Feline gastric lymphoma

I am confused about some of the symptoms of feline gastric lymphoma. In particular, I am curious about bleeding issues. Why does feline gastric lymphoma cause the black stools? Why is there blood loss in GI? Where does it come from?

Thank you.

Hello, and thank you for your questions. While it isn't clear from your letter whether you have a cat that has been diagnosed with gastric lymphoma, I would like to extend my heartfelt warmest wishes to you if you do. And, even if you are asking more out of curiosity or for the education, I appreciate your letter and questions.

Feline gastric lymphoma, which is also commonly referred to as Gastrointestinal Lymphoma or GI Lymphoma, is a malignant (cancerous) tumor that disrupts the normal lining of the cat's stomach, causing erosion of the stomach lining and even ulcers that will bleed. Even the tumor itself bleeds, as well.

As this blood is coming from further up in the digestive tract, the cat's body is digesting the blood as it passes through the GI system. Because of this, the digested blood will appear black in the cat's stool. The stool can also appear very "tarry" in consistency when there is blood present. Blood that occurs further down in the GI tract or even right around the anus will normally appear as red in a cat's stool.

Gastrointestinal lymphomas in cats can be low grade (lymphocytic) or high grade (lymphoblastic), which determines the prognosis for treatment. Lower grade lymphomas are more likely to go into remission with aggressive surgical and/or chemotherapy treatments, while the high grade lymphomas are generally less responsive. In cats suffering blood loss through their stool or vomit, bloodwork checking for signs of anemia would be recommended, but these symptoms often indicate an advanced disease.

Thank you for submitting your questions.

Dr. Neely

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