Adams has released a great high-value coupon for $3 off a Flea and Tick product (excluding collars). This should make for some pretty nice deals since their products are pretty inexpensive. Here is one Walmart scenario to get you started:
Adams Flea and Tick Shampoo $3.98 *regional price
-$3 Adams Coupon
Use the zip code 92324 and sort by pet if you have trouble finding this coupon.
(Thanks Discount Queens!)