How to De-Flea Your Dog or Cat: This special comb is designed to remove fleas and their eggs (nits) from your pet's fur. Its teeth are spaced close together in order to scrape off the tiny pests. Use it on dogs or cats of any size. Before you begin, your pet should have completely dry fur. Mix very warm water and a squirt of dish soap in a bowl or bucket. This will be the destination for the fleas and nits you remove while combing. If possible, work outside. Begin near your pet's face and move towards the back and tail. Comb firmly in the direction of the fur growth to remove all fleas. After combing a section, transfer any captured fleas and nits into the sudsy water, either by swiping them from the comb or swishing the comb's teeth in the water. Don't forget to comb your pet's belly - that's where the sneaky fleas will move while you're combing the back and tail.