[Lynn J]

I just want to comment, that although many of these products are effective at killing fleas and/or ticks, they often do not repel them. So your dog may pick up parasites while out and about and get bitten by them. Hopefully, for ticks especially, parasites are killed before they are able to transfer pathogens such as Lyme Disease. Tick collars may offer some repellant activity, but in my case, when I was using the Preventatic collar, the ticks were dropping off in my house, some still alive, I was not happy about that. Everyone has to balance their dogs tolerance to chemicals, parasite levels where you live, dogs allergic reactions to flea/tick bites, other pets/children in the home, etc.