Respiratory - Lower Airway Disease Flashcards
What is the common signalment of Canine Bronchitis?
- Middle age and older dogs
- Small-medium breeds
What are the clinical signs/PE findings of Canine Bronchitis?
- Chronic Cough
- worse with exercise and excitement, cyanosis/collapse possible
- Productive with gag and swallow or unproductive
- Dyspnea if severe, mostly expiratory, can be mixed/continuous
- PE: can be systemically normal
- Often overweight/obese
- Auscultation: mostly wheezes, may have crackles from mucus
- +/- Barrel-chested appearance: chronic obstruction/hyperinflation
What is the pathophysiology of Canine Bronchitis?
- Chronic airway inflammation
- Excessive mucus production
- hyperplasia of secretory glands in bronchial walls
- Inflammation leading to narrowing
What is the etiology of Canine Bronchitis?
- Multifactorial
- Response of chronic infections
- Response to inhaled irritants
- Primary immune-mediated airway disease
- Ciliary dyskinesia
Why is fluid collection necessary in Canine Bronchitis? How is it done?
- Allows for the most optimal specific care
- Endotracheal Wash/Trans-tracheal wash
- Fast (5min), cheaper, easier way
- May not reach lower airways
- Cannot target specific lobes
- Bronchoalveolar Lavage (BAL) with Bronchoscopy
- Allows visualization of airways and targeted fluid collection
- Requires general anesthesia (long process)
- Inserting scope may further irritate airways
What is the treatment for Canine Bronchitis?
- Remove triggers
- have owners keep journal of when coughing is bad to help identify
- Weight management
- Treat infections if present
- Bronchodilators:
- Aminophylline/Theophylline
- relax smooth muscles in airways, weak chronotropic and inotropic action
- SE: GI upset, Increased HR, CNS stimulation
- Many drug interactions (Baytril)
- Terbutaline
- Beta-2 agonist
- SE: Increased HR, tremors
- Aminophylline/Theophylline
- Glucocorticoids:
- Usually needed for chronic management
- Options are oral or inhaled
- Oral: prednisone (0.5 - 1 mg/kg PO BID)
- Taper to lowest effective dose
- Inhaled fluticasone (steroid)
- 110ug BID for dogs <20kgs
- 220ug BID >20kgs
What is the treatment for excessive mucus associated with Canine Bronchitis?
- Nebulization with saline
- Coupage 3-4x/day, 5-10min each
- Light exercise to dislodge mucus
Should cough suppressants be used with Canine Bronchitis?
- avoid w/ productive cough ⇢ mucus trapping
- Helpful w/ dry cough ⇢ repetitive cough irritates airways
What is Bronchiectasis?
- Irreversible dilation of large airways
- Muscle and elastin in airways are destroyed
- ⇡ airway secretions
- 2° to bronchitis, infection, dyskinesia, smoke, radiation
- Muscle and elastin in airways are destroyed
- Signalment:
- Most >10yrs old (cockers can be younger (25% <4yo)
- Cockers, Westies, Poodles, Huskies, Springers
What are the signs of Bronchiectasis?
- Moist productive cough
- +/- hemoptysis
How is Bronchiectasis diagnosed?
- CT: most sensitive
- BAL: suppurative inflammation
- Culture often positive
What is the treatment for Bronchiectasis?
- Antibiotics per culture
- If focal ⇢ remove surgically
- Humidification, coupage
What is Eosinophilic Bronchopneumopathy?
- Also known as Pulmonary infiltrates with Eosinophils
- Inflammatory disease
- Hypersensitivity to environmental or endogenous antigen
- Other etiologies include drugs, infection (parasites, fungal, bacterial) or cancer
- Signalment:
- young or middle age
- Any breed - husky predisposed
What are the signs of Eosinophilic Bronchopneumopathy?
- Cough, dyspnea, nasal discharge, crackles, wheezes
- often cough up thick greenish mucus
- ⇣ appetite, lethargy
How is Eosinophilic Bronchopneumonpathy diagnosed?
- Most have peripheral eosinophilia
- Radiographs show variable changes
- Bronchoscope: thick green mucus
- Tracheal Wash or BAL: high eosinophil count
- Bacterial culture negative in most dogs
- Rule out heartworms, parasites, fungal, neoplasia
How is Eosinophilic Bronchopneumopathy treated?
