Frequency and number of B-lines using a regionally based lung ultrasound examination in cats with radiographically normal lungs compared to cats with left-sided congestive heart failure.

Objective: To establish a baseline lung ultrasound (LUS) artifact profile using a regionally based protocol in cats without clinical signs of respiratory disease and with radiographically normal lungs compared to a cohort of cats with left-sided congestive heart failure (CHF).

Design: Prospective case series.

Animals: Forty-nine cats without clinical signs of respiratory disease and with radiographically normal lungs and 7 cats with radiographic evidence of left-sided CHF.

Interventions: Application of a previously published LUS protocol. Frequency of B-lines was compared based on signalment, body condition score, investigator, and reasons for radiography and between 49 cats with radiographically normal lungs to 7 cats with radiographic evidence of left-sided CHF.

Results: Overall frequency of B-lines was 12% (95% confidence interval, 5-24%) in cats without respiratory disease versus 100% (95% confidence interval, 65-100%) in those with left-sided CHF. Six cats (6/49) had B-lines with 5/6 having B-lines at a single site; and 4/5 having a single B-line at 1 site, 1/5 having 2 B-lines at 1 site; and the sixth cat having 2 positive sites with a single B-line at each. In the cohort of cats with left-sided CHF, all cats (7/7) had >3 B-lines detected at every site.

Conclusions: The lack of B-lines in cats without respiratory disease (with radiographically normal lungs) and the predominance of B-lines in cats with left-sided CHF suggest that a regionally based LUS protocol may be clinically useful for the identification and evaluation of feline respiratory conditions.