How Long Does Miralax Take To Work In Cats?

Since young, my cat has had one of the most efficient and regular bowel movements in the entire household.

Every day without fail at the same time, he will make his way to his litter box to stink it up.

Even with such a regular schedule, my cat can get a sudden bout of constipation out of the blue.

I guess it can happen to the best of us.

I’ve tried a couple of home remedies and Miralax has worked pretty well for me so far. If you plan to give your cat Miralax, it would be advisable to do a quick phone consult with your vet before doing so.

Miralax usually takes about 24 hours to work on cats with mild constipation. In some cases, it can take up to 48 hours. If your cat has not defecated after 48 hours, it would be best to seek medical attention.

In this article, we will be discussing more about Miralax and whether it is safe for cats. We will also be sharing a few other home remedies for your cat’s constipation.

Let’s get started.

How Does Miralax Work In Cats?

Miralax is first and foremost an over-the-counter medication for constipation. It is meant for humans but many vets have recommended Miralax for pets with mild constipation.

It is in powder form and rather tasteless which is good for cats as they tend to be fussy about taking anything that doesn’t appeal to their taste.

The active ingredient in Miralax is PEG 3350 and these molecules tend to bind with the water molecules in the cat’s intestines.

This helps to enlarge and soften the stools and prevent water from leaving the intestines.

In addition to this, the PEG molecules encourage the contraction of the cat’s intestines to jump-start bowel movement in constipated cats.

How Much Miralax Can You Give A Cat With Constipation?

How much Miralax to give your cat depends on your cat’s age, weight and severity of the constipation.

It would be ideal to let the vet suggest the appropriate Miralax dosage that is safe and effective for your cat. Most of the time, the dosage ranges from 1/8 – 1/4 teaspoon twice a day for most cats.

Many cat owners report seeing their cats start to defecate after 6-12 hours. It can take longer in some cats so just be patient.

It usually takes a few days of taking Miralax for cats to get their bowels moving smoothly again.

Some vets might suggest that you give your cat over a longer period but at a smaller dose if it gets constipation often.

How To Mix Miralax For Cats?

feed difficult cat liquid medicine
Infusion of liquid medicine from a syringe into the mouth of a cat on the table in the veterinary clinic

Miralax comes in a powdered form that is tasteless. I myself have taken it a few times and there isn’t much taste to it. You can mix the powder in your cat’s food or with water and syringe your cat the solution.

I found that Miralax works well for fussy cats by mixing it in their food as they can’t really detect the smell.

If you prefer to syringe your cat, it can be challenging to feed liquid medication to a difficult cat.

Can Miralax Hurt Cats?

If you are wondering “Is Miralax safe for my cat?”, there’s not much to worry about.

Many vets recommend the use of it for cats with constipation.

A few minor side effects would be your cat feeling more dehydrated and Miralax can cause some diarrhea in your cat as it works to unblock your cat.

These side effects usually clear up after a few days.

Miralax vs Lactulose For Cats

Similar to Miralax, Lactulose is also an over-the-counter medication for helping with constipation.

Instead of being a tasteless powder like Miralax, it comes in syrup form and it tastes sweet. I wouldn’t recommend giving this to cats that are sensitive to sugar like cats who are diabetic or obese.

Lactulose also works a lot slower than Miralax, taking up to 5 days for the effects to show.

What Is The Fastest Way To Relieve Constipation In A Cat?

The fastest way to relieve your cat from constipation is to give it an enema. An enema is when saline solution or laxative is squirted directly into your cat’s butt to stimulate a bowel movement.

The effects are very immediate and it is normally used for severe constipation in cats.

Please do not give your cat an enema without a vet’s supervision. If done wrongly, you can damage your cat’s rectum and colon.

Although enemas are safe for cats, your cat might behave differently after getting an enema.

Signs That Your Cat Is Constipated

There will be some signs to look out for if your cat is feeling constipated.

  • Straining to poop in the litter box
  • Meowing on yowling during bowel movements
  • Stool looks hard and pebble-like
  • Lack of appetite
  • Unable to poop for a few days

If your cat has never been constipated before, it might be a good idea to seek veterinary advice to make sure there isn’t an underlying medical condition that is causing your cat to constipate.

