What is this disease and can it be saved?

[nfear24]

Growing all over multiple branches on the tree.

 

[The Green One]

Black Knot of Prunus : Landscape : Center for Agriculture, Food, and the Environment (CAFE) at UMass Amherst

Pathogen Black knot of Prunus is caused by the native fungal pathogen Apiosporina morbosa. Hosts Black knot occurs on more than 25 species in genus Prunus (cherry, plum, chokecherry, peach, nectarine, apricot, almond, etc.), but is particularly destructive on ornamental cherry, plum and...

ag.umass.edu

 

[Basswood]

Black knot. You can do sterilize pruning but I’d make a plan to replace the tree in the near future.

 

[KTSmith]

And best to replace with resistant varieties/species to the black knot disease. I'm not sure from which Milford comes the OP, but throughout New England and beyond, native wild black cherry (especially multi-stemmed brushy little guys) provide an essentially infinite reservoir of the pathogen. Black knot is a big reason why cherry is not an orchard crop in these parts.