Agree! We inherited many fruiting trees, and no clue what to do, but we now know, PRUNE hard about now, let them grow, and then DORMANT SPRAY. And then THIN like 10 inches apart!

Tough love!

Suzi

So, if it's okay to prune now, then what is the big fuss about winter pruning?

When the trees are leafless,it's easy to see the branches and be more detailed about what the desired shape might be.
Summer pruning is more about keeping the size in check. Brady

I like to do any "major" pruning during dormancy- if it needs saw or loppers I prefer it to be done during late winter. Once the tree starts bushing up I go back in and thin to keep it open and remove new stuff going the wrong direction.

Also, as Brady says, summer pruning serves to keep the size of the tree in check, as it deprives the tree of photosynthetic sugars that it would otherwise be storing in the roots to fuel next year's growth. Winter pruning is also ultimately dwarfing, but will be followed in the spring by bushy growth.

Do I need to do anything special to avoid leaving the tree susceptible to disease?

Rain might be the major thing that could introduce unwanted things.So if available,pick a stretch of dry weather. Brady