I have 2 Dogs at home and here are some things I do.

Feed 1 ts of powder yeast daily 
Feed 1 cloves garlic per day added to their food.
Add 1 tablespoon of salt to the bath water to kill fleas.

TO DETER FLEAS: 
Make a tea of lemon peels and water, by steeping overnight, then spongedog

AND/OR
Rub dog over with tansy, fennel, basil or mint, pennyroyal or other strong smelling herb. Grow any of these herbs, or wormwood, pyrethrum, rue and marigolds around kennel areas.
AND/OR
Bathe dog in with a few drops of eucalyptus in bath water

HOME MADE FLEA COLLAR FOR DOGS:
2 tablespoons peppermint essential oil
1/2 cup rosemary essential oil
1/4 cup citronella essential oil
2 tablespoons eucalyptus essential oil

Soak a natural fibre rope in the above mixture and let dry. Tie around pet's neck. DO NOT use on cats.

Herbal anti-flea spray :
Put 2 cups packed fresh Peppermint, Pennyroyal, or Rosemary into a litre of boiling water and allow it to steep for 30 minutes. Strain the liquid and dilute it with the 4 cups of warm water. Put into spray bottle and spray the animal's coat  allowing it to air dry. Use at the first sign of flea activity. This should be used three to four days  till fleas clear.

**Vacuum carpets regularly, vacuum and sanitize pet areas, & also vacuum areas like under beds