Brown patches where your dog toilets are frustrating, but protecting the lawn should not involve compromising your dog’s food or water. Start with the garden setup and toilet routine.
Why patches happen
Concentrated nitrogen-containing compounds and salts in urine can damage a small patch of grass. The amount deposited in one place matters. Both male and female dogs can cause patches.
A brown spot does not tell you that your dog has a dietary imbalance or that their urine needs acidifying.
Rinse the spot and review the lawn
Where practical and permitted by local water restrictions, water a fresh urine spot to dilute it. Established dead grass may need repair. Ask a local lawn specialist about suitable grass and care for your conditions.
Do not assume that adding gypsum, baking soda, detergent or a soil enhancer will neutralise the problem. Keep your dog away from lawn chemicals and follow product directions.
Teach a designated toilet spot
Choose an accessible, comfortable area. Take your dog there at useful times and reward immediately after they finish. Be patient when changing an established habit and continue offering regular opportunities.
Our wet-weather toilet-training guide explains how to keep the routine practical.
Leave diet changes to the vet
Keep fresh drinking water available. Do not alter protein levels, add salt or give urine-changing supplements simply to protect the lawn. Ask your vet before adding a product to food or water.
New thirst, increased urination, discomfort or a change in toileting deserves veterinary advice. Straining without producing urine needs urgent care, rather than being treated as a lawn problem.
Source
Colorado State University Extension: dog urine damage, common myths and practical management.