>>with his neck twisted and stuck to the left , and can now only swim in a sharp downward spiral to the right, or walk in a circle going towards the right.
All I can do is throw in another possibility.. it may be a respiratory infection. Tilted head technically called torticollis sometimes called "wry neck" can be caused by bacterial infection.
The only way to know what is causing this would be to find a vet who can run some tests.
You might try http://www.arav.org/
or look around through this link.
Good luck!
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PHRatz
