My best guess would be hormonal coupled with possible stress that lowers immunity leaving it open to infection to seat itself. Or??????????
I do know what it looks like as I have had it happen twice. I was showing a 2 1/2 year old bitch, got more than half way there to her championship and she came into a heat a bit earlier than expected but 5 months since the last is not unheard of. She had never been bred before, I bred her, don't know for sure if it was the right time of the cycle, she didn't take. Not long after pups would have been born if there had been any, I noticed a discharge. I was lucky in that it was an open pyometria so was obvious. She was spayed and placed in a pet home. Once a pyo occurs, I won't mess with it.
I talked to my repro vet at length and he described a process that I could do involving manipulating hormone levels coupled with antibiotics and breeding on next heat. I didn't want to do that, so had her spayed. Hormones can play a role although bitches can go through heat cycles without ever getting pyometria, unfortunately you won't know if yours is one that will or won't if you leaver her intact until it happens or doesn't.
Another bitch I had, got it 2 weeks after whelping. Don't know what happened there either, it was an open one too, she was spayed and could not nurse the puppies anymore. She had two pups, I lost one to the infection she had, picked it up in the milk. This can happen and I was lucky I didn't lose the other. I bottled the other for another week or so adding a little pablum to the formula when she was 3 weeks old. She is still with me a lovely Yorkie I want to show next year.
The first one had no signs until I saw the discharge. The one with the pups, by the time I realized a problem she was pretty sick but she survived. I was lucky. She is spayed and in a great pet home. |