Ticks - American Dog Tick
Dog Ticks Engorged with Blood:
Engorged Deer Tick (LEFT) and Engorged Dog Tick (RIGHT) — note the difference in overall body size
See also the Maine Medical Center’s Ticks in Maine page for Lyme disease information, tips and photos. Also, the Maine Center for Disease Control & Prevention has a page entitled Ticks and Lyme Disease. Deer ticks can be infected with (and transmit) Lyme Disease, but Dog ticks do not carry or transmit it.
You can find a lot of additional images of ticks online at BugGuide.net