looking for advice on my dog. She’s 11 yr old shepherd collie mix. And allergic to... everything! As far as skin goes. Last night she woke us twice to go out which is unlike her in the middle of the night. When she went out she was walking and squatting like she had to poop but couldn’t. This morning she only ate half her breakfast and then wanted nothing to do with dinner. Seems to be acting ok. Any advice. Think she’s backed up