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.

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.

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.

Malignant Melanoma of the Syrinx and Liver in an African Grey Parrot ( Psittacus erithacus erithacus).

A 20-year-old, female African grey parrot ( Psittacus erithacus erithacus) was examined because of ataxia and weakness. Radiographs were unremarkable, and results of a complete blood cell count revealed leukocytosis and heterophilia. Because of poor response to therapy with meloxicam, doxycycline, and enrofloxacin; deteriorating condition; and poor prognosis, the parrot was euthanatized. Postmortem examination revealed 2 dark red nodules in the liver. No grossly visible mass was observed in the syrinx. Histologic examination of the liver and syrinx revealed similar foci of round, oval, and polygonal cells exhibiting severe pleomorphism, with poorly demarcated cytoplasmic borders and moderate amounts of eosinophilic cytoplasm containing brown to black granules (melanin). The mitotic index was 15. The presence of melanin pigment is consistent with a diagnosis of melanoma at both sites. The multifocal distribution and intravascular invasion indicate metastasis; however, the site of origin was unknown. To our knowledge, this is the first recorded case of melanoma in an avian syrinx.

Imaging diagnosis-pulmonary-tracheobronchial prolapse in a new Caledonian giant gecko (Rhacodactylus leachianus).

A 3-year-old male New Caledonian giant gecko, or Leach's gecko (Rhacodactylus leachianus) presented with acute lethargy and coelomic distention. Findings from survey radiographs and an upper gastrointestinal tract contrast study were consistent with severe aerophagia, a collapsed left lung, and hyperinflation of the right lung due to suspected bronchial obstruction. The gecko was treated with conservative medical management, but was found dead 5 days after presentation. Necropsy findings showed intussusception of the proximal left lung into the left mainstem bronchus and trachea.

Cervical lung lobe herniation in dogs identified by fluoroscopy.

This study aimed to determine the frequency of cervical lung lobe herniation (CLLH) in dogs evaluated fluoroscopically and to identify associated characteristics. Reports of diagnostic procedures and patient summaries from 2008 to 2010 were reviewed retrospectively. Signalment, body weight, duration of cough, presence of heart murmur and airway collapse, and radiographic findings were compared between dogs with and without CLLH. Of the 121 dogs that were examined, CLLH occurred in 85 (70%). The extra-thoracic trachea kinked during herniation in 33 (39%) dogs with CLLH. Collapse of the intra-thoracic trachea (assessed fluoroscopically or bronchoscopically) and collapse of major bronchi (assessed fluoroscopically) were strongly associated with CLLH. Although redundant dorsal tracheal membrane on radiographs was associated with CLLH, extra-thoracic tracheal collapse, assessed fluoroscopically or bronchoscopically, was not. No other associations were found. Cervical lung lobe herniation was present in most dogs evaluated during cough and was associated with intra-thoracic large airway collapse, but not duration of cough.

Herniation du lobe pulmonaire cervical chez les chiens identifié par fluoroscopie. Cette étude a visé à déterminer la fréquence de l'herniation du lobe pulmonaire cervical (HLPC) chez les chiens évalués par fluoroscopie et à identifier les caractéristiques connexes. Des rapports des procédures diagnostiques et des sommaires des patients de 2008 à 2010 ont été examinés rétrospectivement. Le signalement, le poids corporel, la durée de la toux, la présence d'un souffle cardiaque et de l'affaissement des voies aériennes ainsi que les constatations radiographiques ont été comparés entre les chiens avec et sans HLPC. Parmi les 121 chiens qui ont été examinés, HLPC s'est produite dans 85 cas (70 %). La trachée extra-thoracique s'est tordue durant l'herniation chez 33 (39 %) des chiens atteints de HLPC. L'affaissement de la trachée intra-thoracique (évalué par fluoroscopie ou bronchoscopie) et l'affaissement des bronches majeures (évalué par fluoroscopie) étaient fortement associés à HLPC. Même si la membrane trachéale dorsale redondante sur les radiographies était associée à HLPC, l'affaissement trachéal extra-thoracique, évalué par fluoroscopie ou bronchoscopie, ne l'était pas. Aucune autre association n'a été trouvée. L'herniation du lobe pulmonaire cervical était présente chez la plupart des chiens évalués durant la toux et était associée à l'affaissement des grandes voies aériennes intra-thoraciques, mais non à la durée de la toux.(Traduit par Isabelle Vallières).

