jealosy?

Question
"Our dog Madelynn (black lab) was 3 yrs old when we got Celia (full bred german shepherd) as a puppy..11 wks old. They got along wonderfully at first. Madelynn adopted the 'motherly' approach and helped Celia learn the boundaries here. We live own a 3 acre property with woods all around us. Madelynn also taught Celia some of the basic things to do and not to do. It was amazing to see. She slowly (it seemed as Celia learned) made the boundaries larger for Celia. Til now..they are inseperable. Good friends. Together all the time...romping around the property and checking out the countryside together. The problem is that Madelynn can be very mean to Celia as well. When they are both put in a large outdoor fenced in kennel we have for them, Madelynn will bite/snip at Celia til Celia howls, when Madelynn sees us coming toward the kennel (outside kennel, large 6 ft area outside attached to a shed where they can go inside for shelter). I realize this is dominance on Madelynn's part. We have had Celia for a year now. Is there any way I can help this to get better? I feel so sorry for Celia when Madelynn does this."  Our dogs are part of the family and are treated as such...love, caring and attention.  Our dogs are both females.  Is is just my husband and I (we are both in our 40s) and the 2 dogs.

Answer
It appears that Madelynn (M for now) is making a strong rank statement to Celia (C) when enclosed in small area, so that C does not approach YOU FIRST.  (Wonderful names, by the way!)  You may not have appropriately treated M as higher ranking (not a flaw on your part, simply not knowing better.)  So long as M is not actually harming C (leaving bloody marks), C perfectly understands what's going on; you may  have verbally corrected M for this behavior OR you may have "comforted" C (a normal reaction), so C's wailing may be stronger because she anticipates your attention/reaction.  

Two things: using positive reinforcement training and a new word (not "sit", make one up) retrain M for a strong, 100% successful "sit" on command.  This will take approximately two weeks and do this with M alone, out of sight of C.  Go to Karen Pryor's website to obtain information on clicker training and positive reinforcement (you don't need to use a clicker, you can use your index finger touching your nose, this makes the dog FOCUS ON YOU and actually heightens your leadership).  Once M has obtained this reliable behavior, make her EARN your attention for a month.  Do not pet her, feed her, play with her, or in any way interact with her UNTIL she has responded to your new command for "sit".  This will effectively eliminate her need to control C when you approach the enclosure, since she will now understand that she will not get ANY attention until she is asked to perform.  Meanwhile, be certain to treat M as the higher ranking (even when she needs to WORK for attention).  Pet her first (remember, ask for the behavior once it is trained), greet her first, feed her first, let her in/out first, etc.  Learn about multiple dog households by reading Patricia McConnell Ph.D. and throw in a smattering of the late, great John Fisher.  So far, M is clearly in charge, and she intends to stay that way; this may not be the case in real life-- C may actually be more temperamentally suited for the job (by breed.)  If you find that aggression begins to escalate between M and C, regardless of your training attempts, repost with every detail of the problem and we will attempt to tackle the change in rank status (normally this requires hands on approach by a certified applied animal behaviorist...some things cannot be addressed in a text box.)