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OBJECTIVE To compare short-, intermediate-, and long-term results between dogs with tracheal collapse (TC) that received multimodal medical management only and those that underwent tracheal endoluminal stent placement. ANIMALS 159 dogs with TC that underwent medical management only (MM group; n = 84) or were surgically managed by stent placement (SM group; 75). PROCEDURES Medical records of dogs with TC that underwent medical management only or stent placement at a referral hospital between September 1, 2009, and August 1, 2018, were reviewed. Data regarding signalment, information relevant to TC, and outcome were extracted from the records and aggregated into short-, intermediate-, and long-term follow-up periods for analysis. Descriptive data and median survival times (MSTs) were compared between the MM and SM groups. RESULTS Clinical signs of dogs in the MM group generally improved during the short term but regressed and worsened over time. The proportion of dogs with malformation-type TC that underwent stent placement (38/43 [88%]) was significantly greater than the proportion of dogs with traditional-type TC that underwent stent placement (37/107 [35%]). The MST from TC diagnosis was 3.7 years for the MM group and 5.2 years for the SM group. For dogs with severe disease, the MST was 12 days for medically managed dogs and 1,338 days for dogs that underwent stent placement. CONCLUSIONS AND CLINICAL RELEVANCE Multimodal medical management alleviated clinical signs for months to years in dogs with mild to moderate TC disease, but stent placement should be considered for dogs with severe disease.

OBJECTIVE To evaluate long-term outcomes and identify factors associated with death or the need for revision surgery in dogs with permanent tracheostomies (PTs). DESIGN Retrospective cohort study. ANIMALS 69 client-owned dogs that received a PT between January 2002 and June 2016 at 1 of 4 veterinary teaching hospitals. PROCEDURES Medical records were reviewed, and data extracted included signalment, history, clinical signs, radiographic and laryngeal examination findings, presence of esophageal abnormalities, date and reason for receiving a PT, postoperative complications, cause of death, and survival time. Dogs surviving < 2 weeks after receiving a PT were excluded. RESULTS Major complications occurred in 42 of 69 (61%) dogs, with aspiration pneumonia (13 [19%]), skinfold occlusion (13 [19%]), and stoma stenosis (12 [17%]) being most common. Revision surgery was performed in 24 of 69 (35%) dogs, most commonly because of stoma stenosis or skinfold occlusion (9/24 [38%] each). Brachycephalic dogs were more likely (OR, 3.5; 95% confidence interval, 1.2 to 10.2) to require revision surgery than were nonbrachycephalic dogs. The overall median survival time was 1,825 days, and dogs that received corticosteroids before receiving a PT, had tracheal collapse, or were older had shorter survival times. CONCLUSIONS AND CLINICAL RELEVANCE Results of the present study indicated that creation of a PT was a viable treatment option for obstructive upper airway diseases in dogs and that long-term survival after receiving a PT was possible; however, a PT may not reduce the risk of aspiration pneumonia in dogs.

A 2.6-kg (5.72-lb) 10-year-old neutered male Yorkshire Terrier with a 6-month history of tracheal collapse was evaluated at the University of Florida Small Animal Hospital. The dog had been previously treated by the referring veterinarian with theophylline and butorphanol, but had recently been reevaluated because of increased coughing and signs of respiratory distress, for which it received additional treatment with dexamethasone sodium phosphate (0.23 mg/kg [0.104 mg/lb], IM), acepromazine (0.038 mg/kg [0.017 mg/lb], IM), and oxygen therapy via an oxygen cage. Despite additional treatment, there was no noticeable change in the patient’s condition. Initial physical examination on referral revealed a grade 2 of 6 left systolic heart murmur, coughing, dyspnea, cyanosis, and a palpably enlarged liver. Results of a CBC and serum biochemical analysis were within reference limits. Thoracic radiography revealed extraand intrathoracic tracheal collapse with collapse of the principal bronchi, mild right-sided cardiomegaly, and generalized hepatomegaly (Figure 1). Fluoroscopic examination of the thorax revealed severe, dynamic extraand intrathoracic tracheal, principal bronchial, and caudal lobar bronchial collapse. The patient was placed in an oxygen cage set to deliver 40% oxygen in the intensive care unit overnight and received acepromazine (0.02 mg/kg [0.009 mg/lb], IV) and butorphanol (0.2 mg/kg [0.09 mg/lb], IV) every 2 hours or as needed. Food was withheld overnight, and the following morning, the patient was anesthetized for tracheal stent placement. The dog was premedicated with butorphanol (0.19 mg/kg [0.086 mg/lb], IV), and induction of anesthesia with propofol (6 mg/kg [2.7 mg/lb], IV, to effect) immediately followed. The patient was orotracheally intubated with a 6.0-mm (internal diameter) sterile endotracheal tube. Anesthesia was maintained with isoflurane in oxygen (3 L/min) delivered via a Bain (nonrebreathing) system. Lactated Ringer’s solution was administered IV during anesthesia (7 mL/kg/h [3.2 mL/lb/h]). A multiparameter monitor, including a lead II ECG for heart rate and rhythm, was used, and oxygen saturation as measured by pulse oximetry, end-tidal PCO 2 , respiratory rate, and blood pressure (noninvasive Doppler method) were recorded. The patient breathed spontaneously, and all monitored physiologic parameters were determined by the attending anesthesiologist to be within acceptable limits throughout induction and prior to stent deployment. The patient was transported under general anesthesia to the diagnostic imaging suite where, prior to

