The NHS website states that there are 2000 - 3000 cases of Lyme disease (in humans) each year here in UK and the number is rising. The long-term effects include fibromyalgia and chronic fatigue syndrome, even arthritis, but research is needed into which vectors are involved as there are many types of tick. There's a Lyme Disease Society (UK) which says that intravenous amoxycillin is considered effective for people with chronic Lyme. There's also a Daily Mail Online article about the post-vaccination effects on dogs, but this is regarding combined vaccines and possible overload on the immune system (rather similar to the controversy over the MMR vaccine in children) Deer numbers here are going through the roof, and a national cull is being considered. Apart from their ticks, the deer chew up bark and damage trees, destroy habitats and cause road accidents. Poor things, they're so delightful to see, but not apparently a Good Thing!