Search

Background Dogs with tracheal stents often have positive airway bacterial cultures. The pathogenicity of these organisms and risk factors for infection have not been investigated. Objective Describe bacterial infection in dogs with tracheal collapse before and after tracheal stent placement. Animals Fifty-three client-owned dogs. Methods Retrospective review of medical records of dogs receiving tracheal stents with thoracic radiographs, tracheoscopy, and endotracheal lavage. Results There was no difference between the overall prevalence of dogs with positive bacterial cultures before (31/38; 82%) or after stent placement (24/31; 77%) (P = .67). An increased number of geriatric (17/28; 61%) and traditional-type collapse (TTC) (16/26; 62%) dogs had positive pathogenic airway infections before stent placement, compared to young (8/25; 32%; P = .04) and malformation-type collapse (MTC) dogs (9/27; 33%; P = .04). After tracheal stent placement, geriatric dogs had a 52% reduction in pathogenic bacteria infection frequency (P = .02) and dogs with TTC had a 56% reduction in pathogenic bacteria infection frequency (P = .01). Significant risk factors for pathogenic infection included a history of pneumonia (OR = 3.6; 95% CI, 0.28-43.36) and cardiac disease (OR = 1.25; 95% CI, 0.16-9.92) in geriatric dogs, and hepatomegaly in young dogs (OR = 1.5; 95% CI, 0.12-19.44). Conclusions and clinical importance Tracheal stent placement does not increase the overall rate of pathogenic bacterial infection in dogs with tracheal collapse and can decrease the rate of subsequent pathogenic infections in geriatric dogs and dogs with TTC that require tracheal stenting. Airway culture and cytology should be performed in all dogs undergoing tracheal stent placement.

An increased tracheal bifurcation angle on the dorsoventral projection is described as a sign of left atrium enlargement in dogs, with a normal range of 60-90 degrees reported. However in people, this angle is a poor indicator of left atrial size. Our purpose was to evaluate the value of the tracheal bifurcation angle for differentiating normal from enlarged left atrium in dogs. Dorsoventral radiographs and echocardiograms of 33 healthy and 73 dogs with confirmed degenerative myxomatous mitral valve disease were evaluated. Left atrial size was classified according to the echocardiographic left atrium to aorta ratio, as normal, mildly, moderately, or severely enlarged. Independent samples t-tests were used to compare the bifurcation angle between groups. A significant difference was observed between the angle of dogs with normal left atrium (68.1 +/- 8.5 degrees, range: 51.3-92.4 degrees) and dogs with enlarged left atrium (75.8 +/- 8.2 degrees, range: 57.3-91.7 degrees). A significant difference was also noted between the angle of normal dogs and those with moderate (75.5 +/- 6.8 degrees, range: 62.8-88.7 degrees) and severe (80.4 +/- 7.7 degrees, range: 64.7-91.7 degrees) left atrial enlargement, as well as between dogs with mild (70.7 +/- 7.2 degrees, range: 57.3-89.9 degrees) and severe enlargement. Using two discriminators, 85.1 degrees and 76.6 degrees, the bifurcation angle had a specificity of 92.6% and 88.9%, respectively, for identifying left atrial enlargement, and a sensitivity of 15.4% and 40.4%. Although significant differences were observed between dogs with normal and increased left atrial size, the large degree of overlap in the range of bifurcation angles and its poor sensitivity make the measurement of this angle of little value for diagnosing left atrial enlargement.