Goic JB, Reineke EL, Drobatz KJ. J Am Vet Med Assoc. 2014 May 15; 244 (10): 1170-5.
One important assessment of a physical examination in veterinary medicine is the accurate assessment of body temperature. The standard measurement in animals has been rectal temperature, yet the use of axillary temperature has been described and used as an alternate method. Often such an alternate method is desirable due to animal temperament, presence of rectal lesions, or the requirement for frequent temperature monitoring. The evaluation of axillary temperatures has been little studied in companion animals, and the method has not been evaluated in cats.
The authors wanted to compare axillary with rectal temperature in dogs and cats (median axillary temperature in cats was 38.4°C [101.2°F}, median rectal temperature was 38.6°C [101.5°F]) and evaluate multiple clinical variables to identify factors that may alter the accuracy of axillary temperature measurement. Axillary temperature is measured by placing the thermometer midway between the most cranial and caudal aspects of the axilla, against the thorax, and as dorsal as possible until the thermometer beeps. The prospective study included 31 cats.
Results from the study showed there was a large variation in axillary temperature, compared to rectal temperatures. Axillary temperature could not be considered as a reliable surrogate for rectal temperature in cats (or dogs). The results also indicated that an animal with a high axillary temperature was most likely truly hyperthermic, but an axillary body temperature within the reference range does not rule out the possibility of hyperthermia. On the other side, animals with axillary temperatures in the normothermic range are unlikely to be truly hypothermic, but an axillary temperature in the hypothermic range does not rule out normothermia. Cats with a greater weight and body condition score (BCS) had a greater difference between rectal and axillary temperatures than cats with a lower BCS that was noted in the findings. (VLT)
Lamb V, McBrearty AR. Comparison of rectal, tympanic membrane and axillary temperature measurement methods in dogs. Vet Rec 2013 Nov 13; 173 (21): 524.