A pet-supply catalogue arrived in the mail the other day. I set it aside and have just now gone through it.
I usually get catalogues from Pet Edge (www.petedge.com) and Jeffers Pet (www.jefferspet.com).
The current Jeffers Pet catalogue features several products which allege that they can help with pet stains on lawns. Three products are supplements to feed dogs (the supplements supposedly "stop yellow spots on your beautiful lawn" or "prevent lawn yellowing caused by animal waste" or even "neutralize urine, keeping grass green"). Two other products are applied to the lawn rather than fed to the dog(s):
1) Lawn Spot Away(tm): "Colors burned spots caused by pet urine with a natural green coloring. Natural enzymes break down the urine and begin to promote regrowth of the damaged grass." Sold in a 32-oz. spray container.
2) Yard Odor Killer(tm): "Safely and effectively eliminates stool and urine odors. Spray on any outdoor surface. Safe for use on grass, plants, shrubs, patios, patio furniture, kennels, fences or any other surface where odors arise due to pets. Ready-to-use 32 oz. has a spray action adapter nozzle for easy attachmen to any standard garden hose." 16-oz. refills also available.
Maybe Jeffers Pet's products, or someone else's, can help. I haven't used them but thought you'd be interested in knowing what's on the market.
Cynthia H. (who has dogs but no lawn...they just use the area under the Coast Redwood)
USDA Zone 9, Sunset Zone 17