* Flea medication can be absorbed through the skin. Worms can live in your cat's intestines and sometimes in their skin. Deworming first ensures that any worms living in the skin are killed before the flea medication is applied, preventing potential absorption of the medication by the worms.
* Flea medication can kill fleas but not their eggs. Worms can be a contributing factor to flea infestations, as they weaken the cat's immune system. Deworming helps to improve the cat's overall health, making them less susceptible to fleas.
However, it's best to consult with your veterinarian. They can advise you on the best course of action for your individual cat, taking into account their age, health, and any specific medications they may be on.
Remember, it's important to follow the instructions provided by the manufacturer for both deworming and flea medications.