Specialists’ approach to tracheal collapse: survey-based opinions on diagnostics, medical management, and comorbid diseases

Susan V. Carr College of Veterinary Medicine & Biomedical Sciences, Colorado State University, Fort Collins, CO

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 BVSc, MS, DACVIM
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Carol Reinero College of Veterinary Medicine, University of Missouri, Columbia, MO

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 DVM, PhD, DACVIM
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Mark Rishniw College of Veterinary Medicine, Cornell University, Ithaca, NY

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Jessica C. Pritchard School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI

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 VMD, MS, DACVIM

Abstract

OBJECTIVE

To describe the current standard of care among specialists for the routine diagnostic evaluation and medical management of stable tracheal collapse in dogs, identifying gaps between practice and scientific evidence to facilitate the development of future prospective studies. A secondary objective was to describe the perceived incidence of selected comorbid disorders in dogs with tracheal collapse and the diagnostic tests performed to evaluate for those disorders.

SAMPLE

180 veterinary specialists in 22 countries.

PROCEDURES

An electronic survey was sent to 4 specialty listservs to target diplomates. Respondents completed multiple-choice and free-response questions related to the diagnostic evaluation and treatment of a theoretical stable dog with suspected tracheal collapse.

RESULTS

Most respondents routinely utilized radiography, tracheobronchoscopy, and fluoroscopy to diagnose tracheal collapse and performed airway sampling, sedated airway examination, and echocardiograms to rule out comorbidities. The most frequently perceived comorbid disorders included chronic bronchitis, bronchomalacia, and myxomatous mitral valve disease. Respondents most often prescribed opioid antitussives, glucocorticoids, anxiolytics, and antibiotics as treatments. Less frequently, they utilized bronchodilators and nonopioid medications for cough.

CLINICAL RELEVANCE

Despite a lack of published guidelines, specialists have similar approaches in their diagnostic and therapeutic approach to a stable dog with suspected tracheal collapse and believe evaluating for comorbid disorders is important. A description of a typical diagnostic approach and knowledge of realistic treatment goals will assist the general practitioner managing dogs with stable tracheal collapse. Additionally, gaps between current practices established via this survey and data supporting those practices exist, specifically concerning the use of antibiotics and nonopioid medications for cough, representing areas for further study.

Abstract

OBJECTIVE

To describe the current standard of care among specialists for the routine diagnostic evaluation and medical management of stable tracheal collapse in dogs, identifying gaps between practice and scientific evidence to facilitate the development of future prospective studies. A secondary objective was to describe the perceived incidence of selected comorbid disorders in dogs with tracheal collapse and the diagnostic tests performed to evaluate for those disorders.

SAMPLE

180 veterinary specialists in 22 countries.

PROCEDURES

An electronic survey was sent to 4 specialty listservs to target diplomates. Respondents completed multiple-choice and free-response questions related to the diagnostic evaluation and treatment of a theoretical stable dog with suspected tracheal collapse.

RESULTS

Most respondents routinely utilized radiography, tracheobronchoscopy, and fluoroscopy to diagnose tracheal collapse and performed airway sampling, sedated airway examination, and echocardiograms to rule out comorbidities. The most frequently perceived comorbid disorders included chronic bronchitis, bronchomalacia, and myxomatous mitral valve disease. Respondents most often prescribed opioid antitussives, glucocorticoids, anxiolytics, and antibiotics as treatments. Less frequently, they utilized bronchodilators and nonopioid medications for cough.

CLINICAL RELEVANCE

Despite a lack of published guidelines, specialists have similar approaches in their diagnostic and therapeutic approach to a stable dog with suspected tracheal collapse and believe evaluating for comorbid disorders is important. A description of a typical diagnostic approach and knowledge of realistic treatment goals will assist the general practitioner managing dogs with stable tracheal collapse. Additionally, gaps between current practices established via this survey and data supporting those practices exist, specifically concerning the use of antibiotics and nonopioid medications for cough, representing areas for further study.

