Cat Constipation: Home Remedies, Causes & When It's Serious

Constipation in cats is uncomfortable and potentially serious. Chronic constipation can lead to megacolon — permanent colon damage that may require surgery. Here's how to help your cat before it gets worse.

Signs of Constipation

Straining in the litter box with little or no stool, hard dry feces (small pebble-like pieces), decreased appetite, vomiting (especially if constipated severely), lethargy and hiding, distended or firm abdomen, and crying in the litter box. Note: a constipated cat straining can look exactly like a cat with a urinary blockage. A male cat straining is an emergency — it could be a urethral obstruction, which is fatal within 24-48 hours.

Common Causes

Dehydration (the most common cause — dry food diets, kidney disease), low-fiber diet, obesity, lack of exercise, hairballs (especially in long-haired cats), pelvic trauma (old fractures narrowing the pelvic canal), neurological disease (Manx cats with sacral deformities), medications (opioids, anticholinergics), and idiopathic megacolon (degeneration of colonic nerves).

Safe Home Remedies for Mild Constipation

Increase water intake: switch to wet food, pet water fountain, add water to food. Canned pumpkin (pure pumpkin, NOT pie filling): 1-2 teaspoons mixed into food once daily provides safe fiber. Miralax (polyethylene glycol 3350): 1/8-1/4 teaspoon mixed into wet food twice daily — always check with your vet first. Exercise: encourage movement with play. Regular brushing to reduce hair ingestion.

What NOT to Do

Never give human laxatives (especially phosphate enemas like Fleet — fatal in cats). Never give mineral oil (aspiration risk). Don't wait more than 2-3 days without a bowel movement.

When It's Megacolon

Megacolon occurs when the colon becomes permanently dilated and loses the ability to contract. The colon fills with hard impacted feces. Medical management (lactulose, cisapride, high-fiber diet) may help initially. Severe or refractory cases require subtotal colectomy — removal of 80-95% of the colon. Surgery has excellent outcomes with most cats producing soft formed stool within weeks to months.

When to See a Vet

No bowel movement for 3+ days, straining with nothing produced, vomiting + constipation, distended painful abdomen, or blood in stool. Seek veterinary care promptly — don't wait until the colon is permanently damaged.