The questions people search for most, answered in full — plus extinct breeds, the rise of the doodle, and the wild relatives sitting at the edge of the family tree.
Records
Biggest breed
Mastiff
Mastiff (~76cm, up to 110kg)
Labrador Retriever (~57cm, ~32kg)
Adult human (~170cm)
Shoulder height to scale beside a Labrador and the same adult human — mass is what sets the Mastiff apart.
Measured by sheer mass rather than height, the English Mastiff is the heaviest breed in the world, with adult males regularly exceeding 70kg and record individuals well past 100kg.
Shoulder height to scale beside a Labrador and the same adult human — on hind legs a Wolfhound meets your eye.
The Irish Wolfhound is the tallest breed recognised by either club, with males standing a minimum of 79cm at the shoulder and often considerably more. Great Danes hold most individual height records.
Genetic studies place a small group of breeds — including the Basenji, Saluki and Afghan Hound — closest to ancestral dog populations, though "oldest breed" claims should always be treated cautiously.
Insurance claim data repeatedly puts Labradors at the top for accidental injury and foreign-body ingestion, which is less about clumsiness than about eating things they should not.
Faded silhouettes mark breeds that no longer exist.
Dozens of breeds have disappeared entirely, including the Turnspit Dog, the English White Terrier, the Talbot Hound and the St John's water dog that gave rise to the modern retrievers.
How long it takes to establish a new breed
1Consistent type over generations
2Written breed standard
3Active breed club
4Registry recognition
Decades, not years — typically three or more generations before recognition.
Recognition typically requires several generations of consistent type, a written standard, an active breed club and a large enough population of registered dogs — in practice decades rather than years.
The rise of doodles
1990s — noveltyToday — mainstream
Novelty to mainstream in roughly thirty years.
Poodle crosses moved from novelty to mainstream in roughly thirty years. The appeal is a lower-shedding coat and a friendly reputation; the catch is that crossbreeding guarantees neither, and coat care is often underestimated.
Six living relatives sharing the dog's branch of the family tree.
Domestic dogs sit within a much wider family that includes grey wolves, coyotes, jackals, African wild dogs, foxes and the dingo — some capable of interbreeding with dogs, others only distantly related.