Many people are intimidated by the idea of starting crate training with an
adult dog, but if you take it slow crate training an older dog should be no
problem.
If you simply must crate the older dog immediately, many dogs will adapt to
the change well. You can crate the dog at night or when you are gone but remember
to alsocrate the dog randomly at times when you won’t be leaving or will
only be leaving for a few moments so that the dog doesn’t begin to associate
the crate with being alone. You may want to crate the dog sometimes while you
sit nearby and read or watch TV. Occasionally you should, out of the blue, lead
the dog to the crate, ask him to go in, give him a treat, and then walk away
without ever closing the door. This helps the dog understand that "crate"
does not equal "caged".
But if you have the time to take crate training an older dog slower, you should.
A dog will like the idea of crating better if he thinks it is HIS idea to sleep
in the crate instead of yours.
Evaluate whether you think your dog would like a private, cozy crate or one
in the middle of the family and place the crate appropriately (i.e. A bedroom
as opposed to a living room). Fill the crate with comfortable objects: a bed
or blanket that the dog has slept on before (preferably bedding that carries
your scent as well). Add a few old toys, and cover the crate all or part way
with a sheet or crate cover.
Remove the crate door or use twist ties to secure the door open (a dog may be
spooked if he bumps into the door or if it swings shut) and simply act like
nothing is different. Most dogs will think, “Hey, look at this cozy spot
I found!” and begin to claim the space as their own willingly instead
of being forced to, thus crate "training" themselves.
