Another photo

And another photo.

PLUS - I should have added that I am in the UK (Norfolk)

Unfortunately there's really not much you can do if you plan on keeping the grass. I have 3 small dogs that stay in our fenced in backyard only when we are not home. These dogs have paths worn all through the lawn and the largest dog is only 18lbs. Unless you have a very large area for them dogs are just going to be really hard on a lawn.

There have been a lot of folks suggest using mulch instead of grass as it will hold up to constant traffic.

Give the dogs sustained structured exercise 2x a day and keep them in the house except to be let out to eliminate in a specific location, which you keep scooped. It's a win/win for both the dogs and the lawn.

Thanks for the replies :)

The larger dog always gets two walks a day. The smaller is only 9 months, so we are not over exercising her. She either gets an hour walk once a day, or - if it is practical - two shorter walks.

The trouble is, they have to be kept on lead at the moment and for the foreseeable future. So they never get to play or really run about. The only place they can do that is the garden....

I have learned the value of serious exercise over the past year. Our Catahoula puppy tore up the lawn last year. This we we found a group of off-leash walkers real near our house. Now the dog gets about an hour off leash in the woods every day. On Saturday he gets an hour of extremely intense exercise with about six young dogs and six more older ones. That seems to wipe him out for most of Sunday, too. We are at the end of the second season with him and our back yard has fully recovered.