Dogs are special and as such, you need to know that there is only a limited amount of time that they should be stowed in a crate or carrier. At night time, you do not have to concern yourself with this as their body systems will slow down. However, in the middle of the day the younger the dog the less time they should be stored away in a carrier. No matter the age, though, no dog should be stowed away for longer than four to five hours at a time. If you do not abide by this, your dog may begin to act abnormally and experience behavior problems.
In general, you should keep 8 to 10-week-old dogs in a crate no longer than an hour, 11 to 14- week-old dogs no longer than three hours, 15 to 16 week no longer than four, and everything older no longer than five hours.