The relationship between Japanese dogs and Japanese has lasted for a very long time.
From ancient time to present, as a hunting dog, a guard dog and a member of family, the relationship has not changed. They have been living with humans, interacting with human life very closely.
I will introduce some examples from relic of the past.
I can't say for certain, but I guess some dogs that appear in this examples are the near kind of Shiba Inu, which is ancient kind, by judging from their appearance.
④ 信貴山縁起(Japanese：Shigisan enki, Heian period, around 12 A.C.)
This picture scroll is about a story of 命蓮(Myouren).
命蓮 is a Buddhist priest of 朝護孫子寺(Tyogosonshi Temple) at Mt. Shigi in Nara Prefecture.
In the last volume of this picture scroll, a dog barking at Myoren's sister and a dog chased by a peasant are drawn. I can see both dogs have the characteristics of Japanese dog.
Image from " https://letuce.at.webry.info/201605/article_1.html "
⑤ 一遍上人絵伝(Japanese：Ippensyonin eden, Kamakura period, end of the 13 A.C.)
一遍上人(Ippensyonin) is a Buddhist priest who is said to have saved hundreds of thousands of people with 踊念仏(Odori nenbutsu, to invoke the Buddha with dance).
The author of this picture scroll is 法眼円伊(Hogan enni) who uses a unique painting technique of 大和絵(Yamato-e, classical Japan decorative paintings) to draw nature and street.
In the second volume of this picture scroll, it shows a red haired dog which plays with people near 南大門(Nandaimon：the south gate) of 四天王寺(Shitenno Temple), a dog barking to a ox cart, a white haired dog looking back, and a sprinting white haired dog.
Image from " http://rikimaru1951.blog.fc2.com/blog-entry-235.html "
⑥ 彦根屏風(Japanese：Hikone byobu, Edo period, around 17 A.C.)
"Byobu" is a Japanese painting on a folding screen.
This picture shows the situation in the Edo period and a woman walking with her dog next to a handsome Samurai is drawn. However, this dog doesn’t seem to be a Japanese dog, it is presumed that this dog came from a foreign country.