Far be it from me to tell you to put pesticides on your dog or cat. But I’ve never heard of a single nontoxic preparation that was effective at keeping ticks off all dogs. For some dogs, only the potent pesticides seem to keep ticks away. There are, however, some nontoxic products – both commercially produced and homemade formulas – that work to repel ticks well enough to consider using them as part of a comprehensive Lyme disease prevention program.
In 1994, botanist Arthur O. Tucker reviewed the scientific literature on herbs that repel mosquitoes, flies, fleas, ticks, and similar pests. He found that opopanax myrrh (Commiphora erythaea), the myrrh of ancient Egypt, has been shown to repel adults of the African brown ear, deer, black-footed, lone star, and American dog tick. Because opopanax myrrh is not widely sold, Tucker speculated that the more readily available common myrrh (C. myrrha) might have similar properties, but herbalists who experiment with live ticks report that of the herbs said to repel them, including myrrh, rosemary, and California laurel, only rose geranium (Pelargonium graveolens), palmarosa (Cymbagopogon martini motia), which has a similar fragrance, and opopanax myrrh truly repel deer and dog ticks.
CJ Puotinen, author of The Encyclopedia of Natural Pet Care and Natural Remedies for Dogs and Cats, describes an all-purpose repellent that will make pets (and people!) less attractive to ticks and other biting insects:
She suggests blending 20 drops of rose geranium, palmarosa, or opopanax myrrh essential oil (or any combination) with three drops citronella essential oil (which repels mosquitoes) and enough vodka, neem tincture, or bay rum aftershave to dissolve the essential oils. Start with two tablespoons alcohol or tincture and add more as needed to make the oils dissolve completely. Do not use isopropyl (rubbing) alcohol. When there is no longer a thin film of oil on the surface, add one cup water, herbal tea, or aloe vera juice or gel. Put in a spray bottle and shake before using. Apply frequently, avoiding the eyes.