EXPRESS: A Case of Pseudo-obstruction in a Cat Associated with Amebiasis

This report describes a 9-year-old, neutered female domestic shorthair cat presenting with a 7-day history of anorexia and previous chronic constipation. Clinical examination revealed abdominal distension and discomfort. Radiographic and ultrasonographic imaging showed severe, generalized gaseous distension of the entire gastrointestinal tract without evidence of mechanical obstruction. An exploratory celiotomy confirmed severe, non-obstructive dilation of the stomach and intestines, with aperistalsis of the ileum and large intestine. Histopathological analysis of intestinal biopsies revealed neuritis and necrosis of the myenteric plexus, along with the presence of protozoan trophozoites consistent with Entamoeba histolytica. These findings led to a diagnosis of intestinal pseudo-obstruction secondary to amebiasis-associated ganglionitis. Treatment was initiated with pyridostigmine, an acetylcholinesterase inhibitor, and metronidazole. The cat responded favorably, with resolution of clinical signs and normalization of defecation. This case documents a rare instance of intestinal pseudo-obstruction in a cat, uniquely associating it with amebiasis and demonstrating a successful therapeutic outcome with pyridostigmine.