Apple diseases

I would appreciate advice on the best course of treetment for my apple trees all 4 have the same problem which I think is fire blight but dont want to do anything drastic without seeking advice from those with more experience. I suspect i will have to cut off all infected areas but since these are Espaliers that will mean removing large portions of the trees.

Thanks.

The best way to treat that (yes it is fire blight) is to make a good compost tea and spray that on the whole tree and the soil around it, the microorganisms will combat the blight organisms and protect the rest of the tree.
Expect to make three to five applications of compost tea to get it fully under control.