Prolonged diagnostic interval and tumor stage in canine malignant nasal tumors.

OBJECTIVE

The objective of this study was to evaluate whether diagnostic interval is associated with tumor stage in dogs with malignant nasal tumors and whether intranasal bacterial infection contributes to delayed diagnosis.

ANIMALS AND PROCEDURE: Medical records of 96 dogs with histopathologically confirmed malignant nasal tumors were retrospectively reviewed. Data included diagnostic interval, clinical stage, results of intranasal bacterial culture, and prior antimicrobial administration. Associations were analyzed using non-parametric tests.

RESULTS

The median diagnostic interval was 83 d (range: 8 to 995 d). Dogs with Stage I tumors had a significantly shorter diagnostic interval than those with Stages II to IV disease (50.0 versus 89.5 d; P = 0.022). When stratified by the overall median interval (≤ 83 versus > 83 d), advanced-stage tumors (Stages III to IV) were more common in dogs with longer intervals (P = 0.014). Bacterial culture was positive in 33 of 57 tested dogs and was not associated with diagnostic interval or tumor stage. Prior antimicrobial therapy (62.5%) was not associated with stage or culture status.

CONCLUSION AND CLINICAL RELEVANCE: A longer diagnostic interval was associated with more advanced tumor stage. Intranasal bacterial infection did not explain delayed diagnosis. Persistent nasal signs should prompt further diagnostic evaluation to determine the underlying cause, including neoplasia.