Within- and between-Examiner Agreement for Two Thyroid Palpation Techniques in Healthy and Hyperthyroid Cats

Paepe D., Smets P., Van Hoek I., et al.

Journal of Feline Medicine & Surgery, 2008. 10(6): p.558-565.


Thyroid gland palpation is an important aid for diagnosing feline hyperthyroidism in an early stage to prevent development of deleterious complications. Our objectives were to assess within- and between-examiner agreement for two thyroid gland palpation techniques in cats and to correlate palpation results with ultrasonographic thyroid measurements. Nine client-owned hyperthyroid (12.6†±†2.4 years) and 10 healthy control cats (7.4†±†5.4 years) entered this prospective study. Both thyroid glands of all cats were palpated twice by three blindfolded clinicians with the classic palpation technique [technique 1 (T1)] and the technique described by Norsworthy GD, Adams VJ, McElhaney MR, Milios JA [(2002a) Relationship between semi-quantitative thyroid palpation and total thyroxine concentration in cats with and without hyperthyroidism. Journal of Feline Medicine and Surgery 4, 139-143] [technique 2 (T2)]. A semi-quantitative score from 1 to 6 was assigned to the gland size. After clipping of the ventral cervical region, another palpation session followed by ultrasonography of the thyroid glands was performed. Average weighted [kappa]-values within- and between-examiners were 0.864 and 0.644 for T1 and 0.732 and 0.532 for T2. T1 did lead to significantly smaller within- (P†=†0.007) and between-examiner (P†=†0.048) differences than T2. Significant correlation coefficients (P†<†0.001) between the palpation scores of both techniques and ultrasonographic thyroid lobe length (T1: 0.43; T2: 0.38) were observed. No significant difference before and after clipping was found (T1: P†=†0.503; T2: P†=†0.607). The first time that all cats were palpated by either technique, significant score differences between control and hyperthyroid cats were observed both for T1 (P†=†0.002) and T2 (P†=†0.003). Both feline thyroid gland palpation techniques have good within- and between-examiner agreements. Based on this study, the classic palpation technique is preferred.