Addition of a metoclopramide constant rate infusion to prevent ptyalism, regurgitation and vomiting in brachycephalic dogs undergoing spinal surgery.

OBJECTIVE: To assess whether adding metoclopramide to a protocol of maropitant and pantoprazole would reduce incidence of ptyalism, vomiting and regurgitation in brachycephalic dogs undergoing thoracolumbar spinal surgery. STUDY DESIGN: Randomized blinded controlled trial. ANIMALS: A total of 43 brachycephalic dogs undergoing thoracolumbar spinal surgery. METHODS: In addition to a standardized anaesthetic regimen, dogs were randomized to be administered either a 2 mg kg-1 day-1 metoclopramide constant rate infusion (CRI) or a saline solution at an equivalent infusion rate, started after anaesthetic induction and discontinued 5 hours after tracheal extubation. The presence of vomiting, regurgitation and pytalism, and short form of the Glasgow Composite Pain Scale pain scores were assessed by a blinded observer hourly for 4 hours, starting 1 hour postextubation. RESULTS: Regurgitation occurred in six dogs postoperatively; three dogs were in the placebo group and three in the metoclopramide group. The odds ratio (OR) of regurgitation after surgery did not differ between groups [OR: 0.76, 95% confidence interval (CI): 0.13-4.3, p = 0.76]. The odds of observing ptyalism at 3 and 4 hours was approximately 15 times less than 1 hour postoperatively (both OR: 15.4, 95% CI: 1.8-130.7, p = 0.012) and did not differ based on the addition of metoclopramide (OR: 0.73, 95% CI: 0.07-8.0, p = 0.79). The odds of observing pain did not change over time and did not differ based on the addition of metoclopramide (OR: 0.71, 95% CI: 0.12-4.2, p = 0.71). Vomiting did not occur during the study (0.0%, 95% CI: 0.0-8.2%). No adverse effects were observed during the study period in either group. CONCLUSIONS AND CLINICAL RELEVANCE: The addition of a metoclopramide CRI to maropitant and pantoprazole did not result in a significant reduction in ptyalism or regurgitation in brachycephalic dogs undergoing thoracolumbar spinal surgery.

Neural network analysis of pharyngeal sounds can detect obstructive upper respiratory disease in brachycephalic dogs.

Brachycephalic obstructive airway syndrome (BOAS) is a highly prevalent respiratory disease affecting popular short-faced dog breeds such as Pugs and French bulldogs. BOAS causes significant morbidity, leading to poor exercise tolerance, sleep disorders and a shortened lifespan. Despite its severity, the disease is commonly missed by owners or disregarded by veterinary practitioners. A key clinical sign of BOAS is stertor, a low-frequency snoring sound. In recent years, a functional grading scheme has been introduced to semi-objectively grade BOAS based on the presence of stertor and other abnormal signs. However, correctly grading stertor requires significant experience and adding an objective component would aid accuracy and repeatability. This study proposes a recurrent neural network model to automatically detect and grade stertor in laryngeal electronic stethoscope recordings. The model is developed using a novel dataset of 665 labelled recordings taken from 341 dogs with diverse BOAS clinical signs. Evaluated via nested cross validation, the neural network predicts the presence of clinically significant BOAS with an area under the receiving operating characteristic of 0.85, an operating sensitivity of 71% and a specificity of 86%. The algorithm could enable widespread screening for BOAS to be conducted by both owners and veterinarians, improving treatment and breeding decisions.

Histomorphological evaluation of thermal injury following palatoplasty performed with CO2 laser or LigaSure device in dogs with brachycephalic obstructive airway syndrome.

