Coughing in SAs

Question 1

Name some presenting signs typically seen in patients with respiratory tract disease.

Answer 1

A.Changes in rate or character of respiration – dyspnoea, tachypnoea, hyperpnoea, orthopnoea

–Dysnpnoea – some clinicians do not like this as subjective about not being able to get their breath but we don’t know if out patients can or not

B. Coughing.

OTHERS INCLUDE:

C. Sneezing/nasal discharge

D. Respiratory noise.

– URT disease make a lot of noise if they are clinically affected

E. Cyanosis.

–Look at MM colour in light of everything else going on

F. Others.

1. Weight loss.
2. Collapse/syncope.
3. Changes in “voice” - laryngeal lesions.
4. Exercise intolerance.
5. Facial deformity.

Most present with respiratory difficulty or coughing.

Question 2

When presented with a coughing animal, what do you need to make sure you differentiate it from? i.e. what things can sound the same

Answer 2

• Cough
• Sneeze
• Retch

–Is it definitely a cough? It could also be a retch!

• URT disease – laryngeal/pharyngeal
• Dysphagia
• Nasal/pharyngeal/respiratory tract
• May have to describe it for the owner to try to distinguish whether it’s a cough or a retch etc. (Malcolm does some real good noises here, give it a listen back)

Question 3

What is a cough?

Why do we cough generally?

Answer 3

• Inhaled, tried to expel the air that was inhaled
• Closed glottis, then glottis opens, abdominal and thoracic muscles force air out
• Why do we cough? Protective mechanism stimulated by irritation (physical or chemical) as there are receptors in the airway that detect this irritation, receptors found everywhere in lungs apart from alveolus.
• Coughing generally means some irritation of the airway. However, cats can have severe pulmonary oedema and they wont cough..

Question 4

What are some common causes of ACUTE coughing?

Answer 4

• Acute = onset within a few days
• Tracheobronchitis - “kennel cough”
• Irritation by smoke/dust/chemicals/medicines!
• Airway FB - may have been in there some time. With some inhaled FB, it can be a constant cough.
• Pulmonary haemorrhage - often + dyspnea – significant lung involvement
• Acute pneumonia, e.g. inhalation - often + dyspnoea
• Acute oedema - often + dyspnoea
• cardiogenic/non/cardiogenic

• Airway trauma - choke chains/bites etc.

Question 5

What is infectious tracheo-bronchitis?

Answer 5

Kennel cough

Question 6

What are some causes of tracheo-bronchitis (kennel cough)?

Answer 6

•Variety of causes including

–Canine parainfluenzavirus

–Canine adenovirus (2)

–Bordetella bronchiseptica

Question 7

What vaccines are available for infectious tracheo-bronchitis?

Answer 7

• Bordetella bronchiseptica – live by intranasal
• Canine parainfluenzavirus – live by injection
• Canine adenovirus (2) – live by injection

Question 8

How long can it take to recover from infectious tracheo-bronchitis?

Answer 8

Spontaneous recovery – 7-10 days

Question 9

When should you use systemic antibacterial agents for infectious tracheo-bronchitis?

Answer 9

–If pyrexic

–If systemically ill

–Muco-purulent nasal discharge

–All of the above would increase index of suspicion of secondary bacterial involvement for which antimicrobials MIGHT be indicated. However, most of these dogs are WELL

Question 10

What is unproductive retching a characteritis of?

Answer 10

Kennel cough

Question 11

What can bordetella bronchiseptica cause?

What are some treatments for it?

Answer 11

• Puppies, especially groups
• URT/nasal infection – bronchopneumonia.
• Can be fatal disease

–Tetracyclines (NB teeth)

–Clav-ptd amoxicillin

–Ptd sulphonamides

Question 12

What are anti-tussives? Give an example

When should we use them?

Answer 12

•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 – primary lung tumour for example, then it is okay to use anti-tussive for this

–Want animal to cough material out from within its airways! So try not to use them for kennel cough etc.

–do use them is structural airway disease

•Butorphanol

Question 13

What are some common causes of ACUTE COUGHING?

