4 Safe Laxatives for Cats: Our Veterinarian Shares Tips

Constipation is not as common as some owners would assume, but for those cats who do suffer with ongoing constipation, it can cause them a whole host of issues. Owners often need to stay on top of things, to avoid the need for hospitalisation.

Mild cases of constipation, particularly in cats who are still eating and drinking well, can usually be managed from home with laxatives, as long as treatment is started early on. However, owners should not be tempted to diagnose their cat with constipation by themselves, as this requires veterinary input.

How can we manage constipated cats: an overview

Constipation is infrequent or absent defecation that is linked with feces being retained in the colon and the rectum. The aim is to prevent this from happening, so we want to ensure a normal stool is passed at least once daily.

Those prone to constipation often do best on a wet diet that is high in fiber, allowing for a good hydration level and preventing the stool becoming too hard. Owners can increase water intake further by adding water to meals and using a cat water fountain.

Being over weight or inactive can make the guts sluggish, which can also lead to constipation. We want to aim for a body condition score of about 4 to 5 out of 9 and we need to encourage our cats to move with games and interactive toys, as well as outdoor time where appropriate.

For cats prone to fur balls, we want to groom them at least once daily, using a good brush such as a Furminator. We can also use fur ball paste as needed, to help prevent blockages.

Safe laxative options for cats

Laxatives may be prescribed by a vet for owners to use at home, particularly for those cats who are prone to ongoing constipation or who struggle with chronic hard stool.

Some cats who have underlying medical issues, like a narrow pelvic canal due to a previous trauma, may be given laxatives long-term.

There are several safe options available for our feline friends including:

1. Katalax

Katalax paste is one of my ‘go tos’ for kitties who are prone to hair balls and mild constipation. It is highly palatable, and cats will tend to groom it off their paws if we smear it on them. The paraffin oil lubricates the gut, assisting in the passage of fur out into the stool.

2. Laxatone

This is a similar product, available on Amazon here. One real plus of this paste, is that it is tuna flavored, so rarely turned down. This is a safe hair ball paste that is suitable for kittens too.

3. Microlax

Microlax comes in a small tube, which is inserted up the anus, to allow for performing a mini enema from home. We give from 5mls to 10mls (one to two tubes) and the sodium lauryl sulfoacetate usually results in a stool within half an hour.

4. Lactulose

Lactulose is cheap and readily available. It can be given into a cat’s mouth and is a hyperosmotic laxative, meaning it draws water into the bowel. The dose is 0.5mg/kg every 8 to 12 hours as needed. As results can be instant, it is sensible to give it with a cat in the bathtub or near to their litter tray.

How to use a laxative safely with your cat

The right dose and frequency to give will depend on the patient and their needs. Giving too much laxative can lead to diarrhea, weakness, salt imbalances and dehydration. Conversely, low or infrequent dosing can mean the product has no effect.

Vets will often suggest a starting dose, which is then adjusted depending on how the cat is doing and what their stool looks like.

For many cats with acute bouts of constipation, they will only need laxatives a couple of times a day for one to two days. However, those with chronic constipation may need a daily low dose.

When to seek vet help for cat constipation

It isn’t normal for a cat to become constipated, so if you notice your cat is straining or their poo seems very hard or is only being passed in small amounts, it is time to contact your vet.

We need to determine why the cat has developed constipation and to check for any blockages or signs of megacolon (a dilated large bowel).

Worryingly, I’ve seen many owners come in with a ‘constipated’ cat who has been straining for days, only to find they have a life threatening bladder blockage and they have been straining as they cannot pass urine.

What to expect during a veterinary visit

Your vet will ask about your cat’s history and will perform a full physical exam. They should examine the cat’s anus for any mats of fur or clumped stool, and will feel the intestines for evidence of a blockage or constipation. Your cat’s hydration levels will also be assessed.

In some instances, your vet may want to perform imaging, to check for evidence of an obstruction or megacolon.

What are the causes of constipation in cats?

There are a wide range of causes of constipation in cats, but lets take a look at the most common culprits:

1. Cats can become dehydrated when unwell, particularly in chronic disease such as kidney failure. The lack of moisture within the bowel can lead to the stool hardening and trouble with passing feces. Dehydrated cats will have dry or tacky gums and a prolonged skin tent. We should try to improve hydration by offering tempting wet foods and rehydration solutions. In some instances, cats will benefit from subcutaneous or IV fluids.

Water bowls for cats

2. Behavioral . Cats are fussy creatures, who can become easily stressed and this stress has many knock on effects. A change in the routine, a new litter tray or a new cat in the home can all lead to refusal to pass stool and constipation. Owners can try to prevent this by ensuring there are always 1.5 litter trays per cat in the home and that the trays are in quiet areas. Routine should be kept consistent and some cats will benefit from anxiety relieving products like calming plug ins and supplements. With ongoing behavioral issues, it is sensible to seek advice from a feline behaviorist.

Common causes of litter tray refusal

3. Pain tends to go under-diagnosed in cats, particularly in seniors. Arthritis or anal gland issues can both lead to difficulty passing feces and an aversion developing. The key here is in recognizing the pain and treating it. This can mean medicine such as pain relief and anti inflammatories. Senior cats should use large trays with low lips, which are easier for them to posture in.

Cat in pain

4. Colon factors. Narrowing within the pelvis, or masses blocking the way, can lead to ongoing constipation. Diagnosing these issues can take time and may involve imaging such as X-rays and abdominal scans. When a cat has previously been involved in a car accident and/or broken their pelvis, owners should be on the lookout for constipation. Some cats will need daily stool softeners.


This x-ray above shows severe constipation

Frequently Asked Questions

Can I use human laxatives for my cat?

Many of the laxatives we use for cats (like Lactulose) are also used for humans, yes. However, we should never provide them unless under the guidance of a vet.

What are the potential side effects of laxatives in cats?

Laxatives work to make the stool more watery, which can lead to diarrhea and dehydration if over-used or used inappropriately.

How long does it take for a laxative to work in cats?

This depends on the laxative, but most get to work very quickly, within the hour. Even so, it can take a day or so before a good sized stool is passed.