The elongated soft palate is an abnormality that characterizes most brachycephalic dogs and contributes to the brachycephalic obstructive airway syndrome (BOAS). Palatoplasty is routinely performed in brachycephalic dogs; several surgical techniques exist. The use of surgical instruments such as monopolar electrocoagulation, CO2 or diode laser, bipolar vessel sealing device and harmonic shears has become routine to reduce the operating time, the intraoperative risk of bleeding and the postoperative oedema. This prospective study aimed to compare the histomorphological effect of a CO2 laser and LigaSure device in palates of dogs undergoing palatoplasty. Twenty owned brachycephalic dogs were included, 10 palatoplasties were performed using CO2 laser and 10 using LigaSure™ device. The dogs were positioned in sternal recumbency. A transoral approach was performed: the elongated soft palate was grasped with Allis forceps and brought rostrally, the palatoplasty was performed using the tonsillar crypts as anatomical landmarks. Surgical specimens were routinely fixed in 10 % formalin. Two sections perpendicular to the surgical margins were trimmed from each sample, paraffin-embedded and stained with hematoxylin and eosin (H&E). Tissue damage induced by the two types of surgical devices was graded (1-4, from minimal to severe) and the depth of thermal injury measured in µm on captured images (using an image analysis program - ImageJ). Mean values and standard deviations (SD) were calculated based on six measurements for each sample. The tissue damage was graded 3.7±0.48 in group LigaSure™ and 2.8±1 in group Laser. The mean depth of thermal injury was 874.94±184.92 µm in the LigaSure™ group and 451,76±137,86 µm in the Laser group. The comparison between the two groups showed significant lower grade and extension of thermal injury in the palate samples obtained with CO2 laser (p<0.05). Additionally, there is a lack of literature that correlates the histological changes with the clinical outcomes of the different palatoplasty methods in brachycephalic dogs. By comparing histological changes and clinical outcomes, we aim to provide valuable insights for optimizing the surgical approach for palatoplasty in brachycephalic dogs, ultimately improving postoperative outcomes for these patients.

Evaluation of brachycephalic obstructive airway syndrome breeding test results in Finland from 2017 to 2022.

BACKGROUND: Brachycephalic obstructive airway syndrome (BOAS), observed in many flat-faced dog breeds, is one of the most urgent welfare problems in pedigree dogs. Various breeding schemes against BOAS have been implemented in many countries during recent years, but their impact on breed health remains unknown. The BOAS breeding test, used by the Finnish Kennel Club (FKC), includes an exercise component with a recovery assessment, BOAS grading by a veterinarian that evaluates upper respiratory signs before and after exercise, and a nostril stenosis assessment. The aim of our study was to evaluate BOAS breeding test results and estimate the heritability of the BOAS grade using parent-offspring regression from FKC data collected during 2017-2022. RESULTS: The majority (80%) of dogs (n = 957) participating in FKC BOAS testing were English Bulldogs, French Bulldogs, and Pugs. In 2022, 89-100% of the litters from these three breeds registered with the FKC had at least one parent tested for BOAS. The proportion of dogs failing the exercise test was highest in English Bulldogs (11%), followed by French Bulldogs (4%) and Pugs (3%). In these three breeds, moderate to severe BOAS signs were reported in 28%, 22% and 30% of dogs, respectively. The proportion of moderate to severe nostril stenosis was highest (71%) in Pugs, followed by French Bulldogs (55%), and English Bulldogs (40%). Estimates of heritability for BOAS grade were separately calculated for these three breeds and for all dogs, and the estimates were moderate to high, ranging from 0.39 to 0.58. CONCLUSIONS: The exercise test alone did not sufficiently identify dogs with moderate to severe BOAS signs. To better consider the complex nature of BOAS and breed differences, exercise tolerance, the severity of upper respiratory signs (BOAS grade) and nostril stenosis should all be assessed together in breeding animals. The heritability estimates for veterinary-assessed BOAS grade indicated that BOAS grade could be used in selective breeding to obtain less-affected offspring.

Effect of continuous positive airway pressure helmet on respiratory function following surgical procedures in brachycephalic dogs: A randomized controlled trial.