Introduction

Tracheal collapse, a degenerative disorder of primarily toy dog breeds, leads to diminished airway caliber and a spectrum of clinical signs ranging from cough to respiratory distress.1,2 Screening by thoracic radiography is common, although definitive diagnosis may require dynamic evaluation via fluoroscopy or direct visualization using tracheobronchoscopy.3,4 In other cases, a presumptive diagnosis is made on the basis of clinical signs and signalment. Traditionally, tracheal collapse has been described as an isolated respiratory disorder in dogs.5 More recently, an increasing body of literature documents its occurrence with multiple other cardiopulmonary diseases.611 These diseases share clinical signs, with no sign pathognomonic for any one disease, thus increasing the diagnostic challenge. Relevant comorbidities previously described include other types of airway collapse, chronic bronchitis, bronchiectasis, myxomatous mitral valve disease (MMVD), congestive heart failure (CHF), and pulmonary hypertension (PHT).68,10,11 In the authors’ opinion, knowledge of these comorbidities is critical to developing a comprehensive diagnostic and therapeutic plan and providing an accurate prognosis.

Despite the frequency with which tracheal collapse is encountered in practice, no consensus exists regarding ideal diagnostic evaluation and therapeutic management of stable dogs. General guidelines, such as review articles or textbook chapters,1216 represent individual approaches and opinions, but no data from a larger number of experts exist. Only 2 studies describe dogs’ disease course treated medically rather than with stenting or surgery,17,18 and 36% to 50% of dogs deteriorated over the observation period (mean observation period was 936 and 365 days, respectively). As dogs often become refractory to initial management, additional information on therapeutic approaches could provide valuable alternatives for poorly controlled disease in an attempt to prolong the period of effective medical management before interventional procedures or euthanasia. Furthermore, there is a paucity of information on specific details of diagnostic and therapeutic decisions, ancillary testing for and frequency of comorbid disorders, or goals for treatment outcomes. Understanding specialists’ perceptions of the importance of investigating the presence of these comorbidities, whether they perform the advanced diagnostic testing to identify them, and the perceived frequency with which they encounter them could help streamline diagnostic approaches for tracheal collapse.

The goal of this survey-based study was to describe specialists’ standard of care for the diagnosis and medical management of canine tracheal collapse. A secondary aim was to evaluate perceptions of the incidence of comorbid disorders and the ancillary diagnostics performed to that end. While some diagnostic and management practices were speculated to be evidence-based, it was also anticipated that there would be portions for which common practice is not supported by the literature or that have yet to be investigated prospectively.

Materials and Methods

Electronic survey

An electronic survey was used for data collection on topics regarding medical and interventional management of tracheal collapse, from which 4 sections were utilized: demographic information, comorbid disorders, diagnostic evaluation, and medical management (Supplementary Appendix S1). Respondents were asked to consider their most common diagnostic and therapeutic approaches for a hypothetical stable dog (further defined as being suitable for outpatient treatment) referred to them with suspected or confirmed tracheal collapse and to rank the frequency with which they diagnose comorbid disorders and the importance they placed upon investigating their presence. Six diseases that are common comorbidities or differential diagnoses were specifically examined.611 Questions were predominantly multiple choice and commonly utilized a 5-point Likert scale for frequency and importance. The survey was built using Qualtrics software. The University of Wisconsin–Madison institutional review board reviewed the research plan and exempted the study from further institutional review board assessment (submission ID: 2020-0102).

The survey was distributed to American College of Veterinary Internal Medicine and Cardiology diplomates, European College of Veterinary Internal Medicine–Companion Animal diplomates, and American College of Veterinary Emergency and Critical Care diplomates through the specialty listservs of each group, as well as the Veterinary Interventional Radiology and Interventional Endoscopy Society listserv. Responses were limited to boarded specialists, not trainees, within the colleges and society. The survey was available from March 9, 2020, to June 3, 2020.

Statistics

Descriptive statistics in the form of response counts and percentages were calculated for each question. Percentages were rounded up to the nearest whole number; thus, responses may not have added up to 100%. Agreement among respondents was assessed for strength, whereby strong agreement meant > 80% of responses were “usually or always” or “never or rarely,” and moderate agreement meant 70% to 80% of responses were within those categories, as previously described.19 A comparison of responses of internists to all other specialists can be found elsewhere (Supplementary Table S1).

