Coughing Flashcards
What can cause acute coughing?
- Tracheobronchitis - “kennel cough”
- Irritation by smoke/dust/chemicals/medicines!
- Airway FB - may have been in there some time.
- Pulmonary haemorrhage - often + dyspnoea
- Acute pneumonia, e.g. inhalation - often + dyspnoea
- Acute oedema - often + dyspnoea
- cardiogenic/non/cardiogenic
- Airway trauma - choke chains/bites etc.
What causes infectious tracheo-bronchitis? How can you treat it? How can you prevent it?
ANY contact – not just kennels!
Causes include:
- Canine parainfluenzavirus
- Canine adenovirus (2)
- Bordetella bronchiseptica
Spontaneous recovery – 7–10 days
Systemic antibacterial agents often dispensed
- If pyrexic
- If systemically ill
- Muco-purulent nasal discharge
Vaccines available
- Bordetella bronchiseptica – live by intranasal
- Canine parainfluenzavirus – live by injection
- Canine adenovirus (2) – live by injection
Why shouldn’t you use anti-tussives? What could you use instead?
Don’t use cough suppressants unless absolutely necessary – as coughing IS protective in most cases
- Value particularly in anatomical airway disease
- Intractable non-productive pathological cough e.g. neoplasia
Butorphanol/codeine
What causes chronic coughing in dogs?
- Chronic bronchitis/bronchiectasis
- L. heart failure
- Oslerus/Aelurostrongylus infestation
- Tracheal collapse
- Airway F.B.
- Bronchopneumonia
- Pulmonary neoplasia - primary or secondary
- Extra-luminal mass lesions - thyroid, abscess, lymphoma
- Eosinophilic disease – EBP/PIE/allergic airway disease
- (Pulmonary “fibrosis”)
What characterises canine chronic bronchitis? What is a common complication? What is the cause?
Daily coughing for >2months
Characterised by:
* Neutrophilic/eosinophilic infiltration of mucosa and thickening of smooth muscle later, fibrosis and scarring of lamina propria
* Increased goblet and glandular cell size and number
* Oxidative injury and inflammatory products damage cells and lead to mucus hypersecretion
* Loss of ciliated epithelial cells and failure of mucociliary clearance and debris
The combination of these events leads to thickening of bronchial tissue, overproduction of airway mucus and narrowing of the airways (particularly terminal bronchi)
Leads to clinical signs of wheezing and productive coughing
Complications are common – dilation of airways, airway collapse due to wall weakness (bronchomalacia)
Aetiology
- Maybe seen secondary to underlying conditions
- Tracheal collapse, chronic barking
- FB
- Previous infections or inhalant toxins
- Environmental factors
- Chronic smoke inhalation/noxious gas
But usually cause unknown
How do we diagnose CCB?
- Typical history, physical findings - Often exaggerated sinus arrhythmia
- Thoracic Radiographs - Increased bronchial lung pattern
- Bronchoscopy and BAL
BAL results typically show:
* Increased mucus
* Non-degenerate neutrophils, eosinophils and macrophages
* Cushmann’s spirals (airway mucus casts)
* Presence of bacteria / particulate matter are less common and if present would suggest underlying cause present
What condition is this radiograph characteristic of?
CCB - donuts
How do we manage canine chronic bronchitis? What is the prognosis?
General management:
- Weight control
- Harness rather than collar / lead
- Avoid irritants / smoking environment
Mucous is easier to shift if hydrated
- Avoid very dry environments
- Steam in the bathroom
Glucocorticoids
- Oral and inhaled approaches
Bronchodilator therapy ?????
- Theophylline
- Beta-agonists – terbutaline, salbutamol, salmeterol
Inhaled medications – long term goal to reduce side effects Coupage
Don’t use cough suppressants unless absolutely necessary
Antimicrobials based on evidence of need
Long term control possible, not cure
- Your dog will always cough - Most patients continue with periodically productive cough
- Major goal is to prevent long term sequelae which include
- Secondary pneumonia
- Bronchiectasis/bronchomalacia
- Emphysema
What are possible treatments for lower airway diseases in dogs and cats?
