Why Do Dogs Tongues Hang Out. If your dog’s tongue is hanging out and they’re also showing other signs of illness, such. Dogs sleep with their tongues out because they’re very relaxed, dreaming, dehydrated, or cooling down.
However, you can make sure that your pet is more comfortable by keeping out water for. The most common reason why dogs stick their tongue out is to pant. Although this is a harmless trait, it is a good idea to know the exact reasons why dogs sleep with their tongues out.