Here are some interesting articles on the subject.....It will give you some info to digest before you make your decision.....
http://mypetcarnivore.com/Heartworm.pdf Heartworm Medication: Is Year Round Protection Necessary? | Truth4Dogs - Terrierman's Daily Dose -
I realize this is a very individual decision we all have to make......Personally I don't use them, I'm just not comfortable giving my yorkies a insecticide every month of their lives, I worry about the toxic load over time....For me there are other alternatives that I'm more comfortable with..... I could take them in every 6-8 months for a HW test or I minimize their risk by not being outside during peak times for mosquitoes and I use a spray with essential oils, like neem or cedar oils, like this....
Natural Flea Control and Tick Remedy. Official TripleSure Site. Flea and Tick
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