Reliability, repeatability, and age associations of the dogSIT (dog Smell Interaction Test) battery in untrained companion dogs (Canis lupus familiaris).

Current olfactory tests for untrained dogs have limitations due to use of a single odorant, requirement for ambulation, and potential for vision interference. We hypothesized that our new dogSIT odorant test battery measures would be reliable, repeatable, and age-associated in untrained companion dogs. Gently restrained dogs were presented with 18 odorants (in 9 pairs, one pair was subsequently excluded from analysis); odorants were contained in identical stainless-steel tea-balls. Odorants were presented for 30s in a habituation-dishabituation paradigm (4 consecutive presentations of the same odorant followed by a different odorant). Interaction times were measured post-hoc using masked video analysis; outcome measures represented novel interactions, habituation, and dishabituation. We assessed inter-rater reliability and test-retest repeatability (n = 25); and analyzed age, sex, and bodyweight covariates (n = 65). Outcome measures had significant inter-rater and test-retest repeatability. There was heterogeneity in odorant preference between dogs. Age, and to a lesser extent bodyweight and sex, were associated with outcome measures relating to novel odorant interaction and dishabituation. Our dogSIT battery is reliable, repeatable, and identified reduced odorant interaction behaviors in older dogs. Our findings have implications for research on food motivation and scent discrimination in aging dogs.