It's quite a common belief that dogs do have dreams as we watch our pets run or scratch or make noises as they sleep (just like below). 

And the research does in fact point to the answer that YES, dogs do dream when they sleep.

 What research has found is that the human brain and canine brains are structurally similar and also showed that there was similar activity in the brain during sleep.

They also found that when the dogs were in deep sleep, irregular breathing and muscle twitches were observed. These behaviours are all consistent with the idea that dogs do in fact dream just like humans.

 An interesting finding was that upon entering their "dream stage" which takes around 20 minutes into sleep, the duration and frequency of their dreams varied depending on the dog's size and age. The smaller dogs tended to have shorter and more frequent dreams, while the larger dogs would have longer dreams (up to 10 minutes) less frequently (every hour or so). 

And so, we can guess that the puppy in the video above would have more dreams than the adult dogs, as their growing brains would be taking in so much new information every day! 

What does my dog dream about? 

 It's been found that our dogs dream about what happens during the day. Whether it be running in the park, eating a meal or playing with friends... just like the video below. 

On a final note, if it may seem like your dog is having what may seem a stressful dream, try to resist the desire. This is because it will interrupt their restorative sleep, but they may, just like people, may wake up disoriented and potentially angry as their dreams may still feel like reality to them. 

There you have it! 
Enjoy observing your pup frolic through their day during their sleep! 

Information Source: Barkpost