disease rather than a diagnosis. The aetiology and pathogenesis of this disease is unknown.

The effect of ARD are:

• interferance with fluid and nutritional absorption due to dysfunction of the enzymes located at the microvillous.
• disturbance in mucosal permeability.
• deconjugation of bile acids.
• hydroxylation of fatty acids.

ARD can be claasified as idiopathic or secondary. In cases of idiopathic ARD, the only consistent finding is response and remission on antimicrobial therapy. In contrast, there is usually an underlying intestinal disease in cases of secondary ARD. This includes diseases causing:

• decreased gastric acid production
• increased small intestinal substrate
• partial obstructive disorders
• anatomical disorders
• motility disorders

Few studies have documented the scale of increase in bacterial numbers or whether the growth is responsible for the clinical signs.

References

• Ettinger, S.J. and Feldman, E. C. (2000) Textbook of Veterinary Internal Medicine Diseases of the Dog and Cat Volume 2 (Fifth Edition) W.B. Saunders Company.
• Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA
• Nelson, R.W. and Couto, C.G. (2009) Small Animal Internal Medicine (Fourth Edition) Mosby Elsevier.