Awww, the cuteness is off the hook! Watching your fur-baby sleeping can be such a joy, especially when they're in REM sleep. This is when they dream, so you might catch them 'running' after a critter or through a field! If they're involved in a high-speed chase, then you'll probably notice an increase in their breathing rhythm. Don't worry; this is one of the harmless times that might have your dog breathing fast when compared to his regular breathing. Still worried? You can wake him gently by softly calling his name. Don't startle him awake. He hates that (just like you do)! His breathing should return to a normal pace fairly quickly.
A puppy breathing fast is much more common than an adult dog breathing fast. For one thing, puppies dream more than adult dogs do. Puppies are also developing their lungs and expanding their lung capacity. Adult dogs should have outgrown this behavior long ago, although they may pant or breathe rapidly for a brief time during sleep.
First, let's confirm that your dog is actually breathing faster than usual. A puppy will take a breath up to 40 times per minute while an adult dog will take only up to 30 breaths per minute. Watch your fur-baby closely and count his breathing for a full minute to see if it's really out of the normal range. If it is, then let's investigate further.
A warm environment:
In a warm environment, a quick romp around the yard can have your dog breathing heavy. Dogs don't sweat the same way humans do. When a dog is overheated, he'll pant to regulate his body temperature. He may roll onto his back to expose his belly, which helps the excess heat to escape. Once he's cooled down, perhaps by going indoors or finding some shade (or a refreshing pond), then his breathing should return to normal. Remember, your pooch will be more vulnerable to heat exhaustion in warmer climates. If you're uncomfortably warm, then Fido probably is too. If your furry friend's breathing does not return to normal within a reasonable time, then take him to a veterinarian for a check-up.
Some foods are no-nos for dogs! While you may think it's fine to share your leftovers with your fur-baby, the truth is you could be poisoning him! Onions and garlic are especially dangerous as they can cause diarrhea, vomiting, and excessive salivating in addition to the rapid breathing. If your dog shows these symptoms, then get him to a vet for a check-up as soon as possible. Many other foods are bad for dogs, and we'll discuss those in another article.
Your dog may be suffering from anemia, which is a blood condition. Fido's immune system may be attacking his healthy red blood cells, which circulate oxygen throughout your dogs' body. If this oxygen flow is reduced, then your dog may breathe more rapidly to compensate for the shortage.
Heart or lung condition:
Some heart and lung conditions can cause excessive panting. If Fido has a heart condition or fluid in the lungs, for example, then his oxygen level will be diminished. He may be trying to get more oxygen by breathing rapidly. If this is the case, his rapid breathing will not be occurring only when he sleeps, but all day, all the time.
The Bottom line:
Rapid breathing is normal for a dog under several circumstances. Still, if you cannot determine that your dog was dreaming, or just tired, or was temporarily overheated, then it's best to get the advice of a veterinarian as soon as possible. If Fido has a medical condition, then he will require medical attention to resolve the issue. If not, then maybe he's just chasing a squirrel :)