Comparison of the effectiveness of three different rhinoplasty techniques to correct stenotic nostrils using silicone models: A case study.

OBJECTIVE: To compare the effects of three different rhinoplasty techniques on the postoperative cross-sectional areas (CSAs) of the nares and nasal vestibuli. STUDY DESIGN: Experimental study. SAMPLE POPULATION: Ninety-nine 3D-printed, remolded silicone models of a single French bulldog's rostral nose. METHODS: Models were fabricated based on a computed tomographic (CT) scan of the nose of a French bulldog with moderately stenotic nares. Each model underwent either vertical wedge resection (VW), modified horizontal wedge resection (MHW), or ala-vestibuloplasty (AVP) performed by a single surgeon (n = 33 per group). Preoperative and postoperative CT scans of the models were performed, and CSAs of the airway from the nares to the caudal end of the nasal vestibules were calculated. RESULTS: All three rhinoplasty techniques increased CSAs (adjusted p values <.001) but to different levels caudally within the nasal vestibule. Vertical wedge resection achieved this up to the start of the alar fold, MHW up to halfway between the nares and the alar fold and AVP up to the caudal nasal vestibule. Average percentage increases in CSA were 26%, 15% and 74%, respectively. Ala-vestibuloplasty led to larger CSAs than VW and MHW from the nares to the caudal nasal vestibule (adjusted p values <.05). The proportional difference within each technique was <7%. CONCLUSION: Ala-vestibuloplasty resulted in a larger increase in the airway CSA of silicone modeled nares and nasal vestibules of a single French bulldog in comparison with VW and MHW. CLINICAL SIGNIFICANCE: Ala-vestibuloplasty can be considered for French bulldogs with moderately stenotic nares and evidence of nasal vestibular stenosis.

Determining an optimum propofol infusion rate for induction of anaesthesia in healthy dogs: a randomized clinical trial.

OBJECTIVE: To determine an optimum infusion rate of propofol that permitted rapid tracheal intubation while minimizing the duration of postinduction apnoea. STUDY DESIGN: Prospective, randomized, blinded clinical trial. ANIMALS: A total of 60 client-owned dogs presented for elective neutering and radiography. METHODS: Dogs were randomly allocated to one of five groups (groups A-E) to have propofol at an infusion rate of 0.5, 1, 2, 3, or 4 mg kg-1 minute-1, respectively, following intramuscular premedication with methadone 0.5 mg kg-1 and dexmedetomidine 5 µg kg-1. Propofol administration was stopped when adequate conditions for tracheal intubation were identified. Time to tracheal intubation and duration of apnoea were recorded. If oxygen haemoglobin saturation decreased to < 90%, manual ventilation was initiated. A one-way analysis of covariance was conducted to compare the effect of propofol infusion rate on duration of apnoea and intubation time whilst controlling for covariates, followed by post hoc tests. The significance level was set at p < 0.05. RESULTS: Propofol infusion rate had a significant effect on duration of apnoea (p = 0.004) and intubation time (p < 0.001) after controlling for bodyweight and sedation scores, respectively. The adjusted means (± standard error) of duration of apnoea were significantly shorter in groups A and B (49 ± 39 and 67 ± 37 seconds, respectively) than in groups C, D and E (207 ± 34, 192 ± 36 and 196 ± 34 seconds, respectively). Group B (115 ± 10 seconds) had a significantly shorter intubation time than group A (201 ± 10 seconds, p < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: An infusion rate of 1.0 mg kg-1 minute-1 (group B) appears to offer the optimal compromise between speed of induction and duration of postinduction apnoea.

Nebulization of epinephrine to reduce the severity of brachycephalic obstructive airway syndrome in dogs.

