An adult beagle with a 1-month history of vomiting and inappetance, who presents with hypoglycemia and a mass in the stomach, is most likely diagnosed with?

In the case of the adult beagle presenting with a 1-month history of vomiting and inappetence, along with hypoglycemia and a mass in the stomach, the most likely diagnosis is leiomyosarcoma. This type of tumor, which arises from smooth muscle tissue, can occur in the stomach and presents as a mass that often leads to obstruction or nausea, resulting in vomiting and lack of appetite.

The presence of hypoglycemia can be particularly concerning, as some tumors, including leiomyosarcomas, may produce substances that affect glucose metabolism or lead to increased insulin levels, thus causing low blood sugar. The combination of these clinical signs and the identification of a gastric mass at examination strongly supports this diagnosis.

In comparison, other conditions such as gastric ulcers might not typically present with a defined mass and would show different clinical signs. Pancreatic adenocarcinoma is more commonly associated with weight loss and poor appetite rather than hypoglycemia directly caused by the neoplasm itself in the absence of metastasis. Intestinal lymphoma usually affects different areas of the gastrointestinal tract and may not commonly present with a single identifiable stomach mass without accompanying signs of intestinal dysfunction. Therefore, the overall clinical picture aligns closely with leiomyosarcoma