Male siamese fighting with other cats and attacking humans

Question
My boyfriends grandmother had a stroke and could not take care of her siamese bebe. We took him in and along with our other two cats precious (male 3) and princess(female 1) both flame tip siamese decided to take care of all of them. But bebe is attacking our other cats and now goes from sweet to demonic in 3 seconds flat. one minute we are petting him and he is purring and the next he attacks us. He is also throwing up alot. What is going on with him. I hate to get rid of him but I can't have him attacking others. Pleae help me.. Thanks

Answer
Tara,

Cats are creatures of habit.  When they have something change in their lives, it greatly upsets them.  My guess is that your new addition to your family is very stressed, and having a hard time adjusting to a new life and new home.  That is why he is attacking you.  He is stressed, and is simply acting out.  Or, he is just confused, and because he's likely scared, he's acting out.  It doesn't mean this is the way he will be forever and ever.  It's just his way of telling you that he's scared and not sure what's going on, and when you have thrown him into a home with 2 other cats, it's going to make it worse.  And on top of it, he just lost his owner, so he's also grieving that loss.  Cats do grieve, and if he doesn't have his owner around, he's probably wondering where she is.  All of these are adding to his stress, and he will continue to act out until you separate them as I've outlined below, or at least given him a "safe area."  He will likely continue to attack you until he starts to feel more relaxed and comfortable.  Don't discipline him or yell at him, because that will only stress him out more, and dissipate any bond you guys may have.  Instead, try to make him feel safe.  

Vomiting can also be a stress response.  Is he vomiting food?  Or is it just bile?  Is he eating okay?  Does he have diarrhea?  For right now, unless he looks sick and/or is acting sick, I would attribute the vomiting to a stress response.  But I'd keep an eye on it, and also keep an eye on his other behaviors.  Once you separate him into his own room, he should start calming down.  But if he's not eating, has diarrhea, is lethargic, or just seems "off,"  I'd get him to a vet for further inspection.  But since vomiting can be a stress response, my guess is that he's so stressed that he's making himself vomit.  Read on on how to introduce him to the others.  

Cats are also very territorial.  If they weren't brought up together, they need to have a very slow introduction.  But it can be done!  I recommend locking the new cat in a spare bedroom or the bathroom.  Allow all your cats to smell this new member under the door.  This will allow them to get his scent, and get used to his smell being there.  I'd do that for a wk or so.  Next step is to open the door a CRACK and let your cats see him.  They will hiss, and spit, and growl, but that is normal.  It is just everyone's way of defending their territory.  Cats don't like their territory encroached upon!  Open the door a crack several times a day, but only with yours or another adults supervision.  Do that for a wk or so.  

Once you've gone through these 2 steps, the next step is SHORT introductions with the new cat outside of the bedroom or bathroom.  Allow him to come out, again, with your supervision, or someone elses--but always have supervision!!  Let him walk around.  Again, there will be hissing and spitting and growling, and maybe even some scratching and reaching out with paws in an aggressive manner.  Allow this to happen.  They need to work it out amongst themselves.  There's also an hierarchy in your house amongst your 2 existing cats, and now, with a new one, they will need to determine who's the alpha cat--ie, who's the top cat.  Keep doing these short introductions for as long as it takes for the new cat to come out and for the hissing and growling and spitting to decrease.  The other step you will want to do, is when the new cat is in the bedroom or bathroom, (he's not out), feed all the cats at the same time on each side of the door.  They will get used to the new guy's scent, and will soon come to learn that nothing happens when they all eat together.  Another suggestion I would make is to get an old t-shirt or top and rub it all over the new cat.  That will get his smell on the shirt.  Once you've done that, allow the other cats to smell the shirt and get familiar with his scent.  Rub that shirt with the new cat's smell on your 2 cats, and intermingle the scents. Then bring the shirt back into the bathroom or bedroom (wherever you're keeping him) and let him smell.  Rub the shirt on him again.  Bring it out and let your 2 smell the shirt.  Rub it on them, and so on and so on.  This will intermingle their scents, and is simply another way of getting them used to each other.  

The above suggestions are surefire ways to introduce new cats correctly.  Bringing a new cat into a home is very stressful for all cats involved.  It disrupts their hierarchy, and causes them to rearrange their lives to accomodate a new cat.  Since cats are creatures of habit, it is very difficult for cats to do this.  But it can be done successfully, but you have to realize it can take time, and will definitely take patience.  Sometimes it can take months to get new cats introduced and used to each other.  Literally--months and months.  But you have to keep with it, and realize how cats are creatures of habit, and when their routine is interrupted, they get very stressed, and act out.  They may even act out 3 yrs down the road when they've been together for 3 yrs!  You just have to work with them and realize they get very stressed with the littlest interruption in their routine.  

If you don't properly introduce cats, they can still get along and live together.  But it's possible that it could take longer and everyone will be much more stressed--and you have to worry more about cat fights without any warning as well.  But if you do it properly, such as what I discussed above, the success rate is higher, and there is more chance that everyone will come through unscathed--and friends at that!!  

I also want to highly recommend a book that is great.  I think everyone should own this book, especially multiple cat households, as there is a TON of info, and it's just invaluable.  I refer to it all them time when I work with people.  It discusses how to introduce cats and tips and tricks, and what to expect, so it would come in handy for you.  It's called "Cat Wrangling Made Easy" by Dusty Rainbolt.  I bought my copy at Petsmart, but I talked to someone a few months ago who bought a slightly used copy at her local library for $2.  You may want to check Amazon.com as well.  I really can't stress how valuable that book is when you have multiple cats--and even for people who have 1 cat.  

Hope this info helps and remember----it will take time and patience in introducing these 3 cats, and there will be days where they all get along, and other days when they're hissing and spitting and swatting at each other, but that is all normal and is to be expected.  Just remember that anytime you let them out after the first couple of wks of introducing them under the door and with the door open a crack, be sure that an adult is always supervising them just in case a cat fight should break out.  But go slow, and if you need to slow down the introductions, slow it down.  I wouldn't speed it up, but slowing it down won't hurt anyone.  In time, they will get along and be buds, but it's getting through the next several months that will be trying and will test your patience.  Just remember that many, many people have done this, and the vast majority have all come out just fine!!

Good luck!

Savannah