OBJECTIVE: To determine the preoperative and postoperative effect of nebulized epinephrine on brachycephalic obstructive airway syndrome (BOAS) severity in dogs. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Thirty-one client-owned pugs, French bulldogs, and English bulldogs with moderate to severe BOAS. METHODS: Whole body barometric plethysmography was used to determine BOAS severity (BOAS index; 0%-100%) prior to and after nebulization with 0.05 mg/kg epinephrine diluted in 0.9% saline preoperatively. The same protocol was repeated postoperatively (within 24 hours of surgery). RESULTS: Five dogs were excluded because they did not tolerate nebulization, and postoperative data were available for 13 dogs. Epinephrine nebulization resulted in a decreased BOAS index across all breeds of dog both before (9.6% [3.1% to -30.2%], n = 26) and after surgery (14.3% [0.9% to -24.3%], n = 13). The preoperative reduction in BOAS index was greater (17.3% [1.8% to -27.4%]) in dogs with a baseline BOAS index >70% (P = .006) and in pugs (16.9% [0.8% to -27.4%]) compared with French bulldogs (5.2% [3.1% to -30.2%], P = .03). Simple linear regression was used to identify a positive relationship between baseline BOAS index and reduction in BOAS index for pugs (n = 10, P = .001). Nausea was noted as a side effect in four dogs. CONCLUSION: Nebulized epinephrine reduced the BOAS index of dogs in this study. This effect was clinically significant in preoperative dogs with a BOAS index >70% and in dogs recovering from surgery. CLINICAL SIGNIFICANCE: This study provides evidence to support the use of nebulized epinephrine in the perioperative management of BOAS-affected dogs.

Evaluation of the repeatability of kinetic and temporospatial gait variables measured with a pressure-sensitive treadmill for dogs.

OBJECTIVE: To evaluate intrasession and intersession repeatability of measurements for temporospatial and kinetic variables obtained with a pressure-sensitive treadmill designed for gait analysis of dogs. ANIMALS: 16 client-owned dogs. PROCEDURES: The influence of treadmill speed on accuracy of ground reaction force (GRF) measurements was assessed by simulated gait analysis at 0 to 7.5 km/h with a custom test device. A similar test was performed with 1 client-owned dog ambulating on the treadmill at 5 speeds (3 to 7 km/h) for GRF calculations. Fifteen client-owned dogs were then walked on the treadmill at 3 km/h for collection of temporospatial and kinetic data. Intrasession repeatability was determined by comparing 2 sets of measurements obtained ≤ 2 hours apart. Intersession repeatability was determined by comparing the first set of these measurements with those for a second session ≥ 4 days later. Intraclass correlation coefficients (ICCs; consistency test) and difference ratios were calculated to assess repeatability. RESULTS: Increases in treadmill speed yielded a mean 9.1% decrease in weight-normalized force data at belt speeds of up to 7.5 km/h for the test device, compared with the value when the treadmill belt was stationary. Results were similar for the dog at increasing treadmill speeds (mean decrease, 12.4%). For temporospatial data, intrasession ICCs were > 0.9 and intersession ICCs ranged from 0.75 to 0.9; for GRFs, intrasession and intersession ICCs ranged from 0.68 to 0.97 and from 0.35 to 0.78, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Repeatability of temporospatial data for healthy dogs was good to excellent; results for kinetic data varied. Further research is needed to investigate use of this system for gait analysis with larger samples of dogs and dogs with lameness.

Validation of exercise testing and laryngeal auscultation for grading brachycephalic obstructive airway syndrome in pugs, French bulldogs, and English bulldogs by using whole-body barometric plethysmography.

