Respiratory rate of clinically healthy cats measured in veterinary consultation rooms

Abstract

Respiratory rate is commonly recorded during physical examinations. However, reference intervals are only available for resting and sleeping respiratory rates in cats at home. This observational study aimed to establish reference intervals for the respiratory rate in clinically healthy adult cats at primary-care veterinary clinics. Respiratory rates were recorded from 131 cats, in 6 primary-care veterinary clinics, by observation under four circumstances: by the investigator in the consultation room prior to and during a physical examination, by the owner at home when the cat was resting or sleeping, and by the investigator when watching a video-film of the cat recorded by the owner at home. The respiratory rate of the 88 clinically healthy adult (≥12 months) cats in the consultation room ranged 28–176 breaths/min (median 64) with a calculated reference interval of 32–135 breaths/min. Based on video-recordings, the resting (n = 32) and sleeping (n = 38) respiratory rates of the same cats were determined: median 27 (range 16–60) breaths/min and median 20 (range 9–28) breaths/min, respectively, which were lower than the respiratory rates recorded in the consultation room (both P <0.0001). We conclude that the reference intervals proposed for cats in textbooks reflect the resting respiratory rate at home. These values are inappropriate for using in the veterinary consultation room, because based on such reference intervals, many cats would erroneously be categorized as having tachypnea. Since the resting and sleeping respiratory rates at home show less variation, owners should be encouraged to film their pets before they visit their veterinarian.