Objective—To determine the degree of fluctuation in tracheal dimensions between forced inspiration and passive expiration in healthy dogs of various sizes. Animals—10 client-owned dogs with no evidence of respiratory disease or tracheal collapse. Procedures—Anesthetized dogs underwent a computed tomographic examination during forced inspiration and induced but passive expiration to assess tracheal dimensions. Tracheal height, width, and cross-sectional area were measured at inspiration and expiration, and percentage change in dimension was calculated for each variable. Results—Measurements were acquired in 10 dogs that ranged in body weight from 3.5 to 47.8 kg. Tracheal cross-sectional area at inspiration and expiration was associated with body weight at all 3 tracheal regions. The percentage change in tracheal height and cross-sectional area was associated with body weight in the cervical but not the thoracic-inlet or thoracic regions. The tracheal cross-sectional area changed by as much as 24.2% (mean, 5.5%), 20.0% (mean, 6.0%), and 18.6% (mean, 6.0%) in the cervical, thoracic-inlet, and thoracic regions, respectively. Conclusions and Clinical Relevance—The change in tracheal cross-sectional area from inspiration to expiration was as great as 24% in healthy dogs, and the area was associated with body weight. Respiratory fluctuations appeared to result in changes in tracheal dimension during respiration similar to those reported for humans.

Case Description—An 8-year-old castrated male Yorkshire Terrier was evaluated because of a 1-month history of inspiratory dyspnea that began 2.5 years after placement of extraluminal tracheal ring prostheses for tracheal collapse. Clinical Findings—Physical examination revealed severe inspiratory dyspnea. Cervicothoracic radiography revealed a soft tissue opacity within the lumen of the cervical portion of the trachea at approximately the level of the fifth cervical vertebra. Tracheobronchoscopy revealed 2 prosthetic rings protruding into the tracheal lumen. Treatment and Outcome—The dog was anesthetized, and the 2 protruding tracheal ring prostheses were removed via separate tracheotomies. Tracheoscopy was performed after surgery, and a third prosthetic ring that was found freely floating within the tracheal lumen was removed with an endoscopic grasping forceps. The dog recovered without complications. Dyspnea resolved within the first 2 weeks after surgery. Follow-up examination performed 6 months after surgery revealed that the dog was breathing normally, with no dyspnea or coughing reported by the owner. Clinical Relevance—Migration of extraluminal tracheal ring prostheses should be included in the differential diagnoses for any dog with dyspnea or persistent coughing after surgical correction of cervical tracheal collapse. Surgical removal of the protruding prosthetic rings, without provision of additional tracheal support, was a viable treatment option in this case.

Tracheal collapse is a common problem that is typically observed in middle-aged and older small-breed dogs. It is a structural, obstructive airway disease with a dynamic component that can affect the intra- and extrathoracic portions of the trachea and mainstem bronchi. Many methods of treatment have been suggested, including medical management and provision of extraluminal and intraluminal support. All techniques used to treat intrathoracic and mainstem bronchial collapse have been associated with major complications or limitations. This report describes the implantation of intraluminal nitinol stents to successfully treat intrathoracic as well as extrathoracic tracheal collapse in a dog. The stents are composed of material that has characteristics similar to those of the trachea; nitinol stents may provide a method of supporting intrathoracic tracheal and mainstem bronchial collapse in dogs.