Gastric Squamous Cell Carcinoma In The Horse: Seven Cases (2009-2019)

This report describes gastric squamous cell carcinoma (GSCC) in seven horses. It records the clinical signs, treatment and outcomes. Main clinical signs were mostly nonspecific and included weight loss, anorexia, fever, tachycardia and tachypnoea. Some more suggestive clinical signs were observed such as recurrent choke, halitosis and hypersalivation. Chronic anaemia and hypoalbuminaemia were common findings. Gastroscopy identified a gastric mass in four cases (57.1%); however, visualisation of the stomach was precluded in the other three horses due to distal oesophageal neoplastic infiltration and compression. Gastric wall thickening was noticed using abdominal ultrasonography in four horses (57.1%). Neoplastic cells could only be detected in the peritoneal fluid of 2 out of 7 horses. Endoscopic-guided or transabdominal ultrasound-guided biopsies allowed an ante-mortem diagnosis in three horses (42.8%). Gastric masses were identified at post-mortem examination and metastasis were confirmed in the liver and/or the spleen for 4/4 cases. In the cases for which palliative therapy was attempted, most of the horses were subjected to euthanasia within 4 weeks. In conclusion, GSCC is an uncommon neoplastic disease in horses. A combination of diagnostic tests is often necessary to achieve a diagnosis, which is frequently only made late in the course of the disease. As a result, GSCC is commonly associated with a poor short-term prognosis.