The breathing rate per second is of limited value without some reference to tidal volume and previous trends because normal rates can vary so widely. A change in breathing rate is, however, often a sensitive indicator to some physiologic changes (10). In this study, the anaesthetic regimen had no significant influence on respiratory rate, but Kul et al.(16) showed significant changes at 15, 30 and 60 min after xylazineketamine administration in dogs.