I am looking for the story regarding yellow dog which is related to conditions before the second coming.
The story of the yellow dog is really nothing more than one of those Mormon myths. The best that I can do is show you what it says on lds.org
Myth #3: But won’t there be immense destructions in Missouri preceding the Second Coming, so extensive that “not a yellow dog will be left to wag his tail”? It’s true that destruction throughout the earth is one of the conditions prior to the Second Coming. Yet as far as destruction in Missouri is concerned there are two schools of thought among members.
One believes that it has already taken place. Elder B. H. Roberts published a reported prophecy of Joseph Smith to Alexander Doniphan, his lawyer in Missouri. According to Doniphan’s brother-in-law, writing the incident over seventy years after it occurred, Joseph Smith warned Doniphan that “‘God’s wrath hangs over Jackson County … and you will live to see the day when it will be visited by fire and sword. The fields and farms and houses will be destroyed, and only the chimneys will be left to mark the desolation.’
“General Doniphan said to me,” his brother-in-law continued, “that the devastation of Jackson county [during the Civil War] forcibly reminded him of this remarkable prediction.” Elder Roberts cites additional descriptions of Jackson County’s role during the Civil War as fulfillment of this prophecy. (See Comprehensive History of the Church, 1:538–59; italics added.)
The other school of thought on the so-called “yellow dog” prophecy is that some members feel it is yet to occur. However, a study of the supposed source of the prophecy is helpful. It seems to have originated in a conversation between Heber C. Kimball and Amanda H. Wilcox in Salt Lake City in May 1868. She reports him as saying, “The western boundries of the State of Missouri will be swept so clean of its inhabitants that, as President Young tells us, when we return to that place, ‘There will not be left so much as a yellow dog to wag his tail.’” (Prophetic Sayings of Heber C. Kimball to Sister Amanda H. Wilcox, n.p., n.d., p. 6.)
There seem to be a number of questions about the authenticity of this account since Heber C. Kimball was apparently in Provo, not Salt Lake, during the month of May. Also, no other record exists of Brigham Young making a similar statement. However, it is sufficiently similar to Joseph Smith’s statements, except for the “yellow dog,” that someone may have remembered the original substance but in the retelling allowed embellishment to creep in.