What Causes Constipation In Cats?

No one likes feeling blocked in the rear end including cats. However, constipation can happen rather suddenly and without notice.

Here are some common problems that can cause constipation in cats.

Not Drinking Enough Water

Not enough drinking enough water is a big cause of chronic constipation in cats. Many cat owners will tell you that they can’t seem to make their feline friends drink enough water.

There is a reason why cats aren’t big on drinking water in the first place.

Cats are originally desert animals.

And in the desert, water is a sacred commodity.

All living things need water to survive and cats are no exception. Instead of getting water from the ground, cats get it from their food by hunting prey.

Through the years of domestication, cats no longer need to hunt for food and are being put on an unhealthy diet like dry food.

The lack of water in your cat’s diet causes the stool in the intestines to become firm and hard thus leading to constipation.

Excessive Hairballs

natural remedy cat hairball

Hairballs are part and parcel of being a cat. Cats spend many hours a day grooming themselves and licking up all the loose fur.

This ingested fur tends to accumulate in and start to form a mass of hair in the cat’s digestive tract.

Most of the time, your cat is able to get rid of the hairball by vomiting it up or passing it out from the rear.

However, there are times when the hairball gets too large and dry which leads to it getting stuck in your cat’s intestinal tract and causing a blockage.

If your cat has hairballs often try some of these effective home remedies for cat hairballs.

Stress And Anxiety

Some of us get loose stools when we are feeling overly stressed or anxious. In the case of cats, it can lead to their digestive system shutting down and giving the cat constipation.

Cats are very sensitive creatures and at times, even the smallest of changes at home can throw them out of balance.

If you are moving house, getting a new bed or having a new family member at home, all these new changes can add stress to your cat.

Foreign Objects

Dogs are more prone to ingesting inedible foreign objects. But you do get cats swallowing stuff like strings, plastic and metal out of curiosity.

There is a medical condition in cats called PICA where they tend to chew and swallow inedible material like fabric, metal, plastic, etc.

All these objects can harmful to cats and can cause severe blockages leading to a badly constipated cat.

Home Remedies For Constipated Cats

If your cat has been diagnosed with chronic constipation, it might not be in your cat’s best interest to give it Miralax all the time. Some cat owners will give their cats laxatone for hairball-related constipation.

Here are some natural ways that you can help regulate your cat’s bowel movement.

Increase Your Cat’s Water Intake

maine coon drink water from tap

If you can get your cat to start drinking more water, the extra moisture can help keep its stool soft and prevent constipation.

You can do this by placing more water bowls around the house, getting your cat a water fountain and stop feeding your cat dry food.

Dry food contains no moisture at all and contains many bad ingredients. Start feeding your cat wet food or a raw meat diet that has better nutritional value.

Feed your Cat Pumpkin

Feeding your cat pumpkin is a great way to prevent constipation. Pumpkin is high in fiber and magnesium which are important for regular bowel movements.

When buying pumpkin for your cat, get it fresh or pumpkin pulp that doesn’t contain any added sugar or ingredients.

When using fresh pumpkins, just add some water and blend.

Add about 1/4-1/2 teaspoon to your cat’s food daily.

Psyllium Husk

psyllium husk constipation for cats

Psyllium husk works great for cats with constipation and can be bought from most supermarkets.

It comes from the plantago ovata plant and is very high in fiber. The best way to feed this to your cat is to mix a little bit into your cat’s wet food.

Please do not feed your cat this if it is on a dry food diet as psyllium husk needs water to work properly.

There is no smell or taste to it so it won’t affect your cat’s appetite.

Psyllium husk helps to add bulk to your cat’s stool and coat its digestive tract with a gel-like substance to make bowel movement smoother.

A little bit goes a long way as too much psyllium husk can cause an obstruction in the intestines.

Make sure to speak to your vet before giving your cat this to iron out the recommended dosage and timeframe.


It is normal for our cats to get constipated every now and then. Most of the time my cat starts going again after a few days of home treatment.

But if you do notice that your cat is really having trouble pooing even after taking Miralax, it would be best to take your cat to the vet for a proper examination to ensure the blockage isn’t serious.

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