New kittens with older kittens

Question
Hello Ali,
My 18month old cat has just had her second litter. Her first litter had 4 kittens, out of them i kept two males who are now 5 months old and very playful quite agressive. Scatty (mothercat) managed to escape the house before we could get her fixed now 2 months later she has had 5 more kittens. My question is, is the new litter in danger from the older kittens? I have seen them play with mice and thought they might mistaken the kittens for mice and attack them when mother leaves the box. They havent done anything yet but try to sniff then run away. They have different fathers i know for sure because i have moved house. She is a good mother but when she was pregnant she kept hissing and attacking her two kittens and now is equaly affectionate with them but they now keep running away from her. Also one day after having her kittens she is constantly running to the door to be let out. What does that mean? I will keep her inside until i get her fixed. also how long do i need to wait before i can take her to get fixed.

Answer
Karen,

Your momma kitten's newest litter should be completely isolated from the older kittens. Newborn kittens have very little resistance to viral and bacterial infections which your older kittens may have been exposed to and completely unaffected by - an infection at this stage could kill the whole newborn litter. Keeping the newborn kittens isolated from the older kittens in your household will also protect them from any possible injuries inflicted intentionally or by playing too roughly. It's a good plan to actually set momma kitten up with her litter and all of her necessities in a spare room, this will also help to prevent any accidental escapes and further pregnancies. Unfortunately there is a very serious pet overpopulation crisis affecting shelters, rescue groups and good samaritans worldwide so momma kitten really should be prevented from bringing anymore babies into a world where there are already so many homeless pets that need a second chance at having a forever home and two doors to escape from is certainly more challenging than having one door as a barrier to the outside world. Female cats can sometimes come into season just after giving birth so it's possible that your mother cat is looking to mate again so that she can become pregnant with another litter - some queens will actually have litters back to back so that as they wean one litter another is born. I wouldn't rule out the possibility that your Momma cat may feel the need to go out and mark her territory to ensure that other neighborhood cats don't take it over in her absence. I have no doubt that whatever her reason is for wanting to go outdoors she intends to return to her litter, unfortunately there are so many factors beyond your control in the outside world that may mean she isn't able to come home. For instance wild animals like fishers actually kill house cats, raccoons certainly arent opposed to the idea of picking a fight with a house cat and most of the time they win which would mean that you would lose your cat and be left with the responsibility of hand rearing the newborn litter which is labor intensive and time consuming. It's also possible that your momma kitten could be hit by a car or any number of other accidents which could be fatal or cause such serious medical problems that it might become impossible for her to continue raising her babies as she should. If you'd like more information on caring for newborn kittens and giving them the best possible start in life I'd be more than happy to share my experiences with nutrition, handling, socialization, general training, using the litter box and as the litter gets a bit older the dos and donts of playing with human caregivers.

As for having momma spayed I do agree that this should be done at the earliest opportunity. I recommend that kittens should stay with their mom and siblings for a minimum of 10-12 weeks. There are a few reasons for this recommendation, firstly this allows mom to wean her babies on her own, unlike dogs mother cats don't need help to wean their kittens, they will usually do so in the first week of their babies' lives. The first 12 weeks of a kitten's life are crucial in terms of basic socialization, essentially this is when a kitten begins learning about the world and their place in it. This means that learning about things like social order, bite inhibition and following rules enforced by their mother, siblings and human caregivers is also a process that starts during this time. Once the kittens are completely weaned you will need to wait a minimum of 2 weeks for mom to stop producing milk, once mom's milk has dried up she can be spayed, it's perfectly okay for mom to be spayed before her kittens are sent to new homes if they're younger than 12 weeks old. There are many good reasons to sterilize your cat beyond the obvious benefit of population control. Female cats that have been spayed are far less likely to develop breast cancer or mastitis which is an infection of the mammary glands. Potentially life threatening health issues such as uterine and ovarian cancer or an infection called pyometra which is when a cat's uterus fills with pus, if the womb ruptures there's very little hope for survival. Some fairly common behavioral issues can be prevented by spaying/neutering your cat - for instance, cats who are sterilized are far less likely to use urine/feces to mark their territory within the house, they fight less which means that there's fewer vet visits for preventable injuries caused by fighting. Your cat will also stop howling and caterwauling to advertise her availability to mate which also means that you'll be less likely to have to deal with tom cats marking their territory with pungent smelling urine.