Results

Composition of respondents

Overall, 180 specialists completed the survey, with 4 specialists listing board certification in 2 specialties. Not all respondents answered every question, leading to a variable number of responses to each question. The composition of respondents included specialists of Internal Medicine (n = 133), Emergency and Critical Care (29), Cardiology (12), Surgery (8), and other (2), including Nutrition and Fellow of Critical Care Medicine. Ninety-four respondents practiced in the US, and 86 practiced outside the US, including Canada, the UK, Ireland, Spain, France, Australia, Germany, Sweden, Austria, Belgium, the Netherlands, Finland, Denmark, Switzerland, Italy, New Zealand, Israel, Portugal, South Africa, Hong Kong, and Singapore. Most respondents worked in private specialty practice (n = 109) or clinical academia (66), with the remaining 5 respondents working in “another” type of practice; no respondents worked in general private practice or industry. All respondents had medically managed dogs with tracheal collapse, while 60% had performed some type of intervention such as tracheal stenting or surgery. Respondents managed tracheal collapse with variable frequency, as follows: 11% had seen 1 to 3 new cases in the last year, 45% had seen 3 to 6, 28% had seen 7 to 12, and 16% had seen 13 to 52.

Routine diagnostic evaluation

When asked to consider their routine diagnostic evaluation of a stable outpatient with suspected tracheal collapse, most respondents utilized thoracic radiography, followed by bronchoscopy and fluoroscopy. Only 2 respondents did not use thoracic radiography; both made the diagnosis of tracheal collapse using tracheobronchoscopy. There was strong agreement on the diagnostic use of thoracic radiography, with a majority (87% [152/178]) of respondents utilizing it always or usually and a smaller proportion regularly performing inspiratory/expiratory views (38%). Tracheobronchoscopy was always or usually performed by 46% of respondents in their routine evaluation. Of those performing tracheobronchoscopy, 60% never utilized endotracheal intubation, 22% performed the procedure with and without endotracheal intubation, and 18% performed tracheobronchoscopy with endotracheal intubation. Fluoroscopy was utilized always or usually by 36% (65/179) of respondents and in combination with tracheobronchoscopy by 14%. Computed tomography was rarely a routine diagnostic, utilized always or usually by 8% (15/178) of respondents. Of those performing CT as a routine diagnostic test, 79% performed cervical and thoracic CT, while 21% performed thoracic CT alone.

Comorbidities and ancillary diagnostics

Overall, respondents frequently considered it important to rule out the listed comorbidities in dogs with tracheal collapse (Figure 1). Respondents perceived that chronic bronchitis, bronchomalacia, and MMVD were the most commonly diagnosed comorbid disorders from the list provided (Figure 2). Ancillary diagnostic tests performed to detect comorbidities included airway sampling, parasite testing including for heartworms, sedated upper airway/laryngeal examinations, and echocardiograms. Almost half (46%) of respondents usually or always sampled airways, and all but one performed cytology and/or aerobic bacterial culture when they did. Other common tests on airway samples included Mycoplasma spp PCR (performed by 104 [63%] of all respondents that perform airway sampling) and anaerobic culture (81 [45%] respondents). Few respondents (13%) reported performing infectious disease PCR on airway samples, including a commercial respiratory PCR panel, Bordetella bronchiseptica PCR, and Angiostronglyus vasorum PCR. Almost half (44%) of respondents performed a sedated airway or laryngeal function exam either usually or always, but 36% (29 respondents) of those never administered doxapram hydrochloride in these evaluations. Over a third (37%) of respondents tested for respiratory parasites or heartworms either usually or always, and around a quarter (27%) reported performing an echocardiogram either usually or always.

Figure 1
Figure 1

Bar charts illustrating the percentage of respondents ranking chronic bronchitis, bronchomalacia, bronchiectasis, pulmonary hypertension, myxomatous mitral valve disease, or congestive heart failure as extremely, very, somewhat, slightly, or not at all important to rule in or out in their diagnostic evaluation of a stable dog with cough and suspected tracheal collapse.

Citation: Journal of the American Veterinary Medical Association 261, 1; 10.2460/javma.22.03.0108

Figure 2
Figure 2

Box-and-whisker plots showing surveyed specialists’ perceived prevalence (percentage of cases) of chronic bronchitis (CB), bronchomalacia, pulmonary hypertension (PHT), bronchiectasis, myxomatous mitral valve disease (MMVD), and congestive heart failure (CHF) diagnoses in stable dogs presenting for evaluation of tracheal collapse. The boxes indicate the interquartile range, and the circles indicate outliers.

Citation: Journal of the American Veterinary Medical Association 261, 1; 10.2460/javma.22.03.0108

Medical management

Respondents were asked their current treatment preferences for outpatient medical management of a stable dog with canine tracheal collapse based on their prescribing habits over the last 12 months (Figure 3). Opioids were the most prescribed therapeutic with moderate agreement among respondents, being utilized by 78% for most or all dogs. The opioid prescribed most frequently was hydrocodone (56% [100/179]), followed by codeine (24%), butorphanol (10%), diphenoxylate (9%), or another not listed (2%). Forty percent (n = 72) of respondents intended that opioid medication would be given indefinitely, 56% anticipated that opioids would be used intermittently on the basis of need as perceived by the owner, and 4% expected opioids would be discontinued for most dogs.

