Multiple small intestinal pseudodiverticula associated with lymphoma in three horses.

The research investigates three mature horses exhibiting various signs of progressing illness which culminated in euthanasia, and upon post-mortem examination, all were found to have intestinal lymphoma. The researchers relate the clinical signs, the veterinary efforts and eventual findings upon histological examination.

Case Presentation

• The study focuses on three horses that presented with similar symptoms: weight loss, lack of appetite, abdominal swelling, and lethargy. Two of them also exhibited signs of low-grade abdominal pain intermittently.
• At the initial stage, all three horses were hypoalbuminemic, meaning they had abnormally low levels of albumin in their blood. Two of them had high levels of fibrinogen, while one of them was neutrophilic, i.e., it had an excess of neutrophils in its blood.
• Two of the horses were subjected to an oral glucose tolerance test, indicating there were metabolic and digestive issues at play. Both failed to absorb the glucose well, pointing towards further gastrointestinal complications.

Treatment and Outcome

• One horse that was treated with corticosteroids, medicines to reduce inflammation, failed to show improvement and developed peritonitis, leading to euthanasia after two weeks.
• Another horse underwent a small intestinal biopsy via a standing flank laparotomy, revealing a significant mononuclear cell infiltrate into the mucosa. Despite treatment with antibiotics and corticosteroids, it also developed peritonitis along with sternal oedema joining the abdominal oedema and was euthanized after two months.
• The remaining horse, despite various treatments, deteriorated and was finally euthanized after one week.

Post Mortem Examination

• The post mortem examination showed all three horses had images of inflammation in the small intestines, manifesting as thickened intestinal wall, mucosal ulceration, pseudodiverticula, and enlarged lymph nodes in the mesenteric tissue. One horse also had a multinodular mass at the root of the mesentery, a mediastinal mass, and a lung mass.
• Upon histological examination, lymphoma presence was confirmed in the intestinal wall of each horse, and their T cell origin was established through immunohistochemistry, providing conclusive evidence of pan-systemic manifestations of the lymphoma.