An infected tick must be attached for 24 to 48 hours to transmit Lyme disease (and at least 12 to 24 hours to transmit anaplasmosis, another serious tick-borne disease). Lyme disease is unfortunately a fairly common canine disease. Symptoms can include fever, reduced energy, and lameness.
D-day(n.) (Mil.) the day designated for the beginning of a planned attack by a military force; in communications the day is often otherwise unspecified for security reasons; as, the day before D-day the troops will move into position.
A: As odd as it sounds, the D in D-Day is merely meant to designate the day of the invasion. It is used in combat operations where the day needs to be secret (as in the most famous D-Day, the invasion of Normandy on June 6, 1944) or when the day has not yet been determined.