Figure 3
Figure 3

Bar charts illustrating the frequency with which surveyed specialists recalled prescribed varying classes of drugs to stable, coughing dogs diagnosed with tracheal collapse over the previous year.

Citation: Journal of the American Veterinary Medical Association 261, 1; 10.2460/javma.22.03.0108

Nonopioid cough medications (cough suppressants and mucoactive agents) were used by 13% (22/180) of respondents in most or all cases, 43% some of the time, and 35% rarely or never. For respondents utilizing these alternative medications for cough (n = 138), the most used drug in this category was maropitant (55%), followed by dextromethorphan (17%), guaifenesin (9%), or bromhexine (7%).

Most (178/180) respondents also prescribed glucocorticoids, with 59% prescribing these always or most of the time over the previous 12 months. Of those prescribing glucocorticoids, 78% used prednisone or prednisolone most frequently and 21% used inhaled fluticasone most frequently. The most common prednisone or prednisolone starting dose was 1 mg/kg/d (69% of respondents), although 21% began treatment at 0.5 mg/kg/d. Respondents were divided over the anticipated length and duration of treatment, as follows: 50% (n = 89) foresaw that dogs would be continued indefinitely on a low maintenance dose, and 49% (87) used a tapering dose with the goal of discontinuing glucocorticoid treatment.

Anxiolytics or nonopioid sedatives were prescribed most often or always by 29% (53/180) of respondents. Of those who utilized these medications (n = 164), trazodone was the most popular choice for 64% of respondents, followed by acepromazine (15%), gabapentin (9%), diphenhydramine or another antihistamine (5%), alprazolam (4%), and clomipramine (2%). Respondents generally intended these drugs to be used intermittently (85%), although 12% intended discontinuation and 3% intended most of their dogs to take these indefinitely.

About one-quarter (26% [46/180]) of respondents prescribed bronchodilators most of the time or always. Of those utilizing bronchodilators, the most frequent choice was theophylline (69%), terbutaline (14%), albuterol (9%), aminophylline (3%), salmeterol (3%), or another type (1%).

Respondents (n = 180) variably prescribed antimicrobials for the treatment of tracheal collapse, most of the time or always (18%), sometimes (56%), or rarely or never (27%). For respondents prescribing antimicrobials (n = 166), the drug class selected most often was tetracyclines (67% of respondents), followed by penicillins (22%), macrolides (5%), and fluoroquinolones (4%). Zero respondents most commonly chose cephalosporins, and 1% of respondents most commonly chose an antibiotic class that was not listed. The survey did not discriminate between respondents who prescribed antimicrobials on the basis of clinical suspicion versus results of cytology or culture.

The treatment goals for medical management were control of severe clinical signs, and few aimed for complete resolution. While only 5% (10/176) of specialists aimed to control all coughing, > 95% aimed for absence of syncopal events, labored breathing, tachypnea, cyanosis, and an owner-perceived poor quality of life. Regarding other goals, 78% also aimed to diminish coughing during the night causing waking of the owner and 59% aimed for resolution of paroxysmal coughing.

Discussion

Despite a lack of standardized recommendations for the evaluation and management of dogs with tracheal collapse, our survey found some patterns of consistency among specialists in the diagnostic and therapeutic approach to stable dogs. Specifically, there is strong agreement on the use of thoracic radiographs in diagnosis and moderate agreement on the use of opioids in medical management. Survey respondents gave insight into the most common primary diagnostic and therapeutic modalities utilized by specialists for canine tracheal collapse. Additionally, this survey elucidated which of 6 common comorbidities are perceived as essential to investigate in evaluating a dog with suspected or confirmed tracheal collapse and the ancillary diagnostics or therapeutics used by practitioners to that end. Importantly, this survey identified 3 main areas of respondent diagnostic and therapeutic practices: those in which there is consensus between published literature and current practice, in which there exists a disparity between practice and scientific evidence, and that would benefit from future randomized controlled clinical trials due to a lack of evidence to support one practice over another.

