Measurement of serum 7a-hydroxy-4-cholesten-3-one as a marker of bile acid malabsorption in dogs with chronic diarrhoea: a pilot study

Kent, A. C. C.; Cross, G.; Taylor, D. R.; Sherwood, R. A.; Watson, P. J.

In the small group of dogs examined in this study, there was no overall difference in the serum C4 concentration between dogs with and without chronic diarrhoea. In people, the reference range for serum C4 is 14.3-60.7 nmol/l. However, 12 (60 per cent) of the control dogs in this study had a concentration outside that reference range, suggesting that the reference range in dogs may be higher. The ROC analysis suggests that a cut-off value of 187.2 nmol/l would give a high specificity for the suspected diagnosis of bile acid malabsorption. The sensitivity in this study was low; largely due to the small sample size. This is likely to be improved if only dogs with a poor response to conventional therapy were tested, in which the suspicion of bile acid malabsorption might be higher. The high specificity and high PPV suggest that this test would be most useful as a screening test to increase clinical suspicion of bile acid This test is relatively inexpensive to perform (approximately £30 per sample), but is currently only available through a small number of specialist human hospital labs. However, it is being run more commonly in people and so it is likely to become more widely available in the future. The reliability of the test is also excellent, with a low coefficient of variation both intra-assay and interassay (see online supplementary appendix 1).