Then you can use Garlic.
Garlic action against ticks and fleas
A tick looks for his host, e.g. dog or cat, by its scent. This is probably also the case for fleas. When you supplement your pet’s food with garlic, they spread another scent by the substance allicin. The tick and flea will not recognize the host, or they have an aversion against it. Garlic does not kill the parasite, but expels them. And in a natural way.
Garlic is also an ingredient of HOKAMIX, the experience of several dog owners is that HOKAMIX is also effective against parasites.