Hi all,
I am having significant issues with brown spots on my lawn (buffalo grass) - picture attached. 
I have a dog and it has been suggested it could be due to her weeing on the grass however they seem like rather large spots for this.
Two questions:
1) Any thoughts on what the underlying cause is?
2) I plan to buy some buffalo turf to extend the grass, is it worth patching these spots at the same time or could I encourage the existing grass to spread over?
Thanks in advance!