Not sure exactly when the conversion happened, but I kind of preferred kobolds as canine creatures rather than reptillian.
In original D&D, they were described as goblins, but weaker, and there were no pictures of them in any of the supplements what-so-ever.
In 1st edition, all of the pictures of them showed them with scales, horns, and rat-like tails... Here is the description form the 1st Edition Monster Manual:
The hide of kobolds runs from very dark rusty brown to a rusty black. They have no hair. Their eyes are reddish and their small horns are tan to white. They favor red or orange garb, Kobolds live up to 135 years.
So given that, I have never understood why people recall them as ever being the least bit "dog-like"... Except maybe, maybe, their description in 2nd edition, but even that clearly states they have scales, horns, and rat-like tails...
Barely clearing 3 feet in height, kobolds have scaly hides that range from dark, rusty brown to a rusty black. They smell of damp dogs and stagnant water. Their eyes glow like a bright red spark and they have two small horns ranging from tan to white. Because of the kobolds' fondness for wearing raggedy garb of red and orange, their non-prehensile rat-like tails, and their language (which sounds like small dogs yapping), these fell creatures are often not taken seriously. This is often a fatal mistake, for what they lack in size and strength they make up in ferocity and tenacity.
(again, emphasis mine)
Here is a picture showing their "evolution" (from 1st though 3rd edition): Kobold Evolution