Please list non-toxic oral medications, or list the active ingredients we should be looking for. Please address the toxicity of lufenuron, nitenpyram, or spinosad. Spinosad kills bees and causes vomiting in dogs (probably not a good sign), and Nitenpyram (Capstar) is a neonicotinoid. Wouldn’t the neonicotinoid in Nitenpyram also be delievered into the environment, and wouldn’t it also be toxic for your pet? The active ingredient in Lufenuron is a growth inhibitor in fleas, so it would not be toxic for adult fleas, necessitating using an insecticide.