IL4 and pyometritis: Therefore, the present study aimed to (i) assess potential retinal abnormalities and quantitatively evaluate retinal vascular calibers in bitches diagnosed with pyometra-induced SIRS; (ii) compare retinal vascular parameters between affected patients and healthy controls using smartphone-based retinal imaging; and (iii) investigate correlations between retinal vascular measurements and systemic hematological, biochemical, VEGF, and IL-4 profiles.