The invention provides methods for diagnosing cognitive impairment in a canine. The methods comprise measuring a first body temperature of the canine from about 0.5 to about 3 hours after waking measuring a second body temperature of the canine from about 8 to about 13 hours after measuring the first body temperature and determining that the canine is cognitively impaired if the first body temperature is less than 0.6° C. lower than the second body temperature.
