A short snout predisposes dogs to sleep apnea

French bulldogs, pugs and other brachycephalic dog breeds are popular pets. Brachycephalic dogs are shorter-nosed and flat-faced as a result of breeding, making them more susceptible to heat, overexertion and respiratory problems.

In addition, brachycephalic dogs have been found to suffer from recurring episodes of sleep-disordered breathing, resembling human obstructive sleep apnoea caused by upper airway obstruction. During such episodes, normal breathing is interrupted by obstructed airways as the muscles of the upper airways relax, resulting in sleep interruptions and daytime fatigue. Sleep apnoea can have a dramatic impact on both human and canine wellbeing.

"Sleep apnoea places people at considerable risk of conditions such as hypertension and cardiovascular disease. Sleep affects the body's immune system, hormone secretion and metabolism. Sufficient, sound sleep is vital for quality of life. For these reasons and others, we are interested in canine sleep too," explains Doctoral Researcher Iida Niinikoski of the University of Helsinki's Faculty of Veterinary Medicine.

"Previous methods for investigating sleep apnoea have required dogs to sleep either while connected to all sorts of equipment or within a certain type of box in a lab. This has made research challenging and limited our knowledge of dog sleep apnoea."

The University of Helsinki Lung Insight research group investigated breathing during sleep in dogs using a neckband system developed originally for diagnosing human sleep apnoea.

The group measured breathing during sleep using the screening device in the dogs' home environment. Brachycephalic dogs recorded a much higher number of sleep-disordered breathing events than dogs with longer snouts. The short-nosed dogs also snored more than their long-nosed counterparts.

The neckband system was found to be an easy-to-use method for measuring sleep-disordered breathing. Although its use is currently limited to patients involved in research, in the future it may provide novel opportunities for dog sleep apnoea diagnostics in other contexts too.

Next, the research group will explore factors predisposing dogs to sleep apnoea.

As Niinikoski believes, "Good sleep is vital for the health of both humans and our animal friends."