I was thinking about liming. Is this a good idea now or is there something
better to do for it?


Now, is fine for lime. As a rule of thumb for clay soils, use 50 lbs p/1000 sq
ft.

Also, I was reading a post about seeing yellow in the grass. Mine is in a
long line and the rest all around is healthy and green.


A dog's urine tends to have a burn mark in the center with a much darker green
band around the burn. (This is from the excess nitrogen. Too much nitrogen causes
the burn mark, and the nitrogen becomes diluted on the edges and cause a green-up
in the grass). Grubs tend to create circular marks, not streaks.

Here is a link to the local Agricultural Division that tests soils. It is a free
service. I would use them. The price is right. http://agronomy.agr.state.nc.us/