Fig. 2From: Effect of tear collection on lacrimal total protein content in dogs and cats: a comparison between Schirmer strips and ophthalmic spongesSpearman’s rank correlation testing for TPC and VA of tear samples collecting with PVA sponges in 10 healthy dogs. A moderate negative correlation was found (Spearman’s rho = − 0.48, P = 0.033)Back to article page