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Metoclopramide is a prescription medication that veterinarians use to treat gut motility issues in horses. In equine medicine, it is used in select cases of postoperative ileus, delayed gastric emptying, chronic gastric dilatation, and gastric impaction. [1][2][3]
The medication affects several neurotransmitters involved in gastrointestinal motility. These effects can stimulate smooth muscle activity and promote the movement of stomach or intestinal contents. [1][4][5] There is no approved equine formulation of metoclopramide, so its use in horses is off-label and must be directed by a licensed veterinarian.
Because metoclopramide also affects the central nervous system, side effects can include restlessness, sedation, excitement, tremors, abnormal movements, collapse, or dangerous behavior. [1][6] As with all medications, the treating veterinarian weighs the possible risk of use against the potential benefits.
Keep reading to learn how metoclopramide works, when it may be considered for equine use, and possible side effects and drug interactions.
Metoclopramide for Horses
Metoclopramide hydrochloride is a prokinetic and dopamine-antagonist medication. In human and small-animal medicine, it is most commonly used to control nausea and vomiting. Horses cannot vomit, so equine use focuses mainly on treating gastrointestinal motility issues. [1][7]
In equine medicine, metoclopramide has been studied as a treatment option in cases of: [2][3][4][5]
- Postoperative ileus
- Delayed gastric emptying
- Abnormal jejunal motility
- Abnormal cecal and colonic motility
- Chronic gastric dilatation
Research suggests it may be beneficial in some cases, but effects vary by disease, route, treatment protocol, and individual horse. [2][3][4][5]
Available Forms
Metoclopramide is available in human-labeled oral and injectable formulations, including tablets, oral liquids, and injectable solutions. [7]
Veterinarians may prescribe an off-label preparation at their professional discretion. The horse’s condition, ability to absorb oral medication, and need for hospital monitoring all influence the choice of route and formulation.
Brand and other names for metoclopramide include: [7]
- Metoclopramide hydrochloride (HCl)
- Apo-Metoclop®
- Clopra®
- Octamide PFS®
- Ellieten®
- Emperal®
- Enterosil®
- Gastrosil®
- Maxolon®
- Metopram®
- Paspertin®
- Reglan®
- Viscal®
- Primperan®
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Drug Class: Benzamide Prokinetic & Dopamine Antagonist
Metoclopramide hydrochloride is a benzamide prokinetic drug and dopamine antagonist. A prokinetic is a drug that increases movement through the digestive tract, while a dopamine antagonist blocks the effects of dopamine at its receptors.
Benzamide prokinetics increase gastrointestinal peristalsis, the coordinated muscle contractions that move food through the digestive tract. They do this by affecting serotonin, dopamine, and acetylcholine pathways that help control gut movement.
These medications increase acetylcholine release in the enteric nervous system, which causes smooth muscle to contract and move contents through the gastrointestinal tract. [1]
Other prokinetic or motility-modifying medications used or studied in horses include: [1][4]
Mechanism of Action
Gastrointestinal motility depends on coordinated contractions of smooth muscle in the digestive tract. These contractions are controlled by signals from the enteric nervous system and pacemaker cells in the gut wall. Acetylcholine is one of the main neurotransmitters that stimulates intestinal smooth muscle to contract.
Metoclopramide increases gastrointestinal motility partly by increasing acetylcholine release from nerve endings in the digestive tract. This promotes stronger, more coordinated contractions that move gastrointestinal contents forward. [1][4]
Metoclopramide also acts as a dopamine D2 receptor antagonist, meaning it blocks dopamine from activating these receptors. Dopamine can reduce acetylcholine release and inhibit gastrointestinal smooth muscle activity, so blocking D2 receptors increases prokinetic activity.
The drug also affects serotonin receptors. Activation of 5-HT4 receptors increases acetylcholine release, while blockade of 5-HT3 receptors contributes to its effects on gastrointestinal function. [1][4][5]
Metoclopramide can cross the blood-brain barrier, so dopamine receptor blockade also occurs in the central nervous system. This can interfere with normal control of movement and behaviour, resulting in side effects such as: [1][6]
- Restlessness
- Agitation
- Tremors
- Abnormal muscle movements
- Sedation
- Collapse
Given this, prescribing veterinarians weigh the potential nervous system effects alongside the gastrointestinal outcomes when considering metoclopramide for horses.
