Saliva as alternative diagnostic biofluid for non-invasive health and disease appraisal in domestic and wild animals: A review of salivary biomarkers and sialochemistry.

Abstract

Saliva is a readily available biofluid that contains a wide variety of biomarkers similar to blood. In this context, sialochemistry offers a new non-invasive and animal-friendly diagnostic technique, which may ultimately replace traditional invasive blood-based testing. Saliva presents distinct advantages over blood as it can be collected by non-specialist personnel with minimal stress to animals and sialochemistry is a cost-effective and easily replicable technique. The present article highlights the emerging paradigm of salivary biomarkers and diagnostic feasibility of sialochemistry in veterinary medicine. The current state of knowledge of salivary biomarkers of infectious and non-infectious diseases with diagnostic value in domestic and wild/zoo animals is summarised. Evidence illustrated that salivary biomarkers are linked to animal diseases, immune status, stress and systemic inflammation in the body. The presence of economically important pathogens and antibodies in saliva makes it a profoundly useful specimen for early screening and redressal of disease outbreak. Diagnostically, zoo veterinarians find salivary biomarkers handy for health surveillance purposes. Saliva is anticipated to serve as an alternative diagnostic specimen to blood. Future research is sought to validate novel salivary proteins as disease biomarkers and eventually, formulate saliva-based point-of-care assays.