Clinical and microbiologic findings in dogs with bronchoscopically diagnosed tracheal collapse: 37 cases (1990-1995)

The Agreement between Radiography and Fluoroscopy as Diagnostic Tools for Tracheal Collapse in Dogs

Tracheal collapse is a common disease in small, middle-aged dogs, and imaging tools are essential for its diagnosis. Radiography and fluoroscopy are the main diagnostic modalities used, but their agreement in different regions is not well documented. In this study, the agreement between thoracic radiography and fluoroscopy in tracheal collapse was investigated in 29 dogs. The results showed that radiography detected a lower degree of collapsing trachea compared to fluoroscopy at the carina region (p < 0.001). However, there was no significant difference observed between the degree of collapsing trachea detected by radiography and fluoroscopy at the cervical, thoracic inlet, and intra-thoracic regions (p = 0.780, 0.537, and 0.213, respectively). The kappa statistic indicated a slight agreement at the cervical region at a 16.4% cut-off (κ = 0.20), while the other regions showed a non-agreement. In conclusion, although radiography is useful for screening, fluoroscopy was able to detect the degree of the collapsing trachea greater than radiography in the carina region. Additionally, if a collapse in the cervical region is detected by radiography, it is prone to have a positive relationship with fluoroscopy as well.

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

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.

Myxomatous mitral valve disease in Miniature Schnauzers and Yorkshire Terriers: 134 cases (2007-2016)

OBJECTIVE

To characterize features of myxomatous mitral valve disease (MMVD) in Miniature Schnauzers and Yorkshire Terriers.

ANIMALS

69 Miniature Schnauzers and 65 Yorkshire Terriers, each with MMVD.

PROCEDURES

Medical record data for each dog were collected; the study period was January 2007 through December 2016. If available, radiographic data were evaluated, and a vertebral heart scale score was assigned for each dog. Statistical analysis was performed with Student t and Fisher exact tests.

RESULTS

Compared with Yorkshire Terriers, the prevalence of MMVD was significantly higher in Miniature Schnauzers and affected dogs were significantly younger at the time of diagnosis. Miniature Schnauzers were significantly more likely to have mitral valve prolapse and syncope, compared with Yorkshire Terriers. Yorkshire Terriers were significantly more likely to have coughing and have had previous or current treatment with cardiac medications, compared with Miniature Schnauzers. There was no statistical difference between breeds with regard to abnormally high vertebral heart scale scores or radiographic evidence of congestive heart failure.

CONCLUSIONS AND CLINICAL RELEVANCE

With regard to MMVD, features of the disease among Miniature Schnauzers and Yorkshire Terriers were similar, but there were also a few discernable differences between these 2 breeds and from historical findings for dogs with MMVD of other breeds. Clinical signs at the time of diagnosis differed between the 2 breeds, which may have reflected concurrent breed-specific conditions (sick sinus syndrome or airway disease [eg, tracheal collapse]). Future work should include prospective studies to provide additional information regarding the natural progression of MMVD in these dog breeds.

Radiographic evaluation of tracheal collapse in dogs by compressive technique

ABSTRACT The purpose of this study was to verify the applicability of the compressive radiographic technique (pressures of 5, 10, 15 and 20mmHg) in the diagnosis of tracheal collapse in small breed dogs, in lateral cervicothoracic radiography. Out of the 50 dogs evaluated, 25 presented tracheal collapse (TG group), 23 did not present tracheal collapse (CG) and two were excluded because they did not tolerate a pressure of 20 mmHg. The TG group presented a smaller internal diameter of the trachea in the region of the fourth cervical vertebra (D4) and at the entrance of the thorax (TDE) compared to the CG group, in all the radiographic projections performed, as well as within the TG group where the compressive technique differed from conventional. Furthermore, there was a correlation between the clinical sign of coughing during cervical collar use and the presence of radiographic tracheal collapse at a pressure of 20 mmHg. It was concluded that the compressive radiographic technique was feasible and efficient in confirming the diagnosis of tracheal collapse in dogs, especially in the pressure of 20 mmHg, where it was associated with clinical signs, and can be used in isolation or complementary to the conventional technique.

Bacterial infection before and after stent placement in dogs with tracheal collapse syndrome

Background

Dogs with tracheal stents often have positive airway bacterial cultures. The pathogenicity of these organisms and risk factors for infection have not been investigated.

