The present invention encompasses methods and kits employing pattern recognition receptor expression as a measure of systemic health in a subject afflicted with an oral health condition. In particular, the present invention is directed to methods involving measurement of the expression levels of one or more Pattern Recognition Receptors including but not limited to Toll-Like Receptors, myeloid differentiation primary response gene 88 (MyD88), and Nucleotide Binding oligomerization domain containing protein 1 (NOD1), in a companion animal, e.g., a dog or a cat, afflicted with an oral health condition. The described methods enable evaluation of the systemic health of the animal afflicted with an oral health condition by measuring expression levels of the indicated genes as compared to suitable controls.