Flap of the sternocephalicus muscle in the repair of a partial defect in the trachea of a rabbit (Oryctolagus cuniculus)

Purpose: The current study aimed at evaluating the repair of a partial defect of the trachea with a muscle flap, an advanced technique that employs combined suture patterns. Methods: Sixteen healthy male New Zealand white rabbits were used as an experimental model. A partial defect in the trachea within the ventral region of the fourth to eighth tracheal ring was created. Subsequently, repair was initiated with a flap of the sternocephalicus muscle. The animals were divided into four groups for postoperative evaluation using clinical, tracheoscopic, and histopathological analyses. Each group was separated according to the time of euthanasia, programmed at interval of seven (G7), 15 (G15), 30 (G30), and 60 days (G60). Results: One animal from the G60 group died, whereas the other animals had good surgical recovery without serious changes in the breathing pattern. The major clinical signs observed were stridor and coughing. Tracheoscopy revealed secretions in the tracheal lumen, exuberant granulation, and stenosis. Histopathological analysis showed growth of the ciliary respiratory epithelium at the flap site 30 days after implantation. Conclusions: Partial repair showed satisfactory results owing to the anatomical location of the muscle, adequate vascular support, and structural and physiological maintenance without serious changes in the respiratory system.

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.

Surgical Repair of a Complete Transverse Tracheal Rupture in a Mallard Duck (Anas platyrhynchos).

An adult male mallard duck (Anas platyrhynchos) of unknown age was presented for acute intermittent respiratory distress that resolved when at rest. The duck had no history or evidence of trauma and had never been intubated. Radiographic imaging revealed a 1-cm tracheal defect at the level of the sixth vertebra. Surgical correction of the defect was pursued, during which a complete transverse tracheal rupture of unknown origin was identified. The separated tracheal sections were successfully anastomosed without resection of any tracheal rings. Tracheoscopy performed 2 months after the surgical procedure revealed healthy mucosa at the anastomosis site with a slight narrowing of the tracheal lumen.

Identification of the avian tracheal trematode Typhlocoelum cucumerinum (Trematoda: Cyclocoelidae) in a host-parasite-environment system: diagnosis, life cycle and molecular phylogeny.

Typhlocoelum cucumerinum is a tracheal parasite of birds widely distributed across the globe. Nevertheless, aspects of the biology of this cyclocoelid are still poorly understood. Herein, we report the finding of T. cucumerinum in definitive and intermediate hosts from an urban waterbody of Brazil. The parasite was initially detected during the necropsy of domestic Muscovy ducks (Cairina moschata) found dead in the locality. Coproparasitological tests in live animals revealed that 12/47 (25.53%) Muscovy ducks and 2/8 (25%) mallards (Anas platyrhynchos platyrhynchos) were infected with T. cucumerinum. Moreover, rediae and metacercariae morphologically similar to T. cucumerinum were found in 3/248 (1.33%) Biomphalaria straminea collected in the same waterbody frequented by the birds. The conspecificity between the adult and the larval stages was confirmed molecularly (100% similarity in Cox-1). Moreover, the phylogenetic position of T. cucumerinum was determined for the first time based on partial fragments of the 28S, Cox-1 and Nad-1 genes. The species grouped with other members of the subfamily Typhlocoelinae with sequences available, but the data obtained do not support the distinctiveness of the genera Typhlocoelum and Tracheophilus. Further studies involving a broader range of species can result in taxonomic rearrangements in Typhlocoelinae.

APEC infection affects cytokine-cytokine receptor interaction and cell cycle pathways in chicken trachea.

Avian pathogenic Escherichia coli (APEC) can lead to extraintestinal disease in avian species via respiratory tract infection. However, the regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium remains unknown. In this study, we examined pathological changes in chicken trachea at different infection times (4, 8, 12 and 24 h). The RNA sequencing of APEC infection group and the PBS group (negative control) of chicken trachea epithelium were analysed. Our studies revealed that the oedema, heterophil infiltration and hyperaemia appeared at 8 and 12 h post APEC infection. And the hyperaemia phenomenon and heterophilic granulocyte infiltration disappeared at 24 h post infection. Then RNA sequencing showed many genes were dynamically expressed in the APEC infection group. At 4, 8 and 12 h post infection, the mRNA of differentially expressed genes were enriched by cytokine-cytokine receptor interaction and the toll-like receptor signalling pathway. The cell cycle pathway was enriched at 24 h post infection. Altogether, these findings suggest that APEC infection induces pathological change in the chicken trachea, the mRNA of differentially expressed genes participating in inflammation and hyperplasia signalling pathways. Which not only provide more evidence for regulatory mechanism of APEC on the pathogenicity of chicken trachea epithelium, but also facilitate the effective management of APEC infections in poultry through trachea.

