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Metamucil For Dogs – Uses, Dosage, Benefits, Risks & FAQ

↯ Key takeaway points

  • Metamucil is a high-fiber supplement with laxative effects used to treat constipation in dogs and humans.
  • The active ingredient in Metamucil is psyllium, a soluble dietary fiber that absorbs excess water and stimulates normal bowel movements.
  • The recommended dose for dogs is 1-3 teaspoons per day depending on their weight, with two doses being the maximum.
  • Metamucil has potential side effects such as diarrhea, flatulence, and esophageal or intestinal obstructions, which can be mitigated by giving the supplement with sufficient fluids and checking the dose.
  • Metamucil offers other benefits for dogs, such as reducing diarrhea, prebiotic effects, maintaining blood sugar levels, and lowering cholesterol, but it's important to consult with a veterinarian and follow their instructions closely before using it.
Written by Jay
BsC (Hons) Animal Behaviour & Welfare graduate with a passion for advocating for misunderstood animals.
Practicing small pets and equine veterinarian and junior teaching assistant in Veterinary Medicine.
Published on
Friday 18 December 2020
Last updated on
Thursday 15 June 2023
metamucil for dogs
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Metamucil is a brand of psyllium-based products that contains a soluble dietary fiber called psyllium. Psyllium forms a gel-like substance when mixed with water and can help absorb excess water in the intestines, stimulate bowel movements, and relieve constipation. Some veterinarians may recommend Metamucil or other psyllium-based products for dogs with constipation, but it’s important to follow your vet’s instructions closely.

Psyllium is a soluble dietary fiber that is also non-digestible. Instead of being digested, psyllium forms mucilage that absorbs excess water. At the same time, it works to stimulate normal bowel movements. Because of these beneficial properties, Metamucil for a dog is sometimes recommended by vets!

Metamucil Dosage for Dogs

Some veterinarians prescribe Metamucil to treat constipation in dogs. Your veterinarian may give specific instructions for dosing your pet. Follow your vet’s professional advice closely. Generally speaking, the dose is 1 teaspoon for 1 to 10 pound dogs, 2 teaspoons for an 11 to 30 pound dog, and 3 teaspoons for a dog weighing over 30 pounds. Your dog may have up to two doses per day. While it may seem that this is a low prescription, it doesn’t take much Metamucil to be effective!

Be sure to check your dog’s dose before giving them any Metamucil. If you increase your pet’s dose too quickly, or give them too much at one time, they may experience gastrointestinal side effects like gas and bloating. Your pet’s chances of experiencing side effects increase with large doses. Other side effects include vomiting, stomach pain, rectal bleeding, and severe constipation. If your dog shows these symptoms, talk to your vet right away.

Risks of Metamucil for Dogs

While Metamucil has many undeniable benefits, there are some potential side effects as well. It’s important to give your pet this product as directed by a veterinarian to reduce the risk of any side effects. The most common side effects of Metamucil are diarrhea, flatulence, and esophageal or intestinal obstructions. If given in excess, Metamucil may cause vomiting, stomach pain, rectal bleeding, and constipation.


In rare cases, Metamucil can cause mild diarrhea. However, this is unusual. Unlike other stimulant laxatives, Metamucil absorbs and retains water, making any loose stools less watery. This should cause stool movements to be bulkier and less fluid. In eight human studies, it was found that Metamucil improves the viscosity of loose stools whilst also making them firmer.

When choosing your Metamucil product, be sure to go with a version that does not contain any artificial colors, sweeteners, or flavors to avoid causing diarrhea. Metamucil Sugar-Free Original Smooth Powder is one such product that is safe for your pet.

Increased Flatulence

In some cases, Metamucil causes gas or bloating. This side effect is normal and typically goes away within a few days of taking the supplement. The gas usually develops as a by-product of fiber digestion.

If your dog has more gas due to Metamucil, you might notice their stomach gurgling along with unpleasant odors. Gas is a common cause of bloating and flatulence in dogs, and if severe, your dog might experience abdominal pain. If your dog develops painful trapped gas, cease using Metamucil, and speak to your vet about alternatives.

Esophageal and Intestinal Obstruction

Metamucil occasionally causes esophageal obstructions. This is because it works by thickening into a semi-solid mass in order to push blockages through the digestive tract. In otherwise healthy dogs, lodged particles of Metamucil only cause mild discomfort. However, in elderly dogs or dogs with weak throat muscles, this may cause breathing problems or pose a choking hazard. Be sure to offer your pet plenty of water after taking bulk-forming laxatives like Metamucil!

