Fig. 2

Representation of tear ferning patterns according to the Masmali tear ferning (TF) grading scale [9] in the dogs studied. (a) Grade 0: Crystallization with no spaces between the primary branches; (b) Grade 1: Slight reduction in the density of the primary branches and the appearance of small spaces between them (arrow); (c) Grade 2: The primary and secondary branches are reduced and appear thicker, with greater spacing between them (arrow); and (d) Grade 3: The spaces between the primary branches are clearly visible and wide, with the presence of crystals (arrow); e and f) Grade 4: There is no presence of well-defined branches, with large spacing between the crystals (arrow) or no crystal formation