Week 1 - Coughing Flashcards
What are the principle presenting signs of respiratory tract disease?
Changes in rate or character of respiration – dyspnoea, tachypnoea, hyperpnoea, orthopnoea
Coughing
What are the other clinical signs
Sneezing/nasal discharge Respiratory noise
Cyanosis
Others
- Weight loss
- Collapse/syncope
- Changes in “voice” - laryngeal lesion
- Exercise intolerance
- Facial deformity
What is it important to do when owners say their dog is coughing?
Make sure it is a cough (and not a sneeze, retch) -> ask for a video
Cough
- Closed larynx = build up air/pressure
- Open larynx = expel air
In dogs, what differentials are on the list for an acute cough?
Hight: Tracheobronchitis - “kennel cough”
Irritation by smoke/dust/chemicals/medicines! Airway FB
Pulmonary haemorrhage
Acute pneumonia, e.g. inhalation Acute oedema (cardiogenic/non/cardiogenic) Airway trauma - choke chains/bites etc.
For an acute cough in the dog, which differential present often with dyspnea as well as cough?
Pulmonary haemorrhage
Acute pneumonia, e.g. inhalation Acute oedema
What causes infectious tracheobronchitis - “kennel cough”?
Canine parainfluenzavirus
Canine adenovirus (2)
Bordetella bronchiseptica
Which causes of tracheobronchitis are covered in the intranasal and injectable vaccines?
Intranasal:
Bordetella bronchiseptica
Injection:
Canine adenovirus (2)
Bordetella bronchiseptica
What is the treatment for tracheobronchitis?
Spontaneous recovery in 7-10 days.
Animals often clinically well with just a cough.
Systemic antibacterial agents often dispensed when animal is:
* pyrexic
* systemically ill
* Muco-purulent nasal discharge
What does Bordetella bronchiseptica cause along with a cough, and how can it be treated?
Causes: URT/nasal infection – bronchopneumonia
Can be fatal
Common in puppies (and groups)
Treatment: Clavulanate-ptd amoxicillin
When should antitussives be used?
Don’t use cough suppressants unless absolutely necessary
COUGH IS PROTECTIVE (REMOVE FB, MUCOUS, FLUID)
Antitussives in a non-productive pathological cough (e.g. neoplasia)
Butorphanol/codeine can be used to calm patient down -> and that can help calm the cough
In dogs, what differentials are on the list for an chronic cough?
HIGH:
Chronic bronchitis/bronchiectasis
Airway F.B.
Bronchopneumonia *
L. heart failure – heart failure * Parasite (Oslerus /Aelurostrongylus infestation)
Tracheal collapse – “URT”
Pulmonary neoplasia (primary or secondary – neoplasia)
Extra-luminal mass lesions (thyroid, abscess, lymphoma)
Eosinophilic disease
How is canine chronic bronchitis characterised?
MAIN POINT = thickening of bronchial tissue, overproduction of
airway mucus and narrowing of the airways (particularly terminal bronchi)
- Daily coughing for over 2 months
- Neutrophilic/eosinophilic infiltration
- Thickening of smooth muscle -> fibrosis -> scarring
- increased goblet and glandular cell size and number =increased thick mucous production
- Loss of ciliated cells = decrease clearance of mucus and debris
What are some complication so canine chronic bronchitis?
dilation of airways, airway collapse due to wall weakness (bronchomalacia)
What can cause canine chronic bronchitis?
Usually cause unknown.
Not often a primary cause.
Maybe seen secondary to underlying conditions
- Tracheal collapse, chronic barking - - FB
- Previous infections or inhalant toxins
- Environmental factors
- Chronic smoke inhalation/noxious gas
What are typical presentation of canine chronic bronchitis on clinical exam?
Often very little to find on exam
- Typically seen in small / toy breeds (but can be any breed)
- Worse on excitement
- Harsh cough with attempts at production (clear/frothy, yellow suggests infection)
- Externally well
- Obese
- Occasionally pant excessively
- Tracheal pinch positive
How is canine chronic bronchitis diagnosed?
Typical history, physical findings
Often exaggerated sinus arrhythmia
Thoracic Radiographs
* Increased bronchial lung pattern *
Bronchoscopy and BAL
This is a dog with Canine chronic bronchitis - what lung patterns are visible?
Bronchiole = tramlines
This is a dog with Canine chronic bronchitis - what lung patterns are visible?
Bronchiole = donuts
This is a dog with Canine chronic bronchitis - what lung patterns are visible?
Bronchiole = donuts
This is a dog with Canine chronic bronchitis - what is visible on its bronchoscope?
Increased mucous production
When doing a BAL on a dog with canine chronic bronchitis, what is found?
Increased mucus
Non-degenerate neutrophils (non-toxic), eosinophils and macrophages
Cushmann’s spirals (airway mucus casts)
Uncommon: Presence of bacteria / particulate matter -> this would suggest another underlying cause.
What has happened to this dog with canine chronic bronchitis?
Chronic (permanent) change in the airway walls
Increased numbers of goblet cells (mucous metaplasia),
Ciliary loss affecting the epithelium of the airways which is now overlain by stratified squamous epithelium (squamous metaplasia).
What is the general management for a dog with canine chronic bronchitis?
General management:
* Weight control
* Harness rather than collar / lead
* Avoid irritants / smoking environment
* Coupage (tap chest to break down mucous)
Mucous is easier to shift if hydrated
* Avoid very dry environments
* Steam in the bathroo
What is the medical management for a dog with canine chronic bronchitis?
Glucocorticoids (oral or inhaled)
- Inhaled = reduces systemic side effects
Bronchodilators (efficacy ???)
Antimicrobials based on evidence
What is the problem when doing a bacterial culture on the respiratory tract?
URT and large airways are not sterile
* have commensal bacteria
* Numbers are increased in dogs with reduced clearance
LOOK FOR: Evidence of infection
* Intra-cellular bacteria
* Growth from BAL fluid
* Neutrophilic inflammation on cytology
BAL only often performed if antibiotic therapy has not resolved clinical signs.