“Assessing organ parenchymal perfusion is a new area under investigation in veterinary medicine. Low velocity blood flow occurs mainly in small veins, venules and capillaries. The minimum detectable flow velocity is inversely dependent on the ultrasound wave frequency; when using a 2.5 MHz probe, the minimum detectable flow velocity is 1.5 cm/s. In addition, commercial Doppler devices are typically limited to the frequency below 15 MHz; so the minimum detectable flow velocity for most commercial Doppler devices is around 0.35 cm/s.”

—Johnny D. Hoskins, DVM, PhD, DACVIM

From Value of examining low velocity abdominal blood flow in the dog