What is the difference between a 3 Mhz and a 2 Mhz probe?
A 3 Mhz probe has a wider beam so it is more sensitive than a 2 Mhz probe and can pick up dogs / cats heartbeat as early as 5-7 weeks gestation. A 2Mhz probe may not pick up the high paced fetal heart beat in the early stages but works well for litter size detection towards the end of pregnancy (around 55 days gestation). 3 Mhz probe work better early on and throughout the rest of your pets pregnancy.
