Cat aggression towards her kittens

Question
Our cat, Gypsy, showed up in our front yard with 3 tiny babies in September, and we rescued her from the neighborhood dogs. We took her into the back yard, where they lived until it got cold and rainy, then brought them into the house. Gypsy has always been very sweet-tempered and gentle, both with us and with the kittens.

When the kittens were about 3-4 months old, we had her spayed, and now (at 6 months) have had the two boys neutered. (The girl kitten was given to a friend when she was 4 months old) When we brought the boys home from the clinic, Gypsy took one look at them (still in their pet taxi's) and started hissing, and ran away under the bed. Now when she sees them, she spits and hisses and tries to scratch them, and runs under the bed.

Why is she suddenly acting this way towards the kittens? Has neutering changed them so much that she now hates them? We need some peace in the house, so please tell me how to resolve this problem.

Thanks!

Answer
Hi Shiara,

How long has it been since you brought the boys home?  How long were they gone?  This sounds like a normal reaction considering that after being neutered, they are coming home smelling of all manner of unfamiliar things.  They should both have time to recuperate in a separate room away from Gypsy, and then when they start to feel their normal selves, which is usually 3-5 days later, then you can let them free roam in the house again.  At that point, they should have been at home long enough to smell of home.

You should keep in mind that cats don't know that the procedure is done.  What Gypsy is picking up on is how different they smell, and there's two of them and one of her, so it's understandable that she could feel threatened and would react this way.  I would give them some time in their own room to recover from surgery, and keep doing positive activities with Gypsy.  I would give the boys a towel to sleep on, and after a day or two, put it in a place that Gypsy usually sleeps in.  This will help her reacclimate to their smell.  After you let them out again to the rest of the house, there will probably be some hissing, but then she should eventually get used to their smell again and calm down.  Be sure to feed them together, as feeding time is a positive bonding experience, and take care to give each of them the same amount of attention.

If after 3 or 4 days of her being around them she's still acting this way, there may be something else at work.  I would need to know more history and background in this instance, as even if you were bringing a new cat into the home, in doing this method, they usually acclimate somewhere between a few days and a few weeks, depending on the personality of the cats and the way they're introduced.  I have six cats that I have slowly introduced (none are siblings) and have introduced a variety of fosters to them at varying ages over the past few years, and it usually only takes a few days for them to accept each other.

Please keep me updated and let me know if you have any further questions. Good luck!