- Treat underlying infection if present
- Corticosteroids
What are the differentials for coughing cats?
- Asthma/Chronic Bronchitis
- Infectious
- Bacterial- Bordetella, Mycoplasma
- Fungal- Blasto, histo, cryptococcus
- Parasitic- Heartworm, lungworms
- Viral Pneumonia- herpes, calici
- Pleural effusion
- Foreign Bodies
- Neoplasia
- Heart disease
What is the difference between Feline Asthma and Bronchitis?
- Asthma is an acute crisis
- Hypersensitivity reaction causing acute inflammation, bronchospasm, obstruction
- Status asthmaticus van be fatal
- Reversible, resolving spontaneously or w/ treatment
- Bronchitis is a chronic disease
- Chronic inflammatory and obstructive condition causing cough
- Manageable with treatment
What is the pathophysiology of Feline Asthma and Bronchitis
- Complex
- Immune system dysfunction:
- Inflammatory cell infiltration
- Release cytokines
- Smooth muscle hypertrophy
- Mast cell degranulation
- All contribute to bronchoconstriction
- Mucociliary dysfunction:
- Mucosal injury leads to mucociliary dysfunction
- Goblet cells increase mucus production
- Mucous plugs cause obstruction
What is the common signalment of cats with Asthma/Bronchitis?
- Young to middle age cats, males and females
- Siamese predisposed - possible in all breeds
What are the PE findings of feline Asthma/Bronchitis cases?
- If cat is dyspneic, provide oxygen prior to exam
- Respiratory distress
- +/- Open-mouth breathing
- +/- Cyanosis (status asthmaticus)
- +/- Frantic behavior (scared because cannot breathe)
- Wheezes, ⇡ expiratory effort/push, cough
- Lung sound normal in some cats
- Decreased air sounds if air trapping
- Can have completely unremarkable or nonspecific exam
How is Feline Asthma/Bronchitis diagnosed?
- Clinical history, presentation, signs
- Bloodwork: can have eosinophilia
- Thoracic Radiographs
- Response to treatment
- If stable: Endotracheal wash or BAL can be performed to look for underlying infection or neoplasia
- Cytology: mostly eosinophils, some have ⇡ neutrophils/lymphocytes
- Healthy cats have 20-40% eosinophils in their tracheal wash fluid
- Many eosinophils in conjunction with consistent signs and radiographs suggest asthma or bronchial disease
- Culture for aerobic bacteria
- Mycoplasma PCR or culture
- Cytology: mostly eosinophils, some have ⇡ neutrophils/lymphocytes
- Rule out other causes:
- Heartworm Testing
- antibody more sensitive
- Antigen more specific
- Do both to be sure
- Fecal Flotation and Baermann
- Capillaria
- Paragonimous
- Aelurostronglus
- Heartworm Testing
- NT-ProBNP
- Biomarker to help detect cardiac disease
- Associated with stretch and stress on the myocardium
- Can be used to help determine if a dyspneic cat has underlying heart disease if other diagnostics are unavailable or unclear
- IDEXX Snap Test
- Negative means dyspnea is not cardiac and should be thinking respiratory disease
- Biomarker to help detect cardiac disease
How is acute Feline Asthma and Bronchitis treated?
- Emergency treatment - Oxygen
- Minimize stress
- Bronchodilator:
- Albuterol inhaler
- 90ug every 30 minutes as needed for 4-6hrs
- Not for long-term use, just emergencies
- Consider have an inhaler in your ER drug box
- Terbutaline 0.01mg/kg SQ or IM
- Albuterol inhaler
- Fast acting steroid (injectable dexamethasone)
- inhaled steroids can take 10-14 days for peak effect
- Hospitalize for 48hrs for a break from asthma trigger
How is Feline Asthma/Bronchitis managed long term?
- ID and eliminate triggers
- Control airway inflammation
- Steroids:
- Prednisolone 1 mg/kg PO BID for 10 days then taper to lowest effective dose
- Fluticasone inhaler 44ug BID
- Bronchodilators:
- Terbutaline 0.625mg per cat PO BID
- Theophylline 20-25 mg/kg PO q24hr
- Inhaled albuterol or injectable terbutaline for ER at home
- Steroids:
When do asthma cats need antibiotics for treatment?
If an infection is diagnosed