In diagnosing tracheal collapse, respondents used static cervical and thoracic radiography most commonly, with a minority reporting a preference for dynamic inspiratory/expiratory radiography. This practice aligns with evidence that standard radiography is a valuable screening tool for tracheal collapse, with a sensitivity of 70% compared to tracheobronchoscopy as the gold standard.3 Despite its lack of favor with respondents, several studies have shown a benefit to obtaining at least a single lateral expiratory view, as that phase of respiration is most likely to highlight intrathoracic tracheal collapse.3,4 Radiographs also have the added benefit of visualization of the lung parenchyma, cardiovascular structures, and extrathoracic anatomy in assessing for comorbid disorders. While it is possible that respondents chose not to proceed with expiratory views if tracheal collapse was already documented, plain radiography may not accurately reflect the degree and location of collapse. It may also miss collapse in up to 8% of cases.4 Fluoroscopy addresses some of the limitations of radiography by dynamically evaluating collapse of the large airways but is often available only at very large referral centers or academic practices. Limited availability likely accounted for few specialists commonly utilizing fluoroscopy despite spontaneous or induced coughing during fluoroscopic examination having the highest specificity (87%) for tracheal collapse diagnosis compared to tracheobronchoscopy as the gold standard.3

Tracheobronchoscopy allows direct visualization of the airways including more distal bronchi not easily evaluated with fluoroscopy, is more widely available in specialty practice than fluoroscopy, and serves as the current gold standard for diagnosing airway collapse in veterinary medicine.3 All of these factors likely account for it being the second most utilized diagnostic reported in this survey. Of those respondents using tracheobronchoscopy, most performed the entire or part of the procedure without endotracheal intubation. However, 18% had dogs intubated usually or always, a practice that limits complete evaluation of the cervical trachea. Importantly, tracheobronchoscopy may limit identification of the extent of dynamic collapse of both the trachea and bronchi, as many dogs experience apnea or respiratory depression associated with general anesthesia. This limitation could be partly overcome by use of fluoroscopy or paired inspiratory and expiratory radiographs or CT scans.3 While a possible perceived drawback of tracheobronchoscopy is the need for general anesthesia, a recent study found a low risk of postprocedural morbidity or mortality in dogs with respiratory disease undergoing CT and bronchoalveolar lavage.20 It is likely then that the ability to fully investigate comorbidities such as chronic bronchitis and bronchomalacia, among others, outweighs the procedural risk for many dogs.

In dogs with suspected and confirmed tracheal collapse, it is the opinion of the authors that knowledge of comorbid diseases is critical to providing an optimal therapeutic plan and accurate prognosis. We have shown here that, among the surveyed specialists, ancillary diagnostic tests most commonly utilized include functional upper airway examination, echocardiography, tracheobronchoscopy, and airway lavage. Although not every test would be expected to be performed on every patient, without at least considering these diagnostics, it is the opinion of the authors that comorbidities are almost certainly underestimated. Advanced diagnostics generally require referral to a specialist, so knowledge of specialists’ perceptions of how significant and how common these comorbidities are is relevant. In the current study, most specialists acknowledged the importance of identifying comorbid diseases in dogs with tracheal collapse, with 81% declaring it to be very or extremely important to rule out CHF, 68% declaring it to be very or extremely important to rule out PHT, and 67% declaring it to be very or extremely important to rule out chronic bronchitis and bronchomalacia. This was mirrored by many specialists stating they diagnosed chronic bronchitis, bronchomalacia, and MMVD in over 50% of dogs, and with bronchiectasis and PHT being less common and CHF being uncommon but critical to rule out definitively (Figure 2). Importantly, this represents the opinions of surveyed specialists and may not be reflective of the true percentages of dogs with these comorbidities, as answers could have been influenced by recall or recency bias. Based on this survey, there is not a consensus among specialists regarding what a uniform, comprehensive evaluation for primary disease and comorbid disorders entails in a dog with tracheal collapse.