OBJECTIVE: To determine whether the sensitivity of clinical examination for assessing upper airway disease severity in 3 breeds of brachycephalic dogs can be improved by incorporating an exercise test (ET) or by auscultation of a laryngeal stridor to predict laryngeal collapse. STUDY DESIGN: Prospective clinical study. ANIMALS: Client-owned brachycephalic dogs (n = 44 ET; n = 57 laryngeal stridor assessment). METHODS: In the first part of the study, clinical examinations were performed at rest and after 5-minute walk and 3-minute trot tests, and a grade reflective of brachycephalic obstructive airway syndrome (BOAS) severity was assigned. Whole-body barometric plethysmography was used as a comparative, objective measure of disease severity. In the second part of the study, the degree of laryngeal collapse present in dogs undergoing BOAS surgery was compared to pre-exercise and postexercise laryngeal stridor detected during functional testing. RESULTS: The sensitivity of clinical examination for BOAS diagnosis was 56.7% pre-ET, 70% after a 5-minute walk test, and 93.3% after a 3-minute trot test. The sensitivity of laryngeal stridor as a predictor of laryngeal collapse was improved after exercise (70%) compared with before exercise (60%). Specificity of laryngeal stridor for laryngeal collapse was 100% (pre-exercise and postexercise). CONCLUSION: The sensitivity of clinical examination for BOAS diagnosis was improved by inclusion of an ET, particularly the 3-minute trot test. Audible laryngeal stridor was highly specific but only moderately sensitive for laryngeal collapse. CLINICAL SIGNIFICANCE: Inclusion of a 3-minute trot test and careful auscultation for laryngeal stridor are recommended during BOAS assessment of brachycephalic dogs.

Objective effectiveness of and indications for laser-assisted turbinectomy in brachycephalic obstructive airway syndrome.

OBJECTIVE: To evaluate the effectiveness of laser-assisted turbinectomy (LATE) in treating brachycephalic obstructive airway syndrome (BOAS) and to investigate the potential indications. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned pugs, French bulldogs, and English bulldogs (n = 57). METHODS: A BOAS index was obtained from whole-body barometric plethysmography before BOAS conventional multilevel surgery (CMS) and 2-6 months post-CMS. Dogs with BOAS index >50% and BOAS functional grades II-III after CMS were considered candidates for LATE. A BOAS index was repeated 2-6 months after LATE. Intranasal lesions and a measurement of soft tissue proportion at the rostral entrance of choanae (STC) were recorded on the basis of computed tomography images. Logistic regressions were used to assess the intranasal predictors for being LATE candidates. RESULTS: Twenty-nine of 57 dogs were candidates for LATE, all of which were pugs or French bulldogs. The median BOAS index of dogs that were operated on (20/29 candidates) decreased from 67% post-CMS to 42% after LATE (P < .001). Soft tissue proportion at the rostral entrance of choanae was the only predictor for candidacy for LATE. Pugs (P = .021; cutoff = 64%) and French bulldogs (P = .008; cutoff = 55%) with higher STC were more likely to be candidates for LATE. After LATE, 12 of 20 dogs had temporary episodes of reverse sneezing, and nasal noise was noted in 8 of 20 dogs when sniffing and excited. CONCLUSION: Laser-assisted turbinectomy was an effective treatment for dogs with intranasal abnormalities and a poor response to CMS. Soft tissue proportion at the rostral entrance of choanae was a predictor of candidacy for LATE in pugs and French bulldogs. CLINICAL SIGNIFICANCE: Computed tomography-based measurement of STC can be used to predict whether LATE is required in addition to CMS in pugs and French bulldogs with BOAS.

Sleep-disordered breathing in the Cavalier King Charles spaniel: A case series.

OBJECTIVE: To describe sleep-disordered breathing (SDB) in the Cavalier King Charles spaniel (CKCS). STUDY DESIGN: Retrospective case series. ANIMALS: Five client-owned dogs referred for SDB. METHODS: Medical records were reviewed including recheck appointments and routine preoperative and postoperative questionnaires. Whole-body barometric plethysmography was used to categorize SDB. RESULTS: All dogs presented with multiple episodes of stertorous breathing, choking, and apnea during sleep. Severe nasal septal deviation, aberrant nasal turbinates, and soft palate elongation and thickening were noted on computed tomography and rhinoscopy of each dog. Whole-body barometric plethysmography measurements during sleep (in 3 dogs) documented periods of choking, snoring, and apnea. Treatment combined laser turbinectomy, folding flap palatoplasty, tonsillectomy, laryngeal sacculectomy, and cuneiform process resection. All dogs improved in terms of incidence and severity of sleep apnea within 1 week, with 4 of 5 dogs achieving complete resolution. CONCLUSION: The objective measurements used to characterize SDB in this population of CKCS provided some evidence to support an obstructive cause for this condition, which improved with surgical treatment. CLINICAL SIGNIFICANCE: Sleep-disordered breathing in the CKCS is a different clinical presentation of brachycephalic obstructive airway syndrome. Our finding of intranasal abnormalities in these 5 dogs with SDB provides justification for future research into its clinical significance.

