The coughing cat: feline lower
airway disease
Sam Taylor BVetMed(Hons) CertSAM MANZCVSDipECVIM-CA FRCVS

Plan for the talk
• Mysteries and misconceptions• What is asthma?
• What about chronic bronchitis?
• What else makes cats cough?
• The right diagnostics• Treatment• Short term
• Long term

Facts about inhaled therapyMysteries and misconceptions• Lower airway conditions in catsquite poorly understood• Definitions arbitrary• Overlap between conditions• Even in humans, asthma can be‘brittle’ and causes deaths andhealthcare costs• Can be expensive to investigate
and frustrating to treat lower
airway disease in cats

Mysteries and misconceptions• Definitions can be confusing• Lower airway disease is common in cats
• Lack of consensus• ‘Feline lower airway disease’• Asthma• Chronic bronchitis• Other pathologies (parasitic, infectious
bronchitis)• ‘Feline inflammatory non-infectious lower
airway disease’• Asthma• Chronic bronchitis• Feline asthma (FA)• Bronchoconstriction• Eosinophilic inflammation• Hypersensitivity• Chronic bronchitis (CB)• Excessive mucous production• Neutrophilic inflammation• Mucosal hypertrophy

Why is this important?
Does it affect how I treat thepatient?

Definitions…

Simple??
Clear as mud?

Mysteries and misconceptions• ‘She has furballs, they get stuck sometimes’• ‘He has something stuck in his throat’• Coughing cats always have ‘asthma’ like people• ‘I offer the inhaled therapy but the clients don’t think they can do it’

Let’s challenge these!

A case: Jim• 11 year old MN Burmese• History of coughingintermittently for several months(maybe longer)• Seems to be getting worse• Otherwise bright• Recently developed restingtachypnoea• Course of potentiatedamoxycillin made no differenceIs it coughing?

• Coughing in cats looks alarming• To some clients, not like coughing• Ask clients to video an episode• Train reception to ask for this when booking
appointment• Save a video to show clients• You Tube if necessary• Demonstrate!
• Key points• Low posture• Neck outstretched• May have terminal retch or swallow• Variable duration

Non-coughing causes of ‘coughing’• Retching• Vomiting• Actual hairballs….
• Dysphagia• Remember to ask about otherclinical signs/clues• Open mouth breathing episodes• Exercise intolerance (cats get ittoo!)• Resting tachypnoea

What is feline asthma (FA)?
• Definition of asthma:• Spontaneous bronchoconstriction• (initially reversible)• Airway eosinophilic inflammation• Airway hyperresponsiveness• Only affects cats and people• T-cell based type 1 hypersensitivity• Changes can be progressive• Airway remodeling• Declining lung function

What is chronic bronchitis (CB)?
• Common cause of coughing• Secondary to airway insult?
• No bronchoconstriction but airway
narrowing due to mucous andremodeling• Neutrophilic BAL (>7%)• No increased eosinophils• Mucosal oedema and excessive
mucous production• More chronic history – less frequent
emergent presentation BUT can be
dyspnoeic

Species differences: cats are not small dogs
• Small airways• Relatively large airways• Small changes in diameter = massive• Lack of airway
airflow limitation
hyperresponsiveness• Suffer bronchoconstriction• Lack of bronchoconstriction(sensitive airway smooth muscle)(airway smooth muscle less
• Hypoxaemia occurs
sensitive)• Bronchiole blends into the alveolus• Obstructions of the bronchioles cause • Hypoxaemia with chronic
bronchitis raresignificant hypoxia• Airflow redistribution with obstructedairways• Distinction between bronchiole andalveolus

Triggers for lower airway disease• In humans, triggers include
environmental substances,
allergens, emotional stress• Cats likely to have allergenic
triggers for FA• House dust mites• Grasses• CB may have origins in airwayirritation• Makes sense to avoid toxins andallergens as much as possible

Feline lower airway disease – not just asthma
Chronic cough +/episodes of tachypnoea••

Inflammation with mixedcells or neutrophils

Response tobronchodilators
Episodes of dyspnoea

Inflammation witheosinophils in BAL
Chronic bronchitis

Other causes of lower
airway disease

Spectrum of lower airway
diseaseAsthmaFeline asthma vs chronic bronchitis
Cough was most frequent presenting sign
(also dyspnoea, abnormal auscultation)
No significant difference in radiographs
Significantly more cats with FA hadeosinophilia (39.6%)
Erythrocytosis in 37% CB and 29.3% CB
Differentiation of FA and CB was notpossible with clinical signs, signalment,radiographs.