One area in which clinical practice appears to differ from the scientific evidence relates to the technique for a functional upper airway examination. In further investigating comorbid disorders, while many respondents performed a functional upper airway examination, almost half (45%) of respondents never gave doxapram to stimulate respiration, which is necessary if no or weak inspiratory efforts are observed. Several studies have documented the need for respiratory stimulation to fully evaluate laryngeal function and differentiate dogs with laryngeal paralysis from those with normal function.21,22

In general, specialists reported prescribing medications similar to those previously recommended,15,23 although some differences were identified. The difference in treatment approaches likely reflects our incomplete understanding of the pathogenesis of clinical signs. Even once comorbidities have been diligently accounted for, a knowledge gap in the factors driving clinical signs and disease progression remains. For example, in this survey, 50% of specialists expected that most dogs would need indefinite glucocorticoid treatment. A histochemical study1 of dogs with tracheal collapse has documented that this is a degenerative disorder without reported inflammatory changes. Thus, use of glucocorticoids as an anti-inflammatory medication indefinitely specifically to treat tracheal collapse appears without rationale, and there should be consideration of the negative effect of extended glucocorticoid use on tracheal cartilage. In addition to the potential for inducing cartilage degradation,24 chronic glucocorticoid use is also problematic for dogs with tracheal collapse, as it confers a predisposition for obesity.25 It is also possible that specialists might have attempted to treat dogs for comorbidities, such as chronic bronchitis, in the situation that a complete work-up was not performed to rule these out.

Aside from the consensus of opioid cough suppressors and some use of glucocorticoids, respondents demonstrated that additional strategies are being used to manage clinical cases. Maropitant has been described as an adjunctive antitussive for chronic bronchitis26 but not yet published in treatment of tracheal collapse. Bronchodilators have been claimed to benefit dogs by altering pressure dynamics and reducing the tendency of intrathoracic airways to collapse.27 Additionally, some bronchodilators such as theophylline, may have anti-inflammatory properties.28 In a study29 of 47 dogs with tracheal collapse treated with theophylline, cough scores improved. However, concurrent medical therapy and comorbidities, along with subtherapeutic theophylline serum concentrations, confounds interpretation. Bronchodilator use also presents an interesting conundrum and may induce side effects opposite to the goals of maintaining a quiet state, less likely to induce cough. Future studies documenting the value or harm of some routinely used treatments without direct benefit to collapsed airways, such as chronic glucocorticoid exposure, bronchodilators, or behavioral modification, might provide data to alter current practice.

The survey responses reported here defined several additional areas where a consensus for clinical practice lacked evidence-based justification, highlighting opportunities for future prospective studies. Tracheal collapse manifests with chronic cough, and respondents were asked to consider a stable dog being evaluated for the disease; thus, it was surprising that 18% of respondents reported using antimicrobials most of the time or always, contrary to published guidelines.30,31 This is an important finding because the contribution of bacterial infection or inflammation to the pathogenesis and progression of tracheal collapse remains unclear. Infection has not been recognized in dogs with tracheal collapse on histologic examination.1 Other studies have shown conflicting results with positive culture rates as low as 10% or as high as 83%.9,23,32 It is unclear whether antimicrobial use was intended to address secondary bacterial tracheobronchitis or whether respondents perceived a high risk for bacterial pneumonia in their stable dogs. The perception of bacterial pneumonia as a comorbidity among dogs being evaluated for tracheal collapse was not investigated in this survey, as the authors of the study did not consider bacterial pneumonia to be a common comorbid disorder during development of the survey. Given the aforementioned conflicting studies9,32 and the antibiotic use demonstrated here, this represents a critical area for future research and possible improvement in antimicrobial stewardship. The selection of antimicrobials should be targeted to the underlying site of infection, with consideration of the blood-bronchus barrier for dogs with tracheobronchitis. Penicillins do not penetrate respiratory secretions well,33 so their use (22% of respondents using antimicrobials selected penicillins) in this study was of particular interest. However, even expert guidelines remain divided with regard to the use of penicillins in canine infectious respiratory disease complex, as while some B bronchiseptica isolates are susceptible, all mycoplasmas are resistant.30

