1. A method for detecting sepsis in canine subjects comprising the steps of: obtaining a blood serum sample from a canine subject; obtaining the concentration of c-reactive protein in said blood serum sample and assigning a first discrete value to said c-reactive protein concentration, wherein said first discrete value is assigned a value: zero (0) when the concentration of c-reactive protein is less than 40 mg/l, one (1) when the concentration of c-reactive protein is between 40.1 mg/l and 56.4 mg/l, or two (2) when the concentration of c-reactive protein is greater than 56.5 mg/l; obtaining the concentration of C-type natriuretic peptide in said blood serum sample and assigning a second discrete value to said C-type natriuretic peptide concentration, wherein said second discrete value is assigned the value: zero (0) when said concentration of C-type natriuretic peptide is less than 3.8 picomole/l, one (1) when the concentration of C-type natriuretic peptide is between 3.9 picomole/l and 13.3 picomole/l, two (2) when the concentration of C-type natriuretic peptide is between 13.4 picomole/l and 20 picomole/l, or three (3) when the concentration of C-type natriuretic peptide is greater than 20.1 picomole/l; computing an index value by adding: the first discrete value multiplied by a c-reactive protein weighing coefficient of value 1.43, and the second discrete value multiplied by a C-type natriuretic peptide weighing coefficient of value 1.17, and determining that the canine subject is a carrier of sepsis if said index value is above a criterion value of 2.86.