I missed this earlier. Pet Armor Plus is the same active ingredient as Frontline Plus I believe. Get rid of that junk, man. K9 Advantix II, or Bravecto, or Nexgard.
I've been using Frontline Plus for 10 years now and it still works as good as it ever did. I only apply it every 2 and 1/2 months. You've got to make sure you buy it from a reputable source.
