Partial Velum Palatiectomy for the Relief of Dyspnoea in Brachycephalic Breeds

Abstract— The indications for the operation of partial velum palatiectomy, for the relief of dyspnoea in brachycephalic breeds of dogs, are discussed and the procedure for the operation is described.
Résumé— Les indications pour l'opération de l'excision partielle du voile du palais pour le soulagement de la dyspnée chez les races brachycéphales de chiens sont discutées et la technique opératoire est décrite.
Zusammenfassung— Die Indikation für diese Operation und ihre Durchführung wird besprochen und der Operationsvorgang beschrieben.     

Recurrent airway obstruction--heaves.

Heaves, or recurrent airway obstruction (RAO), is a chronic respiratory disease featuring lower airway inflammation, bronchoconstriction, and mucus accumulation. Inhaled organic dusts and T helper 2 type immunologic reactions are involved in the complex pathophysiology of RAO. Clinical signs vary and alternate with remission periods. The diagnosis is often based on history and clinical examination in severe cases, but bronchoalveolar lavage may be useful for the detection of early cases. The most important aspect of treatment is to avoid exposure to allergens. Corticosteroids may be administered systemically or by inhalation in combination with bronchodilators and environmental control.     

Upper airway obstruction caused by a nasopharyngeal polyp and brachycephalic airway syndrome in a Chinese Shar-Pei puppy

Objective: To describe the case management for a dog diagnosed with a nasopharyngeal polyp.
Case summary: A 9-week-old Shar-Pei puppy presented for progressive dyspnea and collapse. Clinical signs were consistent with an upper airway obstruction (UAO) and a temporary tracheostomy was performed. The puppy was at first diagnosed with and treated for brachycephalic airway syndrome but continued to exhibit signs of an UAO after soft palate resection. Nasopharyngoscopy revealed a nasopharyngeal polyp causing the UAO, which was surgically removed. The puppy has been free of clinical signs for 1 year after removal of the polyp.
New or unique information provided: This is the first report of a nasopharyngeal polyp causing a life-threatening UAO in a puppy. It emphasizes the importance of examining the nasopharyngeal space in neonates presenting with UAO.     

Effects of xylazine on airway function in ponies with recurrent airway obstruction.

The effect of IV administration of the alpha 2-adrenoceptor agonist xylazine hydrochloride (0.5 mg/kg of body weight) was examined in ponies with recurrent obstructive pulmonary disease, commonly called heaves. Six ponies with the disease (principals) were studied during clinical remission and during an acute attack of airway obstruction precipitated by stabling and feeding of dusty hay. Six control ponies were also studied. In principal ponies with airway obstruction, xylazine administration significantly (P < 0.05) decreased pulmonary resistance and increased dynamic compliance, but did not affect PaO2 or PaCO2. The alpha 2-antagonist yohimbine blocked the pulmonary effects of xylazine. Administration of saline solution was without effect in both groups of ponies at all periods and xylazine did not have effect in controls or in principals in clinical remission.     

Lower airway diseases of the adult horse.

Lower airway problems of the adult horse are commonly encountered by the practitioner. Particularly susceptible populations include horses transported for any significant distance and young horses grouped together for training and/or competition. This article presents some of the commonly encountered problems of this patient population, including bacterial pneumonia/pleuropneumonia and influenza, and some uncommon ones, including pulmonary edema, pneumothorax/hemothorax, and acuterespiratory distress syndrome. Information is presented that should allow the practitioner to diagnose these problems accurately and initiate rational treatment plans.     

