Study Shows Shape of a Dog’s Head Can Actually Affect Their Sleep

If you have noticed that your dog’s sleep quality is reduced, or that they have begun to snore heavily, there might be an unusual reason behind it – the shape of your pet’s head! Snoring problems can be quite common for many dogs, but they are most often seen in brachycephalic dogs – basically, dogs with flat faces. For example, this is the key characteristic of the  French Bulldog, one of the world’s most popular breeds. 

In the USA, and in Hungary where the research for these claims was conducted, the goofy little French Bulldog holds the place of the number one most common pet dog breed. And that means that some health-related issues, stemming from their flat-face appearance, are coming into the foreground. Their shortened skulls and brachycephalic morphology result in sleep problems, snoring, difficulties with breathing, and deteriorative brain morphology changes. 

According to the latest  study by a Hungarian research team, flat-faced dogs tend to sleep more because their breed suffers from sleep apnea and thus their daytime sleepiness is increased. Thus, their REM (deep) sleep phase is much longer than their non-REM sleep, while the EEG patterns in their sleep indicate signs of white matter loss. 

And while some owners across the world see these Bulldogs and their extremely flat skulls as an attractive or unique feature, it is, nonetheless, a major health hazard. These breeds, for example, the French Bulldog, the Pug, and the English Bulldog tend to live around 3 to 4 years less than other dogs, and in many cases, they don’t even live to adulthood.

Some will even have to undergo surgery to correct their musculoskeletal, respiratory, and eye problems, which can cause them a lot of problems throughout their lives. To make matters worse, the rounded and short skull of these dogs results in a distorted and rounded brain, which could affect neural functioning.

All this resulted in the Hungarian team’s extensive research into the sleep of these breeds. They studied the sleep of 92 dogs, using EEG. 

"In the sleep lab, dogs spend about three hours with their owners. As nothing exciting happens, the dogs fall asleep quickly. Meanwhile, we conduct the electrical potential generated by the brain activity with electrodes glued to their scalps," says Anna Kis, who is considered a pioneer in the study of sleeping dogs and a researcher at the HUN-REN Institute of Cognitive Neuroscience and Psychology. "We wanted to investigate whether flat-faced dogs sleep differently from other dogs, as they are known to suffer from oxygen deprivation due to respiratory problems and therefore have poorer quality sleep. We found that the flat-faced dogs slept more in the three hours given to them during the study. More daytime sleep is probably compensation for insufficient sleep at night.”

Ivaylo Iotchev, the first author of a study of dog sleep patterns that was published in the Journal of Brain Structure and Function, adds "In the present study, we found that brachycephalic dogs had decreased beta waves and increased delta compared to dogs with longer noses. The frequency of sleep spindles increased. This pattern has previously been associated with poorer learning in dogs and loss of white matter in humans."

He also adds "There may be several reasons for our results. The most interesting of these is that it seems as if the flat-faced dogs have retained the sleep pattern of puppyhood, similarly to newborns who spend more time in REM sleep.”

If you own a brachycephalic dog and have been seeing a lack of quality in their sleep, these studies might provide the answers you are looking for – your pooch’s genetics might be to blame for their poor sleep.