OBJECTIVE: To evaluate the effect of continuous positive airway pressure (CPAP) on respiratory function in the early postoperative period of brachycephalic dogs. STUDY DESIGN: Prospective, randomized clinical trial. ANIMALS: A total of 32 dogs. METHODS: Dogs were assigned to recover with or without CPAP (control) and assessed at specific time points over 1 h. Treatment was discontinued for dogs with a CPAP tolerance score of 3 or more (from a range of 0-4). The primary outcome was pulse oximetry (SpO2). Secondary outcomes were arterial O2 pressure (PaO2)/FiO2 ratio (PaO2/FiO2), arterial CO2 pressure (PaCO2), and rectal temperature. For dogs that reached a CPAP tolerance score of 3 or more, only the data collected up to the time point before discontinuation were included in the analysis. The treatment effect (ß) was analyzed using random effects models and the results were reported with 95% confidence intervals. RESULTS: Dogs were assigned randomly to each protocol. Baseline characteristics in both groups were comparable. Arterial blood gases were obtained in seven control group dogs and nine CPAP group dogs. Treatment did not affect SpO2 (ß = -0.1, -2.1 to 2.0) but affected the PaO2/FiO2 ratio (ß = 58.1, 2.6 to 113.6), with no effects on PaCO2 (ß = -4.3, -10.5 to 1.9) or temperature (ß = 0.4, -0.8 to 1.6). CONCLUSION: In postoperative brachycephalic dogs, CPAP had no effect on SpO2 but improved the PaO2/FiO2 ratio in brachycephalic dogs postoperatively. CLINICAL SIGNIFICANCE: Continuous positive airway pressure offers a valuable solution to improve gas exchange efficiency, a prevalent concern in postoperative brachycephalic dogs, with the potential to enhance overall outcomes.

Heart rate variability and vasovagal tone index in brachycephalic dogs.

Brachycephalic breeds of dogs, most of which show signs of the brachycephalic syndrome may have greater parasympathetic stimulation than other breeds, leading to higher values of heart rate variability and vagal tone index. The aim of this study was to establish a computerized electrocardiographic study and an assessment of the vagus sympathetic balance through heart rate variability and vagal tone index of five brachycephalic breeds compared to mesocephalic dogs. Sixty dogs were used, divided into groups made up of Boxers, English Bulldogs, French Bulldogs, Pugs, Shih-Tzu and no defined breed mesocephalic dogs. Statistical analysis was carried out using the Shapiro-Wilk test, Kruskal-Wallis and Dunn's test or ANOVA and Bonferroni (p<0.05). In the evaluation of vagal sympathetic balance among all the dogs, there was a negative correlation between heart rate and HRV 10RR (r = - 0.7678; p < 0.0001), HRV 20RR (r = - 0.8548, p < 0.0001) and VVTI (r = - 0.2770; p = 0.0321). It can therefore be concluded that the dog's breed and morphology did not alter its electrocardiographic parameters or heart rate variability. The vagal tone index, which in other studies differed in brachycephalic dogs, showed no difference when compared separately in brachycephalic breeds.

Comparative analysis of ocular biometry, ocular protrusion, and palpebral fissure dimensions in brachycephalic and nonbrachycephalic dog breeds.

