Non-pregnant bitches have significant levels of progesterone as part of their normal cycle (metoestrus), therefore progesterone alone cannot be used as a canine pregnancy testbut may be used to rule out pregnancy where very low levels are detected.

Relaxin is very specific to pregnancy and so can be used as an accurate pregnancy test. Following conception relaxin rises to detectable levels from about 21 – 28 days. It is advisable to take blood samples at around 28 days or more post mating as this will allow for differences in conception dates.

Sample required is 0.5mL HEPARIN plasma (EDTA plasma MUST NOT be used).