This study had several limitations, many of which are inherent to survey-based research. Limited options were given for the perceived incidence of comorbid disorders, and all comorbid disorders of concern may not have been accurately captured, including bacterial pneumonia and laryngeal dysfunction. Differing geographic locations and drug availability bias prescribing practices in the treatment of tracheal collapse, as does the availability of advanced diagnostic equipment such as fluoroscopy. As such, what respondents reported doing and using may not actually be what they feel would be best practices. The specialist respondents may not be representative of all specialists who manage tracheal collapse, as some groups such as surgeons were not included. The diversity in the types of specialists participating in the survey may bias the type/severity of tracheal collapse they see, thereby influencing survey responses. Thus, these findings may not be applicable to the general population of dogs with tracheal collapse presenting to primary care practices. To maximize the relevance to general practitioners, we selected the most common clinical presentation and asked participants to consider a stable dog that is suitable for outpatient treatment. However, bias is not completely excluded, as individual interpretation of this description could vary. In response to the Likert scale questions, individual interpretations of “rarely,” “sometimes,” or other choices could also differ, and ideally exact percentages (eg, rarely = 1% to 24%, sometimes = 25% to 59%, etc) would have been given instead. Additionally, there is likely some degree of conscious reaction bias among respondents and the degree to which they felt the need to respond in a particular manner to fit in with procedural norms, which cannot be fully eliminated. However, the wide range of answers and identification of areas in which practice diverges from recommendations and evidence lend credence to the idea that conscious reaction bias was limited in our survey as much as possible. Importantly, while this study represents the opinions of specialists based on their training and personal experience, due to the paucity of literature in some areas those opinions may not reflect scientifically validated practices. In addition, while we surveyed a diverse population of board-certified veterinarians residing in private and academic practice worldwide, our 180 respondents may not truly represent specialists treating tracheal collapse. Thus, the data presented here must be interpreted with some degree of caution in generalization. However, we believe that data showing the disparity between common practices and evidence-based medicine and areas in which any published evidence is lacking remain important despite this limitation.

The results of this survey illustrate the most common diagnostic and therapeutic choices of specialists managing this condition. It highlights important information about comorbidities that can be utilized by general practitioners to consider advanced diagnostic testing. In addition, it summarizes real-world treatments and treatment goals, which will help manage client expectations for this chronic condition. Our findings also provide a valuable background for developing future prospective studies evaluating the incidence of comorbid disorders with tracheal collapse, the utility of ancillary diagnostic tests, and the comparison of different treatment regimens in the medical management of the disease.

Supplementary Materials

Supplementary materials are posted online at the journal website: avmajournals.avma.org

Acknowledgments

No external funding was used in this study. The authors declare that there were no conflicts of interest.

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    Tobias KM, Jackson AM, Harvey RC. Effects of doxapram HCl on laryngeal function of normal dogs and dogs with naturally occurring laryngeal paralysis. Vet Anaesth Analg. 2004;31(4):258263.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23.

    Johnson LR, Fales WH. Clinical and microbiologic findings in dogs with bronchoscopically diagnosed tracheal collapse: 37 cases (1990–1995). J Am Vet Med Assoc. 2001;219(9):12471250.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Moskowitz RW, Davis W, Sammarco J, Mast W, Chase SW. Experimentally induced corticosteroid arthropathy. Arthritis Rheum. 1970;13(3):236243.

  • 25.

    Lund EM, Armstrong PJ, Kirk CA, et al. Prevalence and risk factors for obesity in adult dogs from private US veterinary practices. Int J Appl Res Vet Med. 2006;4(2):177186.

    • Search Google Scholar
    • Export Citation
  • 26.

    Grobman M, Reinero C. Investigation of neurokinin-1 receptor antagonism as a novel treatment for chronic bronchitis in dogs. J Vet Intern Med. 2016;30(3):847852.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 27.

    Della Maggiore A. An update on tracheal and airway collapse in dogs. Vet Clin North Am Small Anim Pract. 2020;50(2):419430.

  • 28.

    Sullivan P, Bekir S, Jaffar Z, Page C, Jeffery P, Costello J. Anti-inflammatory effects of low-dose oral theophylline in atopic asthma. Lancet. 1994;343(8904):10061008.

    • PubMed
    • Search Google Scholar
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  • 29.

    Jeung SY, Sohn SJ, An JH, et al. A retrospective study of theophylline-based therapy with tracheal collapse in small-breed dogs: 47 cases (2013–2017) (Erratum published in J Vet Sci. 2019;20[6]:e66). J Vet Sci. 2019;20(5):e57. doi:10.4142/jvs.2019.20.e57

    • Search Google Scholar
    • Export Citation
  • 30.

    Lappin MR, Blondeau J, Boothe D, et al. Antimicrobial use guidelines for treatment of respiratory tract disease in dogs and cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases. J Vet Intern Med. 2017;31(2):279294.

    • Search Google Scholar
    • Export Citation
  • 31.

    Weese JS, Giguère S, Guardabassi L, et al. ACVIM consensus statement on therapeutic antimicrobial use in animals and antimicrobial resistance. J Vet Intern Med. 2015;29(2):487498.

    • PubMed
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  • 32.

    Lesnikowski S, Weisse C, Berent A, Le Roux A, Tozier E. Bacterial infection before and after stent placement in dogs with tracheal collapse syndrome. J Vet Intern Med. 2020;34(2):725733.

