My poor queen

Question
QUESTION: Dear Marcia
I've been having cats for some years but a few days before i experienced one of the most horrible events regarding my cats . my white Persian queen Princess was pregnant and about to give birth .we were extremely glad and everything was going ok , but at Tuesday morning when we got up we realized that our queen sounds so dull and awfully pale and feeble ,while she was pregnant for exactly 62 days . we immediately took her to pet hospital and over there we get shocked , as due to X ray it got obvious that all kittens are death! we couldn't believe it as until last night(Monday night) we could see them moving and playing inside their mom's womb , and our queen also was totally healthy .
soon they operate her as her situation was so critical . i had asked them to save her womb at least but after the operation they told me that they didn't have any other choice but spaying her ,as some parts of her womb had been destroyed totally due to the infection caused by the dead kittens . they show us some pictures taken during operation that showed her womb twisted four times ! you see, they told us that the part of the womb that had twisted , had included 2 kittens that died soon after this . then it caused the inflections which led to the death of other 4 kittens and destruction of the womb and mom's serious situation .
they said that this might happened few day before as those 2 kittens had been fetid badly , but it was obvious that other 4 kittens were alive till few hours before .
the condition of my queen also was so bad as inflection has made her so feeble as she can't even walk properly . vets told us that she was so lucky that survived .thank God she's started to recover slowly.
we all are in terrible mood nowadays as we had not expected her to be spayed at the age of 2 and half .I personally can't forget the scene of 6 death kittens that i saw inside the operation room . its a terribly sad fact that she wont be able to give birth any more .we are just furious and frustrated as we can't detect why it happened ,and vets also can't say anything about the main cause of this tragedy .
you see doctor , we were so careful and cautious about her . feeding her in the best way and taking care of her days and nights , we had not expected this to happen at all .having inspected on her every time , i can firmly tell you that till Monday night she had not shown any sign of any problem inside . but , at Tuesday morning she had suddenly changed to a pale dying cat !
can you please tell us why it happened to her ? why her womb had twisted four times !? she had given birth at first time when she was one year old , and her second litter was about 6 months before . however , between her second litter and this one once she got pregnant about 3 months before , and then when an irresponsible vet squeezed her while she was about one month pregnant ,she miscarriage . and immediately after that she got pregnant of this last one . can i regard this soon pregnancy after the miscarriage as a main cause of the recent tragedy ?
i must add also that she used to jump on high niches many time each day . even in last few weeks she enjoyed to do so while she had turned so heavy and big. can this be the main cause? should i prevent her to do so? I'm just so needy to know the cause of the tragedy as i have an other queen and i absolutely don't want to experience something same . we just can't understand why it happened as she had given birth 2 times before without any problem .
let me add finally that she is due to an inbreeding . i mean , her brother had mated with her own mom and this lead to the birth of my queen and four other kittens . can i regard this also as a cause of that event?
Thanks a lot
Soheil from Iran

ANSWER: Dear Soheil

First I am so sorry for the delay in replying but I have been away for a few days.

I am very sorry to hear of your bad time with your girl.  It is possible that your girl went into slightly premature labour overnight, due to the death of two kittens earlier which had started to decay, and she had been trying to give birth which was when the womb may have twisted.  That would have then meant that the other kittens would possibly have been trapped as the twist may well have blocked their exit.  Princess then became very tired and would account for how you found her in the morning.  She was no doubt exhausted and had run out of reserves to carry on.  I am sure after this she would not have been able to carry kittens again as the damage could have been too severe.  The first twist could have occurred a few days before as sometimes a cat will expel any dead kittens in an attempt to preserve the live kittens which is why you would still have seen live kittens the day before, but when she went into labour for the live kittens, that is when it started to go wrong and the live kittens would have been lost.

I think some damage may have been caused by the vet in her previous pregnancy and could have dislodged her womb from the safe stable place that it should be, thus when going into labour the contractions instead of squeezing a usually stable uterus, had the effect of twisting as it had more room than it should have done so.

The close inbreeding of your queen would not have helped, but I would not go as far as to say it was a cause, but it may have been responsible for some weakness.  The other thing to remember is that 6 kittens is quite a large litter for a Persian, so that in conjunction with a slightly displaced uterus would have all led up to this very sad event.  

I am so sorry that it all went wrong for you, but I do hope Princess recovers quickly, or indeed has recovered a lot now.

Regards

Marcia.

---------- FOLLOW-UP ----------

QUESTION: Dear Marcia
Thanks a lot for your great reply . Princess has been recovering and now she's OK. as i have another Persian queen i think it's necessary to consult experts such as you about breeding Persians generally . can you please tell me how often can a Persian queen give birth ? some breeders tell me once is a year is OK , and some others tell me every other 18 months is suitable . what's your opinion as an expert ? how often can i let her mate , and how long ?
Thank you very much for the precious answer

Answer
Hello again

I'm pleased to hear that Princess is OK now.  Its always a worrying time when things go wrong.  

I would say that it is best to breed no more often than at 12 month intervals.  This gives the cat a chance to recover and for her body to be in peak condition for the next litter.  As to how long, I assume you mean until what age.  I would say around the age of 8, though of course you need to be aware of how the litters are going.  If they are getting smaller or you are having problems getting your cat pregnant then do consider calling a halt to her breeding days.

Marcia.