OBJECTIVE To investigate the prevalence and type of laryngeal abnormalities in dogs examined because of cough that did not have signs of upper airway disease and to compare the prevalence of those abnormalities among dogs with various respiratory tract diseases.
DESIGN Prospective study.
ANIMALS 138 dogs with cough that did not have signs of upper airway disease.
PROCEDURES The study was conducted between July 2001 and October 2014 and included dogs examined for cough that had laryngoscopic and bronchoscopic examinations performed by 1 examiner. Laryngeal hyperemia and swelling were recorded, and laryngeal function was assessed before and after doxapram stimulation when indicated. Results were compared among dogs on the basis of cough duration (acute [< 2 weeks], subacute [2 weeks to 2 months], and chronic [> 2 months]) and disease diagnosed (inflammatory airway disease, airway collapse, lower respiratory tract infection, and eosinophilic bronchopneumopathy).
RESULTS Laryngeal hyperemia was detected in 73 of 134 (54%) dogs with cough of subacute or chronic duration, and its prevalence did not vary significantly among dogs with various diseases. Thirteen dogs had laryngeal paresis, and 13 dogs had laryngeal paralysis; dysphonia (n = 2) and stridor (1) were uncommon findings in those dogs. The prevalence of laryngeal dysfunction (paresis or paralysis) did not differ significantly among diseases.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that 26 of 138 (19%) dogs examined because of cough alone had laryngeal dysfunction, which suggested that a complete laryngoscopic examination should be included in the diagnostic evaluation of dogs with cough.
Objective—To investigate the role of bacteria in bronchoscopically
diagnosed tracheal collapse in dogs by
evaluating qualitative results of bacteriologic cultures.
Animals—37 dogs with tracheal collapse.
Procedure—Clinical records for dogs with tracheal
collapse confirmed with bronchoscopy were
reviewed. A protected catheter brush was used to
obtain samples for bacteriologic culture from the
Results—Results of bacterial culture were negative
for 5 of 29 dogs. For 24 dogs, 1 (n = 10), 2 (6), or ≥ 3
(8) species of bacteria were isolated. Pseudomonas
spp were isolated most frequently (17/29), and a single
Pseudomona ssp grew in 7 samples. Other bacteria
included Enterobacter spp (4/29), Citrobacter spp
(3/29), and Moraxella spp, Klebsiella spp, Bordetella
spp, or Acinetobacter spp (2/29 dogs each). Anaerobic
and aerobic cultures yielded positive results in samples
from 2 dogs. Cytologic results were available for
13 dogs with positive results of bacteriologic culture;
epithelial cells were reported most commonly. Five
samples had a small number of neutrophils; bacteria
were identified cytologically in 2 of 5 samples that
contained neutrophils. Bacteria were also seen in 2
samples that lacked inflammatory cells.
Conclusions and Clinical Relevance—Bacteria are
commonly isolated from samples obtained via airway
brushing in dogs with tracheal collapse; however, in
the absence of cytologic confirmation of inflammation
or infection, an association between bacteria and clinical
signs of tracheal collapse cannot be established.
(J Am Vet Med Assoc 2001;219:1247–1250)
Objective—To compare the use of radiography and fluoroscopy for detection and grading of tracheal collapse in dogs.
Design—Retrospective case series.
Animals—62 dogs with tracheal collapse.
Procedures—For each dog, tracheal collapse was confirmed fluoroscopically and lateral cervical and thoracic radiographic views were reviewed. A board-certified radiologist (who was unaware of the dogs' clinical history) evaluated the cervical, thoracic inlet, thoracic, carinal, and main stem bronchial regions in all fluoroscopic videos and radiographic images for evidence of collapse. Cervical, thoracic inlet, thoracic, and carinal regions in both radio-graphic and fluoroscopic studies were graded for collapse (0%, 25%, 50%, 75%, or 100% decrease in diameter).
Results—Lateral cervical and thoracic radiographic images were available for 54 dogs, and inspiratory and expiratory lateral cervical and thoracic radiographic images were available for 8 dogs. For detection of tracheal collapse, assessment of radiographic views was sensitive and had the best negative predictive value in the cervical and thoracic inlet regions. Assessment of radiographic views was most specific and had the best positive predictive value in the thoracic inlet, thoracic, carina, and main stem bronchial regions. Radiography underestimated the degree of collapse in all areas. Review of inspiratory and expiratory views improved the accuracy of radiography for tracheal collapse diagnosis only slightly.
