A recent study out of Hungary reveals that flat-faced dogs – such as French bulldogs, the most popular breed in the US – have difficulty sleeping because of an unusual attribute: their head shape.
French bulldogs specifically suffer from increased daytime sleepiness, probably due to not getting enough night-time sleep. Sleep apnea in Frenchies and other flat-faced dogs including pugs, English bulldogs and Boston terriers is attributable to their shortened heads, or brachycephaly, a condition where the ratio of the skull length to its width is lower than normal.
With their big eyes staring right back at the owner, and adorable wrinkles rolled over their pinched noses, French bulldogs have shot up in popularity in recent years. This year they even ousted labrador retrievers as the most coveted dog breed in the US. But their distinct features and compact size come with a number of health issues.
“People favor a specific morphology of flat-faced dogs because they have a resemblance to babyface,” said Enikő Kubinyi, an ethologist and biologist studying dog behavior and cognition who co-authored the paper. “The big round head, high forehead, big eyes, and short nose – people find it cute, and they’re the size of a small child as well.”
The researchers studied the sleep patterns of 92 dogs accompanied by their owners. They found that compared with other dogs, the flat-faced breeds experience a longer phase of rapid eye movement, or Rem, sleep, regarded as the stage of sleep with most vivid dreams where the brain is active while the body remains still.
Researchers said this was similar to the way infants sleep, suggesting that dogs like Frenchies retained the sleep patterns of puppyhood. Their night-time sleep is shorter and flat-faced dogs are also more prone to snoring.
“Sleep deprivation is increasingly recognized as a major cause of suffering in dogs with extreme brachycephaly,” said Dan O’Neill, an associate professor at the Royal Veterinary College at University of London who was not involved in the study.
The researchers employed an electroencephalogram (EEG), a test that records electrical activity in the brain, throughout the dogs’ sleep. They looked specifically at spindles, or bursts of coherent brain activity, which are visible on the EEG. They found that dogs with brachycephaly had an increase in sleep spindles, which in humans has been associated with memory impairment and in dogs to poorer learning when it comes to training.
“It’s really fascinating how [the study authors] have tried to correlate some of these sleep parameters with skull anatomy,” said Kari Ekenstedt, an assistant professor specializing in genetics at the Purdue University College of Veterinary Medicine, who was not involved in the study. “We know that some of these dogs will sleep with a ball in their mouth, and people think it’s cute, but they’re actually doing it in order to try to keep their airways open.”
O’Neill agreed. “Perversely, many owners find this phenomenon very funny and post videos online showing how comical their dogs are as they sleep with a toy in their mouth or with their neck extended or repeatedly waking up to breathe during sleep,” he said.
Flat-faced breeds, like French bulldogs and pugs, live on average three to four years less than other dogs, raising concerns over selective breeding and ownership of these dogs.
“People normalize these health problems, thinking that it’s the characteristic of the breed, that it’s normal and not painful for the dog, not being able to breathe,” Kubinyi said. “We need to talk about why people need a dog that resembles a child, and which needs constant care, both financially and emotionally.”
