Do I need to returf - dog urine

In most cases, small areas like that will fill in by themselves. It also depends on the type of grass. If you have some bluegrass in the lawn, it will spread via rhizomes, which is one reason it's in many grass seed mixes. Clump type grass will also grow larger to fill in gaps.

Nothing to worry about. They usually occur when there is lots of moisture and some organic material, like old wood, decaying near the surface. Just make sure you're not overwatering the lawn. Established lawns should get about 1" of water a week, which may be one application or split into two, about 4 days apart, depending on the soil.

if its a rye type grass for example, this will self seed. You just need to cut it high enough to all seed development. It is late winter here but I notice the rye grass already starting to seed where I have cut it high. I have 2 mutts who piss on the lawn, the grass takes care of itself.

rob

Only if it's annual in variety and I consider it a weed.

Where in the world do you guys live where a dog pissing on the lawn is destroying vegitation? Do you feed your dogs something really strange? Are you collecting their urine in 5 gallon containers, distilling it down to a super concentrated mixture, then pouring it on the lawn in a single spot? I've cared for dogs all my adult life and have never seen urine do anything to the lawn. Dog piles yes, but only if I let it sit there for a couple of days in the sun.

The fastest way I found is just buy one roll of sod, remove the burnt grass and take pieces from the sod roll and patch it....instant grass... no wait and it works...

It's also a helluva lot more expensive than just over-watering the spots to leech out the extra nitrogen.