Dogs may scratch due to separation anxiety, noise phobia, or changes causing stress.
Anxiety
Intact males scratch to leave their scent and mark territory. Neutering curbs this.
Marking Territory
Inadequate exercise and mental stimulation cause boredom scratching.
Boredom
Interesting smells on floors prompt excited scratching to pick it up.
Scent Marking
Dogs scratch due to skin irritation and itchiness from food or environmental allergies.
Allergies
Dry, flaky skin and dander lead to scratching behaviors.
Dry Skin
Fleas, mites or yeast prompt scratching due to skin irritation.
Parasites