A few days ago I noticed that many of the leaves on my 3-year old Prairie Fire Crabapple have small dark spots on them, and some of the leave are shriveling up and dying. I'll include photos below. The tree has been healthy for the last 3 years, but my puppy chewed on the trunk last fall and did some damage. I'm guess that it has fire blight or apple scab. I'm hoping that you might be able to recommend a treatment?