Use of nitinol stents for end-stage tracheal collapse in dogs.

OBJECTIVE: To report bronchoscopic placement of nitinol stents (Vet Stent-Trachea®) for improvement of end-stage clinical signs in dogs with tracheal collapse. STUDY DESIGN: Case series. SAMPLE POPULATION: Dogs (n = 18). METHODS: Medical records (January 1, 2004-October 31, 2008) were searched for dogs with a diagnosis of tracheal collapse; 18 dogs met inclusion criteria. Tracheal diameter was compared before and after stent deployment. Stent dimensions were compared after stent deployment and at radiographic follow-up. RESULTS: There was a significant difference in the minimum tracheal diameter when initial and post deployment tracheal diameters were compared (P = .003). Stent length was significantly shorter at follow-up when compared to post deployment measurements (P = .004). Owner assessment of outcome was available for all dogs with 11.1% mortality within 60 days. Complications were documented in 9 dogs. CONCLUSIONS: Use of a nitinol stent (Vet Stent-Trachea®) in dogs with end-stage tracheal collapse is associated with a fair to good outcome despite significant temporal stent fore shortening after bronchoscopic placement.

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.

Conservative management of canine tracheal collapse with stanozolol: a double blinded, placebo control clinical trial.

The objective of this study is to determine the efficacy of stanozolol in the treatment of tracheal collapse (TC) in dogs, which is the analogous disease to tracheomalacia (TM) in humans. Twenty-two dogs with endoscopically confirmed and graded TC were enrolled into five groups. Groups S1 (n=5), S2 (n=5) and S3 (n=4) with grade 1, 2 and 3 TC, respectively, received stanozolol orally for 75 days, while groups P1 (n=4) and P2 (n=4) with grade 1 and 2 TC, respectively, received placebo. The clinical score was evaluated every 15 days, whereas TC grade was reassessed at the end of the experiment. Clinical improvement was detected from the 30th day in S2 and S3 group dogs and from the 45th day in S1 group dogs and continued until the end of the experiment. Also, statistically significant differences were seen between S2 and P2 dogs from the 30th day, and between S1 and P1 dogs from the 60th day, and continued until the end of the study. Amelioration of the TC grade was seen in 13 of 14 (92.9%) dogs, which received stanozolol. Of the 14 dogs, 57.1% were cured and 35.8% demonstrated a less severe TC grade, while only one dog (7.1%) did not improve at all. Stanozolol seems to be an effective drug in the management of canine TC and it may have potential for use in humans with TM.

Morphological study of tracheal shape in donkeys with and without tracheal obstruction.

REASON FOR PERFORMING STUDY: There is limited information on the gross tracheal morphology of donkeys with or without tracheal abnormalities. OBJECTIVES: To: 1) examine the morphology of tracheas of donkeys with and without clinical and/or post mortem evidence of tracheal obstruction; 2) record the cross-sectional dimensions and shapes of tracheal rings at fixed sites; and 3) document prevalence, sites and characteristics of detected tracheal abnormalities. METHODS: The tracheas of 75, predominantly aged (median age 30 years, range 7-48 years) donkeys that died or were subjected to euthanasia on humane grounds were examined. Five had severe dyspnoea due to tracheal obstruction (with intercurrent lung disease in 3), while 7 had post mortem evidence of severe tracheal airway obstruction. Every 5th tracheal ring was dissected free and the inner and outer vertical and transverse dimensions and cross sectional areas were measured. Each dissected ring was photographed and the shape of the trachea was classified as normal or, in one of 6 abnormal grades, according to the type and degree of structural abnormality present. RESULTS: The tracheas had a mean of 43 (range 34-50) tracheal rings that tended to be more oval in shape in the distal cervical region. Only 31.2% of rings examined had a circular to oval shape. Dorso-ventral flattening was present in 0.9% of tracheal rings, dorsal ligament separation in 24.4%, slight cartilage deformity in 26.0%, moderate cartilage deformity in 10.4%, marked cartilage deformity in 1.9% and miscellaneous other abnormalities in 4.9% of tracheal rings. The 12 donkeys with ante or post mortem evidence of tracheal obstruction had significantly increased tracheal abnormality grade in comparison to the remaining donkeys. CONCLUSIONS AND POTENTIAL RELEVANCE: Structural tracheal abnormalities are present in most old donkeys, but generally do not cause clinical problems in these sedentary animals unless intercurrent pulmonary disease is present.

