Hi
I don't really know where to start but I am hoping someone will have some experience and advice for me.
I have a bitch I have been trying to breed from, she is now 4 years. Her season cycle is every four and a half months and sometimes less if there is another bitch in heat to bring her in. She has silent heats, shows swelling but no bloody discharge (seem to remember the first couple had some bleeding).
On the first attempt to breed from her I took her to the proven stud dog at the point she was flirting outrageously with and humping my other girls as she has done in her previous heats. This was later in her heat than might be considered "normal" although I haven't noted the day. At the stud it was a good mating and tie. Unfortunately I wasn't able to return 2 days later and just left it at the 1 mating. Scanned a month later and there were no pups.
On the next heat I had a premate test done on day 7 which said ovulation imminent. Vets advised that every time they had this result and tested the next day the test showed ovulating so I should just take it she would ovulate the following day, they also did an ovulation smear which tied in with the premate test. I did the 7 hour drive to the stud on day 9 and mated her with a good tie. Day 11 back to stud and good tie. On day 17 she was flirting outrageously with my girls so took her to a local stud who know when to do the job. He loved her and was humping thin air! Back to the vet for premate which again said ovulation imminent and smear showed in estrus. Day 20 back to stud for a good mating and tie. In the next few week I was pleased enough with the signs, she had a slight gummy discharge, big teats ,floppy boobs and ribs had a little bump by one month in. Then at the month after she had a bit of colour to the discharge so I took her to the vet who scanned to find to pups but her uterus was enlarged. No idea what the discharge was but put her on antibiotics just in case. Bit disillusioned with the vets as they have suggested spay at every stage. The discharge was small and only for 24 hours.
Her next heat was just 3 1/2 months later. No tests just took her to a closer stud on days 10, 12 and 15. Again big teats, boobs but no gummy discharge. 1 month from mating she has puss discharge so back to vet, scanned no pups but no sign of pyro either.
She is now on antibiotics in hope that it clears infection. If it doesn't clear vets have 2 suggestions. 1 spay. 2 to try a mis-mate drug given on 4 days over I think it was a 10 day period. This would most likely clear the infection but has high probability of leaving her infertile. She would most likely take pyro (this is a treatment for pyro but is not licensed for this use) on her next heat but I could try breeding from next heat but if she doesn't get pregnant she should be spayed asap to avoid the dangers of pyro. She is fit healthy and playing as normal. This is not pyro.
I am very keen to breed from this bitch for several reasons but don't want to take undue risks.
So anyone have anything to offer?

I assume they are suggesting alizin to clear out her uterus.

I'd seriously reconsider whether you should base your breeding proram on a bitch with such erratic untypical seasons, you may end up storing up fertility issues for the future.

Seasons less than 4 months apart often indicate lack of ovulation or cystic ovaries.

Sounds like your bitches hormones are not balanced and she may be getting pregnant but hormone levels are out of kilter and she is absorbing.

My youngest champion bitch is being spayed tomorrow following two litters, last year I have tried mating her twice to different studs.

I believe her hormones may be out of whack now as her vulva is a little swollen, and her nipples have remained more enlarged than I'd expect (though no milk) since her litter two and a half years ago.

I feel sometimes it's best to listen to nature.

Hi
I have a bitch with very similar history.  I don't usually test as I prefer an experienced stud to judge as they are more likely to get it spot on.  As a last resort I discussed with my vet and he said to start testing on the very first day that I noticed swelling.  She ovulated on day 4 but failed to get pregnant.  As her seasons had always been odd and didn't always get much blood I decided that I didn't want fertility problems in my line and had her spayed.  She is still with me and now plays auntie instead.

It took 3 attempts to get my girl pregnant and the repro vet I saw said if seasons are around 4 months between it's unlikely you will get them pregnant. There maybe other things which could be done but best off speaking to one of the repro vets about