I have been browsing through some books that I haven't looked at recently and I found this so I thought I would share with you - I don't know whether it works or not but I intend to try it as they are natural methods of control and I always welcome these. However cats and dogs like humans also have sensitivies so be careful with useage. Was taken from Fragrant Herbal by Lesley Bremness.
For Dogs and Cats
Pennyroyal (don't use if your animal is pregnant)
These ssential oils repel fleas. Tuck herbs or sachets into pet baskets.
An indoor flea collar: can be made by filling a tube of cotton fabric with Pennyroyal leaves (your pet may reject the strong smell) or Lavender flowers and 2 drops Rose Geranium oil
An outdoor flea collar: mix 1 teaspoon cider vinegard with 3 drops Lavender and 1 drop Rose Geranium or Cedarwoood Essential oil. Place mixture in a polythene bag with a shop bought soft collar, shake seal and let infuse for 24 hours before fitting the collar.
To treat a flea infestation
To a bowl of warm water add essential oils of Lavender, Cedarwood or Pine - 4 drops for large dogs, 2 drops fro small dogs or cats. Dip a cloth or comb in the water then groom the animal gently both with and against the animals fur. Wipe over with a clean wet cloth. Avoid larger quantities of oil because pets will ingest this when grooming. Adding 1 to 2 garlic capsules (depending on the pets size) to the daily diet will make the blood unpalatable to fleas.