Flyball is not limited to the size of the breed, as smaller dogs such as Patterdale Terriers, Jack Russell Terriers, Whippets and even miniature poodles, often compete with great success in mixed-breed teams (teams consisting of dogs of various sizes and breeds).
Whippets with a homozygous deletion were apparently less able runners although their overall appearance was significantly more muscular.
The closely coupled driving wheels accentuated the appearance of the high-pitched boiler, earning these engines the nickname of “Whippet” because of a perceived resemblance to the breed of racing dog.
There is also a painting by Pompeo Batoni entitled Portrait of Charles Compton, 7th Earl of Northampton which features a similar Whippet-like dog.
There is evidence that other running and working dog breeds such as Borzoi, Whippet, Saluki and Irish Wolfhound were added into the mix, but the majority of the heritage comes from greyhound and deerhound lines.