While intestinal obstructions secondary to taking Metamucil are extremely rare, they can and do occur. This is because bulk-forming laxatives like Metamucil attract water molecules and stagnate inside the gastrointestinal tract. Because Metamucil can cause intestinal obstruction, it is best taken along with an adequate amount of fluids. In short, it’s important to make sure that your dog is getting enough water when taking Metamucil!

Benefits of Metamucil for Dogs

Metamucil not only relieves constipation, but also aids against diarrhea, and offers some prebiotic effects. As well as this, Metamucil helps to maintain healthy blood sugar levels and lowers cholesterol. For these reasons, some veterinarians prescribe Metamucil and other psyllium-based products for dogs with constipation.

benefits of metamucil for dogs
There are multiple benefits of Metamucil for dogs.

Relieving Constipation

Some veterinarians prescribe Metamucil to treat constipation. But how does it work, and why do vets prescribe it? In short, bulk-forming laxatives like Metamucil work by increasing fluid retention in the stool. Psyllium, the active ingredient in Metamucil, is capable of retaining water in the small intestine. This increases water flow into the ascending colon, increasing the fluidity of colonic content. This then increases stool weight and consistency. In addition to the relief of constipation symptoms, the increase of free water in the bowels alters the environmental condition of your dog’s colon.

In order for bulk-forming laxatives to relieve constipation, the user must drink enough water. Once swallowed Metamucil forms a gel-like mass in the gut. So, without adequate water intake, this mass can become trapped in your dog’s gastrointestinal tract. This can worsen any constipation that was already present.

Treating Diarrhea

By retaining fluid in the intestines, bulk-forming laxatives cause stool to become softer and bulkier. By making stools bulkier and less watery, your dog’s diarrhea can be reduced whilst still encouraging regular bowel movements. One study of dogs with large bowel diarrhea found promising results. The affected dogs were given two tablespoons of Metamucil per day alongside a highly digestible diet. After this treatment, most of the dogs had a “very good” to “excellent” response, and their diarrhea did not return!

If you intend to treat dog diarrhea, be wary of psyllium-based products that contain other laxatives alongside psyllium. These will worsen your pet’s diarrhea to potentially dangerous levels. If severe, watery diarrhea leads to dehydration and malnutrition in dogs. To be safe, stick with Metamucil products with no artificial flavorings, sweeteners, or other laxative ingredients.

Prebiotic Effects

Psyllium-based products like Metamucil have prebiotic effects. But why are psyllium products able to work as prebiotics as well as laxatives? Studies show that psyllium is a soluble dietary fiber that is also non-digestible. Because psyllium is resistant to digestion by the body, it nourishes intestinal bacteria and helps them to grow instead. As a result of bacterial fermentation, psyllium also increases the production of short-chain fatty acids, which are good for colonic health. Overall, prebiotics boost your dog’s gastrointestinal tract, which might just help them overcome mild constipation!

With this being said, it’s also important to be aware that prebiotics cannot help every dog with constipation. Prebiotics cannot address causes such as a lack of exercise, blocked anal glands, intestinal obstructions, or dehydration. If your dog is constipated for more than two or three days, be sure to check in with your vet before administering prebiotics.

metamucil prebiotic effects
Metamucil has prebiotic effects.

Metamucil For Dogs – FAQ

Have any questions or concerns about using Metamucil for dogs? Feel free to browse our Frequently Asked Questions section for more details. If in doubt, always contact your vet for advice.

Can a dog have Metamucil for constipation?

With the appropriate dose and veterinary advice, Metamucil can be safely given to dogs. Some veterinarians may prescribe psyllium-based products like Metamucil as adjunctive therapy for dogs with diarrhea. Due to its similarity, VETASYL® Fiber Capsules may be prescribed instead of Metamucil. VETASYL contains psyllium husks as well as barley malt extract powder for flavor.

Treating constipation or diarrhea at home is only recommended when your dog is otherwise healthy. If your dog has profuse diarrhea, bloody diarrhea, is vomiting, or is very young or very old, be sure to consult your vet first. Similarly, prolonged constipation of more than two or three days warrants a trip to the vet.

Can I add Metamucil in my dog’s food?

A powder-form of Metamucil may be added to your dog’s food. Your vet may ask you to mix Metamucil with wet food. Alternatively, they might suggest adding broth or water to your dog’s dry kibble alongside the Metamucil. Regardless of how you serve your dog’s food, be vigilant that clean drinking water is always available to your pet!

