When walking through wooded areas it is important to keep your dog on good quality monthly tick prevention. Ticks wait patiently on the ends of vegetation and when an unsuspecting animal (or person) walks by the tick attaches itself. Baby ticks, nymphs, are very small, less than 2mm, and difficult to see. They are more likely to spread disease than other larger stages of ticks. You won't even be able to detect the bite because they sneakily use a local numbing agent.
There are several diseases that can be spread by ticks such as Lyme disease, Ehrlichia, Rocky Mountain Spotted Fever, and more. Lyme disease is the fastest spreading tick borne disease. It can infect dogs but illness is usually worse in people.
Make sure to do a thorough tick check on your pet and yourself after walking through a wooded area. Prevention is key.