This study compared skull morphology and ocular parameters in brachycephalic (BC, n = 16) and nonbrachycephalic (NB, n = 16) dogs using head CT scans. The results of a Schirmer tear test I (STT I), intraocular pressure (IOP), ocular biometry, external structure, ocular protrusion, and palpebral fissure dimensions were evaluated and compared between BC and NB dogs. There were no statistically significant differences in the STT I results, IOP, globe dimensions, globe volume, internal structure, and external structure between BC and NB dogs (P > .05). Brachycephalic dogs exhibited significantly greater ocular protrusion and significantly larger palpebral fissure dimensions compared with NB dogs. For all dogs, we found a strong positive correlation between globe volume and body weight (r = 0.836, P = .0000). The globe volumes, external structure parameters, and ocular protrusion were normalized by body weight and were also significantly larger in BC dogs compared with NB dogs (P < .001). The ocular protrusion (r = 0.521, P < .0000) and horizontal palpebral fissure (r = 0.372, P = .0024) showed a moderate positive correlation with the cephalic index (CI). Additionally, normalized globe volume (r = 0.435, P = .0003), normalized orbital depth (r = 0.419, P = .0005), and normalized retrobulbar depth (r = 0.444, P = .0002) had a moderate positive correlation with the CI. The study emphasizes how the distinctive skull structure of BC dogs, with shortened facial bones and thickened retrobulbar soft tissue, influences their ocular appearance and raises the risk of eye problems.

The most common congenital malformations in dogs: Literature review and practical guide.

Congenital malformations can affect almost 7% of canine newborns. The increase of commercial dog breeding and inbreeding used to maintain the striking characteristics of each breed, the appearance of malformations has become increasingly common, especially in brachycephalic dogs. The causes are diverse, and include genetic, nutritional, iatrogenic, and infectious factors, often making it difficult to establish a cause-consequence relationship. The high mortality associated with malformations comes not only from the fact that some are incompatible with life, but also because even if many undergo surgical treatment or correction, they require specific management, monitoring, and clinical treatment for an indefinite period of time. The most common malformations such as cleft lip and palate, hydrocephalus and anasarca have been studied for a long time, and it is currently known that brachycephalic dogs have a greater predisposition, however, for other less common conditions as gastroschisis and hypospadias, there is only a few case reports. The appearance of congenital defects in a litter leads to financial losses for the breeder, emotional losses for the owner and the veterinarian and harms the well-being of that individual. For this reason, the aim of this review article is to gather relevant information on the characteristics, diagnosis, and management of the main malformations in puppies. It is essential that the veterinarian is prepared to diagnose and treat these conditions, reducing negative impacts on animals and owners.

Vertebral and spinal malformations in small brachycephalic dog breeds: Current knowledge and remaining questions.

Small brachycephalic dog breeds, such as the French bulldog, English bulldog and pug have become increasingly popular. These breeds are predisposed to a variety of vertebral and spinal malformations, including hemivertebra, caudal articular process dysplasia, transitional vertebra, cranial thoracic vertebral canal stenosis, spinal arachnoid diverticulum and meningeal fibrosis. Recent studies have provided new insights into the prevalence, anatomical characteristics, pathophysiology and treatment of these conditions. Thoracic hemivertebra, caudal articular process dysplasia, transitional vertebra, and cranial thoracic vertebral canal stenosis occur commonly in neurologically normal dogs. Although the clinical relevance of these vertebral anomalies has therefore been questioned, severe kyphosis and hemivertebra in pugs have been associated with an increased likelihood of neurological signs. Meningeal fibrosis is characterised by the formation of dense intradural fibrotic adhesions, constricting the spinal cord. This condition has been heavily associated with the pug breed. It is in pugs further common to observe multiple concurrent spinal disorder in association with chronic progressive pelvic limb gait abnormalities. This clinical presentation has been referred to as 'pug dog thoracolumbar myelopathy' and potential genetic risk factors have recently been identified. Despite our increased knowledge, many questions remain currently unanswered. This review discusses our current understanding and controversies surrounding vertebral and spinal malformations in small brachycephalic dog breeds.

64-Slice ECG-gated computed tomographic angiography for assessment of coronary arteries in brachycephalic dogs with pulmonary stenosis.