Inhaled medications
- Corticosteroids
- Bronchodilators
- nebulisers
Oral therapy
- Anti-inflammatories: Corticosteroids, NSAIDs, anti-leukotrienes
- Bronchodilators: Terbutaline or Theophylline
- Antibiotics, anthelminthics
- Mucolytics – N-acetyl cysteine (NAC)
What drugs may be delivered through inhalation? How can we deliver inhaled medications? What is their value? What are their disadvantages?
Drugs
- Beta 2 agonist: Salbutamol (albuterol in USA) & Salmeterol – longer acting medication
- Corticosteroids: Fluticasone & Beclomethasone
- Inhibition of mast cell degranulation (unclear efficacy in dogs and cats with airway disease): Cromolyn sodium/sodium cromoglicate
Delivery
* Mask
* Spacing device/chamber
* Metered dose inhaler (MDI)
Value
* Management of chronic airway disease
* Minimal absorption into systemic circulation - Less systemic side effects – particularly steroids
* Faster onset of action
Disadvantages
- Expensive
- Time consuming
- Owner compliance
- Patient compliance
What pathogens cause bacterial bronchopneumonia?
- Primary infections in healthy dogs (and cats) RARE
- If present should prompt search for underlying cause
- Common pathogens are E Coli, Klebsiella, Pasteurella, staphs (coag +ve), streps, mycoplasma and B bronchiseptica.
- Primary infections most common with primary pathogens
- e.g. Bordetella bronchiseptica, Streptococcus equi subspecies zooepidemicus, Mycobacteria
- Often mixed infections, obligate anaerobes may account for up to 25% pathogens
What factors predisopose to bacterial bronchopneumonia? What clinical signs are associated? How is diagnosis undertaken? How is it treated?
Factors
* Debilitation
* Prolonged recumbency
* Systemic immunosuppression (HAC, chemo, pred’s)
* Immunodeficiency states (weimaraners, CKCS)
* Defective respiratory defenses
* Damaged respiratory epithelium
* Aspiration
* Airway obstruction
* Systemic sepsis
* Bronchiectasis
Clinical signs
* occasionally only minor clinical signs
* signs often relate to extent of pneumonia
* cough, respiratory distress, ex intolerance
* More severe infections may produce hyperthermia
* Anorexia and lethargy are common signs
* Increased or decreased lung sounds may be present, may include crackles
* Respiratory distress and cyanosis may develop in severe cases
Diagnosis
- CBC, biochemistry, UA, faecal
- Thoracic radiographs
- Alveolar pattern with variable distribution
- Aspiraion – cranial-ventral
- Early disease may show only interstitial pattern
- Airway sampling is helpful
- TTW/BAL
- Culture and cytology on fluid
- Integration of inflammation and bacterial culture
Treatment
* Antibiotics – broad spectrum?
* Supplemental humidified oxygen
* IVFT
* Anti-inflammatories
* Bronchodilators
* Mucolytics
* Physiotherapy
* Nebulisation
* Surgery
What clinical signs point to a bronchial foreign body? How can you diagnose it?
Sudden onset coughing and gagging
Diagnosis
Thoracic radiographs
- Fully evaluate for signs of pleural involvement
- Determine if there is suggestion of LOCAL lobar involvement or disease seems more diffuse
Bronchoscopy
- BAL and culture for specific antibiotic therapy
- Enables visualisation and retrieval of object
What clinical signs are associated with O. Osleri? How is it diagnosed? How is it treated?
Clinical signs
* chronic cough
* often dry rasping cough, particularly after exercise
* more notable in young dogs: 6-12months
Diagnosis
- Characteristic nodules (1-1.5cm) can be seen via bronchoscopy particularly at the tracheal bifurcation – most reliable method
- Small nodules contain immature worms
- Large nodules often contain tight coil of adults
- Sampling of tracheal mucus to identify eggs and larvae (characteristically coiled in appearance)
- L1 in faeces or BAL fluid (+ eosinophils)
- Faecal L1 counts less reliable – variable shedding
- Requires experienced parasitologist
Treatment
- Fenbendazole
- Licensed products: Panacur (MSD), Granofen – (Virbac)
- 50mg/kg daily for 10 days
- Often need to repeat 4 weeks later
- Check in-contacts
