Gastric Torsion is a critical condition that often follows an episode of bloat. Bloat is something that can occur within the stomach of the dog when an excess of gasses build up to a dangerous level.
This causes a rapid expansion of the stomach, which can lead to such a deformation of the stomach sack that the blood supply is severely restricted, which can then lead to parts of the stomach being so starved of oxygen that there is partial tissue death.
In addition, the entire stomach sack, for reasons not clearly understood, can flip over or rotate into a new position that pinches off both ends, causes a critical emergency. If not corrected swiftly, the ever expanding gases and loss of blood supply to the stomach can lead to rapid decline, shock and death.
The symptoms of canine bloat can be difficult to spot easily.
Your dog's abdominal area will be swollen, but it may be difficult to notice.
He will also pant and salivate excessively.
Dogs with canine bloat will also walk around agitated, may find it difficult to lay down, and may whine.
Some dogs also retch or vomit, although nothing will come up.
It is important for owners of deep chested dogs such as the Leonberger to be aware of this serious condition, to know the signs, and to have the details of a 24 hour emergency vet on hand at all times if possible, in case of such an emergency.
The below video link to Youtube showing an Akita with the initial signs of bloat.
The dog did receive treatment and survived, but this video provides a very graphic illustration of what a bloating dog looks like and how it acts.