Your dog only has 3 legs.

If the paint is acrylic or latex paint i can be removed with isopropyl alcohol if not real thick. Saturate the area and place some plastic wrap on it so the alcohol doesn't evaporate quickly. Use an old toothbrush to scrub the area and draw up the softened paint with a paper towel. repeat until gone.

there is such a thing called string/rope length counter. Just google it.