Cerenia for Dogs: Dosage, How Long It Lasts & Side Effects
Last reviewed: September 2026
The travel dose is four times the vomiting dose
Cerenia (maropitant) prevents vomiting in dogs. The labelled dose for acute vomiting is 2 mg/kg — but for motion sickness it is 8 mg/kg, given two hours before travel. Using the wrong one is the usual reason it "did not work" for a car journey.
What Is Cerenia?
Cerenia is the brand name for maropitant citrate, made by Zoetis. It blocks the NK-1 receptor, which is one of the switches the brain uses to trigger vomiting — so rather than settling the stomach, it works further up, on the signal itself. It is FDA-approved for dogs to prevent acute vomiting and to prevent vomiting caused by motion sickness. The FDA has since approved generic maropitant citrate tablets, so your prescription may be filled with a generic at the same dose.
Cerenia Dosage Chart for Dogs
There are two oral doses and they are not interchangeable. The gap between them is the single most useful thing to know about this drug.
| Reason given | Oral dose | Frequency | Maximum course | Timing |
|---|---|---|---|---|
| Acute vomiting | 2 mg/kg | once daily | up to 5 days | Fast 1 hour before giving |
| Motion sickness (travel) | 8 mg/kg | once daily | up to 2 days | Give 2 hours before travel |
Your vet chooses the dose — use this to check what you were given rather than to change it. If you were prescribed Cerenia for vomiting and are now planning a long drive, that is a conversation to have rather than a calculation to do yourself.
How Long Does Cerenia Take to Work?
About 1 to 2 hours. That is why the label says to give the travel dose two hours before you set off, not as you are loading the car. For a dog that is already vomiting, expect the effect to build over the first couple of hours rather than immediately.
How Long Does Cerenia Last in Dogs?
One dose is built to cover roughly 24 hours, which is why it is a once-daily drug rather than something given every eight hours. It is short-acting in the sense that it should have worn off by the 24-hour mark, so on a multi-day course the timing of each dose matters more than it would with a longer-lasting medication. For a two-day trip, that means dosing each morning rather than relying on the first tablet.
The Puppy Warning Worth Reading
Cerenia tablets are recommended for dogs 16 weeks and older, and should not be used at all under 8 weeks. The reason is tied directly to the dose difference above: bone marrow suppression has been reported in puppies under 16 weeks given the higher 8 mg/kg motion sickness dose. A young puppy that travels badly is exactly the dog an owner is most tempted to medicate, so this is worth a conversation with your vet rather than reaching for a tablet you already have in the cupboard.
Track your dog's medications and symptomsSide Effects and Cautions
Most dogs tolerate Cerenia well. The effect owners notice most often belongs to the injectable form rather than the tablet: pain or swelling at the injection site, which is common enough that many practices now refrigerate the injection to reduce it. Drooling, lethargy and reduced appetite are also reported.
Use with caution in dogs with heart or liver disease. And a practical point: Cerenia stops vomiting, it does not treat the cause. A dog that keeps vomiting once the drug wears off, or that is also lethargic or refusing water, needs a diagnosis rather than a second tablet — see why dogs vomit for what else to consider.
Frequently Asked Questions
What is the Cerenia dosage for dogs?
It depends on why it is being given, and the difference is fourfold. For preventing acute vomiting the labelled oral dose is 2 mg/kg once daily for up to 5 consecutive days. For preventing vomiting from motion sickness it is 8 mg/kg once daily for up to 2 consecutive days, given 2 hours before travel. Using the vomiting dose for a car journey under-doses by four times, which is a common reason owners report that Cerenia did not work for travel.
How long does Cerenia last in dogs?
One dose is designed to cover about 24 hours, which is why it is given once daily rather than several times a day. It starts working within roughly 1 to 2 hours and should have stopped working by 24 hours after the dose.
How long before travel should I give my dog Cerenia?
Two hours before travel, at the motion sickness dose of 8 mg/kg. The label also says to fast the dog for 1 hour before giving the tablet. Giving it as you leave is too late - it takes 1 to 2 hours to take effect.
Can puppies take Cerenia?
Cerenia tablets are recommended for dogs 16 weeks and older, and it should not be used at all under 8 weeks. The age limit matters most for motion sickness, because bone marrow suppression has been reported in puppies under 16 weeks given the higher 8 mg/kg dose. Ask your vet before giving it to a young puppy for travel.
What are the side effects of Cerenia in dogs?
Most dogs tolerate it well. The most commonly noticed effect with the injectable form is pain or swelling at the injection site. Drooling, lethargy and reduced appetite are also reported. It should be used with caution in dogs with heart or liver disease.
Is Cerenia the same as maropitant?
Yes. Maropitant citrate is the drug and Cerenia is the original brand from Zoetis. The FDA has since approved generic maropitant citrate tablets for dogs, so a prescription may be filled with a generic that works the same way at the same dose.
Sources
- FDA — Cerenia (maropitant citrate) Tablets label
- FDA — First generic maropitant citrate tablets approved for dogs
- VCA Animal Hospitals — Maropitant Citrate
- Spotlight on the perioperative use of maropitant citrate (PMC6042506)
Related Reading
Cerenia for Cats
The same drug in cats — dosing, duration and what it treats
Why Is My Dog Vomiting?
Causes, warning signs and when vomiting needs a vet
Dog Diarrhea Treatment
What actually helps when the other end is affected too
Metronidazole for Dogs
The other common GI prescription — dosing by condition