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Metoclopramide is an anti-vomiting drug that also speeds up stomach emptying. Dogs get it for vomiting, reflux, and a stomach or upper gut that has slowed down, usually at 0.2 to 0.5 mg/kg by mouth or injection every 6 to 8 hours.1,2
I use it two ways: as a continuous drip for dogs in hospital, and as tablets sent home for reflux or a stomach that empties slowly.
Key Takeaways
Most dogs get 0.2 to 0.5 mg/kg, and how often depends on how it's given.
| How it's given | Dose | How often |
|---|---|---|
| Tablet or liquid by mouth | 0.2 to 0.5 mg/kg | Every 6 to 8 hours1,2 |
| Injection under the skin or into muscle | 0.2 to 0.5 mg/kg | Every 6 to 8 hours2,3 |
| Continuous IV drip in hospital | 2 to 4 mg/kg per day | Continuous3,4 |
Give tablets 30 to 45 minutes before meals, so the drug is active when food reaches the stomach.5
Follow the label on your own bottle rather than the table. The right dose depends on what's being treated and how your dog responds.
Tablets are the usual form. For small dogs, a compounding pharmacy can make a flavoured liquid that's easier to measure accurately.
In hospital the drip usually starts at 2 mg/kg per day, and goes higher when the gut has stopped moving after surgery or serious illness.3
A few hours, which is why it's given several times a day.1,2
In a study of healthy Beagles given an IV dose, half the drug had cleared from the bloodstream in under an hour. It cleared faster than ondansetron or maropitant in the same study.9
That short action suits a drip in hospital, which holds a steady level instead of letting it rise and fall between injections.
If the vomiting hasn't settled within a day or two, call your vet rather than giving extra doses.
Metoclopramide acts in the brain and the gut at the same time. In the brain, it blocks dopamine D2 receptors in the chemoreceptor trigger zone, the area that detects nausea triggers in the blood and sets off vomiting.1,2 At higher doses it also blocks serotonin 5-HT3 receptors there, which adds to the anti-vomiting effect.2
In the gut, it activates 5-HT4 serotonin receptors and increases the release of acetylcholine from nerves in the gut wall.1,4 Acetylcholine tells gut muscle to contract. The stomach contracts harder, the pylorus at its outlet relaxes, and food moves on into the small intestine sooner.1,2
That effect stops at the upper gut. Metoclopramide has little or no effect on the colon, so it's no help for constipation.1
Its action in the brain also explains the side effects, which tend to show up as changes in behaviour.2
Vomiting and a stomach that isn't emptying properly are the main reasons. The Merck Veterinary Manual lists these uses in dogs:1,2
Across two veterinary hospitals, the most common reasons to start a prokinetic in hospitalized dogs were vomiting, ileus seen on imaging, prevention after abdominal surgery, and regurgitation. Most of those dogs got metoclopramide on its own.4
For parvovirus, it holds up against newer drugs. In a small randomized trial in young dogs with parvo, metoclopramide, ondansetron and maropitant reduced vomiting equally well.10
Its effect on nausea is less certain. A 2017 study scored nausea behaviour in Beagles given a chemotherapy drug, and a single dose of metoclopramide reduced neither vomiting nor nausea, while ondansetron worked best.9 Earlier work found higher doses did cut vomiting caused by the same chemotherapy drug.9
Not for the megaesophagus itself.
The body of a dog's esophagus is striated muscle, the same type as the muscles that move the legs. Metoclopramide acts on smooth muscle, so it has little to work on there and can't be recommended for megaesophagus in dogs.7
It doesn't reliably tighten the valve at the bottom of the esophagus either. Researchers in Zurich measured that sphincter in awake dogs 1, 4 and 7 hours after an oral dose. Metoclopramide didn't change the pressure, while cisapride raised it.8
Managing megaesophagus comes down to how the dog is fed and catching aspiration pneumonia early.7 Metoclopramide still has a place if the same dog also has reflux, because that's a separate problem.1
Most are changes in behaviour or movement: restlessness, hyperactivity, agitation, aggression, trembling, muscle spasms or drooling.1,3,5,6
Some dogs go the other way and turn drowsy or quiet.4,5
Vets call the movement and agitation signs extrapyramidal signs. They're more likely at high doses or when the drug goes into a vein too quickly.2,3 Your vet can counteract them with the antihistamine diphenhydramine.2
Withhold the next dose and call your vet if your dog becomes agitated or aggressive, starts trembling or twitching, or can't settle after a dose. Don't treat it with Benadryl at home unless your vet tells you to.
Don't give metoclopramide to a dog that might have a blockage or a perforation in the stomach or intestines. Speeding up the gut against either one can make things worse.1,2
Parvo puppies are the classic case. Parvovirus can cause intussusception, where one section of intestine telescopes into the next, and that has to be ruled out before metoclopramide starts.1
Pancreatitis, stomach ulcers, HGE and a swallowed object can all look alike at home. A vomiting dog gets examined, and sometimes x-rayed or given a barium study, before a prokinetic goes home.
It's also avoided, or used with care, in dogs with:
Opioid pain medications, atropine and similar anticholinergic drugs cancel its effect on the gut.1,5 Acepromazine and other phenothiazine sedatives, and SSRI antidepressants such as fluoxetine, raise the risk of tremors and other movement side effects.6
Give your vet a full list of what your dog takes, supplements included, before the first dose.
Yes, as long as it's still helping. Seizures are a reason to stop, and kidney disease developing along the way can call for a lower dose.
Watch for it working less well over time. In people, metoclopramide tends to lose its effect with continued use.4 If your dog's signs creep back, tell your vet rather than raising the dose yourself.
If your dog is vomiting, regurgitating, or restless on metoclopramide, give us a call at (519) 896-0532.
Yes. Reglan is a brand name for metoclopramide in human medicine, and dogs take the same drug, usually as generic tablets or a compounded liquid. Don't give your dog a leftover human prescription. The tablet strength may not suit your dog's weight, and a vomiting dog needs to be checked for a blockage before any drug that speeds up the gut.
It depends on why the dog is vomiting. Cerenia (maropitant) blocks a different vomiting signal, the NK1 receptor. Metoclopramide blocks dopamine in the part of the brain that triggers vomiting, and it also speeds up stomach emptying, so it gets chosen when the stomach itself has slowed down. In a small randomized trial in young dogs with parvovirus, the two reduced vomiting equally well.
Give it when you remember, then carry on with the normal schedule. If the next dose is close, skip the missed one instead. Never give two doses together to catch up, because metoclopramide's side effects are more likely at higher doses. Doses come several times a day, so a phone reminder helps.
So it's already working when food reaches the stomach. Give tablets 30 to 45 minutes before a meal. Metoclopramide helps the stomach contract and empty into the small intestine, and a dose only lasts a few hours, so timing it to food matters.
Yes, both. Restlessness, hyperactivity, agitation, trembling and muscle spasms are the more common problem, and they come from the drug's action in the brain. Some dogs become drowsy instead. These effects are more likely at higher doses, in dogs with kidney disease, and in dogs also taking acepromazine or an SSRI antidepressant such as fluoxetine. If your dog is agitated, trembling or can't settle, hold the next dose and call your vet.
Only if your vet has prescribed it for this episode. Metoclopramide speeds up the stomach and intestines, and that can make things worse when the vomiting comes from a blockage, such as a swallowed toy or bone, or from intussusception in a puppy with parvovirus. Those have to be ruled out first. Call your vet if your dog is vomiting repeatedly, can't keep water down, seems painful or flat, or has blood in the vomit.
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