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.

Radiographic tracheal lumen to vertebral ratios in the normal American Miniature Horse.

BACKGROUND: Tracheal collapse in horses is reportedly uncommon; however, American Miniature Horses are more commonly affected. There is no description of the tracheal luminal diameter of American Miniature Horses, making early detection of tracheal luminal narrowing difficult. OBJECTIVES: To 1) describe radiographic tracheal luminal diameter in clinically normal American Miniature Horses, 2) report the prevalence of subclinical tracheal collapse in a population of American Miniature Horses, and 3) use tracheal videofluoroscopy to quantify variation in tracheal luminal diameter throughout the respiratory cycle in horses with no clinical respiratory disease. STUDY DESIGN: Descriptive observational reference interval study. METHODS: Thirty-four American Miniature Horses with no reported history of respiratory illness were recruited. Lateral cervical and thoracic radiographs were obtained in unsedated standing horses. Dynamic fluoroscopic images were obtained of the cervical and thoracic trachea throughout the respiratory cycle. Horses were then sedated as needed and tracheoscopy was performed. Twenty-nine horses were categorised as normal, and five horses were categorised as subclinically affected based on 25% or greater tracheal narrowing using tracheoscopy for visual assessment. Radiographic tracheal lumen to vertebral body measurements were obtained throughout the cervical and thoracic trachea. Maximum and minimum fluoroscopic tracheal diameter at each site throughout the respiratory cycle was recorded. RESULTS: A mean, median, 95% confidence interval and bootstrapped 95% reference interval of radiographic tracheal diameter to vertebral body ratios were generated in normal horses. The prevalence of subclinical tracheal collapse in this population of American Miniature Horses is 14.7%. MAIN LIMITATIONS: Bootstrapped reference range was generated from 29 horses. CONCLUSIONS: Radiographic tracheal measurements and ratios of the tracheal diameter to vertebral body in the normal American Miniature Horse are described herein and can be used as a guideline when screening for tracheal disease in American Miniature Horses. The prevalence of subclinical tracheal collapse in American Miniature Horses may be higher than previously reported.

Atypical lateral tracheal collapse in a Yorkshire terrier.

A 10-month-old, neutered female Yorkshire terrier was presented with a 6-month history of inspiratory dyspnoea, coughing and exercise intolerance. Tracheoscopy revealed marked lateral-to-lateral fixed collapse of the cervical trachea and mild collapse of the thoracic trachea. Surgical exploration revealed a marked reduction in lateral tracheal width and multiple malformed tracheal rings. Placement of extraluminal ring prostheses around the cervical trachea resulted in widening of the tracheal diameter and an immediate improvement in clinical signs. 6 years postoperatively the patient was reported to have an excellent quality of life with complete resolution of clinical signs.

Correlations among tracheal dimensions, tracheal stent dimensions, and major complications after endoluminal stenting of tracheal collapse syndrome in dogs.

BACKGROUND: Endoluminal tracheal stenting can relieve signs associated with tracheal collapse syndrome (TCS) in dogs, but major complications can result. OBJECTIVE: To identify associations among tracheal dimensions, stent dimensions, and subsequent complications requiring additional stent placement after endoluminal stenting for TCS. ANIMALS: Fifty-two dogs from the hospital population. METHODS: Medical records of dogs that received an endoluminal self-expanding tracheal stent for TCS by the interventional radiology service between 2009 and 2014 were reviewed for relevant data. Signalment and clinical details, including tracheal collapse type, tracheal measurements, nominal stent dimensions, follow-up evaluation times, and stent complications, were recorded. RESULTS: Fifty-two dogs that received an endoluminal stent for TCS met the inclusion criteria. Major complications included stent fracture (13/52; 25%), obstructive tissue ingrowth (10/52; 19%), and progressive tracheal collapse (6/52; 12%). Natural tracheal taper (P = .04) and more stent diameter oversizing (P = .04) in the intrathoracic (IT) trachea were associated with caudodorsal stent fracture. Only stents with a 14-mm nominal diameter fractured. Progressive tracheal collapse was associated with smaller maximum tracheal diameters (P = .02). The majority of dogs with obstructive tissue ingrowth (7/10; 70%; P = .30) and all dogs with thoracic inlet fractures (3/3; 100%) had tracheal malformations. CONCLUSIONS AND CLINICAL IMPORTANCE: A higher taper in tracheal diameter may lead to increased risk of fracture in the IT location. Dogs with tracheal malformations may have higher risk for thoracic inlet fracture and development of obstructive tissue ingrowth. Clinicians should be aware of the possible risk factors for tracheal stent complications.

