Clinical signs of lymphoma in the gastrointestinal tract include weight loss, vomiting, diarrhea, and often either a decreased or increased appetite. Physical exam findings may be normal, though thickened intestines or abdominal masses may be felt.
GI lymphoma may be suspected based on the clinical signs of weight loss, vomiting, and/or diarrhea in an older cat. During abdominal palpation, the veterinarian might notice thickened intestines or intestinal masses.

Cats with low-grade GI lymphoma often have mild to moderate vomiting and weight loss for several weeks, to months or years before diagnosis. Sometimes they will experience chronic diarrhea as well. How is low-grade GI lymphoma diagnosed? Biopsies of the intestine are required for a definitive diagnosis of low-grade GI lymphoma.

ABSTRACT: Lymphoma is the most commonly diagnosed neoplasm in cats, and gastrointestinal (GI) lymphoma is now the most common anatomic form. Most cats with GI lymphoma test negative for FeLV and have a median age of 9 to 13 years.The most common clinical sign of GI lymphoma is weight loss followed by decreased appetite, vomiting, and diarrhea. Abdominal ultrasonography can be a strong ...

Symptoms of Lymphoma in cats will depend on type of lymphoma and organs or tissues involved Intestinal lymphoma: Vomiting and diarrhoea. Unexplained weight loss.