Some individuals will have similar reactions to many different spot - on products with different active ingredients, suggesting that their sensitivities may be to some of the inactive ingredients. (vin.com)
All three of these flea collars use different active ingredients so if your dog is having a bad reaction to one, you might want to try switching to another brand. (centralparkpaws.net)
Because different products contain different active ingredients, they all work a little differently. (blog.smartpakequine.com)