Results of surgical correction of abnormalities associated with brachycephalic airway obstruction syndrome in dogs in Australia

OBJECTIVES: To describe clinical features of brachycephalic airway obstructive disease in dogs, the incidence of laryngeal collapse in dogs presenting for surgery and the outcome after surgery in dogs with laryngeal collapse. METHODS: Basic clinical details were reviewed retrospectively in 73 dogs. Presence of laryngeal collapse and short-term outcomes after surgery were determined for 64 dogs with complete medical records. Long-term outcomes were reviewed for 46 dogs by telephone survey between 19 and 77 months following surgery. RESULTS: Stenotic nares were present in 31 dogs (42.5 per cent), elongated soft palate in 63 (86.3 per cent) and everted laryngeal saccules in 43 (58.9 per cent). The most common breeds were the pug (19 dogs, 26 per cent), Cavalier King Charles spaniel (15 dogs, 20.5 per cent), British bulldog (14 dogs, 19.2 per cent) and Staffordshire bull terrier (4 dogs, 5.5 per cent). Laryngeal collapse was present in 34 of 64 (53 per cent) dogs. No dogs died perioperatively and only one dog was euthanased as a result of its respiratory disease three years after surgery. Telephone interviews indicated that 26 dogs (56.5 per cent) were much improved after surgery, 15 (32.6 per cent) had some improvement and 5 (10.9 per cent) showed no improvement. Signs that persisted after surgery were snoring during sleep (34 dogs, 73.9 per cent), stertor/stridor while conscious (23 dogs, 50 per cent), excessive panting (13 dogs, 28.3 per cent) and dyspnoea (10 dogs, 21.7 per cent). Long-term outcome was considered good, even in dogs with laryngeal collapse. CLINICAL SIGNIFICANCE: Laryngeal collapse is relatively common in dogs presented for surgical correction of brachycephalic airway obstructive disease. Dogs with severe laryngeal collapse often respond well to surgery. Clinical signs rarely resolve completely following surgery.     

Pulmonary particle deposition and airway mucociliary clearance in cold-exposed calves.

Effect of cold-induced changes in respiratory pattern on pulmonary particle deposition was investigated in 10 male Holstein calves between the ages of 1 and 3 months. Deposition of intranasally instilled fluorescence-enhanced Pasteurella haemolytica was significantly higher (P less than 0.05) for cold-exposed calves and appears to be caused by the cold-induced respiratory pattern change. Deposition was greater in apical and mediastinal lung lobes, but the reason for this preferential deposition is uncertain. Nasal mucus velocity was measured in 4 nonanesthetized calves at ambient temperature of 2 to 4 C and 16 to 18 C, using tantalum-paraffin oil droplets and serial radiography. Nasal mucus velocity was 24% lower during cold exposure. In addition, the effect of mucosal temperature on tracheal mucus velocity was determined in excised tracheas from 7 calves. A direct relationship existed between mucosal temperature and tracheal mucus velocity within the mucosal temperature range studied (35.0 to 39.5 C). Tracheal air temperature measurements in calves at ambient temperatures of -10.4 C (n = 4) and 18.5 C (n = 5) indicated that conditioning of inspired air is not complete at the tracheal level during extreme cold exposure. Therefore, cold air may directly influence tracheal mucociliary clearance. It is speculated that cold exposure increases pulmonary deposition of pathogens, while simultaneously decreasing mucociliary clearance of the upper airways, thus predisposing cold-exposed calves to respiratory tract infection.     

Efficacy of salmeterol xinafoate in horses with recurrent airway obstruction.

OBJECTIVE: To determine the onset, magnitude, and duration of bronchodilation after administration of aerosolized salmeterol xinafoate in horses with recurrent airway obstruction. DESIGN: Randomized controlled study ANIMALS: 6 horses with recurrent airway obstruction. Procedure Horses received aerosolized salmeterol (210 microg) or no treatment, using a crossover design. Salmeterol was administered, using a mask designed for aerosol delivery in horses. Subjective rating of airway obstruction (RAO), maximal change in pleural pressure (deltaPplmax), and pulmonary resistance (RL) were determined at baseline; 5, 15, and 30 minutes; and 1, 2, 4, 6, 8, 10, and 12 hours after administration of salmeterol and in horses that did not receive treatment. RESULTS: The deltaPpl and RL were improved 15 minutes through 6 hours after administration of salmeterol, compared with values obtained from horses receiving no treatment. The RAO was improved 15 minutes through 2 hours after administration of salmeterol. The maximal response to salmeterol was evident 30 to 60 minutes after administration and was characterized by a 59 + 19% decrease in deltaPpl and a 56 +/- 13% decrease in RL. The deltaPpl and RL were not different from baseline values 8 hours after salmeterol administration. CONCLUSIONS AND CLINICAL RELEVANCE: Duration of action of salmeterol in these horses was approximately 6 hours. Maximal bronchodilation was somewhat delayed (30 to 60 minutes), and the magnitude of response was similar to that of short-acting beta2-adrenergic agonists. Salmeterol provides moderately sustained bronchodilation in horses with recurrent airway obstruction and may be an effective drug for long-term control of this condition.     

