For the last 3 days, my 10-year-old has acted strangely when she first gets up in the am. She eats her breakfast fine, but then is lethargic, wobbly, panting, can't seem to get comfortable and then just sits still. This lasts for an hour or so and then she if fine, running, playing, etc. Does anyone have experience with this? She has end stage cardiac disease and I'm wondering if this is a progression. We adopted her from a shelter as a hospice pet, but she has never shown any signs of the disease once we put her on heart medication. Thanks in advance!