cat diagnosed with dry fip

Hi there my cat Casey has been diagnosed with dry fip, and I was wondering if anyone as any advice for what to do know should I get a second opinion. What types of treatment should I try to slow it down- the vet suggested omega 3 ,vitamins and steroids. Would really appreciate anyone's help if they have gone through this themselves.

I'm sorry for the diagnosis, can you tell me in detail why he decided it is dry fip? VERY difficult to diagnose, there is not a test for this.
Bloodwork? Other symptoms?

If it is infact fip, there is nothing you can do besides keep him as comfortable and stress free as possible, and allow his life to end when he begins to suffer.

Thank you dir the quick reply. I'm lead to believe they draw the conclusion due to weight lose, a swallow stomach, losing the colour in his guns and yellow around the eyes. They were testing for a liver shunt as that's what it was suspected to be amongst other tests. Then when the results came back they said no it's fip. Which I feel just came out if no where as we hadn't been told it was even being considered.
He has been losing is appetite foe months since about January and he his losing being with drawn from the family, which believe they have pur down to a change in personality. Which I don't believe to be the case I think it's due to him being in pain but I think the vet is certain it's another sign of fip