Dogs have a special place in sailors' hearts. There has been a strong belief that dogs bring a ship good luck. Their fidelity and good will toward humans was thought to bring a crew together, making men more like the dog if you will. Seamen were rarely overly affectionate to the ship's dog, however. Like every other manjack aboard, Dog was expected to pull his weight and then some.
It is unknown when dogs began long voyages with man but it can most probably be traced to the first outright pirates, the Phoenicians. Many people imagine that small dogs were the norm aboard cramped and crowded vessels but the opposite is true. A small dog was fine for ratting, but that was generally left to the cats. So what was it that a dog did aboard ship besides eat, sleep and soil the deck? Save your life, mate. And then some.
In the early days of sail - from the Medieval period until the 18th century - mutts were brought aboard. They were expected to move heavy loads, sometimes even being strapped by a harness to the capstan in order assist in pulling up the anchor. These guys were the burly, musclebound mastiffs that are sometimes labelled "pitbulls" today. They could handle a lot of hard work and their short muzzles allowed them to breath more easily while carrying an object in the water. More times than not, that object was some sailor who had tipped overboard, couldn't swim and was fit to drown had it not been for trusty Dog.
Humans can't stop tinkering and the 18th and 19th centuries saw a boom in genetically engineered dogs. These breeds, like their forebears, were born to do specific tasks and the Newfoundland/Landseer (shown above) was particularly popular aboard ship. Bred to pull heavy fishing nets, boats and waterlogged people they were welcomed not just as loyal crew members but as hard workers and lifesavers. On his sail back from Elba to his Hundred Days in France, Napoleon fell overboard and was saved by a Newfie.
Other famous dogs dotted the landscape of the Golden Age of Sail. British Admiral Collingwood had a dog, most likely a beagle, named Bounce whom he refused to sail without. Admiral Lord Nelson had a strapping dog named Nileus, no doubt after his master's glorious victory at the Nile (humble sort, that Horatio) and an interesting - and telling - family story goes along with him if you will permit me to digress.
Nelson carried on an open liaison with Emma, Lady Hamilton, until his death at Trafalgar. Their affair produced a set of twin girls but Emma felt she could only handle one child. She abandon one girl to a foundling hospital. The other she named Horatia and raised without informing Nelson of her twin. Horatia spent her young life in privileged surroundings and despite her mother being married to Lord Hamilton, Horatia knew who her father was. She believed to her dying day that the Hamiltons had adopted her. Even though she already had a pony, the girl begged incessantly for a dog. Her father, who wrote her frequently, sent her a gold locket with a dog's picture inside and told her it must replace the dog he "could never have promised" her "as we have no Dogs on board ship..." Lying, like fame, seemed to come quite easily to Horatia's parents.
Pirates and privateers were very similar to their naval cousins and dogs were a common sight aboard them. The canine crewmen did the same jobs they did in the navies - just like the men. Unlike cats, though, they rarely came in multiples. One dog was surely more than enough in the close confines of a ship, especially since he or she would spend a lot of time wet. Even dog lovers are not very tolerant of that smell.
A famous Newfoundland named Bosun accompanied Lewis and Clarke on their expedition west and George Gordon Lord Byron, the poet who authored The Corsair, had a landseer named Boatswain.
Like their feline compatriots, dogs got the official boot when the navies on both sides of the Atlantic branded them "unhygienic". Also like their kitty friends, however, dogs are still carried aboard ship in other parts of the world and probably will be until there are no more seas to sail. Let us not forget, though, that a cat might keep the rats down, but he won't fetch your Emperor - or you - out of the drink.