Why are domestic cats all the same size but dog size varies a lot?

Domestic dogs vary in size much more that cats because they have been selectively breed for a much longer time. With a head start of thousands of years the relentless selective breeding of dogs has forced their sizes to new upper and lower limits. Today, the lightest dog might be 1.5% the weight of the largest, whereas for cats the figure is around 13% (miniature cat compared to F1 Savannah).

Small and large cats and dogs

Photos: public domain

Domestic cats do vary in size quite considerably amongst the breeds. F1 Savannah cats are relatively large at more than twice the size of standard moggies and eight times the size of miniature cats. Random bred cats also vary in size, the smallest being perhaps around half to one-third the size of the largest.

The reason for this variation in cat breed size is selective breeding over many years. For example, miniature cat breeders select small cats each time and the size shrinks while F1 Savannah cats are wild cat hybrids, the father being a large wild cat, the serval.

The extended length of dog selective breeding is because the cat has been domesticated for a maximum of around 10,000 years while dogs have been domesticated for possibly three times that; 30,000 years (or longer). The dog was the first species to be domesticated.

It is believed that the selective breeding of dogs has taken place for as long as the cat has been domesticated. A study showed that 9,500 years ago dogs were selectively breed in northeastern Siberia as either hunting or sled dogs. This is the time when the first North African wildcats were informally domesticated.

There must have been informal dog breed standards even then. Purebred cat breed standards only exist in the cat fancy which started in the late 19th century.

Cat breeding officially started with the cat fancy in England. That being the case dog breeding has a 9,500 year start on cat breeding resulting in a much more diverse range of sizes and shapes among the domestic dog population.

The study proposed that the evolution of the domestic dog commenced some 30-40,000 years ago starting with natural selection, then the artificial selection of dogs that were the easiest to tame, and then selection of dogs for specific tasks supporting human activities.

Dogs were domesticated much earlier than cats because they were useful as working animals. The selective breeding of them tailored breeds to specific human activities. The domestic cat is seen primarily as a companion which today applies to dogs but originally the primary role was as a working animal.

Associated pages (this is a selection. Please search for more):

Persian Cat Breeding

The last 35+ years.. Through Persian cat breeding the appearance of the cat that you know (probably the extreme Persian look) has been altered over a period of time (over the last 100 years and a perhaps more substantially over … please continue reading

Cat Breeds: It’s a Mashup

In analysing the differences between the cat breeds using DNA testing, I am compelled to come to the conclusion that it’s all a mashup. Nothing is what it seems. Everything is blurred and grey without clean distinctions. The breeds, themselves, … please continue reading

Supernormal Stimulus and Cats

Cat breeders are trapping themselves….by breeding emotionally desirable cat features, consciously and subconsciously. It’s part of the need for emotional onanism in humans. Cats that trigger their own parenting instincts get more nurturing, and are then often used to breed … please continue reading

FB comments (see below)

Leave a Reply

Your email address will not be published.

Please try and upload photos that are small in size of max 500px width and 50 KB size. Large images typical of most default settings on digital cameras may fail to upload. Thanks. Comment rules: (1) respect others (2) threatening, harassing, bullying, insulting and being rude to others is forbidden (3) advocating cat cruelty is forbidden (4) trolls (I know who they are) must use real name and upload a photo of themselves. Enforcement: (1) inappropriate comments are deleted before publication and (2) commenters who demonstrate a desire to flout the rules are banned. Failure to comply with (4) results in non-publication. Lastly, please avoid adding links because spam software regards comments with links as spam and holds them in the spam folder. I delete the spam folder contents daily.