Answer 13

• Tracheobronchitis - “kennel cough”
• Irritation by smoke/dust/chemicals/medicines!
• Airway FB - may have been in there some time.
• Pulmonary haemorrhage - often plus dyspnoea.
• Acute pneumonia, e.g. inhalation - often plus dyspnoea.
• Acute oedema - often plus dyspnoea.
• cardiogenic/non/cardiogenic

• Airway trauma - choke chains/bites etc.

Question 14

What are some common causes of CHRONIC COUGHING - in DOGS?

Answer 14

Chronic bronchitis/bronchiectasis

– degenerative condition

• L. heart failure

– degenerative condition

• Oslerus /Aelurostrongylus infestation
• Tracheal collapse

– degenerative

• Airway F.B.
• Bronchopneumonia

– infectious

• Pulmonary neoplasia - primary or secondary
• Extra-luminal mass lesions - thyroid, abscess, lymphoma
• Eosinophilic disease – EBP/PIE/allergic airway disease

– inflammatory

• (Pulmonary “fibrosis”)
• (Pleural irritation)

Question 15

What is canine chronic bronchitis?

What is it characterised by?

Answer 15

• Daily coughing for >2months. Often has been for months and months!
• 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

• Structural change in lining of airways – neutrophilic infiltration and leads to scarring, so loses structural integrity and lining fails to produce and move normal mucus as it should do. Mucus that is produced is abnormal in quantity and quality. Physically structurally ABNORMAL AIRWAY. This animal will NOT get better, once this process has begun – this lining is damaged for good and this animal will have the problem for the rest of its life

Question 16

The combination of events in canine chronic bronchitis leads to what?

What clinical signs does this cause?

Answer 16

• 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
• Looking down at airways of this disease – airways are distorted and there are degrees of collapse when the animal breaths in or out. Coughing, unproductive, wheezing on auscultation due to this narrowing of the airways

Question 17

What is the aetiology of canine chronic bronchitis?

Answer 17

–Often seen secondary to underlying conditions

• Tracheal collapse, chronic barking
• FB
• Previous infections or inhalant toxins
• Environmental factors
• Chronic smoke inhalation/noxious gas or particle rich environment

Question 18

How do dogs with canine chronic bronchitis present?

What breed is it most common in?

Answer 18

•Typically seen in small / toy breeds

–Although can see in any age/breed

• Worse on excitement
• Harsh cough with attempts at production

–Usually clear/frothy, yellow suggests infection

–But very often they cough nothing up

•Usually externally well, often obese

–Excessive weight causes these animals to be worse

–Occasionally pant excessively

–Tracheal pinch positive

•If it doesn’t cough, doesn’t mean it doesn’t have airway disease!! But tells us about the nature of the cough

–Crackles and expiratory wheeze on auscultation of the lungs if very severe

• Exaggerated expiratory phase – but this is quite rare, as they are usually well dogs that just cough a lot
• Expiratory push due to airway narrowing

Question 19

How do we diagnose chronic canine bronchitis?

Answer 19

•Typical history, physical findings

–Often exaggerated sinus arrhythmia

•Thoracic Radiographs

–Increased bronchial lung pattern

• Bronchoscopy and BAL
• Sinus arrhythmia – more difficult getting air out, resp cycle is more exaggerated, so more exaggerated sinus arrhythmia.
• If normal sinus arrhythmia (regularly irregular), a heart murmur is not causing the clinical signs if they do have a heart murmur

Question 20

What is wrong here?

What are the blue arrows pointing to?

Answer 20

Chronic bronchitis

If reasonably okay on radiograph, they may not be severe enough for us to see anything – could still be airway disease though.

Arrows: can see airways going to cranial lung lobes, can see both walls of airways and this is far too wide at this point.

Question 21

Describe the findings of this radiograph

Answer 21

• Chronic bronchitis
• Severe dilated airways
• Can see some doughnuts
• Need to take good quality thoracic radiographs, can always send off to someone to interpret but need a good picture to begin with
• This is a good inspiratory radiograph

Question 22

With canine chronic bronchitis, what does a BAL show?

