[BLOG] Spaying & Neutering : the Rule of Diestrus


This Friday, I’m doing a presentation on « Spaying and Neutering in Canines & Felines ».

While polishing my Powerpoint, I couldn’t help but smile.

« Younger me » used to think that everything was said and done around this topic.

In 2017, it is still a hot discussion in veterinary medicine.

Here is something I love about biology: nothing is written in stone, we never stop reinventing everything.

The rule of diestrus

Fortunately for « younger me », there are few things that haven’t changed.

For instance : spaying bitches during diestrus.

That is still not recommended.

Diestrus = this 2-month period that follows the season, during which the corpora lutea on the bitch’s ovaries secrete the hormone progesterone.

Spaying during this period means abrupt removal of this progesterone impregnation… which, in 20% of the cases – far from being negligible- , will lead to lactation.

Beware of persistent lactation

The  problem ? Because the ovaries have been removed, this induced lactation often persist… longer than expected..

I remember a small Yorkie bitch that produced milk for MONTHS before it finally came to an end (thanks to a medical treatment) !

This type of lactation is seen as a predisposing factor for the development of mammary tumors.

For sure, sometimes we don’t really have the choice. In case of an emergency, we might have to spay during diestrus.

Routine procedure ? Be patient if needed

We know we have efficient medical treatments we can use to stop lactation. But still, in this specific situations, it might take longer than expected to obtain medical success…

That’s why “no spaying during diestrus” is a rule I’ll definitely abide by when it comes to a routine procedure.

« When was her last season ? » If the answer is « less than 2 months ago », be a bit patient.

It will make a positive difference for sure.

2 thoughts on “[BLOG] Spaying & Neutering : the Rule of Diestrus

  1. Thank you Dr. Fontaine for your article. I just moved back into the small animal realm, so this article is right on time for me.

    Good luck with your presentation, although you won’t need luck. Do great!

    Dr. Turnera Croom


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