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Home > Cats > How Long Will It Take a Cat Laxative to Work? Vet Approved Facts & FAQ

How Long Will It Take a Cat Laxative to Work? Vet Approved Facts & FAQ

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Dr. Maxbetter Vizelberg

Veterinarian, DVM

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Constipation is a fairly common health issue found in cats. So, if you live with a cat, there’s a good chance that you may have to help it get through a case of constipation. Using laxatives is a very common way to help alleviate constipated cats. You can usually expect them to start working within 1-2 days, but it isn’t uncommon for some to take as long as 5 days to take effect.

Before you purchase cat laxatives, it’s important to determine constipation in cats and how laxatives work. Knowing these things will help you avoid overdosing and causing more complications for your cat.


Causes of Constipation in Cats

Constipation in cats refers to feces accumulating in the colon and slowing down or stopping bowel movements. It usually occurs with dehydration as dried feces become hard and more difficult to pass.

Other causes of constipation include hairballs, ingesting foreign objects, pelvic injuries, and obesity. A lack of exercise can also contribute to constipation.

One common health condition that causes constipation is megacolon. Megacolon refers to when colon muscles weaken and can’t push feces out of the colon. It’s possible for this condition to develop after long-term constipation. So, it’s important to address constipation quickly.

cat hairball
Image By: Montakan Wannasri, Shutterstock

Signs of Constipation

The signs and symptoms of constipation that you’ll see will depend on the cause.

Some common signs are the following:
  • Pain when defecating
  • Unsuccessful defecating
  • Dry and hard feces
  • Loss of appetite
  • Lethargy
  • Abdominal pain
  • Vomiting

If you notice any of these signs, consult with your veterinarian right away. Veterinarians will be able to make a proper diagnosis and confirm if your cat is constipated. They can usually feel around your cat’s lower body to find any buildup. X-rays, bloodwork, and urine testing can also help veterinarians determine the cause of constipation.

Types of Cat Laxatives

Veterinarians may recommend certain laxatives to help alleviate constipated cats. Two common laxatives are Colace and Miralax. They work similarly by softening stools to make them easier to pass. This is achieved by increasing the amount of water in the gut. You can expect Colace and Miralax to take effect in 1-2 days after administering.

Another laxative that cats can use is Laxatone. It’s typically used to help cats control hairballs, but it can also be used to treat constipation. Laxatone is mineral oil-based lubricant laxative that can encourage bowel movements when ingested. You can see results with Laxatone within a day, but it can also take up to 5 days to see any changes.

veterinarian feeds the cat using a syringe
Image By: frantic00, Shutterstock

Where To Get Cat Laxatives

Colace, Miralax, and Laxatone are all over-the-counter medicines. However, it’s important to purchase them after receiving a recommended dosage from your veterinarian. Overdosing on Colace and Miralax can lead to significant diarrhea and expand to even more health issues, such as severe dehydration.

When treating constipation, make sure to keep your veterinarian in the loop with your cat’s condition. It’s important to contact them right away if you don’t see the laxatives working within their expected timeframe.

Veterinarians may use other means to help your cat through constipation. Enemas or manual deobstipation of impacted feces may need to be performed under anesthesia or heavy sedation. In more severe cases, your cat may be prescribed medication that stimulates colon contractions. Extreme cases may require colon surgery.



Constipation in cats is uncomfortable and painful, and laxatives can help alleviate and resolve the issue. Laxatives can take between 1-5 days to work. If you don’t see any changes for your cat, make sure to contact your veterinarian right away for the next steps.

Featured Image Credit: Nils Jacobi, Shutterstock

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