Content continues after advertisement

Differentiating Feline Inflammatory Airway Disease

Laura A. Nafe, DVM, MS, DACVIM (SAIM), University of Missouri

Respiratory Medicine

|October 2021

Sign in to Print/View PDF

In the Literature

Lee EA, Johnson LR, Johnson EG, Vernau W. Clinical features and radiographic findings in cats with eosinophilic, neutrophilic and mixed airway inflammation. J Vet Intern Med. 2020;34(3):1291-1299.


FROM THE PAGE…

Inflammatory airway disease is a common respiratory condition in young to middle-aged cats and has historically been divided into feline asthma and chronic bronchitis. These respiratory diseases have overlapping clinical and radiographic features, and a bronchoalveolar lavage sample is needed to differentiate between them.  

This study evaluated the clinical and radiographic features of 49 cats with inflammatory airway disease. Cats were categorized as having eosinophilic (>20% eosinophils with <14% neutrophils, or >50% eosinophils), neutrophilic (<20% eosinophils with >14% neutrophils), or mixed airway inflammation (20%-50% eosinophils with >14% neutrophils). Group comparisons included type and duration of clinical signs, signalment, CBC results, and thoracic radiograph findings. The goal of the study was to determine factors that may aid in differentiating between inflammatory airway syndromes in cats.  

Cats in the eosinophilic inflammation group tended to be younger (4.4 ± 3.3 years) as compared with cats in the neutrophilic (8 ± 5.6 years) and mixed (7.5 ± 4 years) inflammation groups. Cough was the most common presenting clinical sign (84%) in all cats, and duration of clinical signs, CBC results, and thoracic radiograph findings did not differ among groups. Sneezing (or nasal discharge) was the second most common clinical sign (39%) in all cats; however, this was not found to be correlated with any of the inflammatory airway disease groups. This finding is in contrast with a recent study in which cats with chronic bronchitis were more likely to have nasal discharge than cats with feline asthma.1 A correlation between nasal discharge and type of airway inflammation was not found in this study. 

Although few cats in the study had peripheral eosinophilia (>1100 eosinophils/µL) on CBC, 5 of 6 cats with peripheral eosinophilia had eosinophilic airway inflammation, and 1 of 6 had mixed inflammation. The predominant pulmonary pattern was bronchial (79%), followed by interstitial (51%) and alveolar (38%). Only 9% of cats had normal thoracic radiographs. These findings correlate with previous studies evaluating radiographic features of cats with airway inflammation.2


…TO YOUR PATIENTS

Key pearls to put into practice:

1

Feline inflammatory airway disease commonly results in cough, tachypnea, and, occasionally, nasal discharge. Differentiating among neutrophilic, eosinophilic, and mixed airway inflammation with noninvasive diagnostics (eg, CBC, thoracic radiography) can be a challenge.

2

Infectious diseases that can mimic feline asthma and chronic bronchitis based on clinical features and radiographic findings should be considered. It is also important to consider noninvasive diagnostics for pulmonary parasites, feline heartworm disease, and fungal disease (eg, Histoplasma capsulatum) based on geographic location.

3

Although clinical signs and diagnostic results may overlap, treatment for inflammatory airway disease is similar, with anti-inflammatory doses of oral prednisolone being the mainstay of treatment. Transition to inhaled fluticasone should be considered in select cases.

References

For global readers, a calculator to convert laboratory values, dosages, and other measurements to SI units can be found here.

All Clinician's Brief content is reviewed for accuracy at the time of publication. Previously published content may not reflect recent developments in research and practice.

Material from Clinician's Brief may not be reproduced, distributed, or used in whole or in part without prior permission of Educational Concepts, LLC. For questions or inquiries please contact us.

Podcasts

Clinician's Brief:
The Podcast

Listen as host Alyssa Watson, DVM, talks with the authors of your favorite Clinician’s Brief articles. Dig deeper and explore the conversations behind the content here.
Clinician's Brief provides relevant diagnostic and treatment information for small animal practitioners. It has been ranked the #1 most essential publication by small animal veterinarians for 9 years.*

*2007-2017 PERQ and Essential Media Studies

© Educational Concepts, L.L.C. dba Brief Media ™ All Rights Reserved. Privacy Policy (Updated 05/08/2018) Acceptable Use Policy (Updated 11/22/2021)