BACKGROUND: Brachycephalic dogs with pulmonary stenosis are known to have a higher incidence of concurrent coronary artery abnormalities than non-brachycephalic breeds, which increases risk when performing balloon valvuloplasty. The use of ECG-gated CT angiography has been reported for the evaluation of coronary arteries in normal dogs and dogs with pulmonary stenosis. The purpose of this study was to report findings of coronary artery origination and morphology of main branches using ECG-gated CT angiography in brachycephalic dogs with pulmonary stenosis. METHODS: An ECG-gated CT angiographic protocol was used to image coronary artery anatomy in nine brachycephalic dogs with pulmonary stenosis. Images were assessed for quality as well as coronary artery morphology by one veterinary radiologist, one veterinary cardiologist and one veterinary radiology resident. RESULTS: All nine dogs had good to excellent image quality. Coronary artery anomalies were identified in three of nine dogs: one R2A anomaly, one L2A anomaly and one L2C anomaly. Two dogs were assessed to be poor balloon valvuloplasty candidates based on CT angiographic images. LIMITATION: Coronary artery morphology was not confirmed via postmortem examination in all patients. CONCLUSION: ECG-gated CT angiography is a minimally invasive imaging modality capable of diagnosing various coronary artery anomalies in brachycephalic dogs with pulmonary stenosis and aiding in the determination of patient candidacy for balloon valvuloplasty.

'All I do is fight fires': Qualitative exploration of UK veterinarians' attitudes towards and experiences of pre-purchase consultations regarding brachycephalic dogs.

BACKGROUND: Demand for brachycephalic dogs has dramatically increased over the past decade, despite growing evidence of strong associations between brachycephaly and severe, chronic disease. Positive post-purchase attitudes of owners towards brachycephalic dogs are highly intractable, facilitated by normalisation of breed-related disease and strong dog-owner bonds. Veterinarian-led pre-purchase consultations (PPCs) have been promoted as an opportunity to influence acquisition decisions regarding brachycephalic dogs. METHODS: Using reflexive thematic analysis, this qualitative study investigated veterinarians' attitudes towards, and experiences of, engaging in PPCs for brachycephalic dogs. RESULTS: Veterinarians described significant structural barriers, such as lack of time and staff, and perceptual barriers, such as perceived futility, negative outcomes of PPCs and public distrust in the profession, that combine to inhibit many veterinarians from offering or delivering brachycephalic PPCs. Some of these barriers are intractable at an individual-veterinarian level and lead to moral distress due to conflicts between veterinarians' responsibilities to animal welfare versus clients' and business needs, with resultant censorship of authentic views on brachycephalic ownership compromising professional integrity and autonomy. LIMITATIONS: Wider views and/or experiences may exist outside of the sampled population. CONCLUSION: Stronger veterinary leadership, including from the RCVS, BVA and veterinary corporates, is now urgently required to build profession-wide solutions that overcome the barriers identified to create public-facing consensus and innovative solutions to the 'brachycephalic crisis'.

A retrospective observational cohort study on the postoperative respiratory complications and their risk factors in brachycephalic dogs undergoing BOAS surgery: 199 cases (2019-2021).

OBJECTIVES: To observe the occurrence of postanaesthetic respiratory complications and to determine their prevalence and risk factors in dogs undergoing brachycephalic obstructive airway syndrome surgery. MATERIALS AND METHODS: Data from 199 clinical records were retrospectively analysed. Univariable logistic regression followed by multivariable logistic regression was used to identify associations between the dependent variables (set as the postoperative respiratory complications observed in the study dogs) and various independent covariates. The quality of model-fit was assessed using the likelihood ratio test. P≤0.05 was considered statistically significant. RESULTS: Four postoperative respiratory complications were observed: hypoxaemia (n=10/199; 5%), dyspnoea requiring tracheal re-intubation (n=13/199, 7%), dyspnoea requiring tracheostomy (n=10/199, 5%) and aspiration pneumonia (n=12/199, 6%). Univariable logistic regression showed an association between postoperative aspiration pneumonia and increasing body condition score and American Society of Anaesthesiology classification; however, when these covariates were evaluated in the multivariable model significance was not maintained. Risk factors for tracheostomy were preoperative and postoperative aspiration pneumonia (odds ratio: 9.52, 95% confidence interval: 1.56 to 57.93) and increasing brachycephalic obstructive airway syndrome grade (odds ratio: 4.65, 95% confidence interval: 0.79 to 27.50). CLINICAL SIGNIFICANCE: High brachycephalic obstructive airway syndrome grade and aspiration pneumonia, either developing peri-operatively or as pre-existing condition, may represent risk factors for postoperative tracheostomy. Preoperative diagnosis of aspiration pneumonia may further increase the risk of postoperative complications.

