Yes and no. The spot-on is formulated with almond oil. Almond oil has 3 purposes: a- protect the skin from the active ingredient b- help diffuse the active ingredient throughout the skin c- protect the active ingredient from rainfall. So if your pet is outside when it is raining, the active ingredient will not disappear as it will be protected by the almond oil, which is water resistant. But if you wash your dog with a shampoo, the shampoo will “dissolve” the oil and a spot needs to be re-applied after you wash your dog.