Clinical biochemistry in dog and cat malabsorption syndrome.

Various diseases, e.g. exocrine pancreas insufficiency (PEI), digestive mucosal diseases and small intestine bacterial overgrowth (SIBO), can cause a maldigestion-malabsorption syndrome (MSS). These can usually not be differentiated by clinical examination nor by routine chemistry, except for protein-losing enteropathy. The measurement of TLI (Trypsinlike immunoreactivity) allows a definitive diagnosis of PEI and now prevails on all qualitative and semi-quantitative indirect tests of pancreas function. Folates and vitamin B12 can be measured simultaneously for the diagnosis of SIBO or of mucosal disease. However they are not as efficient as TLI and results are at best evocative of a specific disorder. Other diagnostic procedures have been developed, namely breath hydrogen and absorption/permeability tests. They have not yet replaced histopathologic examination, which remains necessary for the diagnosis of mucosal diseases, the main cause of primary MSS.