Usefulness of Doppler ultrasonography to assess digital vascular dynamics in horses with systemic inflammatory response syndrome or laminitis

Objective To evaluate the usefulness of Doppler ultrasonography as a method to assess changes in digital vascular dynamics in horses with systemic inflammatory response syndrome (SIRS) or laminitis. Design-Cross-sectional study. Animals-42 adult Andalusian horses. Procedures-Group 1 included 9 healthy horses, group 2 included 19 horses with SIRS without (n = 9) or with (10) a palpable increase in digital pulse intensity, and group 3 included 14 horses with laminitis without (8) or with (6) radiographic evidence of rotation or distal displacement (sinking) of the third phalanx. Qualitative spectrum characteristics and quantitative Doppler measurements of the lateral palmar digital artery were obtained for horses in each group. Results-4 spectra, characterized by a positive systolic peak followed by several positive diastolic peaks, were observed in group 1 horses, group 2 horses, and group 3 horses that lacked radiographic changes. In the group 3 horses that had radiographic changes, laminar blood flow was detected. Diameter of the lateral palmar digital artery was significantly larger in the group 3 horses than in the group 2 horses; blood flow was significantly higher in the group 2 horses that had an increase in digital pulse intensity than in the group 2 horses without an increase in digital pulse intensity; velocity-time integral and acceleration time were significantly lower in group 3 horses, compared with group 2 horses. Conclusions and Clinical Relevance-Results suggested that Doppler ultrasonography may be a useful complementary tool to detect digital blood flow changes of horses with SIRS, especially if they have a palpable increase in digital pulse intensity, or laminitis.