Methods of detecting markers for inflammatory conditions and food sensitivity in companion animals

A method for detecting combinations of at least the following endogenous IgA markers in serum obtained from a canine patient:

• a. endogenous IgA to gliadin;
• b. endogenous IgA to a bacterial outer membrane protein C (OmpC), and
• c. endogenous IgA to canine calprotectin;
• said method comprising the following steps, to be carried out simultaneously or sequentially in any order:
• a1) contacting said serum with a gliadin antigen bound to a substrate, wherein the gliadin antigen comprises one or more antigenic sequences from gliadin;
• and
• a2) detecting the binding of endogenous IgA to the gliadin antigen using a labeled antibody which binds canine IgA;
• b1) contacting said serum with an OmpC antigen bound to a substrate, wherein the OmpC antigen comprises one or more antigenic sequences from bacterial OmpC;
• and
• b2) detecting the binding of endogenous IgA to the OmpC antigen using a labeled antibody which binds canine IgA;
• c1) contacting said serum with a calprotectin antigen bound to a substrate, wherein the calprotectin antigen comprises one or more antigenic sequences from canine calprotectin;
• and
• c2) detecting the binding of endogenous IgA to the calprotectin antigen using a labeled antibody which binds canine IgA.