The American Water Spaniel and its look a like cousin, the Irish Water Spaniel, share many commonalities. They were both bred to hunt on land and water, have shaggy coats that help protect them from cooler temperatures and are well renowned with hunting enthusiasts around the world. They are both intelligent, lively breeds that thrive on human companionship. The American Water Spaniel and Irish Water Spaniel are also rare breeds and locating one can mean spending months on a waiting list. At the same time, they also have a number of differences that have made many hunters choose one over the other for decades.

As their names might tell, the Irish Water Spaniel's country of origin is Ireland and the American Water Spaniel was developed in the United States. However, the Irish Water Spaniel is a much older breed; in fact, it is believed to be one of the oldest. The American Water Spaniel did not make its appearance until the mid to late 1800's. At sixty five pounds, the Irish Water Spaniel is the largest of the Spaniel breeds while the American only weighs in at approximately forty five pounds. Though they are commonly mistaken for each other, the Irish Water Spaniel has a tuft of frizzy hair on the top of its head while the American has a smooth rounded skull.

The American Water Spaniel was developed to be a smaller dog for the special purpose of retrieving from boats. When hunting on lakes and ponds, the larger Irish Water Spaniel retrieves from the shoreline. The American Spaniel's tail is curved with a covering of feathered hair while the Irish Spaniel's tail is covered in smooth fine hairs and often referred to as ratlike. Neither breed requires docking of the tail as they use them as rudders when running and swimming. While both have a double coat that protects them from extremely cold water, only the Irish Water Spaniel can be referred to as a hypoallergenic breed.

Already established, the Irish Water Spaniel was fine tuned in the 1830's so that it could be officially recognized by reputable kennel clubs. In approximately 1850, the breed achieved its goal and was accepted by the Westminster Kennel Club. About the time the Irish Water Spaniel gained recognition in the WKC, the American Water Spaniel was in the earliest stages of its development. Not until 1940 was the American Water Spaniel officially recognized by the American Kennel Club. The Irish Water Spaniel however had been making its own appearances in the AKC since 1877. Through the years, the American Water Spaniel and the Irish Water Spaniel have proven to offer great benefits both in the field and in the show ring.