β-adrenergic receptors are G-protein coupled receptors that increase intracellular cAMP on agonist binding (Johnson, 2001). Canine models are often used to study the functional pharmacology of β-adrenoceptor ligands (Badino et al, 2005), however, there is little published information directly comparing the pharmacology between canine and human species. We have compared the potency and selectivity of standard β2 adrenoceptor agonists at canine and human β1 and 2 adrenoceptors recombinantly expressed in Chinese Hamster Ovary cells. Assays were carried out in a 96 well format with 2×10⁴ cells per well. Cells were incubated at 37^oC in phosphate buffered saline, PH 7.4, containing 0.5mM IBMX (3-isobutyl-1-methylxanthine) for 30-60 minutes. Concentration response curves to salmeterol (Salm), formoterol (Form), salbutamol (Salb) and isoprenaline (ISO) were carried out using an incubation time of 30 minutes. Intracellular cAMP was detected using the DiscoverX HitHunter cAMP II Assay (GE Healthcare). Potency (represented as geometric mean EC₅₀) is the concentration required to achieve half maximal stimulation for that agonist. Efficacy (represented as arithmetic mean Emax) is the maximum stimulation achieved by 10μM ISO. Relative Potency (represented as geometric mean RP) is the potency relative to ISO for each n-number. Data is a mean of 4-10 with 95% confidence intervals in brackets. Statistical analysis was conducted using ANOVA in Excel Labstats and compared the mean RP of each agonist between species – see table 1. The relative potency, selectivity and efficacy of Salm, Form, Salb and ISO were not found to be significantly different between human and canine β-adrenoceptors (p>0.05). This suggests that agonist pharmacology of canine β1 and 2 adrenoceptors is identical to that of human.