Objective

Describe bacterial infection in dogs with tracheal collapse before and after tracheal stent placement.

Animals

Fifty‐three client‐owned dogs.

Methods

Retrospective review of medical records of dogs receiving tracheal stents with thoracic radiographs, tracheoscopy, and endotracheal lavage.

Results

There was no difference between the overall prevalence of dogs with positive bacterial cultures before (31/38; 82%) or after stent placement (24/31; 77%) (P = .67). An increased number of geriatric (17/28; 61%) and traditional‐type collapse (TTC) (16/26; 62%) dogs had positive pathogenic airway infections before stent placement, compared to young (8/25; 32%; P = .04) and malformation‐type collapse (MTC) dogs (9/27; 33%; P = .04). After tracheal stent placement, geriatric dogs had a 52% reduction in pathogenic bacteria infection frequency (P = .02) and dogs with TTC had a 56% reduction in pathogenic bacteria infection frequency (P = .01). Significant risk factors for pathogenic infection included a history of pneumonia (OR = 3.6; 95% CI, 0.28‐43.36) and cardiac disease (OR = 1.25; 95% CI, 0.16‐9.92) in geriatric dogs, and hepatomegaly in young dogs (OR = 1.5; 95% CI, 0.12‐19.44).

Conclusions and Clinical Importance

Tracheal stent placement does not increase the overall rate of pathogenic bacterial infection in dogs with tracheal collapse and can decrease the rate of subsequent pathogenic infections in geriatric dogs and dogs with TTC that require tracheal stenting. Airway culture and cytology should be performed in all dogs undergoing tracheal stent placement.

The Microbiome: The Trillions of Microorganisms That Maintain Health and Cause Disease in Humans and Companion Animals

The microbiome is the complex collection of microorganisms, their genes, and their metabolites, colonizing the human and animal mucosal surfaces, digestive tract, and skin. It is now well known that the microbiome interacts with its host, assisting in digestion and detoxification, supporting immunity, protecting against pathogens, and maintaining health. Studies published to date have demonstrated that healthy individuals are often colonized with different microbiomes than those with disease involving various organ systems. This review covers a brief history of the development of the microbiome field, the main objectives of the Human Microbiome Project, and the most common microbiomes inhabiting the human respiratory tract, companion animal digestive tract, and skin in humans and companion animals. The main changes in the microbiomes in patients with pulmonary, gastrointestinal, and cutaneous lesions are described.

Tracheal stent placement for the emergency management of tracheal collapse in dogs

Dogs with tracheal collapse may present with life-threatening upper airway obstruction. In most instances, a conservative approach to treatment including oxygen support coupled with sedation and cooling measures will relieve respiratory effort and thus relieve airway obstruction. Dogs that fail this conservative approach require endotracheal intubation to ensure a patent airway. This population of patients would benefit from a more definitive, yet palliative treatment option to acutely relieve upper airway obstruction. Placement of a self-expanding metallic stent that spans the affected portion of the trachea will acutely provide the patient with a sustained patent airway and optimize the likelihood of a positive outcome.

The skin microbiome in healthy and allergic dogs

BACKGROUND

Changes in the microbial populations on the skin of animals have traditionally been evaluated using conventional microbiology techniques. The sequencing of bacterial 16S rRNA genes has revealed that the human skin is inhabited by a highly diverse and variable microbiome that had previously not been demonstrated by culture-based methods. The goals of this study were to describe the microbiome inhabiting different areas of the canine skin, and to compare the skin microbiome of healthy and allergic dogs.

METHODOLOGY/PRINCIPAL FINDINGS

DNA extracted from superficial skin swabs from healthy (n = 12) and allergic dogs (n = 6) from different regions of haired skin and mucosal surfaces were used for 454-pyrosequencing of the 16S rRNA gene. Principal coordinates analysis revealed clustering for the different skin sites across all dogs, with some mucosal sites and the perianal regions clustering separately from the haired skin sites. The rarefaction analysis revealed high individual variability between samples collected from healthy dogs and between the different skin sites. Higher species richness and microbial diversity were observed in the samples from haired skin when compared to mucosal surfaces or mucocutaneous junctions. In all examined regions, the most abundant phylum and family identified in the different regions of skin and mucosal surfaces were Proteobacteria and Oxalobacteriaceae. The skin of allergic dogs had lower species richness when compared to the healthy dogs. The allergic dogs had lower proportions of the Betaproteobacteria Ralstonia spp. when compared to the healthy dogs.

