Friday's REPRO TIP: For all of you who perform vaginal artificial insemination, it can sometimes be unclear as to whether or not the dog completely ejaculated (did you get a full breeding dose??).
The best way to answer this question is to have what's known as a SEMINAL ALKALINE PHOSPHATASE assay run on the sample. As this enzyme is found in highest concentrations in the epididymis (where semen is stored), high values (>5000 IU/l) directly correlate with complete ejaculation, and low values are typically associated with either incomplete ejaculation or bilateral epididymal obstruction.
Having a semen sample analyzed for this enzyme is not cost prohibitive either (usually runs around $55). Oftentimes knowing for sure whether or not ejaculation was complete is helpful when making plans regarding the breeding future of the stud dog in question.