Patent ID: 8435187

Claim:
A method of distinguishing whether an animal is experiencing a viral infection, the method comprising: monitoring on at least three days breath taken from the animal over time to measure a relative amount of a first isotope to a second isotope therein over time, wherein the first and second isotopes are selected from the group consisting of a pair of 13 C and 12 C, a pair of 15 N and 14 N, a pair of 17 O and 16 O, and a pair of sulphur isotopes; and based on a comparison of (i) changes to the relative amount of the first isotope to the second isotope over time, with (ii) a known periodic cyclic pattern of changes of the relative amount of the first isotope to the second isotope when there is viral infection, the known periodic cyclic pattern of changes evidencing periods of increased cell rupture that are time separated by periods of less cell rupture, determining whether viral infection is present; wherein either the absence of such a known periodic cyclic pattern of changes indicates a lack of a viral infection, or the presence of such a known periodic cyclic pattern of changes indicates the presence of a viral infection.