Conclusions and Clinical Relevance—Compared with fluoroscopy, radiography underestimated the frequency and degree of tracheal collapse. However, radiography appears to be useful for screening dogs with potential tracheal collapse.
Objective—To evaluate bronchial morphology endoscopically in rabbits and develop a valid nomenclature for the endobronchial branching pattern.
Animals—10 mature New Zealand White rabbits.
Procedures—Flexible bronchoscopy was performed in rabbits anesthetized with isoflurane via nasal mask. Airways were systematically evaluated from the larynx to the terminal branches accessible with a 2.5-mm–outer diameter flexible endoscope. Airway branching patterns were identified and assessed for variation among subjects.
Results—Airways of all rabbits were readily examined with the 2.5-mm flexible endoscope. Laryngeal structure and function were normal in each rabbit, and airway branching patterns in all rabbits evaluated were identical. At the carina, branching into left and right principal bronchi was evident. The left principal bronchus divided immediately into the left cranial and left caudal lobar bronchi. The left cranial lobe bronchus further divided into dorsal and ventral segmental bronchi. The left caudal lobe bronchus gave rise to branches originating dorsally, ventrally, and medially before continuing caudally. The right principal bronchus divided into the right cranial, right middle, and accessory lobar bronchi and continued distally as the right caudal lobar bronchus. The right cranial lobe bronchus also divided into dorsal and ventral segmental bronchi, and the right caudal lobe bronchus had branches that originated dorsally, ventrally, and medially.
Conclusions and Clinical Relevance—Definition of a standard nomenclature for airway branching in rabbits will allow precise localization of disease in clinical cases and accurate collection of airway samples in clinical and scientific evaluations.
Objective—To determine the role of rhinoscopic evaluation and repeated serologic testing in assessing the success rate of intranasally administered clotrimazole for treatment of dogs with nasal aspergillosis.
Design—Prospective case series.
Animals—23 dogs with nasal aspergillosis.
Procedures—Dogs with nasal aspergillosis were treated with an intranasal infusion of 1% clotrimazole solution. Response to treatment was assessed with repeated rhinoscopic evaluation, with histologic examination and fungal culture when available. Results of repeated serologic testing for aspergillosis were monitored throughout the treatment course.
Results—11 of the 23 (48%) dogs had no rhinoscopic evidence of disease after the first treatment. Three of 7 dogs were free of disease after the second treatment, and 1 of 3 dogs was free after the third treatment. Presence or absence of nasal discharge and results of repeated serologic testing were not consistent with disease status. Overall, the efficacy of intranasally administered clotrimazole for treatment of nasal aspergillosis could be confirmed in 15 of 17 dogs. Delayed recurrence or reinfection was confirmed in 3 of 15 dogs. When recurrences were taken into account, the success rate was 67% (12/15 dogs).
Conclusions and Clinical Relevance—Clinical signs were not predictive of disease state, and follow-up rhinoscopy is recommended to assess response to treatment. The success rate of intranasally administered clotrimazole was similar to rates in previous reports; however, the number of dogs with recurrent disease was relatively high. Monitoring of the results of serologic testing is not recommended for use in determining response to treatment.
Objective—To determine results of diagnostic testing, including detection of nasal or frontal sinus fungal plaques, in dogs with nasal aspergillosis.
Design—Retrospective case series.
Animals—46 dogs with nasal aspergillosis.
Procedures—Medical records were reviewed for information on computed tomographic findings; rhinoscopic findings, including whether fungal plaques were seen in the nasal cavity; results of frontal sinus trephination and sinuscopy, including whether fungal plaques were seen in the frontal sinus; and results of histologic examination of biopsy specimens.
Results—In 38 (83%) dogs, fungal plaques were seen in the nasal cavity during rhinoscopy, whereas in the remaining 8 (17%), fungal plaques were not seen in the nasal cavity but were seen in the frontal sinus. Duration of clinical signs, proportions of dogs in which the referring veterinarian had performed a nasal examination prior to referral, proportions of dogs with computed tomographic evidence of nasal cavity cavitation or sinus involvement, and proportions of dogs with rhinoscopic evidence of destructive rhinitis were not significantly different between dogs with nasal fungal plaques and dogs with fungal plaques only in the frontal sinus.