    • PubMed
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  • 33.

    Stewart SM, Fisher M, Young JE, Lutz W. Ampicillin levels in sputum, serum, and saliva. Thorax. 1970;25(3):304311.

Contributor Notes

Corresponding author: Dr. Pritchard (jpritchard2@wisc.edu)
  • Figure 1

    Bar charts illustrating the percentage of respondents ranking chronic bronchitis, bronchomalacia, bronchiectasis, pulmonary hypertension, myxomatous mitral valve disease, or congestive heart failure as extremely, very, somewhat, slightly, or not at all important to rule in or out in their diagnostic evaluation of a stable dog with cough and suspected tracheal collapse.

  • Figure 2

    Box-and-whisker plots showing surveyed specialists’ perceived prevalence (percentage of cases) of chronic bronchitis (CB), bronchomalacia, pulmonary hypertension (PHT), bronchiectasis, myxomatous mitral valve disease (MMVD), and congestive heart failure (CHF) diagnoses in stable dogs presenting for evaluation of tracheal collapse. The boxes indicate the interquartile range, and the circles indicate outliers.

  • Figure 3

    Bar charts illustrating the frequency with which surveyed specialists recalled prescribed varying classes of drugs to stable, coughing dogs diagnosed with tracheal collapse over the previous year.

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    Radkey DI, Hardie RJ, Smith LJ. Comparison of the effects of alfaxalone and propofol with acepromazine, butorphanol and/or doxapram on laryngeal motion and quality of examination in dogs. Vet Anaesth Analg. 2018;45(3):241249.

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    • Export Citation
  • 22.

    Tobias KM, Jackson AM, Harvey RC. Effects of doxapram HCl on laryngeal function of normal dogs and dogs with naturally occurring laryngeal paralysis. Vet Anaesth Analg. 2004;31(4):258263.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23.

    Johnson LR, Fales WH. Clinical and microbiologic findings in dogs with bronchoscopically diagnosed tracheal collapse: 37 cases (1990–1995). J Am Vet Med Assoc. 2001;219(9):12471250.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24.

    Moskowitz RW, Davis W, Sammarco J, Mast W, Chase SW. Experimentally induced corticosteroid arthropathy. Arthritis Rheum. 1970;13(3):236243.

  • 25.

    Lund EM, Armstrong PJ, Kirk CA, et al. Prevalence and risk factors for obesity in adult dogs from private US veterinary practices. Int J Appl Res Vet Med. 2006;4(2):177186.

    • Search Google Scholar
    • Export Citation
  • 26.

    Grobman M, Reinero C. Investigation of neurokinin-1 receptor antagonism as a novel treatment for chronic bronchitis in dogs. J Vet Intern Med. 2016;30(3):847852.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 27.

    Della Maggiore A. An update on tracheal and airway collapse in dogs. Vet Clin North Am Small Anim Pract. 2020;50(2):419430.

  • 28.

    Sullivan P, Bekir S, Jaffar Z, Page C, Jeffery P, Costello J. Anti-inflammatory effects of low-dose oral theophylline in atopic asthma. Lancet. 1994;343(8904):10061008.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 29.

    Jeung SY, Sohn SJ, An JH, et al. A retrospective study of theophylline-based therapy with tracheal collapse in small-breed dogs: 47 cases (2013–2017) (Erratum published in J Vet Sci. 2019;20[6]:e66). J Vet Sci. 2019;20(5):e57. doi:10.4142/jvs.2019.20.e57

    • Search Google Scholar
    • Export Citation
  • 30.

    Lappin MR, Blondeau J, Boothe D, et al. Antimicrobial use guidelines for treatment of respiratory tract disease in dogs and cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases. J Vet Intern Med. 2017;31(2):279294.

    • Search Google Scholar
    • Export Citation
  • 31.

    Weese JS, Giguère S, Guardabassi L, et al. ACVIM consensus statement on therapeutic antimicrobial use in animals and antimicrobial resistance. J Vet Intern Med. 2015;29(2):487498.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 32.

    Lesnikowski S, Weisse C, Berent A, Le Roux A, Tozier E. Bacterial infection before and after stent placement in dogs with tracheal collapse syndrome. J Vet Intern Med. 2020;34(2):725733.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 33.

    Stewart SM, Fisher M, Young JE, Lutz W. Ampicillin levels in sputum, serum, and saliva. Thorax. 1970;25(3):304311.

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