Oral bacteria may affect conjunctival microorganisms in brachycephalic dogs: a preliminary study.

OBJECTIVE: To evaluate the prevalence of oral bacteria in the conjunctiva of brachycephalic and nonbrachycephalic dogs. ANIMALS: 12 brachycephalic (9.58 ± 3.55 years) and 12 nonbrachycephalic (8.33 ± 4.92 years) dogs without systemic disease, regardless of breed and sex, were included in the study, and half of the dogs in each group had periodontitis. METHODS: This prospective study investigated clinical data including craniofacial ratio, ophthalmic examination results, and periodontal status of the included dogs. Bacterial samples were collected by swabbing the oral mucosa and conjunctival surfaces. The presence and quantity of bacteria were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 16S rRNA sequencing analysis, and the 10-fold dilution method. Statistical analyses were performed to assess correlations and factors influencing the presence of oral bacteria in the conjunctiva. RESULTS: The most common bacteria in the conjunctival flora in both groups were Micrococcus luteus, Corynebacterium spp, and Staphylococcus spp. The prevalence of oral bacteria on the conjunctival surface was 33%, with a significantly higher incidence in brachycephalic dogs (P = .027). Oral bacteria detected in the conjunctiva were predominantly Frederiksenia canicola, Neisseria spp, and Moraxella spp. Multiple regression analysis identified age, craniofacial ratio, and gingival index as factors influencing the presence of oral bacteria in the conjunctival flora. CLINICAL RELEVANCE: Oral resident bacteria have often been isolated from severe infectious corneal ulcers. This study provided evidence that brachycephalic dogs may require dental prophylaxis to reduce their oral bacterial load and that the association of oral bacteria in ocular diseases should be considered.

Evaluation of risk factors for sleep-disordered breathing in dogs.

BACKGROUND: Brachycephalic dogs display sleep-disordered breathing (SDB). The risk factors for SDB remain unknown. OBJECTIVES: To identify risk factors for SDB. We hypothesized that brachycephaly, increasing severity of brachycephalic obstructive airway syndrome (BOAS), excess weight, and aging predispose to SDB. ANIMALS: Sixty-three privately owned pet dogs were prospectively recruited: 28 brachycephalic and 35 normocephalic (mesaticephalic or dolicocephalic) dogs. METHODS: Prospective observational cross-sectional study with convenience sampling. Recording with the neckband was done over 1 night at each dog's home. The primary outcome measure was the obstructive respiratory event index (OREI). Body condition score (BCS) was assessed, and BOAS severity was graded for brachycephalic dogs. RESULTS: Brachycephaly was a significant risk factor for high OREI value (ratio of the geometric means 5.6, 95% confidence interval [CI] 3.2-9.9; P < .001) but aging was not (1.1, 95% CI 1.0-1.2; P = .2). Excess weight, defined as a BCS of over 5/9, (3.5, 95% CI 1.8-6.7; P < .001) was a significant risk factor. In brachycephalic dogs, BOAS-positive class (moderate or severe BOAS signs) was a significant risk factor (2.5, 95% CI 1.1-5.6; P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: Brachycephaly decreases welfare in a multitude of ways, including disrupting sleep. Brachycephaly, increasing severity of BOAS and excess weight are risk factors for obstructive SDB.