Tracheobronchopathia osteochondroplastica: a rare tracheal lesion in a free-ranging grizzly bear.

A mature male grizzly bear (Ursus arctos) that died of blunt-force trauma had numerous hard 1-3-mm nodules protruding from tracheal rings into the lumen of the distal trachea. Histologically, these were round aggregates of mature cartilage within the submucosa. Such lesions are consistent with tracheobronchopathia osteochondroplastica, a rare tracheal disease in humans and animals.

Pulmonary pythiosis in a canine patient.

A Staffordshire terrier presented for evaluation of a chronic, nonproductive cough that was unresponsive to antibiotic therapy. A large mass identified in the pulmonary hilum was most consistent with tracheobronchial lymphadenopathy on radiographic and computed tomography (CT) images. Bronchoscopy confirmed a mass compressing the dorsal portion of the intrathoracic trachea. Bronchoscopic biopsies of the tracheal mass revealed necrosuppurative and eosinophilic inflammation with intralesional Pythium insidiousum hyphae. Pythiosis should be included as a differential diagnosis for tracheobronchial lymphadenopathy and bronchopneumopathy in dogs, especially when the patient is from or has visited a region endemic for Pythium insidiosum.

Anticoagulant rodenticide toxicosis causing tracheal collapse in 4 small breed dogs.

OBJECTIVE: To describe 4 cases of tracheal narrowing attributed to tracheal mucosal hemorrhage caused by anticoagulant rodenticide toxicity in breeds predisposed to tracheal collapse. CASE SUMMARY: Over the years 2005-2014, 4 dogs were presented for respiratory distress secondary to diffuse tracheal narrowing. All dogs had possible anticoagulant rodenticide ingestion and prolonged prothrombin time. All dogs received fresh-frozen plasma transfusions, vitamin K1 supplementation, and supportive care. Tracheal narrowing improved on follow-up radiographs in 3 of 4 patients. One of 4 did not have follow-up radiographs performed. All dogs survived. NEW OR UNIQUE INFORMATION PROVIDED: Anticoagulant rodenticide toxicity causing clinical signs consistent with tracheal collapse is a rare but recognized phenomenon that has not been previously reported in breeds prone to tracheal collapse.

Association of neutrophil morphology with bacterial isolates in equine tracheal wash samples.

BACKGROUND: Tracheal wash sample neutrophilia is common in lower airway inflammation of various causes; however, relevance of cytomorphological features to culture of bacterial pathogens has not been established. OBJECTIVES: To investigate whether the presence of nondegenerate or degenerate neutrophils in tracheal washes is associated with culture of bacteria and, if so, whether this is influenced by age or temporal factors. STUDY DESIGN: Cross-sectional study. METHODS: Tracheal wash samples submitted to Rossdales LLP from 1/1/2013 to 31/7/2015 were evaluated using set criteria. Neutrophilia and degenerate neutrophilia (graded ≥2/4 on Rossdales cytological scale [0-4]) were analysed in relation to bacterial isolates considered potentially pathogenic in respiratory disease. Statistical analyses included multivariable logistic regression to identify associations between two separate outcomes: 1) the presence of neutrophilia compared with no neutrophilia and 2) the presence of degenerate neutrophilia compared with nondegenerate neutrophilia and four independent variables. RESULTS: Sufficient data for inclusion in the multivariable model for nondegenerate neutrophilia were available from 1100 horses. Culture of potentially pathogenic bacteria was associated with increased odds of degenerate neutrophilia compared with samples with negative culture (OR 4.5, 95% CI 3.1, 6.4, P-value<0.001). Horses over 9 years old had lower odds of having degenerate neutrophilia than those aged 1-3 years (OR 0.6, 95% CI 0.4, 0.9, P-value<0.02). In the spring/summer, horses had reduced odds of a degenerate neutrophilia compared with winter (OR 0.4, 95% CI 0.3, 0.7, P-value <0.001). MAIN LIMITATIONS: The study relied on routine laboratory submissions, with no control over sample collection or submitted clinical history. CONCLUSIONS: Cytological evaluation of tracheal washes should include cytomorphological features of the neutrophil response. The presence of degenerate neutrophils, especially in young horses, indicates added value of culture and sensitivity for antimicrobial therapeutics. The absence of degenerate changes, in combination with clinical factors, can help support diagnosis of a nonseptic cause of airway neutrophilia.

Avian coronavirus isolated from a pigeon sample induced clinical disease, tracheal ciliostasis, and a high humoral response in day-old chicks.

