Malinois 4 year old chewing up furniture

Question
I have 2 beautiful 4 year old malinois, they are the best dogs, except for the fact that when left alone they will, from time to time attempt to "eat" the leather couch ... this has been a constant in their behavior, I have scat mats, but yesterday they went for the part of the couch that was not covered by the scat mat, when I came home they had the "guilty attitude". Please help me I do not know what to do, they are well trained in basic obedience and have an impressive protection instinct, since they were puppies they have destroyed 3 couches and 2 love seats, also pillows are something really attractive for them. Please help me. Thanks

Answer
Hi, Veronica,

The only suggestion I can make is to restrict their access to the furniture, either by crating them or putting them in a laundry room, bath room, etc.

In my opinion, crating would be more humane than being closed up in a bathroom.  Dogs can be crate trained at any time in their life, but how fast you progress depends a lot on how you do it.

I'm including info here:

http://www.ddfl.org/behavior/crate-train.pdf
http://www.hsmo.org/m_obedience/behavior/dogcrate.html