i have a 16 mth staff and she hasnt been eating properly for 2 weeks she seems healthy and active but doesnt want her usuall food  i think shes losing weight now what should i do ?

Is she due to come in season, my bitch is terrible for eating around this time.

Firstly if she is under the weather get het checked by the vet.
What do you do when she refuses her food? Have you offered her alternatives?
Archer 

she could be coming into season .could you not try her with something like chicken .my staffy is a terribly picky eater.she wont eat the same food for more than 2 days at a time .that includes chicken. lamb ect.

Id advise a visit to the vet too- is she eating anything or just picking? She could be feeling ill or have a sore tooth?