My 2 cat fight suddenly fight

[lovelyalaskan]

They live together very close for 3 years till now. I found out that my big cat didnt recognise his brother because of his smell (after shower of not yet neutered, i dont know). I already separeated them in 2 rooms and sometimes let the big cat smell the little one's blanket. Any ideas??? Help me. I have to go for 3 weeks in 10 more days. I cant leave them like this

 

[calicosrspecial]

I have a few questions.

You have 2 cats, 2 males that are brothers, correct?

Are they both neutered?

You have had them for 3 years?

Have they ever fought before?

What exactly happened before the fight?

How did they fight?

What happened after the fight?

How did each act after the fight?

How are they acting in their separate rooms?

Please let me know and I will try to help you through this.

 

[lovelyalaskan]

Yes. 2 males 3 years old. one is neutered one isn't. They fight after their shower (1 hour after). The neutered is seems to be don't recognise his brother. I can see because of his smell. It never happend before but this is the second time recently. When they see each other, the neutered try to attack, hissing, bitting. The other one is so scare.
When I put them in 2 rooms the neutered try to scracht on the door, want to go to the other room and when he see the other he try to hissing and attack.

 

[calicosrspecial]

It is strange that it just started happening and never happened before. Usually cats attack because they are afraid of their safety. Many times cats feel afraid of an intact cat or a male that is not neutered. 

Why it is starting now I am not sure.  

Is there a reason that the one male is not neutered? I feel like neutering him would most likely be helpful. Neutering is good for their health, limits the risk of bad behavior and finding females to mate with creating unwanted kittens, and reducing fighting. http://www.aspca.org/pet-care/general-pet-care/spayneuter-your-pet

We always look for something that might have caused the change in behavior.

Are there are feral cats where you live? Do they come up to your door or window? Especially female cats that have not been spayed? I wonder if there is a female coming by where you live and the males are vying for her attention. Even neutered males can still fight over a female in heat.

Did the intact or non neutered male spray or mark in the house at all?

I would be very surprised if the neutered male does not recognize his brother after his bath. Was there any other change or anything that might have happened? 

I work with ferals (cats living outside without homes and people to take care of them). I always neuter and spay every cat possible to reduce reproduction, to improve their health, and especially for males to reduce the fighting. I have males that nearly fought to death and after I got them neutered they now are best friends and sleep and go everywhere together. Usually human societies or rescues will help with the cost of neutering.

I suspect it has something to do with the brother not being neutered and/or a feral cat coming around (either male or female).

Please let me know what your answers are to the questions I asked and we'll try to figure this out. We want them to live happy and healthy and safely together.

 

[calicosrspecial]

There is another thread on the site about cats not recognizing each other after a bath. Here it is:  http://www.thecatsite.com/t/327983/desperate-for-help

In that Dreamer Rose gave what I thought was great advice. Here it is: Have you got any blankets or bedding that the long hairs used to sleep on? If you do, it should have some of their former scent on it and you can rub it all over the long hairs to restore some of the scent.

I would use Dreamer Rose's advice and see if it helps. Good luck.