Endotracheal tube placement during computed tomography of brachycephalic dogs alters upper airway dimensional measurements.

Computed tomography (CT) is used to document upper airway lesions in dogs with brachycephalic obstructive airway syndrome. The presence of an endotracheal tube during CT scanning is often required for general anesthesia. We hypothesized that the endotracheal tube placement would change the soft tissue dimensions of the upper airway. The aims of this prospective, method comparison study were to evaluate the reliability of the previously reported upper airway CT measurements with endotracheal tube placement, and to propose measurements that are minimally affected by the endotracheal tube. Twenty brachycephalic dogs were included in this study. Each dog underwent head/neck CT with an endotracheal tube, followed by a second scan without the endotracheal tube. Ten measurements of the soft palate, nasopharynx, and trachea were performed. Tracheal dimension was significantly larger with the endotracheal tube compared to without, whereas the soft palate cross-sectional area was significantly smaller with the endotracheal tube than without the endotracheal tube. The influence of the endotracheal tube on the caudal nasopharynx cross-sectional (transverse-sectional) area varied with a mean proportional absolute difference of 35%. Rostral soft palate thickness, tracheal perimeter, and cross-sectional area of the rostral nasopharynx were the measurements least affected by the endotracheal tube (intraclass correlation coefficient = 0.964, 0.967, and 0.951, respectively). Therefore, we proposed that these three measurements may be most useful for future brachycephalic obstructive airway syndrome studies that require CT scanning of intubated animals. However, with endotracheal tube placement, measurements of soft palate length, caudal nasopharyngeal cross-sectional area, and trachea height and width may not be reliable.

Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogs.

Extremely brachycephalic, or short-muzzled, dog breeds such as pugs, French bulldogs, and bulldogs are prone to the conformation-related respiratory disorder-brachycephalic obstructive airway syndrome (BOAS). Affected dogs present with a wide range of clinical signs from snoring and exercise intolerance, to life-threatening events such as syncope. In this study, conformational risk factors for BOAS that could potentially aid in breeding away from BOAS were sought. Six hundred and four pugs, French bulldogs, and bulldogs were included in the study. Soft tape measurements of the head and body were used and the inter-observer reproducibility was evaluated. Breed-specific models were developed to assess the associations between the conformational factors and BOAS status based on functional grading. The models were further validated by means of a BOAS index, which is an objective measurement of respiratory function using whole-body barometric plethysmography. The final models have good predictive power for discriminating BOAS (-) and BOAS (+) phenotypes indicated by the area under the curve values of >80% on the receiver operating curves. When other factors were controlled, stenotic nostrils were associated with BOAS in all three breeds; pugs and bulldogs with higher body condition scores (BCS) had a higher risk of developing BOAS. Among the standardized conformational measurements (i.e. craniofacial ratio (CFR), eye width ratio (EWR), skull index (SI), neck girth ratio (NGR), and neck length ratio (NLR)), for pugs EWR and SI, for French bulldogs NGR and NLR, and for bulldogs SI and NGR showed significant associations with BOAS status. However, the NGR in bulldogs was the only significant predictor that also had satisfactory inter-observer reproducibility. A NGR higher than 0.71 in male bulldogs was predictive of BOAS with approximately 70% sensitivity and specificity. In conclusion, stenotic nostrils, BCS, and NGR were found to be valid, easily applicable predictors for BOAS (+).

