Fig. 1
From: Prevalence and risk factors for hyperthyroidism in Irish cats from the greater Dublin area
Initial total thyroxine (T4) concentrations in cats classified as euthyroid, equivocal and hyperthyroid. The reference interval for total T4 (15–60 nmol/L) is indicated by the shaded area. Values above 193.0 and below 6.4 nmol/L are all assigned as those values, respectively