Flat-faced dogs suffer from more sleep issues, study finds
The patterns could be associated with poor learning success in dogs.
A recent study has found that flat-faced dogs are sleeping more in the day, as a result of the sleep apnea associated with the breed.
The research, conducted by Eötvös Loránd University, discovered that brachycephalic dogs had a rapid eye movement (REM) sleep phase which was longer than their non-REM sleep. Their electroencephalogram (EEG) patterns also indicated signs of white matter loss.
During the study, researchers studied the sleep of 92 dogs using an EEG. The dogs spent three hours in the lab with their owners, where they quickly fell asleep.
Initial observations saw that the flat-faced breeds slept more during the three hour session than other breeds. The researchers theorised that this could compensate for a lack of sleep during the night, caused by their sleep apnea.
The scientists then used electrodes on the dogs’ scalps to conduct the electrical potential generated by their brain activity.
EEG patterns are used to identify the activities of brain waves during the REM phase of sleep, when there is a high frequency of brain activity. The amplitudes of beta and delta brain waves especially may indicate learning success in dogs and intelligence in humans.
The EEG results for the flat-faced dogs found decreased beta waves and increased delta waves, compared to dogs with longer noses. They also displayed an increase in the frequency of sleep spindles.
These patterns are associated with poor learning success in dogs, and a loss of white matter in humans.
The study could not clarify whether this was a result of breathing and thermoregulation issues, neuro-psychological conditions caused by brachycephaly or a juvenile sleeping pattern.
However, the researchers suggest that flat-faced dogs may be retaining their sleep pattern from puppyhood, alike newborns who are mainly in REM sleep. They say this could be connected to the infant-like traits that attracts many owners of brachycephalic dogs to the breed.
Prof Enikő Kubinyi, an author of the study, said: “It is possible that the selection of dogs to be infant-like in appearance has also infantilized their brain function,
"But this is a bold assumption for now. What is very likely, however, is that breeding for brachycephalic heads leads to potentially harmful changes in brain function."
The full study can be found in the journal Brain Structure and Function.
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The Veterinary Medicines Directorate (VMD) is inviting applications from veterinary students to attend a one-week extramural studies (EMS) placement in July 2026.
