Dogs on Trains

[2Funki4Wheelz]

Which means the website is totally inconsistent because...

The FAQ clearly states the need for a ticket for (unfolded) bikes:

Q. Can I bring my bicycle onto the train?
A.
Bicycles can not be conveyed on DART or Commuter trains unless folded and suitably covered. On Intercity trains bicycles not folded and covered can be conveyed in the guards compartment or the special cycle racks where provided. A valid ticket for the bicycle must be obtained before travelling.

Please check at your local station before travelling.

So it's reasonable from the above that a dog should only require a ticket if travelling in the guard's compartment.