Maropitant dosing differs by indication and species, with dogs requiring higher doses for motion sickness than for acute vomiting, and cats dosed by total tablet weight rather than a per-kg injectable equivalent.
For acute vomiting in dogs, the oral dose is 2 mg/kg PO q24h; in dogs actively vomiting, the injectable formulation at 1 mg/kg SC or IV q24h is recommended first to ensure the full dose is delivered, after which oral maropitant at 2 mg/kg q24h can be used interchangeably for up to 5 days total.FDA DailyMed An… Dogs 2–7 months of age are limited to 5 consecutive days of treatment.FDA DailyMed An…
For motion sickness in dogs, the dose is 8 mg/kg PO q24h for up to 2 consecutive days, administered at least 2 hours before travel with a small amount of food.FDA DailyMed An… At this dose, 93% of motion-sickness-prone dogs did not vomit during a one-hour car journey, compared with 48% of placebo-treated dogs.FDA DailyMed An… The injectable formulation is not interchangeable with tablets for the motion sickness indication.FDA DailyMed An…
In cats, the published antiemetic dose for prevention of opioid-induced emesis is 8 mg total dose PO (mean 2.9 mg/kg), administered 2–2.5 hours before morphine and dexmedetomidine.Journal of Feli… At this dose and interval, retching was reduced from 36% to 13% and emesis from 32% to 13%; sialorrhea and lip licking were not reduced, indicating maropitant suppresses vomiting but not nausea in cats.Journal of Feli… When maropitant is given SC to cats within 30 minutes of an emetogenic opioid, peak plasma concentrations may not be achieved before the emetogenic agent acts, reducing efficacy — a lead time of at least 30–60 minutes is required.Journal of the…
For perioperative use in dogs, maropitant must be given at least 15 minutes before an opioid to significantly reduce vomiting, and at least 60 minutes before to also significantly reduce signs of nausea.Journal of the… After SC administration in dogs, peak plasma concentration is reached within approximately 45 minutes of a 1 mg/kg dose.Journal of the… Maropitant reduces overall intraoperative isoflurane requirements — mean end-tidal isoflurane was 1.19% in maropitant-treated dogs versus 1.44% in controls during ovariohysterectomy — but did not reduce the incidence of postoperative nausea and vomiting in that protocol.Veterinary Anae… Maropitant promotes more rapid return to normal feeding and improves quality of anesthetic recovery but has a lesser effect on the incidence of gastroesophageal reflux and regurgitation.AAHA Clinical G…
For chemotherapy-induced nausea and vomiting (CINV), maropitant IV or SC is recommended as pretreatment for high-risk drugs such as doxorubicin and rabacfosadine, followed by oral maropitant for 4–5 days post-chemotherapy to prevent delayed CINV in dogs.AAHA Clinical G… Cats typically require less preventive treatment unless they have a prior history of gastrointestinal issues.AAHA Clinical G…
A critical limitation across species: maropitant reliably prevents vomiting but does not eliminate nausea.Journal of the…+2 Signs of nausea — sialorrhea, lip licking, excessive swallowing — persist even when emesis is fully blocked.Journal of the…+2 Ondansetron addresses both nausea and vomiting via 5-HT₃ receptor antagonism and has shown advantages over maropitant specifically for nausea control.BMC Veterinary…
| Indication | Species | Dose | Route | Duration | Key Caveat |
|---|---|---|---|---|---|
| Acute vomiting | Dog | 2 mg/kg q24h | PO | Until resolution; max 5 days in dogs <7 mo | Use injectable 1 mg/kg first if actively vomitingFDA DailyMed An… |
| Acute vomiting (injectable) | Dog | 1 mg/kg q24h | SC or IV | Up to 5 days | Interchangeable with oral for acute vomiting onlyFDA DailyMed An… |
| Motion sickness | Dog | 8 mg/kg q24h | PO | Up to 2 days | Give ≥2 h before travel; injectable not interchangeableFDA DailyMed An… |
| Opioid-induced emesis prevention | Cat | 8 mg total dose (~2.9 mg/kg) | PO | Single pretreatment | Give 2–2.5 h before opioid; nausea signs not reducedJournal of Feli… |
| Perioperative nausea | Dog | 1 mg/kg | SC or IV | Single pretreatment | Give ≥60 min before opioid for nausea benefitJournal of the… |
| Delayed CINV prevention | Dog | Oral q24h | PO | 4–5 days post-chemo | Cats need less routine preventionAAHA Clinical G… |
Would you like guidance on when to add ondansetron alongside maropitant for patients where nausea control — not just vomiting prevention — is the priority?