WhelpCalc app for iPhone and iPad
For dogs, entering standard ultrasound measurements will calculate an expected whelping date, number of days to go, and the number of days since the luteinising hormone peak.
For cats, the standard ultrasound measurements taken after day 35 of pregnancy will calculate expected queening date, and the number of days since mating.
Useful if these calculations are not available in the Ultrasound device for any reason