Biomarker may help differentiate respiratory diseases in cats, study shows

26 October 2026

Serum amyloid A, a readily available biomarker, may help to distinguish inflammatory respiratory disease from cardiac or neoplastic respiratory disease in cats, according to new research published in the Journal of Small Animal Practice.

Respiratory distress is a common feline emergency and a rapid diagnosis is essential to guide treatment of these patients. Serum amyloid A (SAA), an acute-phase protein mainly synthesised by the liver, is a biomarker of inflammation in cats, and is an accessible point-of-care diagnostic test through blood sampling in an emergency setting. However, its usefulness in differentiating respiratory conditions in cats has not yet been clearly determined.

The study, carried out by researchers at Centre Hospitalier Vétérinaire AniCura Nordvet in France, is the first to evaluate SAA as a biomarker of inflammation for respiratory disease in cats, to assess its potential usefulness in differentiating inflammatory lower respiratory tract diseases from cardiac or neoplastic respiratory diseases in cats. The researchers retrospectively evaluated 22 cats presented with respiratory distress, with SAA assay performed on cats within 48 hours after admission.

Serum amyloid A concentrations were significantly higher in cats with inflammatory lower respiratory tract disease (median concentration 57.5 μg/mL) than in cats with cardiac or neoplastic respiratory disease (median concentration 5 μg/mL).

The optimal SAA cut-off value for distinguishing inflammatory from cardiac or neoplastic respiratory disease was 8.6 μg/mL. At this threshold, SAA demonstrated 80% sensitivity and 100% specificity.

These results show that serum amyloid A concentration may have potential as a supportive diagnostic test for rapidly differentiating cats suffering from inflammatory respiratory diseases from those with cardiac or neoplastic respiratory diseases.

Dr Eva Berro, lead author of the study, said: “This is the first study to look at SAA in feline lower respiratory tract disease, and the difference we found between inflammatory and cardiac or neoplastic cases was striking. However, this was a small retrospective study, so larger prospective studies are needed before SAA can be used routinely. For now, it looks like a promising supportive tool alongside clinical examination and imaging”.

Read the full study in the Journal of Small Animal Practice: https://onlinelibrary.wiley.com/doi/10.1111/jsap.70209