Uses in Horses
There are currently no approved equine formulations of metoclopramide available, so its use in horses is off-label, also known as extra-label. [1][7] Off-label use of medication is permitted under veterinary prescribing regulations. In these cases, the veterinarian uses their clinical judgement and existing scientific evidence to make their recommendations.
Equine studies on metoclopramide have found different effects across gastrointestinal regions and clinical settings. Continuous intravenous infusion was associated with less postoperative gastric reflux after small-intestinal surgery, and oral metoclopramide increased jejunal motility in healthy horses. [2][4][5]
Another study found increased cecal and colonic contractions without a clear increase in duodenal contractions. [8]
Veterinarians may consider metoclopramide for conditions associated with reduced or poorly coordinated gastrointestinal motility, including: [1][2][3][5]
- Postoperative ileus: Reduced gastrointestinal movement after colic surgery, often accompanied by gastric reflux and delayed return of normal intestinal function
- Delayed gastric emptying: Slow movement of stomach contents into the small intestine, which may contribute to recurring colic, poor performance, or reduced appetite in some horses
- Chronic gastric dilatation or gastric impaction: Persistent enlargement or filling of the stomach, sometimes associated with delayed emptying
- Anterior enteritis or other hypomotility disorders: Cases in which a veterinarian considers prokinetic support appropriate after evaluating the underlying problem
Administration Routes
Metoclopramide has been administered to horses by several routes in clinical reports and research studies:
- Orally: Given by mouth
- Intravenously: Injected directly into a vein
- Subcutaneously: Injected under the skin
Oral treatment has been described in horses with chronic gastric dilatation and delayed gastric emptying, while intravenous constant-rate infusion has been studied in postoperative ileus.
Pharmacokinetic research has also evaluated subcutaneous administration and confirms that route and protocol influence drug exposure in horses. [2][3][6][9]
In hospital settings, veterinarians may choose an injectable route when a horse cannot safely receive oral medication, has gastric reflux, or requires intensive monitoring. Oral administration may be suitable for selected stable horses when stomach emptying is adequate for the medication to reach its absorption site.
Since metoclopramide use in horses is off-label, there are no standardized dosing guidelines. A licensed veterinarian must determine the dose, route, frequency, and treatment duration based on the horse’s condition, concurrent medications, and monitoring needs.
Storage
Metoclopramide should be stored according to the instructions on the product label.
Tablets and oral liquids should be kept in their original container at room temperature and protected from light to help maintain the stability and quality of the medication. [7][9]
Safety Warnings & Precautions
Metoclopramide should be used only after a veterinarian has examined the horse and determined that prokinetic therapy is appropriate. Stimulating gastrointestinal movement may be harmful when a mechanical obstruction, strangulation, perforation, gastrointestinal bleeding, or severe gastric impaction is present. [1][9]
Use caution when metoclopramide is given with medications that affect the central nervous system, gastrointestinal motility, dopamine signaling, or serotonin signaling. Tell the prescribing veterinarian about all medications, supplements, and recent treatments the horse has received.
Neurologic or behavioral reactions can create a serious handling risk. If a horse becomes severely agitated, uncoordinated, or unsafe to approach, keep people clear and contact the veterinarian immediately.
Monitoring
Horses receiving metoclopramide should be monitored for:
- Appetite and water intake
- Manure output and consistency
- Signs of colic, abdominal distension, or gastric reflux
- Changes in attitude, including restlessness or agitation
- Sedation, stumbling, tremors, or abnormal movements
Follow-up assessment may include ultrasound, gastroscopy, or reassessment of feeding management in horses with chronic gastric dilatation or delayed emptying. [3]
Contact the veterinarian if the horse’s signs do not improve, worsen, or return after treatment begins.
Contraindications
Contraindications refer to circumstances where a drug should be avoided or used with caution.
Metoclopramide should not be used in horses with known or suspected hypersensitivity to the drug. It should also be avoided with suspected obstruction, perforation, or gastrointestinal bleeding unless the attending veterinarian determines otherwise. [7]
Metoclopramide should be used cautiously in horses with any of the following conditions: [7]
- Seizure disorders
- Pheochromocytoma (a rare form of adrenal gland cancer)
- Abnormal neurologic signs
- Significant kidney disease
- Significant liver disease
Impaired metabolism or excretion may prolong the drug’s effects. [7][9]
Colic requires veterinary assessment before a prokinetic is used because stimulating motility may worsen discomfort or complications in some conditions. New or worsening colic signs after treatment begins require immediate veterinary attention.
