Fleas can carry disease and other parasites, including tapeworm. And fleas are extremely irritating for your dog. They often cause intense itching, which in turn can cause your dog to damage his/her skin by vigorous scratching.
Dogs can suffer from allergies just as readily as humans can.
And there can be a variety of causes of dog allergies, just as there can with human allergies.
One thing your dog can’t tell you, though, is what he or she has come into contact with that could be causing the dog allergy.