Table 3 Periodontitis scoring criteria used for Yorkshire terriers

Stage 2 (PD2) Early periodontitis (< 25% attachment loss)

≥2 mm (≥2.5 mm on canine teeth)

> 0 mm

Stage 1; feel an indentation between the roots and the probe may advance 1 mm.

Stage 3 (PD3) Moderate periodontitis (25–50% attachment loss)

≥4 mm (≥5 mm on canine teeth)

≥2 mm (≥3 mm on canine teeth)

Stage 2; obvious indentation between the roots and probe advances 50%.

Stage 4 (PD4) Advanced periodontitis (> 50% attachment loss)

≥8 mm (≥10 mm on canine teeth)

≥4 mm (≥6 mm on canine teeth)

Stage 3; obvious space between the roots and probe advances 100%.