In a recent investigation conducted by Murillo et al. [50], acute-phase proteins [serum amyloid A (SAA), haptoglobin (Hp), albumin, and paraoxonase 1 (PON1)] were measured in domestic cats (Felis catus), postulating that they can aid in the diagnosis of leptospirosis because their levels can be used as an early marker for the disease and they can be used to assess inflammation, monitor the evolution of the infection, help in detecting subclinical infection, and differentiate acute from chronic diseases. The gene discussed is HP; the disease is leptospirosis.