Arterial blood gas measurements are different for brachycephalic and nonbrachycephalic dogs acclimatized to an altitude of 1,535 meters.

OBJECTIVE: To define reference intervals (RIs) for arterial blood gas (aBG) measurements in healthy, nonsedated, dolichocephalic, and mesocephalic (nonbrachycephalic) dogs at approximately 1,535 m above sea level and compare these findings with healthy, nonsedated, brachycephalic dogs living at the same altitude. ANIMALS: 120 adult nonbrachycephalic dogs and 20 adult brachycephalic dogs. METHODS: Cases were prospectively enrolled from October 2021 to June 2022. Dogs were enrolled from the community or after presentation for wellness examinations or minor injuries including lacerations, nail injuries, and lameness. Physical examinations and systolic blood pressure (sBP) measurements were obtained before blood sample collection. Arterial blood was collected from the dorsal pedal artery or femoral artery. After data collection, brachycephalic dogs underwent pre- and postexercise tolerance assessments. RESULTS: The mean and RI values for arterial pH (7.442; 7.375 to 7.515), partial pressure of oxygen in arterial blood (Pao2; 78.3; 59.2 to 92.7 mm Hg), partial pressure of carbon dioxide in arterial blood (Paco2; 28.0; 21.5 to 34.4 mm Hg), saturation of arterial oxygen (Sao2; 98.4; 84.3% to 101.4%), HCO3 (18.9; 14.9 to 22.4 mmol/L), concentration of total hemoglobin (ctHb; 17.5; 13.4 to 21.1 g/dL), and sBP (133; 94 to 180 mm Hg) were established for healthy nonbrachycephalic dogs at 1,535-m altitude. All aBG measurements were statistically and clinically different from those previously reported for dogs at sea level. Brachycephalic dogs had significantly lower Pao2 and Sao2 (P = .0150 and P = .0237, respectively) and significantly higher ctHb (P = .0396) compared to nonbrachycephalic dogs acclimatized to the same altitude; the nonbrachycephalic RIs were not transferable to the brachycephalic dogs for Pao2. CLINICAL RELEVANCE: This study represents the first collation of aBG measurements for healthy nonbrachycephalic dogs acclimatized to an altitude of 1,535 m. Additionally, this study identified differences in arterial oxygenation measurements between brachycephalic and nonbrachycephalic dogs. RIs in brachycephalic dogs need to be established.

The mobility of the brachycephalic canine nostril in relation to the degree of nostril stenosis.

Previous studies have shown that the most reliable external conformational risk factor of whether a brachycephalic dog will develop Brachycephalic Obstructive Airway Syndrome (BOAS) is the status of nostril stenosis, assessed as a static observation using the brachycephalic nostril grading scheme. The nostrils however are a dynamic structure, opening further when the dog is exercising, sniffing or panting. The hypothesis of this study was that brachycephalic dogs with open or mildly stenotic nostrils are more likely to have nostril mobility whilst dogs with moderately or severely stenotic nostrils are more likely to have immobile nostrils. A retrospective study of dogs presented for BOAS assessment at two UK referral centres between 2012 and 2020 was performed. Data extracted included nares stenosis status and nares mobility. A mesocephalic pilot control group was recruited from a third referral centre. Statistical analysis was performed with χ2, Cochran-Armitage, spearman's rho and linear-by-linear tests as appropriate. Of the 974 brachycephalic dogs included in the study: 124 had open nostrils (68.5% mobile); 212 mildly stenotic nostrils (58.5% mobile); 379 moderately stenotic nostrils (35% mobile) and 259 severely stenotic nostrils (19.3% mobile). The nostril stenotic status was significantly associated with nostril wing mobility (χ2 =135.55; P<0.0001). When considering open and mildly stenotic (considered acceptable) nostrils versus moderate and severely stenotic nostrils, mobility was 62% versus 25.5% (χ2= 135.88; P = <0.0001). All 27 mesocephalic dogs had nostril mobility. Brachycephalic dogs with moderate and severely stenotic nares have reduced nasal mobility compared to brachycephalic dogs with mildly stenotic and open nares. Data is further evidence that dogs with moderately and severely stenotic nares should not be bred.