Side Effects
Metoclopramide can cause gastrointestinal, behavioral, and neurologic effects. Reported or potential side effects in horses include: [1][4][6][7][9]
- Restlessness or agitation
- Sedation or unusual drowsiness
- Excitement, irritability, or other behavioral changes
- Tremors, muscle spasms, or abnormal repetitive movements
- Ataxia or uncoordinated movement
- Collapse or falling
- Colic signs or increased abdominal discomfort
- Constipation or changes in manure
- Increased urination
Effects on dopamine signaling in the nervous system can cause abnormal movements or loss of muscle control. [1][6] In horses, agitation, collapse, or aggressive behavior can endanger the horse and handlers.
Acute Toxicity (Overdose)
Overdose of metoclopramide may intensify neurologic or behavioral effects. Signs of metoclopramide overdose in horses may include: [7]
- Marked restlessness
- Agitation
- Excessive sedation
- Tremors
- Muscle spasms
- Abnormal repetitive movements
- Incoordination
- Collapse
- Seizures
Worsening colic, distress, or reflux may also occur. [7]
If overdose is suspected, prevent further access to the medication and contact the veterinarian immediately. Move the horse to a quiet, safe area only when this can be done safely. If the horse is severely agitated, collapsing, or unsafe to approach, keep people clear and wait for veterinary assistance.
Veterinarians may use centrally acting anticholinergic medications, such as diphenhydramine or benztropine, to manage neurologic effects in adult horses. [9] Owners should not administer another medication unless directed by the treating veterinarian.
Drug Interactions
Formal interaction studies about metoclopramide use in horses are limited, but interactions reported or proposed in broader literature include: [1][7][9]
- Anesthetic agents: Acute hypotension has been reported when intravenous metoclopramide is used with general anesthetics
- Anticholinergic medications, including atropine: These may oppose metoclopramide’s gastrointestinal prokinetic effects
- Cholinergic medications, including bethanechol: These may enhance its gastrointestinal effects
- Central nervous system depressants: Anesthetics, antihistamines, phenothiazines, barbiturates, and tranquilizers may have stronger depressant effects when combined with metoclopramide
- Cyclosporine: Metoclopramide may increase the rate and extent of gastrointestinal absorption
- Opioid analgesics: These may oppose metoclopramide’s effects on gastrointestinal motility
- Monoamine oxidase inhibitors: Medications including amitraz and possibly selegiline may increase the risk of hypertension
- Phenothiazines and butyrophenones: Medications such as acepromazine, chlorpromazine, droperidol, and azaperone may increase the risk of neurological effects
- Other sedatives, tranquilizers, and narcotics: Concurrent use may enhance central nervous system effects
- Tetracyclines: Metoclopramide may increase the rate and extent of gastrointestinal absorption
Regulatory Status & Legal Considerations
Metoclopramide is approved for human use and is approved for some animal species in some regions. Equine use is typically off-label and must comply with local veterinary prescribing rules. [7]
Off-label prescribing means a veterinarian uses an approved medication in a species, dose, route, or for a condition that is not specifically listed on the product label. In horses, this use must occur within a valid veterinarian-client-patient relationship and follow applicable prescribing, compounding, and competition regulations.
While off-label use is permitted in veterinary medicine, the drug manufacturer may not warranty the product when it is not used according to the approved label. Horse owners should ask their veterinarian how off-label use affects dosing, withdrawal or detection guidance, monitoring, and any manufacturer warranty or liability considerations.
Status in Competition
The FEI Equine Prohibited Substances List classifies metoclopramide as a Controlled Medication under dopamine antagonists. Controlled medications are generally prohibited during competition, although applicable FEI veterinary procedures may allow use in specific circumstances. [10]
The 2024 FEI List of Detection Times does not provide a detection time for metoclopramide. A detection time is not the same as a withdrawal time, and the absence of a published detection time does not establish a safe interval before competition. The treating veterinarian must determine an appropriate withdrawal time using professional judgment. [10][11]
Check the current rules for the horse’s sport, federation, and jurisdiction before administering any medication.
