What is mange?

What is Mange? I have a 2 year old black lab.  A few weeks ago I noticed that he had dandruff really bad.  Then I noticed that he started losing his hair in areas.  I thought he got in a fight with 2 new dogs in the neighborhood.  He has red/scally areas where some hair fell out that seem crusty/dry?  Could that me mange?  He seems fine like he isn't sick.  He is allergic to bee's and probably some other stuff but he hasn't been able to get into anything?  

[krickett]

Mange is a mite but there are many different types of skin conditions that could cause hair loss. It might be mange, might be staph, maybe it's ringworm, or maybe it's just allergies. You'll need to take him to the vet to be certain. Don't risk not taking him and it being something you could get.

[mami1323]

My dog had this as well.  It's called cushings disease.  Is your dog losing hair on the sides and by the ears?  Are the legs and head the main areas that have hair and everything else is thinning?  My dog developed little scabs and the hair would fall off of those scabs.  It's treatable.  I'm not saying this is what it is but I would take your dog to the vet.

Below is a description of what cushings is:

Cushing