Thank you so much for this answer, it really helps alot. There is one other thing that I forgot to mention before I accept this answer. My cat used to be very healthy and solid bodywise (muscular toned) and also has had fleas before in which none of the scabs, hairloss and itching began until about a year ago. He also has lost weight, which was hard to notice at first with all the hairloss, however, he is very flabby now in his lower abdomin region and the best way to describe it is, he lost weight in his belly/intestinal area but his skin didn't shrink to compesate his weightloss. Is this all most likely related to the flea allergy or could it be something else with the loose skin? Like I said before, he acts normal and seems to eat normal also. thanks for your answer and I will accept after this.