Lyme disease (Borrelia Burgdorferi) is the most common disease spread by ticks in the Western United States, and causes lameness and generalized pain. This disease is easily prevented by having your dog vaccinated. Ticks are carried by deer, squirrels and other wild animals. They also love to hang out under oak leaves, and can live for months in the environment waiting for your dog to come along to snack on. If your dog goes with you on walks and hikes, or lives on a ranch, you should consider this vaccine.