Agreed, gefmayhem. Allow your dog to **** anywhere without clearing it up, and you're liable for a hefty fine; what makes cats so special? My considerate neighbours have trained their cats to use litter trays, and they don't cause me any problems.
Although I haven't tried them, you can buy ultrasonic devices which are supposed to deter cats, foxes and other unwanted visitors. Unfortunately, they also affect dogs which can hear the same frequencies, so they won't be suitable for everyone. Not too pricey, and the battery operated ones are easy to install; some of my customers reported good results, so they may be worth a go.