Missing cat advice

[darumafan]

I need some advice urgently and I know that someone here will be able to help me 🙂
My cat has returned home after his latest 2 year adventure at the local scrap yard.
He has got an ear infection which he has got medication for, was unbelievably dirty but seems to be in very good condition.I
The problem is with our other cats, they did live with him quite happily for several years before but seem very unsettled.
One of them, who is actually his litter mate is pretty much ignoring him but we have had the occasional half hearted hiss.
The other one who is very timid and nervous is very unhappy.
What do I need to do to reintroduce them all and keep them all happy?

Have you tried Feliway or Feliway Friends?

I think you have to tackle this as though you're introducing a completely new cat - so give him time apart from the others and short, supervised time together, gradually increasing.

You must have been over the moon when he came back!

We only got him back yesterday morning and he spent all day upstairs with me whilst I worked so it was only last night after his bath that they came face to face.
They seemed fairly settled when we went to bed last night but I worry.
We are absolutely over the moon to have him home.

Zylkene capsules mixed in with his food.

@Fluffycloudland77, I have just been and got some so I'll try it this evening

Give them time! It might take a few weeks!!
Someone will be “boss cat” and they will all know the pecking order soon enough. Especially if they have access to roam.
They will probably end up pretty much ignoring each other.