Happy has been getting weaker over the last few days, especially early today. And her poop was very dark this morning. So we took her to the vet today.
Her red blood cells are down "dramatically; " she's anemic. Her last blood test was just May 23, and this wasn't there. She has tenderness in her abdomen and low appetite. Which means she has an ulcer or something worse. She's bleeding somewhere in her GI tract, if I understand.
The vet sent blood to the lab for a complete workup, and we started her on a medicine for ulcer - sucrasomething. We should have lab results tomorrow, and we'll go from there. The vet says if it's not an ulcer, it could be something like a tumor in her belly. The next step would be an ultrasound.