Cocker Spaniels are dogs belonging to two breeds of the spaniel dog type: the American Cocker Spaniel and the English Cocker Spaniel, both of which are commonly called simply Cocker Spaniel in their countries of origin.
In the early 20th century, Cocker Spaniels also included small hunting Spaniels. Cocker Spaniels were originally bred as hunting dogs in the United Kingdom, with the term cocker deriving from their use to hunt the Eurasian Woodcock. When the breed was brought to the United States, it was bred to a different standard, which enabled it to specialize in hunting the American Woodcock. Further physical changes were bred into the cocker in the United States during the early part of the 20th century.
While their origins are unknown, "spaynels" are mentioned in 14th century writings. It is commonly assumed that they originated in Spain, and Edward of Norwich, 2nd Duke of York in his 15th century work The Master of Game introduces them as "Another kind of hound there is that be called hounds for the hawk and spaniels, for their kind cometh from Spain, notwithstanding that there are many in other countries."
The Master of Game was mostly an English translation of an earlier 14th century Old French work by Gaston III of Foix-Béarn entitled Livre de Chasse. In 1801, Sydenham Edwards wrote in Cynographia Britannica that the "Land Spaniel" is divided into two types: the hawking, springing/springer and the cocking/cocker spaniel.The term cocker came from the dog's use in hunting Woodcocks.
During the 19th century a "cocker spaniel" was a type of small Field Spaniel; at the time, this term referred to a number of different spaniel hunting breeds, including the Norfolk Spaniel, Sussex Spaniel, and Clumber Spaniel. While there were no Sussex Cockers or Clumber Cockers, there were dogs known as Welsh Cockers and Devonshire Cockers. The Welsh or Devonshire were considered cockers until 1903 when they were recognized by The Kennel Club as the Welsh Springer Spaniel.
The major differences between the English and American varieties is that the American is smaller with a shorter back, a domed head and a shorter muzzle, while the English variety is taller with a narrower head and chest. Cocker spaniels coats come in a variety of colors including black, liver, red and golden in solids. There are also black and tan, and sometimes liver and tan, as well as a variety of color mixtures of those solid colors including roans, roan and tans, tricolors and those solid colors with additional white markings"
Rare colors can appear unexpectedly in certain lines, for instance while an all-white cocker is usually bred by selective breeding of very light golden strains, they can still appear very uncommonly to parents who are dark colored. A noted occurrence of this happened in 1943, when a grandson of My Own Brucie, Best in Show at the Westminster Kennel Club Dog Show in 1940 and 1941, was born all-white."
n a survey conducted by the Kennel Club (UK), the American Cocker Spaniels had a median age of death of ten years and four months, while the English Cocker Spaniel had a median age of eleven years and two months.
According to the survey, the most common cause of death for both breeds was cancer, while old age was the second most common cause. The two modern breeds are susceptible to several health problems. Issues common to the two breeds include ear infections, and a variety of eye problems.
Leading health issues to which Boxers are prone include cancers, heart conditions such as Aortic Stenosis and Arrhythmogenic Right Ventricular Cardiomyopathy (the so-called "Boxer Cardiomyopathy"), hypothyroidism, hip dysplasia, and degenerative myelopathy and epilepsy; other conditions that may be seen are gastric dilatation and torsion (bloat), intestinal problems, and allergies (although these may be more related to diet than breed).
Entropion, a malformation of the eyelid requiring surgical correction, is occasionally seen, and some lines have a tendency toward spondylosis deformans, a fusing of the spine, or dystocia.
Other conditions that are less common but occur more often in Boxers than other breeds are hystiocytic ulcerative colitis (sometimes called Boxer colitis), an invasive E. coli infection, and indolent corneal ulcers, often called Boxer eye ulcers.