Cat acting out towards Father cat after birth

Question
My 11 month old cat named Morgan gave birth to 3 kitties on friday.  The male cat(jack) was right there helping her clean them and sat by her side the whole time. I took jack the next day to get fixed, when I brought him home the two of them seemed fine for about 20 minutes then Morgan went into attack mode.  she has never done that before. so we seperated them for the night.  The next morning I held one and my son held the other and they were fine.  I put down some wet food and they shared it and was fine.  Jack started walking through the living room and Morgan tore into him again making his incession bleed.  I have them seperated now and have all night and day.  the kitties are in the den with Morgan but I am concerned they will always attack each other and I will have to give one of them away?  Is this normal.  Jack wasn't even near the kitties when morgan attacked him. They have been apart all day again and once again I held one and my son held the other and they both just freaked out and went into attack mode.  What can I do?  I can't keep them locked up forever

Answer
Hi Lindy.  This is a common reaction when one cat comes home from a day at the vet's.  Jack is carrying scents on him from the animal hospital that are foreign to Morgan, and these are upsetting to her.  Many cats will need to be separated for a few days after a spay or neuter.  I would recommend to keep them completely separated and not allowing them to see each other at all for at least 3 days, then see about reintroducing them.  When you try to reintroduce them, keep Jack in a carrier and let them look at one another through it.  This way they can't hurt each other (each physical fight only makes chances that they'll get along in the future smaller and smaller).  If it seems to go well, you can try letting Jack out of the carrier, and hopefully things will be back to normal.

However, some cats will go a little insane when they have a litter.  The fact is that any animal could be a threat to newborn kittens, and although Jack does not appear to want to harm his babies, instinct does not make always make a distinction.  Morgan may have been fine with him the first night they were born, but now that she has encountered him with this different scent on him, her mind has been changed, and potentially, she may never be okay with him as long as her litter is young.  You might need to keep Jack and Morgan separated until her kittens are just about weaned.  It's actually a somewhat common behavior for mothers with young litters to "go for the jugular" of any animal they see.  That's why any moms I have are isolated in their own room or in a cage with a blanket covering it.  There are plenty of moms who have a much nicer disposition, but also plenty of moms who react to their housemates just like Morgan is.  

One could never guarantee it, but I don't believe your problem will be permanent.  Morgan's behavior will likely improve once the hospital smells wear off of Jack, and if not, almost certainly once the kittens are weaned.

Best wishes!

Jessica