Megacolon in cats causes severe, painful constipation and obstipation. Welfare management ranges from dietary and medical interventions to subtotal colectomy in refractory cases.
Megacolon causes escalating welfare harm as disease progresses. Early constipation causes straining, discomfort, and intermittent abdominal pain. As the colon dilates and loses contractility, obstipation develops — cats are unable to defecate despite repeated attempts. The welfare impact of accumulated fecal material includes abdominal distension, pain, nausea, and systemic toxin absorption. Cats with severe obstipation require veterinary deobstipation under general anaesthesia — a welfare-improving emergency procedure.
Recurrent obstipation between deobstipation episodes represents cycles of repeated severe welfare harm. Cats that require deobstipation more than twice per year are generally considered candidates for subtotal colectomy — surgical removal of most of the colon, which resolves the structural cause of obstipation and provides long-term welfare relief.
Subtotal colectomy has excellent long-term welfare outcomes in most cats. Post-operative diarrhoea is common for 6-8 weeks but typically resolves as the remaining colon adapts. The vast majority of cats achieve normal or near-normal defecation frequency without the pain and straining of megacolon. Most owners report dramatic quality of life improvement in their cats following surgery.