Nexgard, the brand new beef-flavoured chew, will give your dog tick and flea protection, for up to 30 days. The main ingredient, afoxolaner, helps protect your pet from adult fleas by killing them before they have a chance to lay eggs so reducing the chance of a flea infestation which can cause flea dermatitis. Nexgard kills ticks, decreasing any deadly tick-borne diseases.