Thanks for your query.
off n on 1 week ,poor intake, smelly urine, sore neck & letharginess.
He might be having a simple viral illness but it might turn out to be a urine infection or meningitis
( infection & inflammation of the lining that surrounds brain & spinal cord
Please get him checked soon.
In the meantime give him frequent small drinks & panadol
Hope you find this information useful.