VetMedMotion sickness in dogs: does maropitant before car travel prevent vomiting? — LIKELY
In dogs with motion sickness, does maropitant vs placebo prevent vomiting during car travel?
Shelf #397 · gate-verified and displayed under the developer's blinded-trial rule
LIKELY: In dogs with a history of motion sickness, a single oral maropitant dose before a car journey sharply reduced vomiting in two independent licensure-era programmes. In Benchaoui 2007 (two blinded, placebo-controlled studies), the larger multicentre parallel study found 69 of 105 placebo dogs (65.7%) vomited during the journey versus 15 of 106 maropitant dogs (14.2%, P < 0.0001) — an absolute difference of about 51 percentage points, a 78% relative reduction — and the exploratory crossover found 10 of 17 dogs vomited on placebo versus 3 of 17 on maropitant. In Conder 2008 (two randomised crossover trials, 189 dogs enrolled, 163 fully evaluable), maropitant at a minimum of 8 mg/kg given about 2 or 10 hours before an approximately 60-minute ride reduced the occurrence of vomiting compared with placebo by 86.1% and 76.5% respectively (relative reductions; that record gives no per-arm percentages). Design class (a): randomisation and blinding are both established by carded records — Conder 2008 states 'two randomized clinical trials' in its own wording, and Benchaoui 2007 states 'two blinded, placebo-controlled studies' with publication type Randomized Controlled Trial and MeSH Double-Blind Method. The honest limits: both programmes are the manufacturer's development programme, the dose tested for motion sickness is the high oral dose (minimum 8 mg/kg, not the 1 mg/kg injectable antiemetic dose), and the trials measure vomiting only — nausea signs during travel were not the endpoint. That single-programme basis is why the stamp is LIKELY and not PROBABLE. Drafted Nov 10, 2026 (VetMed build, topic #397); all figures from abstracts fetched and verified at drafting.
Benchaoui 2007: in the larger blinded placebo-controlled study, 69 of 105 placebo dogs vomited in the car versus 15 of 106 on maropitant (P < 0.0001); in the exploratory crossover, 10 of 17 vomited on placebo versus 3 of 17 on maropitant
Two blinded, placebo-controlled studies (record's own wording: 'two blinded, placebo-controlled studies'; publication type: Randomized Controlled Trial; MeSH includes Double-Blind Method)
Who: Dogs: dogs with a history of motion sickness resulting from transportation by car. Exploratory study: 17 dogs in a two-way crossover trial. Larger study: multicentre parallel-design study, 105 dogs treated with placebo and 106 with maropitant. Treatment in both studies was a single oral dose of maropitant (this record's abstract does not state the dose) or placebo before a car journey.
Result: In the exploratory crossover study, 10 of the dogs given placebo vomited during a car journey but only 3 of the dogs vomited under maropitant treatment. In the larger multicentred parallel study, 69 of 105 dogs treated with placebo vomited during the journey compared with 15 of 106 dogs treated with maropitant (P < 0.0001) — 65.7% versus 14.2%, an absolute difference of about 51 percentage points (a 78% relative reduction).
Watch out: This is the manufacturer's licensure-era programme (several authors are from the maropitant developer), and the abstract does not state the oral dose used — the dose (minimum 8 mg/kg) comes from the companion Conder 2008 record, not from this one. The endpoint is vomiting during the journey; drooling, lip-licking and other nausea signs of motion sickness are not reported in this abstract.
