TICKS
Ectoparasites are organisms that live on the outside of an animal. Ticks are fairly common ectoparasites of dogs (and cats).
Ticks attach to your dog by inserting their mouthparts into your dog’s skin. Many ticks also produce a sticky, gluelike substance that helps them to remain attached. After attaching to your dog, ticks begin feeding on your dog’s blood. The places where ticks attach can become red and irritated.