Greetings Philippe,
I understand that some dams can lose condition with a litter, however if she is still seriously thin, you might want to have her checked for thyroid or other problems that might effect her life span. If you believe it is just nervousness, maybe you should think about the cause of that...
I know mushers keep their dogs chained outside and this seems to work for them, but wolfdogs are not huskys, they are extremely sensitive to their environment, they are pack orientated and need constant physical contact.
I would not tell you what you should do with your animals, and you may think of them as property to do with as you please, but I am not afraid to speak up and give my opinion.
I do not believe that my life is any more important than my animals. I give them love and respect and in return I get love and respect. I would trade places with them any time, they have a much easier life than I do..
However, if I had to be confined with a chain around my neck for the majority of my life...I can tell you it would effect my personality, my temperment, my willingness to love, and I would have no respect for anything...or anyone...and might be a little prone to nervousness...just a thought, something you might want to ponder....
It is not my intention to offend you with my opinion, merely to offer it as another life view of someone across the world. It is just my opinion, and I am neither right nor wrong, I am just me, and you are you. I will say no more.
Be well.
Respectfully,
Stands Alone