Conclusions and Clinical Relevance—Results confirm that frontal sinus involvement is common in dogs with nasal aspergillosis and suggest that frontal sinus trephination and sinuscopy may aid in the diagnosis of aspergillosis in dogs, particularly dogs with rhinoscopic evidence of destructive rhinitis and computed tomographic evidence of sinus involvement that lack detectable fungal plaques in the nasal cavity.
CASE DESCRIPTION A 17-month-old sexually intact male Vizsla and a 2-year-old spayed female mixed-breed dog were examined because of suspected intrathoracic grass awn migration.
CLINICAL FINDINGS Thoracic CT revealed focal areas of pulmonary infiltration in the right caudal lung lobe in one dog and in the left caudal lung lobe in the other. In 1 patient, bronchoscopy revealed 2 grass awns in the bronchi. Results of thoracic radiography and bronchoscopy were unremarkable in the second patient; however, a grass awn was recovered from the tonsillar crypt during oropharyngeal examination.
TREATMENT AND OUTCOME In both dogs, grass awns were successfully retrieved from the pleural cavity by means of video-assisted thoracic surgery during 1-lung ventilation. In one patient, a grass awn was recovered bronchoscopically from the left caudal lung lobe bronchus and another was visualized distally in an accessory lung lobe bronchus but could not be retrieved. This dog underwent accessory lung lobectomy. The second dog underwent left caudal lung lobectomy. Both patients recovered uneventfully from surgery, were discharged from the hospital, and had no apparent recurrence of clinical signs at telephone follow-up 31 months and 18 months after surgery.
CLINICAL RELEVANCE With careful case selection, successful management of intrathoracic grass awn migration in dogs can be achieved by means of video-assisted thoracic surgery. Comprehensive preoperative evaluation including both computed tomography and bronchoscopy is suggested. Further investigation is necessary to evaluate whether treatment of this condition with video-assisted thoracic surgery is as effective as with traditional open thoracotomy.
A 7-year-old 8.6-kg (18.9-lb) castrated male Pug was evaluated because of chronic nasal discharge. Respiratory signs, which started 3 weeks following ingestion of coffee beans, had been noticed for the past 2.5 years and had developed into respiratory distress. Six months after the onset of clinical signs, the patient developed a mucoid discharge from the left nostril. Rhinoscopy revealed hyperemia and mucus in the left nasal cavity. The mucoid discharge resolved temporarily with the use of amoxicillin–clavulanic acid (14.5 mg/kg [6.59 mg/lb], PO, q 12 h), but occasional treatment with neomycin–polymyxin B–dexamethasone ophthalmic drops (in
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-week-old female domestic shorthair cat was treated for patent ductus arteriosus (PDA) with surgical ligation. Seven weeks postoperatively, the cat was evaluated because of increased upper respiratory noise, inspiratory stridor, wheezing, and episodes of intermittent open-mouth breathing that had developed 1 week following the surgical ligation.
Clinical Findings—The cat was sedated, and examination of the larynx revealed left-sided laryngeal paralysis.
Treatment and Outcome—At the time left-sided laryngeal paralysis was diagnosed, the clinical signs of laryngeal dysfunction were not considered severe enough to warrant surgical intervention. No treatment was administered, and the owner monitored the cat for respiratory distress and worsening of clinical signs for an additional 5 months. During those 5 months, the clinical signs improved but persisted. Seven months after PDA ligation, the cat was again sedated and the larynx examined. The examination revealed persistent left arytenoid dysfunction, which was believed to be the result of permanent damage to the recurrent laryngeal nerve that was sustained during the surgical ligation of the PDA. The owner was counseled about surgical and medical treatment options for laryngeal paralysis but elected to forego treatment at that time.
Clinical Relevance—Unilateral laryngeal paralysis caused by iatrogenic damage to the recurrent laryngeal nerve is a potential complication subsequent to surgical ligation of a PDA. The frequency of iatrogenically induced laryngeal paralysis is likely underestimated in small animal patients. Laryngoscopy should be performed in any small animal with a history of PDA attenuation and clinical signs of respiratory tract disease.