Constipation in Dogs and Cats: Causes, Treatment, and Prevention
Constipation is common in pets but shouldn't be ignored. Learn what causes it, how to relieve it at home, and when it needs veterinary attention.
Constipation — difficult or infrequent passage of stool — is a common problem in dogs and cats, especially in older pets. While mild cases often resolve with simple dietary changes, chronic constipation can lead to obstipation (complete inability to pass stool) and megacolon, a serious condition where the colon loses its ability to function. Understanding the causes and knowing when to intervene can prevent these complications.
- Constipation is more common in cats than dogs, especially in older felines
- Dehydration is the #1 cause of constipation in pets
- A high-fiber diet and adequate water intake are the best preventive measures
- Straining to defecate can be mistaken for urinary problems — look carefully
- Chronic constipation can lead to megacolon, especially in cats
- Never give human laxatives to pets without veterinary guidance
What Causes Constipation?
The most common cause is dehydration — when the body lacks adequate water, the colon absorbs more fluid from the stool, making it hard and difficult to pass. Other causes include: low-fiber diet or excessive bone consumption (common with raw feeding), lack of exercise (slows intestinal motility), obesity, hairballs in cats, pelvic injuries or narrowing, side effects of certain medications (antihistamines, opioids), stress or changes in routine, arthritis (makes squatting painful so pets hold it), and underlying diseases like kidney disease, diabetes, or hypothyroidism. In male cats, obstruction from urethral blockage is a different emergency — always confirm your cat is trying to defecate, not urinate.
Signs to Watch For
Signs of constipation include: straining or crying out when trying to defecate, producing small, hard, dry stools, less frequent bowel movements (fewer than once daily for cats), passing mucus or blood-streaked stool, small amounts of liquid stool leaking around the blockage (mistaken for diarrhea), reduced appetite, vomiting, and lethargy. Cats may stop using the litter box if sitting in the box is painful. A constipated cat that goes days without passing stool is at risk of developing megacolon.
Home Remedies and Prevention
For mild constipation: increase water intake — add water to dry food, offer wet food, and use pet water fountains. Add fiber to the diet — canned pumpkin (plain, not pie filling), psyllium husk (Metamucil, in appropriate doses under vet guidance), or a teaspoon of olive oil for dogs. Increase exercise — regular walks stimulate bowel motility. For cats, regular brushing reduces hairball formation. Keep the litter box clean and accessible. Never give enemas, mineral oil, or human laxatives without veterinary guidance — they can be dangerous.
When Veterinary Treatment Is Needed
If home remedies don't resolve constipation within 48 hours, or if your pet is in obvious distress, veterinary care is needed. Your vet will perform a physical exam (including digital rectal exam) and may take X-rays to assess the colon. Treatment ranges from subcutaneous fluids for dehydration to manual disimpaction (removing impacted stool under sedation) to enemas administered by a professional. In severe cases, hospitalization with IV fluids and stool softeners is needed. For pets with recurrent constipation, a prescription high-fiber diet or motility-enhancing medication may be recommended.
- Your pet is straining to defecate with no stool produced for 48+ hours
- Your pet is crying out or showing signs of pain when trying to pass stool
- Small amounts of watery stool leaking (could indicate a blockage)
- Your pet is vomiting in addition to being constipated
- You notice blood in or around the stool
- Your constipated cat has stopped eating for more than 24 hours
RVC
RVC provides complete digestive care for constipated pets. We offer thorough examinations, abdominal X-rays, safe professional enemas, and long-term management plans including prescription diets and medications. For chronic constipation cases, we work with you to find the right combination of diet, hydration, and medication to keep your pet comfortable. Call +853 6677 6611.
+853 6677 6611