Flat-faced dog breeds, such as French bulldogs and pugs, are immensely popular worldwide. However, recent research by Hungarian scientists sheds light on the detrimental health effects associated with these breeds. The study, which focused on sleep patterns, revealed that flat-faced dogs experience increased daytime sleepiness due to breed-specific sleep apnea. The research further found that their REM sleep phase is prolonged compared to non-REM sleep, and their sleep EEG patterns indicate signs of white matter loss.
While the distinctive appearance of flat-faced dogs, characterized by large, round heads, appeals to many pet owners, it comes at a significant cost to their health. These breeds, on average, live 3 to 4 years less than other dogs and often face various health issues, leading to surgeries for musculoskeletal, eye, and respiratory problems. The abnormal shortening of the skull, associated with a distorted brain, raises concerns about its impact on neural functioning.
In the study, Hungarian researchers examined the sleep patterns of 92 family dogs using EEG. Anna Kis, a researcher at the HUN-REN Institute of Cognitive Neuroscience and Psychology, explained that flat-faced dogs exhibited increased daytime sleep, likely compensating for insufficient nighttime sleep due to respiratory problems. The EEG analysis revealed intriguing results, showing that brachycephalic dogs (short-nosed breeds) had altered brain wave patterns during sleep.
Zsófia Bognár, a Ph.D. student specializing in brachycephalic dogs, highlighted the findings related to the REM phase, emphasizing decreased beta waves and increased delta waves in these breeds compared to dogs with longer noses. These patterns, associated with poorer learning in dogs and white matter loss in humans, raised concerns about the potential impact of breeding for specific head shapes on brain function.
Ivaylo Iotchev, the first author of the study published in the journal Brain Structure and Function, noted that brachycephalic dogs seemed to retain a sleep pattern resembling puppyhood, characterized by increased REM sleep. Enikő Kubinyi, a professor leading the MTA-ELTE Lendület “Momentum” Companion Animal Research Group and ELTE NAP Canine Brain Research Group, suggested that breeding for infant-like traits in appearance might have infantilized the brain function of these dogs. While this remains a bold assumption, the study underscores the potentially harmful consequences of breeding for specific head shapes in dogs.