When adding Metamucil to your dog’s food, always double-check the dose and be sure that the product is free from artificial flavorings and sweeteners. Giving too much Metamucil increases your dog’s risk of choking, diarrhea, and bloating. Furthermore, certain flavorings may cause irritation to your dog’s GI tract. While citrus products are not toxic to dogs, they are high in sugars and may cause an upset stomach. Similarly, while cinnamon is not toxic to dogs, large amounts can irritate your dog’s mouth and stomach. To be safe, stick with plain, sugar-free Metamucil products.

Can you sprinkle Metamucil on food?

While Metamucil can be sprinkled on top of your dog’s food, it’s best to mix it in with their meal. Your vet may instruct you to use wet food or to add broth or water to your pooch’s kibble. Doing so helps to ensure that your dog is getting enough water whilst taking this psyllium-based supplement.

There are some situations where it’s not appropriate to sprinkle Metamucil onto food. For example, you should never sprinkle Metamucil into hot liquids, even if you intend to use the liquid in your dog’s food. Adding Metamucil to a hot liquid causes it to gel rapidly. This increases the risk of choking and intestinal obstruction for your dog.

How long does Metamucil take to work on dogs?

If you don’t see any improvement right away, don’t be disheartened. Metamucil becomes effective after 12 to 72 hours. This is because your dog’s digestive system needs time to adjust to the additional fiber. The time it takes for Metamucil to work will also depend on your dog’s diet. Some studies find that a highly-digestible diet alongside Metamucil gives speedier results. It’s also important to ensure that your dog drinks plenty of water to prevent intestinal obstructions that could slow the process. Some vets will advise you to mix Metamucil with wet food to ensure that your dog is getting enough water.

Metamucil effectively treats constipation and diarrhea while also improving cholesterol levels. However, while Metamucil helps many constipated dogs, it’s important to only use it in moderation to prevent uncomfortable side effects.

6 comments on “Metamucil For Dogs – Uses, Dosage, Benefits, Risks & FAQ”

  1. Joe G

    How do you come up with the dosage for Metamucil for dogs?what you are suggesting is far more than the amount for an adult human.

    1. Hi Joe! Thank you for your question!

      You’re absolutely right to question the dose of any product like this. It’s always best to talk to a vet before giving a dog any medicine at home, especially when unsure about the dosage. However, the doses described here are guides based on current research on Metamucil/psyllium for dogs.

      In one teaspoon of Metamucil there are 2 grams of soluble fiber and 3 grams of insoluble fiber. For humans, this dose can be taken three times a day.( There is no recommended amount of fiber for dogs as of posting this comment, but it’s generally agreed that soluble and insoluble fiber are beneficial for managing several illnesses ( – This is a study using a median dose of 2 tablespoons of Metamucil per day (added to a highly digestible diet) with “a very good to excellent response in most dogs.” In some dogs, this dose was reduced successfully without causing diarrhea to return. This suggests that 2 tablespoons per day for a 30lbs dog was a safe and effective dose. – This is a study on police working dogs, using 4 tablespoons of psyllium husks per day for 1 month. 50% of the dog’s responses were “very good”, 40% were “good”, and the last 10% were “poor.” 90% of the dogs had consistent stools regularly and did not lose weight. The weight of these dogs is not described in the abstract, unfortunately!

      A PetMD article written by Dr. Jennifer Coates ( recommends giving dogs one teaspoon per five pounds of body weight. Our recommendation of 1 teaspoon for a dog weighing up to 10 pounds corresponds with this.

      If any new research comes out that suggests that these doses are unsafe for dogs, changes will be made right away. However, no studies currently suggest that the current recommendation is unsafe, especially when a vet approves the use of Metamucil.

    2. Apologies for the formatting of my reply, not sure why it bunched everything together that way – hopefully it still makes sense!

  2. Dr Paul Boland

    Holistic Doggie Fibre supplement for dogs contains soluble and insoluble fibre, probiotics, prebiotics and bentonite clay. This fibre supplement for dogs provides enough fibre in a pet’s diet helps support normal digestive function, balance levels of water in the intestines and firms up faecal matter. Adequate fibre can also reduce the need for anal gland emptying as it increases natural expression.

  3. Dave

    My 27lb Boston terrier ate a single Metamucil Fiber Thin Cookie (Chocolate) flavor. Is he in danger of any kind?

  4. Gina Craig

    Can you give a 108lb dibetic dog Metamucil to help and support slowing down sugar absorbency?
    To better manage his blood glucose from not being so high, hyperglycemia?

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