Peggy,
I buy food grade DE (very important to buy food grade if you don't buy one labeled for pets - this is an absolute must :shock: :shock: ). I buy a 50lb bag for about $15.00 + shipping - and it lasts me for 2+ years (that's using it for dogs, cats, geese, and inside rugs).
If you search "diatomaceous earth" + "pet food" on Google, you'll find all sorts of information on DE, how it's used, why it works, etc. I think it would make sense to do that so you feel comfortable with the theory and uses. Here is the dosing schedule I use :
Daily recommended food grade diatomaceous earth feeding rates:
Kittens - 1/2 teaspoon
Cats - 1 teaspoon
Puppies - 1/2 to 1 tsp.
Dogs under 35 lbs. - 1 teaspoon
Dogs over 35 lbs. - 1 tablespoon
Dogs over 100 lbs. - 2 tablespoons
Cattle, Dairy Cows, & Hogs - 2% of dry feed ration
Chickens/Gamebirds - 5% in feed
Goats, Sheep, Alpacas, & Llamas - 2% in grain
Horses - 1/2 to 1 cup in daily ration
Zoo animals - 2% in daily feed
*Humans - 1 heaping tablespoon daily
PS - I'm not sure why....but I always find myself looking like the "mad baker" once I'm done mixing DE!