The Sealyham Terrier is a small but sturdy terrier breed originally developed in Wales, United Kingdom. It is believed this dog is a mix of Corgi, Dandie Dinmont, West Highland White, Wirehaired Fox Terriers, Bull Terrier, and some hounds. The breed is named after the Sealy Ham Haverfordwest estate of Captain John Edwards on the Seal River in southwestern Wales. Edwards is credited with its creation, and the breed's history dates back to the mid-to-late 19th century. Captain Edwards desired to create a dog capable of hunting badgers, otters, and foxes, and thus began a breeding program that resulted in the Sealyham Terrier. Some of the breeds he likely incorporated include the Bull Terrier, the Fox Terrier, the West Highland White Terrier, and the Dandie Dinmont Terrier, among others. In 1911, the Sealyham Terrier was officially recognized by the Kennel Club in the UK, and by the American Kennel Club (AKC) in 1911. Although quite popular in the mid-20th century, Sealyham Terriers have since become one of the rarest dog breeds.
Sealyham Terriers can suffer from allergies, though they are rarely serious. There are several genetic eye diseases that parents should be tested for prior to breeding, such as primary lens luxation. They may also be affected by chondrodystrophy (with or without chondrodysplasia) and coagulation factor VII deficiency. The breed can suffer from deafness, so hearing exams are recommended. Genetic testing can assist veterinarians with diagnosis and proactive care, as well as help breeders identify affected and carrier dogs.
Despite their initial purpose as tenacious hunters, Sealyham Terriers are known for their friendly and outgoing nature. They are intelligent, courageous, and generally have a calm demeanor. However, their terrier lineage means they can be somewhat independent and occasionally stubborn. Early socialization and positive reinforcement-based training are recommended. Sealyhams are often good with children and can do well with other dogs if they are properly socialized. Their hunting instincts may lead them to chase smaller animals, so care should be taken around small pets.
Sealyham Terriers have been owned by a variety of famous personalities, including Humphrey Bogart, Cary Grant, and Agatha Christie.
In the past, the breed was sometimes referred to as the "Cowboy's Companion" due to their popularity in America.
They have a keen sense of smell and were once used in South Africa to sniff out a beetle that was destroying crops.