Other causes of coughing• Not just asthma and chronic
bronchitis!
• Can be asthma and chronic
bronchitis PLUS infection• Cats can have lower respiratory
tract disease AND cardiac
disease• Cats with cardiac disease CAN
cough (but perhaps they also
have some lower airway disease)• Lungworm: Aelurostronglylus• Heartworm-associatedrespiratory disease• Bacterial infection?

Mycoplasma: primary or secondary invader?
• Mycoplasma can be normal floraof the upper airway• In humans M pneumoniae
associated with asthma• Studies complicated bycontamination from upper
airway of BAL samples• Found in lungs from cats without
CB and FA• Utility of quantitative PCR?
• Does it worsen FA or CB?
• I would usually treat, but beaware (and inform owners) it is
not likely to be the whole story

Radiography• Thoracic radiography isinsensitive for the diagnosis oflower airway disease• Highly variable appearance• Normal (23% cases)• Bronchial/bronchointerstitial• Right middle lung lobe collapse• Hyperinflation in FA• Lucent lung fields• Caudal displacement of thediaphragmRadiography• Will not give you a diagnosis• Excludes neoplasia (almost)• Plan it• Take 3 views• Ideally inflated• Consider further tests at thetime• Commonly ‘mild
bronchointerstitial pattern…’

Advanced imaging: CT• Much more useful• Normally can’t see bronchioles• Bronchial wall thickening• Patchy alveolar pattern• ‘Tree in bud’ mucous plugging• Subtle changes differentiate fromother causes of coughing

Can we CT conscious cats?
• Mousetrap device• Allows us to CT dyspnoeic cats
• Often slight movement blur
• Can’t usually give contrast• Could with mild sedation• POCUS for dyspnoeic cats is
optimal until stable

Back to Jim

Bronchoscopy

Bronchoscopy

Bronchoscopy and BAL: scary right?
• Not without risk
• Bronchospasm in asthmatic cats can belife-threatening• Haemorrhage• Pneumothorax• Plan well
• Pre-oxygenate• Anaesthesia monitoring vital• Monitor during and post• Capnograph and pulse oximeterGA• Pre-treat with terbutaline (0.015mg/kg)• Capnography useful• Will cause tachycardia• Provide oxygen at all times• Preparation is important• Equipment list
• Can use a urinary catheter• Ensure sample handling is appropriate
down side of scope• Communicate with lab• Create a smear (in-house examination)

• Not all clinics have an endoscope• Useful for diagnosis• Pre-treat with terbutaline• Sterile ET tube
• Feeding tube (8F) passed into lowerairways• Aspirate with 20ml syringe

What about a blind BAL?

Back to Jim: BAL• Bronchoscopy showed small
amounts of thick mucous inlarge airways• Some airway inflammation• Initial BAL seemed to be thickmucous• Repeated to get a good sample• Warm saline in 5ml aliquots• Check sample is ‘foamy’• Don’t need to coupageBAL cytology• Distinguish between asthma and chronic
bronchitis• Eosinophilic predominance in asthma• Neutrophilic in chronic bronchitis• Allows culture• Allows infectious disease PCRs
• Identification of lungworm

BUT:

Eosinophils can be within normal
limits in cats with FANormal cats can have an eosinophilic
BAL
Interpret with imaging and clinicalsigns

Back to Jim
BAL results

Eosinophilic inflammation
Mycoplasma (low level)

PCR useful to exclude lungworm

Treatment of inflammatory FA and CB
Avoidance of allergens• Plug in air fresheners• Cigarette smoke• Perfumes

Injectablecorticosteroids

Oral
corticosteroids
Treatment of FAand CB?reduce stress?

