What It Is:
Miralax is the brand name for polyethylene glycol 3350, an over the counter stool softener often used in cats to treat constipation. It works by drawing water into the colon, making stools softer and easier to pass.
Although Miralax is not labeled for veterinary use, it is commonly recommended off label by veterinarians for cats with mild to moderate constipation or chronic bowel issues.
🐾 Common Uses
Miralax is used to manage:
- Mild or chronic constipation
- Early stages of megacolon
- Constipation due to arthritis or decreased mobility
- Post surgical recovery involving the intestines
- Constipation from dehydration or low fiber diet
It is often used in combination with dietary changes, hydration therapy, or other medications like lactulose.
🧪 How It Works
Miralax is an osmotic laxative, which means it pulls water into the intestines and colon. This extra moisture:
- Softens hard stool
- Increases stool volume
- Stimulates natural bowel movement
Unlike stimulant laxatives, Miralax does not irritate the colon. This makes it suitable for long term use in many cats, with proper veterinary guidance.
💊 Dosage and Administration
Miralax is a flavorless powder that dissolves easily in wet food or water. It is typically given once or twice daily, depending on the cat’s needs.
Typical dose:
- Eighth to one quarter teaspoon per day for most cats
- Mixed into canned food or a small amount of liquid
- Doses may be adjusted based on response and stool quality
Always start with the lowest effective dose, and do not increase without veterinary approval.
⚠️ Potential Side Effects
Miralax is generally safe, but improper dosing can lead to side effects such as:
- Diarrhea
- Gas or bloating
- Dehydration
- Electrolyte imbalances if used long term without monitoring
If your cat develops soft or watery stool, the dose should be reduced. Persistent diarrhea or lethargy should be reported to your vet.
🩺 Monitoring and Safety
Miralax is not absorbed into the bloodstream and is considered low risk. However, it should be avoided or used with caution in cats who have:
- Severe dehydration
- Known intestinal blockages
- Kidney disease (requires vet monitoring)
- Sudden or unexplained constipation
Long term use may require periodic vet checkups to monitor hydration and electrolyte balance.
💡 Cat Owner Note
If your cat is straining to poop or skipping days between litter box visits, Miralax might be the gentle nudge they need. It is tasteless, easy to give, and often works within a day. Just be sure to follow your vet’s dosing advice — a little goes a long way.
❓ Frequently Asked Questions About Miralax in Cats
Can I give Miralax to my cat without a vet prescription?
While it is sold over the counter, you should consult your vet first to confirm it is appropriate and safe for your cat.
How long does Miralax take to work?
It typically works within twelve to twenty four hours, though response time may vary.
Is Miralax safe for long term use in cats?
Yes, with proper monitoring. Many cats with chronic constipation use it long term under veterinary supervision.
What if my cat has diarrhea while on Miralax?
Reduce the dose and notify your vet. Diarrhea can lead to dehydration if not addressed.
Can I use Miralax and lactulose together?
Yes. Some cats benefit from using both, especially if one alone is not effective. Always use under vet direction.
Is Miralax safe for senior cats?
Yes, but older cats may be more prone to dehydration. Ensure they are drinking enough water and eating wet food when possible.