Frequently Asked Questions
Here are some frequently asked questions about metoclopramide use in horses:
Metoclopramide is used off-label in horses to promote gastrointestinal motility. Veterinarians may consider it for selected cases of postoperative ileus, delayed gastric emptying, chronic gastric dilatation, gastric impaction, or other disorders involving reduced gut movement. It does not correct the underlying cause of gastrointestinal disease and should only be used after a veterinary evaluation.
Metoclopramide works in horses by affecting acetylcholine, dopamine, and serotonin pathways involved in gastrointestinal movement. It increases acetylcholine release, blocks dopamine D2 receptors, and acts on certain serotonin receptors. These effects may help coordinate smooth muscle contractions and move contents through the stomach and intestines, although the response can vary between horses and gastrointestinal regions.
Metoclopramide may help selected horses with postoperative ileus after colic surgery. Continuous intravenous infusion has been associated with reduced postoperative gastric reflux in horses following small intestinal surgery. Postoperative ileus is a serious complication that requires hospital treatment, close monitoring, and management of the underlying disease and any fluid or electrolyte abnormalities.
Metoclopramide is not appropriate for every horse with colic because stimulating gastrointestinal movement can be dangerous in some cases. It should generally be avoided when an obstruction, strangulating lesion, gastrointestinal perforation, bleeding, or severe gastric impaction may be present. A veterinarian must determine the cause of the colic and decide whether prokinetic treatment is appropriate.
Metoclopramide may be administered to horses orally, intravenously, or subcutaneously under veterinary direction. The appropriate route depends on the horse's diagnosis, clinical condition, ability to absorb oral medication, and need for monitoring. Horses with gastric reflux, severe illness, or postoperative complications may require injectable treatment in a hospital.
Owners should not give human metoclopramide, including Reglan, to a horse without specific veterinary instructions. Metoclopramide is a prescription medication, and its use in horses is off-label. The veterinarian must select the formulation, route, treatment protocol, and monitoring plan based on the individual horse's condition.
Side effects of metoclopramide in horses can include restlessness, agitation, sedation, excitement, irritability, tremors, muscle spasms, abnormal repetitive movements, ataxia, or collapse. Gastrointestinal effects may include changes in manure, constipation, increased abdominal discomfort, or worsening colic signs. These reactions can become dangerous for both the horse and its handlers, particularly when behavior or coordination is affected.
A veterinarian should be contacted immediately if a horse receiving metoclopramide develops marked agitation, tremors, abnormal movements, stumbling, collapse, severe sedation, or worsening abdominal pain. Keep people away if the horse is behaving dangerously or is unsafe to approach. New, severe, or rapidly worsening signs require prompt veterinary assessment.
Horses should not receive metoclopramide if they have a known or suspected hypersensitivity to the drug. It should also be avoided when increased gut movement could be harmful, such as with suspected gastrointestinal obstruction, perforation, or bleeding, unless the attending veterinarian determines otherwise. Additional caution is needed in horses with seizure disorders, abnormal neurologic signs, pheochromocytoma, or significant kidney or liver disease.
Long-term use of metoclopramide in horses has not been studied extensively. Oral treatment has been associated with clinical improvement in some horses with chronic gastric dilatation and delayed gastric emptying, but individual responses vary. Horses receiving longer courses should be reassessed regularly to confirm that treatment remains appropriate and the underlying condition is improving.
A horse receiving metoclopramide should be monitored for appetite, water intake, manure production, manure consistency, abdominal discomfort, bloating, and gastric reflux. Owners and veterinary staff should also watch for restlessness, unusual sedation, agitation, stumbling, tremors, or abnormal movements. Persistent, worsening, or returning gastrointestinal signs may require further examination, such as ultrasound or gastroscopy.
Metoclopramide can interact with medications that affect gastrointestinal motility, dopamine, serotonin, or the central nervous system. Anticholinergic drugs may reduce its prokinetic effects, while cholinergic drugs may increase its gastrointestinal effects. Sedatives, anesthetics, tranquilizers, narcotics, phenothiazines, butyrophenones, and some other drugs may increase the risk of sedation, abnormal movements, or additional adverse effects, so the veterinarian should review every medication and supplement the horse receives.
