I have 8 beautiful cherry laurel bushes and on of them appears to be dying.
Have not been able to see any insect infestation that might be the cause.
Leaves on affected branches have been drying turning yellow and withering. I have removed several dead branches, but the problem appears to be spreading.
Would appreciate any advice on what steps I might take to save the bush. Thanks for your help

It probably is diseased. I see some shot hole fungus damage (that's what causes the round holes in some of the leaves). I think that another disease might be causing the yellow leaves.
You probably should treat it with a good disease control product.

I had Cherry Laurels in the past, and I eventually replaced them because I got tired of spraying them. Mine were growing in a shady area, so fighting disease was an uphill, constant struggle. I hope you have better luck!