Use of a unique method for removal of a foreign body from the trachea of a cat.

CASE DESCRIPTION: A 2.96-kg (6.5-lb) 9-month-old spayed female domestic longhair cat was admitted for removal of a tracheal foreign body. CLINICAL FINDINGS: The cat had moderate respiratory distress but otherwise appeared to be healthy. Thoracic radiography revealed a foreign body in the trachea. TREATMENT AND OUTCOME: The cat was anesthetized and endoscopy of the trachea was performed in an attempt to retrieve the foreign body. Endoscopic removal was unsuccessful because of the shape and smooth texture of the foreign body. Surgical removal of the foreign body was not considered ideal because of its location and the risks associated with tracheotomy. Fluoroscopic-guided placement of an over-the-wire balloon catheter caudal to the foreign body was followed by inflation of the balloon and gradual traction in an orad direction, which resulted in successful removal of the foreign body (identified as a piece of landscaping gravel). The cat required supplemental oxygen and supportive care following removal of the foreign body. CLINICAL RELEVANCE: A fluoroscopic technique was used as a minimally invasive alternative to endoscopy or open-chest surgery for removal of a foreign body from the trachea of a cat. Use of this technique allowed uninterrupted ventilation of the cat throughout the procedure.

Brachycephalic airway obstructive syndrome in dogs: 90 cases (1991-2008).

OBJECTIVE: To determine the prevalence of individual anatomic components of brachycephalic airway obstructive syndrome (BAOS), including everted tonsils, and analyze the frequency with which each component occurs with 1 or more other components of BAOS in brachycephalic dogs. DESIGN: Retrospective case series. ANIMALS: 90 dogs with BAOS. PROCEDURES: Medical records were reviewed for signalment, clinical signs at time of admission, historical and physical examination findings, BAOS components found on laryngoscopic examination of the pharynx and larynx, surgical procedures performed, and perioperative complications. RESULTS: English Bulldogs (55/90 [61%]), Pugs (19/90 [21%]), and Boston Terriers (8/90 [9%]) were the most common breeds with BAOS. The most common components of BAOS were elongated soft palate (85/90 [94%]), stenotic nares (69/90 [77%]), everted laryngeal saccules (59/90 [66%]), and everted tonsils (50/90 [56%]). Dogs most commonly had 3 or 4 components of BAOS, with the most common combination being stenotic nares, elongated soft palate, everted laryngeal saccules, and everted tonsils. Dogs with stenotic nares were significantly more likely to have everted laryngeal saccules (50/69 [72%]), and dogs with everted laryngeal saccules were significantly more likely to have everted tonsils (39/59 [66%]). Postoperative surgical complications occurred in 12% (10/83) of dogs that received corrective surgery. No specific BAOS component made dogs more likely to have complications. CONCLUSIONS AND CLINICAL RELEVANCE: The prevalence of components of BAOS in brachycephalic dogs of this study differed from that reported previously, especially for everted tonsils. Thorough examination of the pharynx and larynx is necessary for detection of BAOS components.

Dysplastic tracheae in eight blue duikers (Cephalophus monticola) from Bioko, Equatorial Guinea.

Nine blue duikers (Cephalophus monticola), purchased in the Malabo bushmeat market, were necropsied. Eight of the nine animals were found to have dysplastic tracheas, characterized by lateral apposition of tracheal rings, entrapment of the trachealis muscle and annular ligaments, and bunching of the tracheal epithelium. Communications with zoologic pathologists and a thorough search of the veterinary literature have not uncovered a single case of this pathologic finding. As such, this finding may represent an evolutionary marker indicative of a bottleneck that may have occurred in the history of this species of duiker, endemic to the island of Bioko, in the Gulf of Benin.

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.

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.