Bronchodilators(for FA)
Inhaledcorticosteroids

Be aware the conditions (particularly FA) can wax and wane
making it hard to judge the effect of therapy*

Allergen avoidance: does it help?
• Not well studied in veterinary medicine• Likely ‘polysensitization’• Avoidance of obvious triggers• Plug in air fresheners• Perfumes• Cigarette smoke (including on clothes)• House dust mites• HEPA filter in vacuum• Impermeable pillow and mattress covers (orshut cats out of the bedroom!)• Dust from litter trays and perfumed catlitter• Compliance issues….

Glucocorticoids: pred or dead?
• Evidence that treatment withglucocorticoids is effective
experimentally and clinically for
FA and CB• Glucocorticoids can be given
orally or as inhaled therapy• Some evidence that both oral
and inhaled glucocorticoids will
reduce airway eosinophilia inasthmatic cats

Oral glucocorticoids: the nitty gritty• Majority of clinicians will startwith oral therapy at 1-2mg/kg
prednisolone SID• Emergency treatment ofdyspnoea with dexamethasone
0.1-0.2mg/kg IV or SC• Transition to inhaled therapy(takes 7-10 days to have aneffect) but training may takelonger• Remember compliance!

Negative behavioural responses to medicating
60%

50%

40%

30%

20%

10%

0%
My cat ran awaywhen I approachedit

My cat was morewary of me ingeneral

My cat hid awayfrom me

Results from Taylor et al 2021 – Owners’
experiences of medicating cats – oralmedication

None of the above My cat came to me
for medication to
get a treat/foodInhaled therapies• Inhaled therapies have been used incats for some years now• Following from the treatment ofchildren• Using an MDI and chamber with avalve and mask

Inhaled vs systemic glucocorticoids• Systemic glucocorticoids may cause
adverse effects• Diabetes mellitus• Immunosuppression• May be contraindicated in someconditions• Pre-existing DM• Cardiomyopathy• Some systemic absorption but
minimal suppression of theHPAA axis
• Effective at reducing airway
inflammation.

Inhaled glucocorticoids• Dose of inhaled fluticasone not fully
established by research• One study suggested equal response to44, 110 and 220ug twice daily• Efficacy may plateau• General recommendation 125ug: one
puff twice a day (titrated up or down)

Bronchodilators• Reverse smooth muscle contraction• Not suitable for monotherapy• Short acting beta agonists• Terbutaline• Appropriate to use via injection in acuteairway constriction• *preferred in acute bronchoconstriction inclinic• Albuterol/salbutamol• Via MDI in acute bronchoconstriction• May be pro-inflammatory with long term
chronic use• Can be used at home

• Long acting beta agonists• Salmeterol combined with fluticasone

Inhaled therapies: long term
• Prevention is better than severe
relapse• Look after the inhaler• Clean it!

• Look for any long-term adverse
effects• Corneal ulcers• Hair loss
• Coughing when administering• Demodecosis (facial)• Complacency from owner can risk
relapseFELINE ASTHMA AND CANINE BRONCHITISTREATMENT PATH & DOSING GUIDELINES
1TreatExacerbation!

2

Gain
Airway Control

3

Transitionto Inhalers

TRUDELL

Animal Health

4DailyManagement

Ensure animal can breathe

Clear the airways

Introduce Inhaled Therapy

Maintain disease control• Immediate dilation of airways to provide
respiratory relief• Provide injectable steroid and either inhaled
or injectable bronchodilator• Injections administered in clinic/hospital• Inhaled bronchodilator may be administerd
in clinic or at home by owner• Reduce airway inflammation
and regain control of airways• Provide short term course ofsystemic steroids• 10-day therapy course• Taper systemic steroids while
introducing inhaled steroids• Overlap therapy for 2 weeks• Inhaled steroids effectively target theairways for disease control without theside effects of systemic steroids• Maintenance therapy to keep
inflammation controlled and prevent
exacerbations• Daily therapy for symptom management• Cat owners can administer inhaledbronchodilator during flare ups fromexposure to triggers

MEDICATIONSMEDICATIONSMEDICATIONSMEDICATIONSANDOROR
Dexamethasone

Terbutaline

Dosing
Guideline
Dexamethasone
Terbutaline
Salbutamol

0.1–0.5 mg/kg IM or IV
0.01 mg/kg IM or SC
1–2 puffs, every 30 minutesfor ≤4–5 hours

