Similar to human subjects with ocular surface disease such as dry eye or vernal keratoconjunctivitis (Leonardi et al., 2009; Enríquez-de-Salamanca et al., 2010), an increase in VEGF A, pro-inflammatory cytokines (IL-8, IL-12), and anti-inflammatory cytokine (IL-10) was detected in tears of dogs with experimentally induced conjunctivitis. Here, IL10 is linked to dry eye syndrome.