Travelling with Dogs to St Malo

I am thinking about a trip to Brittany in June and, as we travel with our two labradors, I was wondering about the best ferry route.  The dogs are happy with the trip from Dover to Calais but its a long run down to Cotes D'Armor or Finistere regions to start the tour.  Landing at St Malo would reduce this trip but I'm not sure what happens with the dogs.  Do they stay in the 'van or are there kennels on board the ship? Are kennels a better option for the night crossing?  Do they get a comfort break?  Any thoughts or experiences that can be shared would be appreciated.