They can't consider the size of bedrooms, the kitchen layout, the view from the front window, or the five dogs barking all day long next door.

If it's in decent shape, I would do a couple upgrades to appeal to potential homeowners (adding window shutters or bark mulch outside, an accent wall, nicer light fixture in living room, etc. etc.)

Other times, you will get tenant calls for things like “the dog across the street is barking again,” a problem that should be the tenant’s to handle.

When you deal in good faith you need to consider the financial size of a transaction, it needs to be reasonable, and what is customarily given, otherwise  you're just barking trying to finagle a contract that you can't carry through with yourself as you agreed to do.

Stop barking at her.

All of a sudden they are wanting to “re-discuss” the lease because the neighbor’s dog barks a lot and they play music in the middle of the night ie 2:30am until 5:30am quite often - week days, weekends, it doesn’t matter.

The neighbor has a dog in chain outside the property that bark at any visitor.

With so little info, we're all barking at the wind.  

I just want to know if her dog barks a lot.

.😳 One property I was trying to sell the neighbor would turn up his music and walk around with his shirt off at all the wrong times when I was trying to show a potential buyer.Another Property, the next-door neighbor had two Doberman pincher dogs that would come rushing up to the fence, barking and growling ferociously when we had a potential buyer.