A doctoral study completed at the University of Helsinki investigated the diagnostic possibilities for canine sleep apnoea, as well as its predisposing risk factors and potential symptoms.
Sufficient, high-quality sleep is important to the welfare of dogs. During sleep-disordered breathing, airflow is obstructed, and the body does not get enough oxygen.
A study conducted at the University of Helsinki found that sleep apnoea is more common among brachycephalic dogs, or dogs whose snouts and skulls are shortened and flattened, than among dogs with longer snouts. The former also snore more than the latter. However, sleep apnoea does not impair brachycephalic dogs alone. Instead, it was also observed in long-snouted dogs in the study. In addition to brachycephaly, factors predisposing to sleep apnoea include excess weight as well as moderate or severe symptoms associated with brachycephalic obstructive airway syndrome (BOAS).
The study demonstrated that a sleep apnoea collar worn at home enables the reliable and easy detection of sleep apnoea in dogs. The device, placed around the dog's neck to measure breathing during sleep, was worn in the study for one night. Previously, research on canine sleep apnoea has only been possible in the laboratory. The collar used in the study is not yet in general use.
"Based on the symptoms observed by the owner, sleep apnoea can be suspected even before the collar examination. Symptoms that may indicate sleep-disordered breathing include atypical sleeping positions, respiratory pauses during sleep and nocturnal restlessness. However, snoring alone does not necessarily mean that a dog has sleep apnoea," says Iida Niinikoski, Licentiate of Veterinary Medicine.
In addition, the study demonstrated that a low-grade inflammatory state occurs among English Bulldogs, similar to that observed in human sleep apnoea. In humans even such mild inflammation increases the risk of cardiovascular diseases, among other disorders.
According to Niinikoski, the detection of sleep apnoea in dogs is important, as it causes recurring disruption and fragmentation of sleep, which reduces sleep quality. It is also known that severe, untreated sleep apnoea in humans is associated with significant health risks, such as premature mortality.
"You should contact a veterinarian if you suspect that your dog has sleep apnoea. Symptoms can be treated with a range of surgical and pharmacological methods. Since obesity predisposes all dogs to sleep-disordered breathing, avoiding weight gain is important. It's important to note that the occurrence of this serious problem could be reduced by selectively breeding brachycephalic dogs to have longer snouts," Niinikoski says.
Iida Niinikoski, LVM, defended her doctoral thesis entitled Sleep-disordered breathing and inflammatory response in dogs on 15 June 2024 at the Faculty of Veterinary Medicine, University of Helsinki. Rowena Packer, BSc (Hons) PhD PGCert (VetEd) FHEA, from Royal Veterinary College, the University of London served as the opponent and Minna M. Rajamäki as the custos. The doctoral thesis was published in the Dissertationes Universitatis Helsingiensis series.