Fluticasone

Prednisone / Prednisolone

Salbutamol

Dosing
Guideline

Cats

Prednisolone

1.0–2.0 mg/kg
every 24 hours

Prednisone

Dogs

Dosing
Guideline

Fluticasone‡
0.5–1.0 mg/kg
every 24 hours

Fluticasone+ salmeterol

Cats & Dogs
≤ 20 kg (44.1 lb)
1 puff
110 µgevery 12 hours
1 puff
125 µg / 25 ug
every 12 hours

Dogs> 20 kg (44.1 lb)

Fluticasone

Fluticasone+ salmeterol

Dosing
Guideline

Cats & Dogs
≤ 20 kg (44.1 lb)
1 puff
125 µgevery 12 hours
1 puff
125 µg / 25 µg
every 12 hours
1–2 puffs
as needed (cats)

1 puff
220 µgevery 12 hours
1 puff
250 µg / 25 ug
every 12 hours

Fluticasone‡‡ Cats with more serious disease may require 250 µg
every 12 hours

Salbutamol

Fluticasone+ salmeterol

ANDOR

Fluticasone+ salmeterol

Salbutamol

Dogs> 20 kg (44.1 lb)
1 puff
250 µgevery 12 hours
1 puff
250 µg / 25 µg
every 12 hours

Notes

Notes

Notes

‡ Cats with more serious disease may require 250 µg
every 12 hours• Owners unable to regain control at home should
bring animal to veterinary care

• Review environmental modifications• Ensure pet owners understand systemic steroids
are only temporary• Owners already using inhalers who treatedexacerbation with albuterol can continue withinhlaled steroid• Inhaled steroids can take 2-weeks to take effect

Notes• Salbutamol is a rescue medication and should not be
used as mono therapy• Canines not shown to bronchoconstrict. Little evidence
salbutamol is effective for canine bronchitis

Inhaled Medications

Learn more, plus where available.
TrudellAnimalHealth.com/inhalers* Trade-marks of Trudell Medical International. © Trudell Medical International. 2020. All rights reserved.
Managing Feline Asthma and Canine Bronchitis. Clinician’s Brief. 2020. cliniciansbrief.com/article/managing-feline-asthma-canine-bronchitits

TrudellAnimalHealth.com

Usefuldosageguidelines

Back to Jim
Responded well!
Coughing stopped
Reduced long term
dose to once a day
Will do anything for aDreamie!

• Initial treatment with doxycycline 10mg/kg
SID for 2 weeks (remember the water/food)• With prednisolone 1.2mg/kg SID PO• Start inhaler training• Direct owner to sources of training materials:
https://www.trudellanimalhealth.com/cats

Responded well, minimal coughing, maintained on
one puff once a day (125ug)

Alternative therapies• Allergen specific immunotherapy• Further research needed• Some evidence of effect• Need to choose correct allergens• Can take time to have an effect(inhaled therapy still needed)• Omega 3 fatty acids• Tyrosine kinase inhibitors• Adverse effects• Cyclosporin• Some reports of use in diabetic catsfor example• Stem cell therapy

Relapse can occur and be severe….Coco• 2 year old FN Ragdoll• Diagnosed and treated forasthma 3 months before• Weaned off oral prednisolone
after initial response• Hit and miss compliance toinhaled medication• Taken for vaccination (stress)• Next day severe dyspnoea andcoughing
Refractory to treatment….. PTS

Follow up and check in• To avoid relapse, as with any chronic
condition, check how the cat is doing• Check the owner is using the device
correctly (nurse clinics)• Explain importance of maintenancetherapy• Consider as any other chronic
inflammatory condition on medication– adjustments and check ups areneeded• Use a validated device (Aerokat)

The take home messages• A lot still to learn about lower
airway diseases in cats!
• Coughing is the most common
presenting sign of inflammatory
lower airway disease• Treatable – inhaled therapies
effective• Long-term treatment needed toavoid relapse

Do not miss the next webinar on training!
All very well me tellingyou to use inhaled
therapies but did anyonetell the cats?
Successful inhaler
training VITAL to longterm successfulmanagement

Relax! And support your clients to use aninhaler!