Comparison of mortality of brachycephalic dogs undergoing partial staphylectomy using conventional incisional, carbon dioxide laser, or bipolar vessel sealing device.

OBJECTIVE: To compare mortality of dogs undergoing partial staphylectomy using conventional incisional, carbon dioxide (CO2 ) laser, and bipolar vessel sealing device (BVSD) techniques for the treatment of brachycephalic obstructive airway syndrome (BOAS). STUDY DESIGN: Retrospective multicenter cohort study. ANIMALS: A total of 606 client-owned English bulldogs, French bulldogs, and pugs. METHODS: Medical records from 2011 to 2021 were reviewed for signalment, history, surgical technique, length of hospitalization, and complications. Multivariate statistical analysis was performed to compare odds of mortality between the three techniques of staphylectomy. RESULTS: The overall mortality rate was 24/606 (4.0%). Of those 24 dogs, staphylectomy was performed with BVSD technique in 13 cases, with CO2 laser in nine, and using conventional incisional technique in two. Nine dogs were graded II or III laryngeal collapse, 14 were graded I, and one was unknown. BVSD technique was associated with mortality prior to discharge compared to the other two techniques (OR = 6.0, 95% CI: 1.3-28.4, p = .023). No differences were detected between conventional incisional and CO2 laser techniques. Concurrent higher grade (stage II or III) laryngeal collapse was independently associated with mortality prior to discharge (OR = 4.6, 95% CI: 1.8-11.8, p = .002). CONCLUSION: The use of BVSD and grade of laryngeal collapse were associated with a higher risk of perioperative mortality. CLINICAL SIGNIFICANCE: Clinical studies using a randomized trial design should be conducted to further determine the putative influence of surgical instrumentation in the perioperative mortality rate following multilevel surgery in dogs with BOAS.

Evaluation of the addition of adrenaline in a bilateral maxillary nerve block to reduce hemorrhage in dogs undergoing sharp staphylectomy for brachycephalic obstructive airway syndrome. A prospective, randomized study.

OBJECTIVE: To assess the use of adrenaline (0.00198%) in a bilateral maxillary nerve block to reduce intraoperative hemorrhage in dogs undergoing staphylectomy for the treatment of brachycephalic obstructive airway syndrome (BOAS). STUDY DESIGN: Prospective, randomized, double-blinded controlled study. SAMPLE POPULATION: A total of 32 client owned, clinically affected dogs undergoing a cut and sew sharp staphylectomy for treatment of BOAS. A total of 16 dogs randomly assigned to adrenaline (A) group and 16 to no-adrenaline (NA) group. METHODS: A bilateral maxillary nerve block was performed in all dogs prior to staphylectomy using lidocaine alone (group NA) or a combination of lidocaine and adrenaline (group A). Total hemorrhage was measured by weighing cotton-tipped applicators and swabs used on precision scales. In addition, a semi-quantitative hemorrhage score (1-5) was determined. Dogs were monitored for intraoperative hemodynamic stability during the procedure. RESULTS: Total hemorrhage was significantly (p = .013) lower in group A compared with group NA. The median semi-quantitative hemorrhage score was significantly lower for group A (p = .029) compared with group NA. No significant adverse effects were noted due to adrenaline usage. CONCLUSION: This study demonstrated that the use of adrenaline in a bilateral maxillary nerve block results in significantly lower intraoperative hemorrhage during cut and sew sharp staphylectomy and appeared safe to use. CLINICAL SIGNIFICANCE: Potential clinical advantages include improved visualization, prevention of unnecessary blood loss and reduction in risk of blood aspiration.