Recently a publication came online about problems of which the researchers assumed they might occur in short muzzled breeds more often then known.
Short muzzled breeds are breeds with a muzzle that is significantly shorter than the (usually broad) skull. Brachycephalic is the official name for those head types, which means the skull is relatively broad. It is a phenomena usually seen in bulldogs but in quite a lot of other breeds as well.
Because the muzzle is shortened bit the inner parts don’t shorten along problems may occur. The tongue for example doesn’t get shorter, nor does the soft palate. This can be in the way while the dog is breathing and explains why dogs like this often cannot stand heat very well. The respiratory tract is partly blocked thus causing severe problems for the animal. The snoring, by many people something considered something “cute”,, in reality is a sign of anguish.
Another consequence caused by this snoring is dogs like this often suffer from sleep apnea, which means the breathing stops for a moment during sleeping. This causes a disturbed pattern of sleep and eventually can lead to health problems. In humans this is a known problem that is treated because of the possible consequences. In dogs though not much is known about it so far. The researcher asked themselves whether the apnea many dogs suffering from BOAS (Brachycephalic Obstructive Airway Syndrome) show could have an effect that could be shown by testing. In people with apnea some abnormalities in the blood are known to be caused by apnea.
In the recently published research several dogs with severe BOAS were tested, alongside a group of Labradors with normal head and muzzle. Both groups were tested with blood samples to see what would actually happen during sleeping. Techniques used were thromboelastography, a method to measure how and when clotting in the blood occurs. This “clotting status” is very important because it concerns thrombosis but also the healing of wounds.
All BOAS dogs turned out to be hypercoagulable, which means the clotting time diverges from normal. It can cause thrombosis in different variations and may lead to bad healing of wounds. Although this problem is sometime genetic, most often the reason is secondary and may well be caused by sleep apnea. In the BOAS dogs the cause very likely is the disturbed breathing.
BOAS dogs also had evidence of delayed fibrinolysis. This is the process that prevents blood clots from growing and becoming problematic. The cause of this delay is almost always secondary, in other words: caused by something other than genetic predisposition. The fibrinolysis is also seen as a direct result of the breathing problems.
All these problems were found in the test animals that all seemed fine and healthy. The researchers therefore stated the Brachycefalic Obstructive Airway Syndrome causes more problems than was assumed.