Where are dogs kept when you travel with them by ferry to Tenerife?

I have lots of friends who travel with dogs over to Ireland via the ferry and you just leave the dogs in the car, what happens on longer journeys like Cadiz to Santa cruz, or Portimao?

On the Spanish ferry from Huelva to Santa Cruz they are out on the top deck of the vessel. Mostly in the shade and can be tied with a lead to lay outside the large wire 'cages' and plenty of bowls of water and an exercise space.

I don't know about now, but when I traveled down from Cadiz in '94 all the dogs had kennels on the top deck of the boat.

I saw owners there walking their pets too.

Forgot to say that the info I gave was only a couple of month ago April 2013!

The ferry to Huelva has two decks where you can keep your dogs, the car deck and the top deck. The top deck is open to the elements and on a windy day it's tricky getting to your pets cage, the lower deck is sheltered but you can only access the deck about 5 times in the day to walk and feed/water your pet. The pets do not stay in the car!

I posted a thread about the crossing if it helps.
The Cadiz crossing is longer,dirtier and more expensive

Most importantly take a M5 Nut and bolt or some string or cable tie to secure the cages as the locks are useless!!!!!!