lost indoor cat became aggressive

Question
I've had Mojo, a neutered 17 pound, 11 year-old Siamese Mix who has been an indoor cat his entire life.  He's never been outside for more than 5 minutes his whole life until last Friday night.  He snuck out and got locked out and we didn't realize that he was gone until Saturday night.  I left out fresh water and opened cans of food, so he was eating and drinking while he was out (or the neighborhood cats were eating and drinking his stuff).  We found him underneath a neighbor's car on Sunday night, and he was growling and rolling onto his side.  I scruffed him on the back of his neck and tried to put him in his crate, and he became very aggressive, biting and scratching, bloodying me up pretty good.  I did manage to get him into his cage and lock him up.  I took him to the vet and they ruled out any disease or injury.  I am at a total loss as to why he acted so aggressive.  He was outside for a total of two nights at the most.  Mojo has been a total pussycat his whole life, never attacking anyone, always acting sweet and good (on the other hand, he's alway growled and hissed at the Vet; I'm guessing he doesn't like the smell of strange cats.  I worry that if I take him to the SPCA or other animal shelter, he'll become violent at the smell of other cats and they'll have no choice but to euthanize him). He completely forgot who I was, and his violence was shocking to say the least.  As of this morning, he's back to acting like his old pussycat self as if the violent episode never happened.  My questions are these:

1.  Will he become this violent again?  I have small children and I don't feel safe if there is a likelihood of him becoming this savage again.

2.  What could possibly have been the cause of this aggressive behavior?

3.  How could he forget who I was?  I took care of him for 10 years and he forgot me in two days?  

4.  If there is a likelihood of this violence happening again, are there alternatives to the SPCA?

Answer
Hello Kurt,

How awful for you and Mojo!  I have rescued over 100 cats and kittens and yes, when first caught they all were aggressive acting.  

If we think in human terms, Mojo was totally out of his normal environment and territory, terrified and had to fight for his life.  It isn't that he forgot you.  He would have fought anyone until he felt safe again.  

I've trapped many lost cats before, and once caught, I would put them into my car (still in the trap), cover the trap and let them settle down for about 1/2 hour... if they were strays (and not feral cats), they ALL turned back into purring, loving cats when they felt safe again!  One even "lived" with me in my car while I was on the streets watching for my lost 10 year old indoor cat! Once he felt safe, he purred and kissed me for "saving" him.  I found his owner and he was well loved again : -) But the point is, he fought me so hard, he bit right through one of my fingernails!  After Tetnus shots I didn't make the mistake of trying to touch any of the trapped cats right away again.  

I bet he gave you his best fight, as that is all they are thinking after being indoors a lifetime.  They do go into a scared, wild mentality and unbelievable to most folks... Almost EVERY lost indoor cat will not come when called by it's owners, and most don't even let themselves be SEEN by people for weeks, sneaking out of where they are hiding only very late at night or wee morning hours before hunkering down and hiding from everyone again.

You were very lucky to be able to snag him so quickly, and get him back inside to safety.  I truly belive this experience will NOT change his behaviour!  He will remain the loving cat you've always had now that he feels safe and is back in his own little territory and environment.  He may act more afraid when near a window or door, but I honestly do NOT think he will become an aggressive cat or turn on you or the children again.  He was only terrified outside trying to fend for his life.  

I know it sounds odd that in only 2 days it seems to you he forgot 10 years, but he went into "wild stray mode" within a 1/2 hour of being "lost".  That is a normal reaction and again in human thoughts... if you were suddenly dropped from the sky into some strange country where you feared for your life the minute your feet touched the ground... well that is what he went though.

Keep loving your Mojo for the rest of his life Kurt.  It sounds like he has many more years of love to give to your family and after 10 years of love, he only needs to to feel safe (and not get out again).  

I will keep you all in my thoughts, and am so happy you were able to get him back in only a few days!  I applaud your quick thinking on keeping food and water out as that potentially kept him from wandering further, and made it easier to hunt him down - great thinking and a terrific job capturing him!

You should talk to your doctor about how recent a tetnus shot you've had.  Cat or kitten scratches and bites can lead to infections and it's not worth the risk, so please take care of yourself too.

As a senior cat, your right... his reaction to any shelter (especially his breed) would not get him adopted rather punished.  Siamese and any of those mixed breeds are known to NOT do well in cages in any shelters.  And at his age they would not keep him long if no-one adopted him.  You are his best shelter.  Please keep Mojo and continue to love him.  I really believe he fought the good fight only because he was terrified, and now that he is safe again his "normal" behaviour won't change.

GREAT job on your part, and don't forget to check on your tetnus shot status.  God Bless you for capturing your lost scared one so quickly!

Debbie