My dog has sensitve skin.  The chemical filled flea/tick collars and the pills, made him scratch so much he sometimes would bleed.  I had to try something. 
 
My cousin, who is an entomologist, told me to check out Diatomaceous Earth. So I looked into it.  It is a natural way to kill fleas, ticks and other internal parasites, that would normally need medicine/pesticides to kill.  I purchased food grade Diatomaceous Earth, which I can feed to Ruffie to keep his internal organs healthy and parasite free, as well as put on him to keep fleas and ticks from using him as a moving condo.  I put the Diatomaceous Earth in the Bugs Away spray! PLUS!  It works beautifully!

I have been using this blend on Ruffie all spring/summer and he has had zero ticks and zero fleas.  
He also doesn't scratch all the time, which is nice. 

He's chemical free now and smells better too, (which doesn't make him happy, but it makes me happy!)