A metoclopramide overdose can cause exaggerated neurologic or behavioral effects in horses. Warning signs may include severe restlessness, agitation, excessive sedation, tremors, muscle spasms, abnormal repetitive movements, poor coordination, collapse, seizures, worsening colic, or gastric reflux. Prevent further access to the medication, place the horse in a quiet and safe area when possible, and contact a veterinarian immediately.
Alternatives to metoclopramide include other prokinetic or motility-modifying drugs that have been used or studied in horses, such as lidocaine, mosapride, cisapride, erythromycin, bethanechol, neostigmine, and tegaserod. These medications are not interchangeable because their effects, risks, routes of administration, and activity in different parts of the gastrointestinal tract vary. A veterinarian must select treatment based on the cause and location of reduced motility, the horse's overall condition, and any applicable competition rules.
Metoclopramide is not used to treat vomiting in horses because horses cannot vomit in the same way as humans and many other animals. Its main role in equine medicine is to encourage gastrointestinal movement. Signs such as gastric reflux or abdominal distention in a horse can indicate serious gastrointestinal disease and require veterinary attention.
Metoclopramide is not a performance-enhancing treatment and should not be used for that purpose. A horse with delayed gastric emptying or chronic gastric dilatation may perform better if appropriate treatment relieves gastrointestinal discomfort, but the priority is diagnosing and managing the medical condition. Competition restrictions also apply to metoclopramide.
Metoclopramide is listed by the FEI as a Prohibited Substance and Controlled Medication under dopamine antagonists. It may be used for legitimate veterinary treatment outside competition, but it must not be detectable during competition. The FEI does not currently publish a detection time for metoclopramide, so owners should consult their veterinarian and check the current rules of every applicable federation before returning a treated horse to competition.
Summary
Metoclopramide is a prescription prokinetic medication used off-label to promote gastrointestinal motility in selected horses.
- It acts through acetylcholine, dopamine, and serotonin pathways to influence movement in the stomach and intestines
- A veterinarian must determine the dose, route, frequency, and duration for each horse
- Evidence supports potential use in specific settings, including postoperative ileus and chronic gastric dilatation with delayed emptying, but results vary and controlled clinical data remain limited
- Potential side effects include restlessness, sedation, excitement, tremors, abnormal movements, collapse, and worsening colic signs
- The FEI classifies metoclopramide as a Controlled Medication that is generally prohibited during competition, with no detection time listed in the 2024 FEI document
References
- Wong. D. M. et al. Motility of the equine gastrointestinal tract: Physiology and pharmacotherapy. Equine Veterinary Education. 2011.
- Dart. A. J. et al. Efficacy of metoclopramide for treatment of ileus in horses following small intestinal surgery: 70 cases (1989-1992). Australian Veterinary Journal. 1996.
- Bätjer. F. et al. Outcome of horses with chronic gastric dilatation and delayed gastric emptying treated with oral metoclopramide. Equine Veterinary Education. 2025.
- Okamura. K. et al. Effects of mosapride citrate, metoclopramide hydrochloride, lidocaine hydrochloride, and cisapride citrate on equine gastric emptying, small intestinal and caecal motility. Research in Veterinary Science. 2009.
- Beder. N. A. et al. Ultrasonographic evaluation of the effects of the administration of neostigmine and metoclopramide on duodenal, cecal, and colonic contractility in Arabian horses: A comparative study. Veterinary World. 2020.
- Brandon. A. M. et al. Evaluation of pharmacokinetics of metoclopramide administered via subcutaneous bolus and intravenous constant rate infusion to adult horses. Veterinary Surgery. 2024.
- Metoclopramide veterinary client information handout. Metoclopramide. Plumb's drug handouts. 2026.
- Hunt. J. M. and Gerring. E. L. A preliminary study of the effects of metoclopramide on equine gut activity. Journal of Veterinary Pharmacology and Therapeutics. 1986.
- Plumb. D. C. Plumb's Veterinary Drug Handbook: Desk. 9th ed. John Wiley & Sons. 2018.
- 2026 Equine Prohibited Substances List. Fédération Equestre Internationale. 2026.
- FEI List of Detection Times 2024. Fédération Equestre Internationale. 2024.
