16 month female full breed

Question
I recently noticed the dog has one pupil much larger than the other.  Is there a concern?
Also, She continously chews her collar off at night when she is in her crate.  She actually cuts it like a knife.

Answer
The pupil size difference can be a concern, and a vet would have to be the one to fully examine her.  However, dogs with two different colored eyes (not sure if yours is one of them) often have one pupil that is more dilated than the other.  This is usually not a concern but has to do with the way light reflects from the iris.

As for the collar, tough one, but you may want to try removing the collar at night while she is in the crate.  If she only does it during this time, it might be a bored game she is playing.  After some time, you should be able to leave the collar on when she goes to bed.  But for now, there should be no harm in taking it off for bed.