I caught Jada eating her poop last week-end.

I caught her again this evening. I have had her almost a year and this has just started. She is a little over 3yrs old. Why would this start all of a sudden.

I did change kibble about 2 months ago to the Blue Buffalo small breed. Could that do it? I am at a loss unless that is it. She doesn't do it all the time either,maybe once or twice a week. Any ideas or thoughts would be greatly appreciated.