could it be that the yeller dogs came from the old time leapords ?
No. Everybody who's anybody knows yeller dogs were created in the throne room of Valhalla as a gift to mankind to rid the world of pigs before the apocalypse. Throughout human history there was never a group of people found worthy to be entrusted with the holy dogs from on high, until Man discovered Texas. It was the best of the human race who were smart enough to make this rugged land their home and Oden decided the time of the yeller dog was at hand.
Someone has to much time on their hands
Besides everyone knows the crows were Odin's favorite dogs