I went with a friend recently up to a pack of feral dogs who live at Cabo Girao on the island of Madeira.This is one of the few dogs which allow humans to get close enough for inspection and treatment. Removal of ticks is one of the weekly tasks.
The larger ticks are the females which can engorge with blood and get much larger. It is important when removing ticks to remove the front mouthparts along with the rest of the tick. The smaller ones are the males whose task in life is just to fertilise the females.