A flea comb has closely spaced teeth that pull out adult fleas and flea dirt, making it a monitoring and physical-removal tool. An environment spray treats floors, cracks and fabrics to reduce larvae and eggs in the surroundings.

Combs suit routine checks, especially when itching or black specks first appear and you need to confirm fleas are present. Sprays suit environmental treatment once an infestation is confirmed, and work best alongside vacuuming and washing of fabrics.

The trade-off is coverage: a comb reaches only some adults on the cat and cannot address eggs and larvae in the home, while a spray avoids contact with the cat but its ingredients and dilution must follow the label, with the cat out of the room during use.

The approach is monitoring plus environmental control, with on-cat flea treatment chosen by a veterinarian for weight and age, never a dog product. Repeated scratching, hair loss or broken skin needs a vet visit; home tools do not replace proper treatment.