Assessment of the circulating inflammatory mediator interleukin-8 in dogs with tracheal collapse.

Objective: Tracheal collapse (TC) is an obstructive respiratory disorder in dogs that can affect lifespan and quality of life. Systemic inflammation has been identified in other obstructive airway conditions in dogs and humans. We hypothesized a systemic pro-inflammatory state exists in dogs with TC.

Animals: Dogs with TC (TC, n = 15) and healthy, non-affected controls (C, n = 15), were prospectively enrolled.

Procedure: Signalment and body condition score (BCS) were recorded for all dogs. For TC dogs, cough duration, pharyngeal collapse, bronchial collapse, and previous stent placement were recorded. Plasma samples were banked at -80°C and batch-analyzed for interleukin-8 (IL-8). Differences between groups were evaluated.

Results: Yorkshire terriers were overrepresented in the TC group. The TC group was older than the C group and had a higher BCS. Interleukin-8 was significantly greater in the TC compared to the C group. Interleukin-8 was not correlated with age sex, BCS, breed, cough duration, pharyngeal collapse, bronchial collapse, or stent placement.

Conclusion and clinical relevance: Increased plasma IL-8 concentration supports the presence of systemic inflammation in canine TC. Dogs with TC were older than controls, with a higher BCS, but this did not account for the increased IL-8. Further investigation of IL-8 as a potential biomarker for monitoring TC progression and therapeutic response is warranted.