Table 1.

Failure rate of 600 pulse oximeter measurements with a transmittance pulse oximeter probe placed on the tongue and a reflectance pulse oximeter probe placed on the tail or tibia in 100 anesthetized dogs.

Total			Transmittance probe tongue		Reflectance probe tail		Reflectance probe tibia		P-value
	n	Failure rate	n	Failure rate	n	Failure rate	n	Failure rate	Tongue vs. tail	Tongue vs. tibia	Tail vs. tibia
BUT	600	14.3%	300	3.7%	150	12.0%	150	38.0%	0.0007	<0.0001	<0.0001
DEX	600	27.5%	300	12.5%	150	28.0%	150	57.3%	<0.0001	<0.0001	<0.0001

n, number of measurements; BUT, premedication butorphanol 0.2 mg/kg IV; DEX, premedication dexmedetomidine 5 μg/kg + butorphanol 0.2 mg/kg IV.

Measurement failure was defined as: pulse rate or SpO₂ not displayed, signal intensity ≤2 of 10 signal intensity bars, or pulse rate differed from ECG heart rate by >10 beats per minute. Bold values mean significant differences.