Selected comparative aspects and unexpected findings in acute phase proteins and other biomarkers of animal health and welfare.

Recent years have seen advances in clinical biochemistry of domestic animals which have highlighted comparative differences between species and have also identified fundamental aspects of the biochemical mechanisms in physiological conditions and disease, that have implications across species, including human, health and welfare. From investigations in diverse species using biochemical, immunological, proteomic and metabolomic approaches a series of species particularities and unexpected results for some biomarkers have been made. These observations cover (1) the differences between species in the acute phase protein (APP) response to infection and inflammation; (2) the non-hepatic synthesis and release in the mammary gland, adipose tissue and intestine of APP (3) the response of haptoglobin (HP) as a biomarker for stress; (4) observations in non-mammalian species related to hemopexin and HP; (5) the response of bile acids in milk to mastitis; (6) barley serine protease inhibitors being identified in bovine faeces; (7) alkaline phosphatase being present in bovine nasal secretion; (8) saliva findings with analytes such as adenine deaminase showing different activity between saliva and serum and a detergent-like surfactant protein, latherin being found in equine saliva and sweat and (9) serum enzymes and selective muscle protein reaction of Atlantic salmon as an example of the differences in biochemistry between terrestrial and aquatic species.