Coughing,mucus accumulation,airway obstruction,and airway inflammation in control horses and horses affected with recurrent airway obstruction

OBJECTIVE: To investigate relationships between cough frequency and mucus accumulation, airway obstruction, and airway inflammation and to determine effects of dexamethasone on coughing and mucus score. ANIMALS: 13 horses with recurrent airway obstruction (RAO) and 6 control horses. PROCEDURE: 6 RAO-affected and 6 control horses were stabled for 3 days. Coughing was counted for 4 hours before and on each day horses were stabled. Before and on day 3 of stabling, tracheal mucus accumulation was scored, airway obstruction was assessed via maximal change in pleural pressure (deltaPpl(max)), and airway inflammation was evaluated by use of cytologic examination of bronchoalveolar lavage fluid (BALF). Effects of dexamethasone (0.1 mg/kg, IV, q 24 h for 7 days) were determined in 12 RAO-affected horses. RESULTS: To assess frequency, coughing had to be counted for 1 hour. In RAO-affected horses, stabling was associated with increases in cough frequency, mucus score, and deltaPpl(max). Control horses coughed transiently when first stabled. In RAO-affected horses, coughing was correlated with deltaPpl(max), mucus score, and airway inflammation and was a sensitive and specific indicator of deltaPpl(max) > 6 cm H2O, mucus score > 1.0, and > 100 neutrophils/microL and > 20% neutrophils in BALF Dexamethasone reduced cough frequency, mucus score, and deltaPpl(max), but BALF neutrophil count remained increased. CONCLUSIONS AND CLINICAL RELEVANCE: Because of its sporadic nature, coughing cannot be assessed accurately by counting during brief periods. In RAO-affected horses, coughing is an indicator of airway inflammation and obstruction. Corticosteroid treatment reduces cough frequency concurrently with reductions in deltaPpl(max) and mucus accumulation in RAO-affected horses.     

Effects of infectious bovine rhinotracheitis virus infection on bovine airway reactivity.

The response of isolated tracheal and bronchial strips to isoproterenol in vitro was studied in eleven male Jersey calves. Clinical, microbiological and pathological evaluations of the calves were carried out. In calves exposed once or twice to infectious bovine rhinotracheitis virus, the relaxation threshold of the trachealis muscle to isoproterenol was significantly (p less than 0.05) impaired (threshold 5.0 X 10(-7) M, single exposure and 1.0 X 10(-7) M, double exposure), when compared with uninfected controls (threshold 1.0 X 10(-8) M). Single infection significantly impaired tracheal relaxation to isoproterenol doses from 1.0 X 10(-7) to 5.0 X 10(-4) M, and double infection significantly impaired tissue responses at drug doses from 1.0 X 10(-7) to 1 X 10(-4) M. Bronchial relaxation threshold was not significantly inhibited (p less than 0.05) in singly infected or doubly infected animals (threshold 5.0 X 10(-8) M and 1.0 X 10(-8) M, respectively), when compared with uninfected controls (threshold 1.0 X 10(-9) M). Single infection significantly impaired bronchial relaxation at isoproterenol doses from 1.0 X 10(-7) M to 5.0 X 10(-6) M while double infection significantly impaired relaxation only at 5.0 X 10(-7) M. The disruption of normal homeostatic bronchodilatory mechanisms may predispose animals infected with infectious bovine rhinotracheitis virus to secondary bacterial infections due to excessive airway constriction and subsequent compromise of lung defenses.