Benchaoui HA, Siedek EM, de la Puente-Redondo VA, Tilt N, Rowan TG, Clemence RG. Efficacy of maropitant for preventing vomiting associated with motion sickness in dogs. Vet Rec. 2007;161(13):444-7. PMID: 17906225. Registry ID: none in the record. MeSH: Animals · Antiemetics/therapeutic use* · Cross-Over Studies · Dog Diseases/prevention & control* · Dogs · Double-Blind Method · Female · Male · Motion Sickness/prevention & control, veterinary* · Quinuclidines/therapeutic use* · Treatment Outcome · Vomiting/prevention & control, veterinary*
Conder 2008: maropitant (minimum 8 mg/kg orally) reduced vomiting by 86.1% when given about 2 hours before travel and by 76.5% when given about 10 hours before, in two randomised crossover trials in 189 dogs
Two randomized clinical trials, two-period crossover design (record's own wording: 'two randomized clinical trials'; blinding not stated in the record)
Who: Dogs: 189 dogs with a history of motion sickness enrolled at 26 veterinary clinics across 12 US states across two trials; 163 were fully evaluable, 19 evaluable only for safety and 7 not evaluable. Each dog was treated orally with placebo or maropitant (minimum dose of 8 mg/kg body weight using unit dosing) tablets approximately 2 hours (Trial 1) or 10 hours (Trial 2) before an automobile ride of approximately 60 minutes, then, after a 10–14-day washout, given the opposite treatment and taken for another journey (same route, driver and vehicle).
Result: Maropitant reduced the occurrence of vomiting compared to placebo by 86.1% when given approximately 2 hours prior to travel and by 76.5% when given approximately 10 hours prior to travel — relative reductions as reported by the record, which gives no per-arm vomiting percentages, so no absolute rates can be stated from this record. No significant clinical signs were observed after maropitant treatment.
Watch out: The headline percentages are relative reductions without the underlying per-arm rates in the abstract, so this card supports the size and durability of the effect (protection still present 10 hours after dosing) rather than an absolute risk. Blinding is not stated in this record and none is claimed for it; the blinding basis for the shelf comes from Benchaoui 2007. Manufacturer's development programme, as with Benchaoui.
Conder GA, Sedlacek HS, Boucher JF, Clemence RG. Efficacy and safety of maropitant, a selective neurokinin 1 receptor antagonist, in two randomized clinical trials for prevention of vomiting due to motion sickness in dogs. J Vet Pharmacol Ther. 2008;31(6):528-32. PMID: 19000275. Registry ID: none in the record. MeSH: Animals · Cross-Over Studies · Dogs · Drug-Related Side Effects and Adverse Reactions · Female · Male · Motion Sickness/complications, veterinary* · Neurokinin-1 Receptor Antagonists · Quinuclidines/adverse effects, pharmacology, therapeutic use* · Vomiting/etiology, prevention & control*
Synthesis: a single high oral dose of maropitant before car travel prevents most motion-sickness vomiting in dogs with a history of it — LIKELY
Synthesis
Who: Synthesis of the cards above: Benchaoui 2007 (two blinded placebo-controlled studies in dogs with a history of motion sickness; 17 dogs crossover and 211 dogs in the parallel study) and Conder 2008 (two randomised crossover trials, 189 dogs enrolled at 26 US clinics, maropitant minimum 8 mg/kg at 2 or 10 hours before travel).
Result: (1) Placebo vomiting rates in susceptible dogs are high: 65.7% (69/105) in the Benchaoui parallel study and 10 of 17 in its crossover. (2) Maropitant cut vomiting to 14.2% (15/106) in the parallel study (P < 0.0001) and to 3 of 17 in the crossover. (3) The effect persists across the labelled dosing window: relative reductions of 86.1% (dose 2 hours before travel) and 76.5% (dose 10 hours before) in Conder. Two consistent, placebo-controlled programmes with large effects in exactly the target population support LIKELY.
Watch out: Both carded programmes are the manufacturer's; no independent replication was found. The evidence is for the high oral motion-sickness dose (minimum 8 mg/kg) in dogs already known to be travel-sick — it does not address nausea signs without vomiting, first-ever journeys in dogs with no history, or the 1 mg/kg injectable dose used for other indications (see Shelf #168 for acute vomiting and Shelf #695 for perioperative vomiting, whose claim-carrying records are not re-carded here).
Synthesis of Benchaoui HA et al. PMID: 17906225; Conder GA et al. PMID: 19000275. Registry IDs as on the individual cards.
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