The detection of avian coronaviruses (AvCoV) in wild birds and the emergence of new AvCoV have increased in the past few years. In the present study, the pathogenicity of three AvCoV isolates was investigated in day-old chicks. One AvCoV isolated from a pigeon, which clustered with the Massachusetts vaccine serotype, and two AvCoV isolated from chickens, which grouped with a Brazilian genotype lineage, were used. Clinical signs, gross lesions, histopathological changes, ciliary activity, viral RNA detection, and serology were evaluated during 42 days post infection. All AvCoV isolates induced clinical signs, gross lesions in the trachea, moderate histopathological changes in the respiratory tract, and mild changes in other tissues. AvCoV isolated from the pigeon sample caused complete tracheal ciliostasis over a longer time span. Specific viral RNA was detected in all tissues, but the highest RNA loads were detected in the digestive tract (cloacal swabs and ileum). The highest antibody levels were also detected in the group infected with an isolate from the pigeon. These results confirm the pathogenicity of Brazilian variants, which can cause disease and induce gross lesions and histopathological changes in chickens. Our results suggest that non-Galliformes birds can also play a role in the ecology of AvCoV.

Immediate, short-, and long-term changes in tracheal stent diameter, length, and positioning after placement in dogs with tracheal collapse syndrome.

BACKGROUND: Intraluminal tracheal stenting is a minimally invasive procedure shown to have variable degrees of success in managing clinical signs associated with tracheal collapse syndrome (CTCS) in dogs. OBJECTIVES: Identify immediate post-stent changes in tracheal diameter, determine the extent of stent migration, and stent shortening after stent placement in the immediate-, short-, and long-term periods, and evaluate inter-observer reliability of radiographic measurements. ANIMALS: Fifty client-owned dogs. METHODS: Retrospective study in which medical records were reviewed in dogs with CTCS treated with an intraluminal tracheal stent. Data collected included signalment, location, and type of collapse, stent diameter and length, and post-stent placement radiographic follow-up times. Radiographs were used to obtain pre-stent tracheal measurements and post-stent placement measurements. RESULTS: Immediate mean percentage change was 5.14%, 5.49%, and 21.64% for cervical, thoracic inlet, and intra-thoracic tracheal diameters, respectively. Ultimate mean follow-up time was 446 days, with mean percentage change of 2.55%, 15.09%, and 8.65% for cervical, thoracic inlet, and intra-thoracic tracheal diameters, respectively. Initial mean stent length was 26.72% higher than nominal length and ultimate long-term tracheal mean stent shortening was only 9.90%. No significant stent migration was identified in the immediate, short-, or long-term periods. Good inter-observer agreement of radiographic measurements was found among observers of variable experience level. CONCLUSIONS AND CLINICAL IMPORTANCE: Use of an intraluminal tracheal stent for CTCS is associated with minimal stent shortening with no clinically relevant stent migration after fluoroscopic placement. Precise stent sizing and placement techniques likely play important roles in avoiding these reported complications.

Radiographic and computed tomographic appearance of tracheal collapse with axial rotation in four dogs.

Tracheal collapse with axial rotation was diagnosed in four dogs. Radiographs showed increased tracheal dorsoventral height at the caudal cervical and thoracic inlet with and apparent intraluminal soft tissue opacity, mimicking an intraluminal tracheal foreign body. Computed tomography confirmed dorsoventral tracheal collapse with axial rotation in all dogs. Short-term outcome with medical treatment of all dogs was excellent.

Fluoroscopic characteristics of tracheal collapse and cervical lung herniation in dogs: 222 cases (2012-2015).

This retrospective study included 222 dogs suspected to have tracheal collapse (TC) and examined between 1 January 2012 and 31 December 2015. Fluoroscopic and radiographic images and medical records were evaluated to investigate the fluoroscopic characteristics of TC and cervical lung herniation (CLH), and to determine their relationships to various influencing. Grade of TC, existence of tracheal kinking, location of CLH (right or left side), and grade of CLH were evaluated fluoroscopically. One hundred ninety-nine dogs (89.6%) were diagnosed with TC. Presence of TC was not associated with the patients' cough history; however, CLH was positively correlated with cough history (odds ratio [OR], 2.896; 95% confidence interval [CI], 1.556 to 5.390) and was affected by tracheal kinking (OR, 3.841; 95% CI, 1.884 to 7.831). Chronic cough was not related with CLH. Since TC can be observed in patients without a history of cough, presence of TC should be ruled out by using physical examination and diagnostic imaging. Although CLH is associated with a history of cough, it is a common appearance in dogs, and transient coughing can elicit CLH in patients without a history of cough.