Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you today. I do apologize that your question was not answered before. Different experts come online at various times; I just came online, read about your situation, and wanted to help.
Again I do apologize that my colleagues could not aid you sooner. If you would still like assistance, can you tell me:
How long has he been showing this behavior?
How long did he sit in this manner this time?
If you call him or interact with him, does he stop?
Has he had any other signs (ie head tilt, circling, flickering of his eyes back and forth as if he were watching tennis)?
Any change to his appetite, thirst, or weight?
Is he passing more, dilute, or orange urine since this started?