Figure 2. Proportions of dogs “sensitive” and “insensitive” to induction of chromosomal damage following ionizing radiation exposure.

Dogs were defined as “sensitive” if the number of gross chromatid breaks exceeded the 75^th percentile of the reference (normal mixed-breed dog) population. The proportion of dogs demonstrating chromosomal sensitivity was significantly higher in golden retrievers with lymphoma (LSA) than in clinically normal golden retrievers (GR) at the 4-hour time point for both radiation doses and at the 24 hour time point for 1.0 cGy. A similar but insignificant trend was observed for most of the other doses and times. These results suggest compromised DNA repair capacity in the lymphoma dogs. ** = p < 0.05 vs. normal GR.