My 9 year old bitch is going to be spayed (laparoscopic) and have a couple of small mammary tumours removed.  Unfortunately, she is close to her season but the vet thinks it best to proceed due to the risk from the tumours.  Has anyone experienced spaying a bitch close to season?

I would imagine many bitches are when spayed prior to a first season, as it is unknown when they might be due.

The main issue is increased blood supply, so extra care needs to be taken, and the sudden drop in hormones.

As well as a marked increase in blood supply to the uterus around the time of a season, the hormones mean that the ovaries themselves are more friable and less easy to remove intact, increasing the chance of some cells breaking off and remaining. These will continue to function and the bitch will cycle as before. In a conventional spay where the uterus is removed this doesn't matter so much because even if mated the bitch won't become pregnant. With a laparascopic spay there isn't this safeguard!

Thank you both for your replies.

The vet did mention out the increase in blood supply which I was already aware of, the dilemma is whether the risk of doing it now is greater than the risk of waiting given that we don't know if the tumours are benign or malignant.

Thank you Jeangenie, there is little possibility of her getting pregnant - I do not own an entire dog and I have managed to avoid pregnancy will all my girls apart from intentional ones.
But if there is an increased risk of leaving cells from the ovary in which would mean she would continue to cycle, this is a serious factor.  The main reasons she is being spayed is that it a) if the tumours are benign they are likely to be hormanally driven and spaying will help prevent them occuring and b) to remove the risk of pyometra.  If a piece of her ovaries are left in and she continues to cycle, that would negate the spay.  Do you have any idea of how often such things happen?

Actually spaying after a bitch has had mammary tumours does not have any effect on chances of the recurring, so if this is your reason for spaying I would not spay now and leave it for a year or whatever. I spay mine usually at around 7 years. There is evidence of increase d longevity when spaying is delayed, and also less spay incontinence.

Just realised your girl is 9. Hard choice.

Thanks - I was going to spay anyway due to her age and the increased risk of pyo.  It's a shame they can't do a needle aspiration as knowing what they are would make the decision whether to do it now or leave it till after her season easier. But Jeangenie's comments about the ripened ovaries having more of a chance of parts being left behind is a risk.

Try putting your concerns to your vet re fragments and ask them to give it some thought also try pushing for small sample to be taken first. They may have good reason to want to go straight ahead and if that is the case then once they realise you're concern they should give those reasons so you can make an informed decision