I think Ellie May might know a lot about this subject so hopefully she'll be along and offer comments. I've always used interceptor and when it was discontinued I started to use heartgard. I personally feel heartgard is very safe.
__________________ Washable Doggie Pee Pads (Save 10% Enter YTSAVE10 at checkout) Cathy, Teddy, Winston and Baby Clyde...RIP angels Barney and Daisy |