Answer 22

•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. Rarely do we see bacteria, mainly evidence of chronic inflammatory change

Question 23

What are some newer, molecular methods for identifying the presence of inflammatory change?

Answer 23

•Newer molecular methods for identifying the presence of inflammatory change, but not currently commonly available

–Upregulation of proteins in CB and IPF dogs

•β-actin, complement C3, α-anti-trypsin, apolipoprotein A-1, haptoglobin and transketolase

–No difference between CB and IPF dogs however

•Pro-collagen III concentration lower in BALF in CB than EBP and IPF

–Marked upregulation of mucin gene expression in tracheobronchial brushing specimens in CB compared to control dogs

Question 24

What are some managements for chronic bronchitis?

Answer 24

•General management:

–Weight control

–Harness rather than collar / lead

–Avoid irritants / smoking environment

–Unlikely this dog will ever stop coughing!

•Mucous is easier to shift if hydrated

–Avoid very dry environments

–Nebuliser – rarely do that to these animals

–Steam in the bathroom steam things mucus out and helps animal get rid of it – but warn owner they will cough more afterwards as the mucus will be easier to cough up and this is a good thing.

Question 25

What are some medications and extra things you can do for the management of chronic bronchitis?

Answer 25

•Glucocorticoids

–Oral and inhaled approaches

•Bronchodilator therapy – will only work if bronchoconstriction is an element of the disease but with these animals, there is structural change so unlikely to help much

–Theophylline

–Beta-agonists – terbutaline, salbutamol, salmeterol

• Inhaled medications – long term goal to reduce side effects
• Coupage – cupped hands and pat/whack the chest either side, particularly after the animal has been steamed and thump the chest and this mobilises the mucus and also gives the owner something to do!
• 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

• Antimicrobials based on evidence of need – rarely used for this
• Oxygen as necessary but needs to be humidified
• By assuming bronchodilators will work assuming that there is still the capacity for the airways to dilate ie bronchoconstriction is occuring
• Beta agonists can increase exp airflow, reduce wheezing, increase exercise intolerance and reduce cough
• Theophylline act synergistically with steroids to control airway inflam – antecdotal reports
• Relax bronchial smooth muscle, increase mucocilary transport rates, stabilise mast cell membanes, decrease bronchovascular leak, increase contractility of tired diaphagmatic muscles

SE adenosine antagonism – GIT SE, restlessness tachycardia etc

Question 26

What is the prognosis for chronic bronchitis?

Answer 26

•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 as a consequence of chronic bronchitis, which include:

–Secondary pneumonia

–Bronchiectasis/bronchomalacia (Weakening of bronchial wall and they start to collapse)

–Emphysema

–Pneumothorax / Pneumomediastinum

Question 27

What is feline bronchial disease in brief? (its covered in another lecture)

Answer 27

• Feline lung disease covered next week more so
• Various synonyms over the years

–e.g. feline asthma, feline allergic airway disease

–General considered to be a type I hypersensitivity condition to inhaled allergens

–Suspected genetic predisposition

•Some breeds more commonly affected – siamese

–Underlying factors

• Smoke, feathers, aerosol inhalation, dust, cat litters
• Seasonality often seen and helps with ID of cause

Question 28

What is the presenting signs for bronchial foreign bodies?

Which dogs is it most common in?

Answer 28

• Sudden onset coughing and gagging
• High frequency in working dogs or those living in rural environments

–Often have history of signs after exercising in agricultural fields

–Acute onset coughing and retching

–Typically go into right diaphragmatic lung lobe as this is more straight on than the left lobe

–Often see good initial response to antibiotics

–They often get pneumonia

–Halitosis may be present and progressive

–May see weight loss if infection associated with FB becomes significant

–More substantial respiratory signs may suggest progression to pleural disease

Question 29

With a bronchial foreign body, which lung lobe is it most likely to go into?

Answer 29

Typically go into right diaphragmatic lung lobe as this is more straight on than the left lobe

Question 30

How can you go about diagnosing a bronchial foreign body?

