Hi
We have a Golden Retriever pup called Rory - aka Puking Pedro...
The furthest he has been able to travel is 20 minutes before being sick.
We have used Cerenia tablets - the 160mg as he is 25kg & they have worked brilliantly.
You give them at least 1.5 hours before travelling with some food & it lasts 24 hours.
They come in packs of 4 £25 'ish & you need a prescription or get them at the vet.
These have worked well for him I have to say... we are now weaned to half a tablet