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Constipated dog pooping in a park

The essentials

  • Unflavored milk of magnesia is generally safe for dogs — So long as your vet approves and you give the right dosage, the medication can relieve constipation, acid reflux, and indigestion in dogs.
  • The medication isn’t always advisable — Dogs experiencing vomiting or diarrhea should avoid milk of magnesia.
  • Milk of magnesia works by neutralizing stomach acid — This in turn helps with digestion and clears the intestines for water to pass through.

A dog’s stomach problems can be unpleasant for our pooches, not to mention owners who have to clean up their—shall we say—mess. Luckily, some over-the-counter supplements and medications can go a long way in relieving our best friends’ tummy troubles.

One of those possible solutions is milk of magnesia, a laxative and antacid used to treat constipation and acid reflux in pets and humans alike. But every dog is different, and you should consult your veterinarian about whether or not the medication is safe for your individual furball. Read on to learn the reasons your vet may recommend milk of magnesia, and how to administer it properly.

Milk of magnesia details

Medication type: Laxative, antacid

Form: Liquid, tablet

Prescription required? OTC (but first seek approval from your vet)

FDA approved? Yes (for humans)

Life stage: Puppy, adult, senior

Popular brands: Phillips, Humco, Equate

Common names: Milk of magnesia, Magnesium hydroxide, MoM

Available dosages: Varies

Expiration range: Pre-open date on label, expires six months after opening

What is milk of magnesia?

Milk of magnesia (sometimes shortened to just MoM) is an over-the-counter medication that uses the naturally occurring mineral magnesium to neutralize stomach acid. This allows more water to pass through the intestines, aiding digestion and easier bowel movements.

How milk of magnesia works as an antacid

The mineral magnesium neutralizes acids in the stomach. The combination of both hydroxide and acidic ions in milk of magnesia creates water to reduce indigestion and alleviate any digestive pain.

How milk of magnesia works as a laxative

Because milk of magnesia stimulates the intestines to produce water, it helps soften hard stools and make it easier to “go” when constipated. MoM can also be used as a diluent to reduce the ill effects of ingesting harmful substances.

Is milk of magnesia safe for dogs?

Unflavored milk of magnesia is considered generally safe and non-toxic for dogs. But, before you dish it over to them, it’s imperative that you check with your vet first so they can take your pup’s medical history into account and provide guidance on dosage. Milk of magnesia can also interact poorly with certain medications or antibiotics your dog may be on. Lastly, while human milk of magnesia is sometimes safe for pets, ask your vet about brands of the medication that are formulated specifically for animals.

🚨 Avoid giving your dog flavored milk of magnesia as it may contain xylitol or other harmful ingredients.

When should you give a dog milk of magnesia?

A vet may recommend milk of magnesia to soothe symptoms of constipation, acid reflux, and indigestion. Schedule a check-up if your pup has any of these signs of GI duress:

  • Flatulence. Dog owners are all too familiar with their pup’s silent-but-deadly gas releases. But if their flatulence becomes more and more frequent, they may be constipated or bloated.
  • Irregular bowels. You probably have a good sense of your dog’s “poop schedule,” so if they fall off this routine and aren’t going when they usually do, it may mean they have a stomach issue.
  • Difficulty passing stool. If your dog is squatting for a long period of time while trying to go #2, they’re likely a bit blocked up. Factors could include dehydration, lack of fiber, or an injury.
  • Misshapen or discolored stool. Examine your dog’s stool for signs of GI upset, such as discoloration, small rabbit-like droppings, blood droplets or streaks on the feces, or hard stools.
  • Itching around the anus. Dogs may itch or lick around their anuses if they have an upset stomach, infection, or their anal glands are full. In some cases, you may notice blood or swelling in the area.
  • Acid reflux. Bad breath, burping, and lethargy are all signs your dog may have acid reflux or GERD, which should be treated with antacids like milk of magnesia.

👉 Some vets recommend applying milk of magnesia externally to a dog’s skin to soothe sores, scratches, and rashes.

When shouldn’t you give a dog milk of magnesia?

Of course, there are certain instances where a vet will advise against giving a dog milk of magnesia (or continuing to give it to them). Avoid the medication if your pup has any of the following symptoms or conditions, and seek prompt veterinary or emergency care:

  • Vomiting. Don’t give a vomiting dog MoM because it can lead to aspiration pneumonia and make them even sicker.
  • Diarrhea. Milk of magnesia is a laxative, so it will only make diarrhea worse. If your dog experiences runny stools after taking the medication, they may be allergic or have ingested too much.
  • Pregnant. Dogs who are pregnant or weaning should refrain from medication like milk of magnesia and instead look to natural remedies like fruit for constipation or low-fat protein for acid reflux.
  • Other underlying or pre-existing conditions. Your vet will be able to assess if any of your dog’s underlying or pre-existing health issues may make them a bad candidate for milk of magnesia.

How much milk of magnesia should you give a dog?

Milk of magnesia brands offer varying dosage guidelines. While your vet is the best resource, one to two teaspoons should be taken orally every four to six hours when using it as an antacid for dogs. As a laxative, pups should take one to three tablespoons once daily.

Be sure to give your dog plenty of clean water and food high in fiber with milk of magnesia to increase its effectiveness. Maintain an exercise regime with your pup to build up their immune system and keep their gastrointestinal tract moving.

While milk of magnesia is safe to give to older dogs, it can interact with other medications, making them toxic or ineffective. Avoid using MoM in conjunction with pancreatic enzyme supplements or replacements.

Always seek vet assistance for milk of magnesia

As with any new medication you’re introducing to your canine companion, you should consult a qualified vet first — even if your dog’s ailments match a certain diagnosis. Most symptoms can be found in a wide range of illnesses, so it’s best to avoid attempted diagnoses at home.

While the laxative/antacid can do wonders for our fur babies, it’s important to remember that milk of magnesia is not a cure for any underlying conditions like gastrointestinal upset or irritable bowel syndrome (IBS). It simply helps to temporarily alleviate symptoms. Don’t give your dog the medication over a long period of time, and be sure to address the root cause of the problem.

Frequently asked questions

Can I give my dog magnesium for a laxative?

It is safe to give dogs magnesium as a laxative, so long as you check with your vet first and administer the correct dosage according to their guidance.

How much magnesium hydroxide can I give my dog?

Generally speaking, one to two teaspoons of magnesium hydroxide can be administered to a dog every four to six hours.

Is milk a good laxative for dogs?

Many dogs are considered lactose intolerant and therefore should not be given milk, even as a laxative. In addition to causing diarrhea, it can exacerbate their underlying health issue. Despite the name, milk of magnesia doesn’t contain dairy.

What can I give a constipated puppy?

In addition to laxatives like milk of magnesia, you can try adding fiber to a dog’s diet to relieve constipation. Water and exercise are also natural remedies to the condition.

When shouldn’t you give a dog milk of magnesia?

Dogs experiencing vomiting or diarrhea shouldn’t be given milk of magnesia because it will only make their symptoms worsen. You also shouldn’t give the medication to pregnant dogs.