Risk Factors Associated with Development of Histiocytic Sarcoma in Bernese Mountain Dogs.

ABSTRACT

BACKGROUND: Histiocytic sarcoma (HS) is a rare but aggressive malignancy in humans that is poorly responsive to existing treatments. Although rare in most breeds of dogs, HS is common in Bernese mountain dogs (BMDs). OBJECTIVE: Determine risk factors associated with development of HS in BMD. ANIMALS A total of 216 BMD were registered with the Berner-Garde Foundation. METHODS: An internet-based cross-sectional survey was used to collect information from owners of BMD diagnosed with HS and owners of disease-free littermates of dogs with HS. Mixed-effects logistic regression (MELR) and conditional logistic regression (CLR) were used in parallel to examine associations between potential risk factors and the occurrence of HS. RESULTS: When controlling for litter as a marker of relatedness, dogs diagnosed with orthopedic conditions were found to be more likely to develop HS (MELR, OR 2.5, 95% CI 1.5, 5.2; CLR, OR 2.81, 95% CI 1.1, 7.3), whereas dogs receiving prescription anti-inflammatory medications were found to be at considerably lower risk of developing HS (MELR, OR 0.42, 95% CI 0.2, 0.8; CLR, OR 0.32, 95% CI 0.1, 0.8). CONCLUSIONS AND CLINICAL IMPORTANCE These results suggest inflammation may be a modifiable risk factor for the development of HS in BMD.