🔍 Key Findings

• Near-infrared fluorescence cholangiography (NIRFC) was feasible and safe in all healthy dogs studied, with no major adverse effects noted.
• Low-dose ICG (0.05 mg/kg) at 3 h pre-op achieved the highest target-to-background (cystic duct-to-liver) contrast ratio, reaching nearly 4:1 at 280 minutes.
• Early imaging (time 0) favored low-dose ICG for optimal cystic duct visualization; high-dose ICG led to excessive liver fluorescence and reduced contrast.
• Visualization of biliary tree occurred within 10–20 min post-injection regardless of dose, but longer delays improved background clearance and contrast.
• No significant cardiovascular or histamine-related side effects were observed with either dose of ICG.
• Repeated ICG injections showed minimal residual fluorescence when using a >72 h washout period; shorter intervals caused mild carryover in high-dose groups.
• Surgeon scoring matched contrast ratios, confirming clinical relevance of imaging outcomes.
• Recommended dose for laparoscopic imaging: 0.05 mg/kg ICG given 3–5 h before surgery, or at premedication for urgent cases.