Answer 30

• Most useful thing to do with a classic history – endoscopy – have a look! Send dog to centre where they can scope and take radiographs at the same time as the sooner you can get it out, the better!
• Laboratory testing

–Fully CBC and biochemistry

•Thoracic radiographs

–Fully evaluate for signs of pleural involvement

–Determine if there is suggestion of lobar involvement or disease seems more diffuse

•Bronchoscopy

–BAL and culture for specific antibiotic therapy

–Enables visualisation and retrieval of object

Question 31

What is bacterial bronchopneumonia?

What are some common causing pathogens?

Answer 31

•Unusual for primary infections in healthy dogs (and cats)

–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

Question 32

What is S equi subsq. Zooepidemicus?

Answer 32

•Newer causative organism has been recognised with increasing frequency often occurring in outbreaks

–S equi subsp. Zooepidemicus

• Has been linked with the outbreak of acute fatal haemorhagic pneumonia in dogs in several countries – recently this is happening
• Highly contagious sudden onset

–Pyrexia, dyspnoea, haemorrhagic nasal discharge and haemoptysis

–Causes a severe fibrino-suppurative necrotising haemorrhagic pneumonia

–Coughing up blood

–Asscoaited with streptococci – like an outbreak of infectious disease in large animals, often occurs in groups of animals and get an outbreak of this severe disease associated with streptococci

Question 33

What are some factors predisposing to bronchopneumonia?

Answer 33

–Debilitation

–Prolonged recumbency

–Systemic immunosuppression (HAC, chemo, pred’s)

–Immunodeficiency states (weimaraners, CKCS)

–Defective respiratory defenses

–Damaged respiratory epithelium

–Aspiration – common cause. If upper GI problem, just be aware that they can develop aspiration pneumonia

–Airway obstruction

–Systemic sepsis

–Bronchiectasia

Question 34

How can clinical signs vary for bacterial bronchopneumonia?

Answer 34

–occasionally only minor clinical signs

–signs often relate to extent of pneumonia

–Cough (as its bronchi involved), respiratory distress (if significant), 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

•Don’t rule out pneumonia if you DON’T heart abnormal sounds – it can sound completely normal!

–Respiratory distress and cyanosis may develop in severe cases

Question 35

Describe the findings here

Answer 35

• This is why we get air bronchograms with alveolar disease!
• Bronchopneumonia – quite mild. Typical distribution
• pneumonia develops in ventral lung fields, particularly cranial. This is where the disease appears and this is typical
• airways still have air in them even when they extend out into lung but alveoli are full of fluid

Question 36

What is the diagnostic approach to bacterial bronchopneumonia?

Answer 36

–CBC, biochemistry, UA, faecal

–Arterial blood gas

–Thoracic radiographs

• Alveolar pattern with variable distribution
• Early disease may show only interstitial pattern
• Dorsal and caudal lobes with haematogenous spread
• Can see pleural effusion and pneumothorax

–Airway sampling is crucial – need to know what bugs are down there in order to treat it effectively!!

• TTW/BAL
• Culture and cytology on fluid

–Integration of inflammation and bacterial culture

Question 37

What is the treatment for Bacterial bronchopneumonia?

Answer 37

–Antibiotics

–Supplemental humidified oxygen – if they are really severe, but make sure its humidified to thin the puss out so that they can cough it up

–IVFT

–Anti-inflammatories

–Bronchodilators – as there may be some bronchospasm

–Mucolytics

–Physiotherapy

–Nebulisation

–Surgery

Question 38

Why do we see coughing with primary pulmonary neoplasia?

Answer 38

They often cough as the tissue that turns over fastest is the lining of the airway, with genetic mutations with neoplasia, this will occur in tissues that are turning over the fastest – so the lining, causing them to cough.

They are removable

Question 39

Do you see coughing with secondary pulmonary neoplasia?

Answer 39

Secondary neoplasia - often breathlessness rather than coughing

Often easier to see over other soft tissue densities – so over the diaphragm, can see cannon ball metastasis

They will have got here through haematogenous spread, so they would be in the interstitial tissue as this is where the blood vessels are – these dogs will not cough really, usually breathlessness as their interstitium is full with mets, they may cough, but less likely