Normal self-grooming or licking is fine after application once the solution has dried. While the ingredients are plant-powered and safe when used as directed, they were not designed or tested for consumption. Overconsumption may lead to an upset stomach.
Discourage pets from licking off the Spot On by offering a toy or treat to keep them occupied after the initial application, which will also help build a positive association. Keep your pet distracted while the solution is being absorbed, which will help it remain on the pet and be most effective.
Temporary salivation may occur in cats if they manage to lick areas that have had Spot On recently applied. This is a reflex when they taste a bitter substance and will not last.