All 3 of my dogs get the immunization for Lyme's because ALWAYS in the woods and Minnie has SEVERE reactions to any topic chemical based flea/tick repellent (I use all natural collars on all 3 for almost 2 years now and only 1 tick got by!). Unfortunately, the vet told us the other day that Lyme's is the least of your worries now a days with tick born illnesses, there are more severe viruses they carry that cannot be treated or prevented in any way. Just a word to the wise for all pet owners, the next vet visit, have the heart worm/tick borne pathogens panel ran, it's a sensitive enough test to detect the other types of viruses ticks carry. And for those who don;t believe heart worm is in the area, not true as many people are moving north (especially since Katrina and all those displaced animals) and bringing their pets who are not treated. I really don't like to allow my dogs to play with other dogs that I don't know how well they are cared for, especially after it cost me over $150 to treat all 3 for hookworm that Minnie got from playing with the puppy that used to live next door that they never took care of or vetted.