Being a dog lover, I can understand your concern. You probably want to make sure you have a good fence around the yard. Some homes in Trilogy do not have fencing, but some do. They allow only rod iron fencing between homes (except for a few lots that were block fencing). Trilogy is beautiful and has wonderful amenities. I can set up a search for only homes with fencing around them in Trilogy and the other age restricted communities. Some of the other communities are Westbrook Village, Corta Bella and the Sun Cities. Sun City West is a bit newer than Sun City and many of the homes are fenced.
Once you move here, be sure not to leave your dog outside along at night. Coyotes roam the area (especial near Trilogy and some parts of Sun City) and they can jump right over a 6-foot block wall fence.
If you could give me a call or email me, I can send you a link to the listings that would best fit your needs (size, price, fence, age of home etc). My number is 623-760-8390 or feel free to email me at email@example.com http://www.azhouseagent.com
(if you'd like to search homes, visit my website).
Have a wonderful day. I hope to hear from you soon.