Outcomes and prognostic factors of surgical treatments for brachycephalic obstructive airway syndrome in 3 breeds.

OBJECTIVE: To determine prognostic indicators for the surgical treatment of brachycephalic obstructive airway syndrome (BOAS) and to compare the prognosis of 2 multilevel surgical procedures. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned pugs, French bulldogs, and bulldogs (n = 50). METHODS: Noninvasive whole-body barometric plethysmography (WBBP) was used to assess respiratory function before, 1 month and 6 months after upper airway corrective surgery. Postoperatively, BOAS indices (ie, ascending severity score generated from WBBP data, 0%-100%) that equaled to or exceeded the cut-off values of BOAS in the diagnostic models were considered to have a "poor prognosis." A multivariate logistic regression was used to assess predictors for prognosis. RESULTS: The median BOAS indices decreased after surgery (from 76% to 63%, P < .0001), although dogs with indices in this range would still be considered clinically affected. Age (odds ratios [OR] = 0.96, 95% confidence interval [CI]: 0.93-0.99, P < .05), body condition (OR = 0.06, 95% CI: 0.01-0.39, P < .01), laryngeal collapse (OR = 6.1, 95% CI: 1-37.22, P < .05), and surgical techniques (OR = 7.94, 95% CI: 1.17-54.01, P < .05) were associated with postoperative prognosis. The multivariate model suggests modified multilevel surgery (MMS) may have a better outcome than traditional multilevel surgery (TMS) (P = .034). The positive predictive value of the logistic model was 84% (95% CI: 68-94%) and the area under the receiver operating characteristic (ROC) curve was 89% (95% CI: 78-99%, P <.0001). CONCLUSIONS: Younger age, normal body condition, presence of laryngeal collapse, and treatment with TMS were negative prognostic factors after surgical treatment of BOAS. MMS is recommended, particularly in dogs with a higher probability of poor prognosis.

Characterisation of Brachycephalic Obstructive Airway Syndrome in French Bulldogs Using Whole-Body Barometric Plethysmography.

Brachycephalic obstructive airway syndrome (BOAS) is an important health and welfare problem in several popular dog breeds. Whole-body barometric plethysmography (WBBP) is a non-invasive method that allows safe and repeated quantitative measurements of respiratory cycles on unsedated dogs. Here respiratory flow traces in French bulldogs from the pet population were characterised using WBBP, and a computational application was developed to recognise affected animals. Eighty-nine French bulldogs and twenty non-brachycephalic controls underwent WBBP testing. A respiratory functional grading system was used on each dog based on respiratory signs (i.e. respiratory noise, effort, etc.) before and after exercise. For development of an objective BOAS classifier, functional Grades 0 and I were considered to have insignificant clinical signs (termed here BOAS-) and Grades II and III to have significant signs (termed here BOAS+). A comparison between owner-perception of BOAS and functional grading revealed that 60 % of owners failed to recognise BOAS in dogs that graded BOAS+ in this study.WBBP flow traces were found to be significantly different between non-brachycephalic controls and Grade 0 French bulldogs; BOAS- and BOAS+ French bulldogs. A classifier was developed using quadratic discriminant analysis of the respiratory parameters to distinguish BOAS- and BOAS + French bulldogs, and a BOAS Index was calculated for each dog. A cut-off value of the BOAS Index was selected based on a receiver operating characteristic (ROC) curve. Sensitivity, specificity, positive predictive value, and negative predictive value of the classifier on the training group (n=69) were 0.97, 0.93, 0.95, and 0.97, respectively. The classifier was validated using a test group of French bulldogs (n=20) with an accuracy of 0.95. WBBP offers objective screening for the diagnosis of BOAS in French Bulldogs. The technique may be applied to other brachycephalic breeds affected by BOAS, and possibly to other respiratory disease in dogs.