Overeating, aggressive cat

Question
I have 2 male, neutered, mixed-breed, brother cats, a year and a half old, but one is a nutty overeater.  His mother was hit by a car so he and his siblings were all bottle fed by humans from the time their eyes were barely open (not a stray or anything).  I adopted them from friends when they were 6-8 wks old.  His brother is the ideal kitty.

He eats 1-2 cups of food 3-4 times a day.  That's what I've been able to get him down to.  Any less food and he spends most of the day attacking people (clawing, biting)--anyone who passes his food dish or the room it's in (kitchen), plus people sitting in the living room (esp me), or anyone in the floor (his domain) like the baby.  

He spends all of his time lying in the doorway to the room with his food in it or lying curled around the dish.  About half the time, he claws anyone who walks by whether the dish has food in it or not, and just about all the time, he starts snarfing his food as fast as he can when someone walks in the room, as if we're coming in just to eat it!  We've tried moving the food rooms, but the behavior stays the same.

Needless to say, he doesn't like to share food with his brother either.  He lays across the food dish and eats from the far side (he has since he was a kitten and his entire body covered the food dish!) as soon as the dish is filled.  Eventually, he will let the other cat eat, but remains by the dish watching, until he kicks his brother off by eating again.

All this was annoying and unpleasant, but NOW he seems to be eating so much so quickly that he eats to the point of throwing up almost daily.  Or is it that?  Is he sick and vomiting which is causing him to eat again and again?  The vomit is usually just food, almost whole and soggy.  Sometimes it may have a bit of hair (but not a hairball) maybe 5%, other times it has something's entrails in it--he has taken to eating a lot of vermin since we've cut the feedings down and have been putting him out more.

The vomiting is a recent development.  Do you think it's linked to hair buildup (he's long-haired), eating vermin, overeating, worms, or what?  

Even if you don't have advice on the vomiting, is there anything we can do to change his mean, food-obsessed behavior even a little?

Answer
Hi Jennifer,

Wow, that is quite a unique issue.  Honestly, my first instinct is that he either has a dietary deficiency caused by the food you feed or he has a medical problem creating the behavior.  You always want to rule out anything medical first.  When is the last time he was seen by a vet?  What was he seen for?  Did he have anything other than routine vaccinations?  I would definitely have some bloodwork and a urinalysis done to check to make sure his organs are functioning normally.  You also need to have a viral panel run, as since he goes outside, he is exposed to such things as Feline Leukemia, FIV, and FIP.

The other trouble is that it is REALLY hard for me to help you get to the root of the problem since he is allowed outside.  I personally do not believe there is any reason to let them out, largely because of the enormity and severity of the reasons it is not safe, especially cats who were bottle raised and given such a good start in life.  If it were me, I would start with keeping them both strictly indoors.  They should both be seen by a vet to make sure that it is not something as simple as parasites.  If they have a really bad infestation, their bodies don't absorb much nutrients from the food as the parasites get to it first.  Furthermore, if you're not feeding a holistic food, they're inclined to overeat because of the nutritional deficiencies associated with primarily carbohydrate-based food.  Cats are obligate carnivores and not only require a high protein, meat-based diet, but they need more wet than dry.  Cats actually absorb 2.5 times more water from their diet (wet food) than water itself.

That being said, let me know what you feed and I'll tell you if it's a good food and what the issues may be.  After the medical and dietary needs are addressed, then we can see if it doesn't change his behavior.  As far as the vomiting, again, that can be a symptom of so many things, and I honestly think he may have a disease or condition that has developed.  I really think that based on the severity of his overeating (an adult cat should ONLY eat 1/2 to 3/4  cups of food PER DAY) and the fact that you have seen recent changes tells me something is changing within him.  I have a similar problem with my oldest cat Indy--I have to portion her food out when I feed her because she will eat too fast and throw it up.  That being said, it could be as simple as that or be a symptom to a condition he's developed.  

Unfortunately, that's the best advice I can give you.  From all I've seen and experienced, I feel the root problem is medical.  Please follow up with the answers to the questions and make an appointment as soon as you can.  We can go from there after you get the results back.

I wish you the very best!

Best regards,

Holly Martin
Cat Care & Behavior Counselor
Texas A&M University
B.S. Animal Science