A symptom of a disease is not to create holes. You might have a fungal disease that causes brown spots on a plant but not holes.
Chances are that you have an insect problem. Perhaps a slug or snail problem as they might nibble the edges of the leaves. Beetles, grasshoppers and a few other insects can nibble leaves.
But without knowing where you live, in what climate zone, makes it more of a guess to name a cause.
Is this a shrub or a bush that drops all of its leaves before winter. If it is, you can treat next year when you first find the damage starting. If the insects are there now, you could treat but if the leaves are going to drop for the winter, why treat something that is going to drop anyway.
