Pattern of breathing in brachycephalic dogs.
The pattern of breathing was assessed in 19 brachycephalic dogs, using tidal breathing flow-volume loop (TBFVL) analysis. Fifteen dogs had TBFVL consistent with a fixed-type upper airway obstruction, whereas 4 dogs had a TBFVL indicative of a nonfixed upper airway obstruction. The dogs did not have a TBFVL shape the same as that considered normal for healthy nonbrachycephalic dogs. Tidal breathing flow-volume loops from brachycephalic dogs that were considered to have a normal respiratory tract (n = 11) were similar to those of dogs with clinical signs of upper airway obstruction (n = 8). Respiration was monitored continuously for short periods (20 to 50 minutes) in 3 brachycephalic dogs resting in a cage in a quiet, darkened laboratory; 2 of these dogs had periodic breathing patterns characterized by multiple episodes of alternating hypopnea and arousal. Brachycephalic dogs may be at risk for the development of disordered breathing during sleep.
D000402:Airway Obstruction / Q000503:physiopathology / Q000662:veterinary*; D000818:Animals; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs; D005147:Facial Bones / Q000002:abnormalities*; D005260:Female; D008297:Male; D012119:Respiration; D012890:Sleep; D012913:Snoring / Q000503:physiopathology / Q000662:veterinary