The use of messenger dogs during World War I by both sides is well-attested to, but they were also used by Frederick the Great during the Seven Years’ War. Wikipedia says he is reportedly the first person to refer to the dog as “man’s best friend”
The use of dogs for military purposes in various roles stretches back to ancient times, but I’m interested in their use as messenger dogs. Whereas the use of pigeons apparently dates back to “the ancient Egyptians and Persians over 3,000 years ago”, the earliest reference I’ve found for dogs is the Seven Years’ War (so 1756 -63).
Is there any evidence of dogs being used to carry messages before this time?
What is the earliest recorded incident of a dog being used to carry a message?
I’m primarily interested in military situations, but would also welcome evidence of non-military uses which pre-date the Seven Years’ War.