CONCLUSIONS/SIGNIFICANCE

The study demonstrates that the skin of dogs is inhabited by much more rich and diverse microbial communities than previously thought using culture-based methods. Our sequence data reveal high individual variability between samples collected from different patients. Differences in species richness was also seen between healthy and allergic dogs, with allergic dogs having lower species richness when compared to healthy dogs.

Prevalence of respiratory signs and identification of risk factors for respiratory morbidity in Swedish Yorkshire terriers

Yorkshire terriers may be prone to respiratory disease; however, limited epidemiological information is available. A cross-sectional study design was used to compare the prevalence of respiratory signs in Yorkshire terriers with the prevalence in a population of dogs in general and to identify risk factors for respiratory clinical signs within the Swedish population of Yorkshire terriers. Data on clinical signs and risk factors were obtained from a questionnaire. The prevalence of respiratory signs in general (RS) was significantly higher among Yorkshire terriers compared with control dogs (RS 56.3 per cent and 23.0 per cent), and likewise more frequent respiratory signs (FRS) (26.0 per cent and 5.0 per cent). Age, sex and breed were shown to be significant risk factors, and an interaction between age and sex was discovered. The study indicated a sex ratio reversal in the prevalence of RS - the probability of females having RS increased with advancing age, while the probability for males was fairly constant.

Survival after surgery for tracheal collapse and the effect of intrathoracic collapse on survival

OBJECTIVES

To determine (1) long-term survival of dogs with tracheal collapse (TC) receiving cervical extraluminal prosthetic rings (ELR) and (2) whether intrathoracic collapse effects long-term survival of dogs receiving ELR.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n = 33) with TC that had ELR.

METHODS

Medical records (July 2002-July 2008) were searched for TC dogs treated with ELR. Age, breed, gender, location of TC, and age at follow-up (death or censor) were recorded. Kaplan-Meier survival curves were generated.

RESULTS

Of 114 TC dogs, 33 had ELR. Breeds and gender were consistent with previous reports; mean (±SD) age at presentation was 6.3±2.6 years. TC was categorized as cervical or cervical and intrathoracic. All dogs had cervical TC and 15 had concurrent intrathoracic collapse; 8 of these had collapse of mainstem bronchi. Median survival time was >2500 days (median not reached) for cervical TC alone and 1500 days for cervical and intrathoracic TC with no difference in median survival time between groups (P = .26).

CONCLUSION

Dogs with TC have a median survival time of 1680 days (4.6 years) after ELR and no differences were seen when dogs had intrathoracic collapse. Intrathoracic collapse does not exclude a dog from receiving ELR.

Primary Tracheal Collapse in a Cat

A 7-year-old, neutered male, domestic shorthair cat was presented for severe inspiratory dyspnea of 2 to 3 days’ duration. Radiography and tracheobronchoscopy confirmed the diagnosis of primary extrathoracic tracheal collapse. The cat was treated with oxygen, dexamethasone, and terbutaline, but no improvement was seen. Surgical correction was performed using nine prosthetic tracheal ring implants. Clinical signs improved after surgery, and the cat continued to do well 11 months after surgery, despite development of unilateral laryngeal paralysis.

Endotracheal stenting therapy in dogs with tracheal collapse

Tracheal collapse in dogs is a common respiratory disorder, typically presenting with a history of chronic cough, increasing respiratory difficulties, and episodes of dyspnoea. Medical treatment is the therapy of choice and surgical repair is considered when patients do not respond well. Minimally invasive endotracheal stenting is a promising new therapy under investigation, but there remain significant challenges to overcome potential complications. The purpose of this article is to provide a comparative overview of intra-luminal stenting of the trachea in human and veterinary medicine. The currently available stents and their potential clinical application to the veterinary patient will be discussed.

Advances in respiratory therapy

Effective respiratory therapy depends on obtaining a definitive diagnosis and following established recommendations for treatment. Unfortunately, many respiratory conditions are idiopathic in origin or are attributable to nonspecific inflammation. In some situations, disorders are controlled rather than cured. Recent advances in pulmonary therapeutics include the use of new agents to treat common diseases and application of local delivery of drugs to enhance drug effect and minimize side effects.