The only true way to prevent this is to train the dog to urinate somewhere else. The chemicals in animal urine (dog, fox, badger) will change the appearance of a lawn. If the event is witnessed then the area concerned can be washed down with plenty of plain water; diluting the chemicals to prevent any major damage. A poorly fed lawn will show urination spots as lush, dark green, quick growing patches. In a well fed lawn the animal urine will cause brown patches where the turf looks dead and perhaps a dark green surrounding edge. If you have lush, dark green patches these need to be systematically mown down to the height of the rest of the lawn; and the lawn needs to be given a high quality feed. Brown patches need to be raked to remove dead fibres, then overseeded, using a 50/50 soil/seed mix.
