My American Stafforshire Terrier mix, who I've had for over a year and a half now, and just turned two in early July, seems to have many symptoms of PICA. She doesn't have much of an appetite for her regular dry food (we've tried switching it up, she refuses to eat any brand/flavor, she eats wet food without protest), however she does seem to have an appetite for coins (seeing as within two weeks of my family having her she needed an endoscopy to remove 3 from her stomach), rocks, sticks, the metal part of her leash, and even dust and bugs inside the house. We have been told by many vets and pet store owners/employees that she may have an iron deficiency, which makes sense, however the supplement we tried for a month seemed not to work. We have also been told it may be because she is bored. We are hesitant to give her any toys including the ones advertised as unbreakable because she will chew on them long enough to break them and then continue to eat the filling or pieces. She gets plenty of exercise and is outside for the majority of most days. When she's inside, my family and I keep her in a small area of our house gated off from the rest, because she will eat anything on the floor. She also has habits of growling at people when they try to stop her from doing any of these actions, although she's never hurt anyone. Anything you may suggest is greatly appreciated. Thanks for reading this.