Objective—To evaluate a modified posterior rhinomanometric method for clinical application in dogs.
Animals—15 healthy Beagles and 8 Bulldogs (4 healthy and 4 with respiratory problems).
Procedures—Rhinomanometry was performed 3 times within a 15-minute period in anesthetized dogs.Transnasal pressure (PNA) and nasal resistance (RNA) were determined by use of artificial airflow (adjusted for body weight) for inspiration (PNAin and RNAin, respectively) and expiration (PNAout and RNAout). Procedures were repeated for the Beagles 7 days later.
Results—For the Beagles, mean ± SD of PNAin for both days (0.162 ± 0.042 kPa) was significantly lower than PNAout (0.183 ± 0.053 kPa). Similarly, RNAin (1.47 ± 0.41 kPa/[L/s]) was significantly lower than RNAout (1.64 ± 0.46 kPa/[L/s]). Pairwise comparison of values for PNA and RNA for the 2 days revealed no significant difference. Repeatability of the method (estimated as within-day variation) for RNA was ± 0.19 kPa/(L/s), whereas variation between the days was ± 0.36 kPa/(L/s) for RNAin and ± 0.44 kPa/(L/s) for RNAout. The 4 clinically normal Bulldogs had RNA values ranging from 1.69 to 3.48 kPa/(L/s), whereas in the 4 Bulldogs with respiratory problems, RNA ranged from 9.83 to 20.27 kPa/(L/s).
Conclusions and Clinical Relevance—RNA is inversely dependent on body size and nonlinearly associated with airflow. We propose that RNA in dogs should be determined for airflows standardized on the basis of body size. The PNA and RNA in Beagles can be measured with sufficient repeatability for clinical use and nasal obstructions are detectable.