Don't know what's wrong
Zoe is a our 14 months old and has been very healthy. Friday morning I let her outside and she was acting completely normal. I put her in her crate and thought everything was fine. When my wife got home she had peed in her crate. She was taken outside then given a bath. Afterward my wife noticed she was acting very lethargic. Saturday morning she was acting a little better but still not normal. She was drinking and ate. Saturday evening she was acting even better. She was a little playful and had a little pep in her step. Still not 100% but way better than 24 hours earlier. Today she has regressed. She is still drinking but not eating. No vomiting or diarrhea. But she has zero energy. She is also extremely hesitant going up or down stairs. I am taking her to the vet tomorrow am but was just curious if anyone had any clue what could cause her to act like this so suddenly.