Hello I am Dr. Joey. Thanks for trusting me to help you and your pet today. I am a licensed veterinarian with over 15 years of experience. I look forward to working with you.
Based on what you report I am quite worried about Pearl. Unfortunately her symptoms are vague and could indicate any one of several possible causes but the howling at her age makes me concerned she is in pain. Where the pain is coming from is something I could not guess without a physical exam. It could be urinary (hence lying near the box) such as urinary tract infection or bladder/kidney stones. Or it could be orthopedic (spinal pain) or it could be heart related and throwing blood clots. Or she could have an internal issue causing weakness from something like anemia.
Since this has been join ton a while, I highly recommend have her examined today as soon as possible. She will likely need some lab testing which might include a complete blood count, chemistry profile and urine check.
I so much wish I had an easy at home solution for you to try but if she absolutely refuses to move and continues to cry (be distressed) these are emergency symptoms.
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