NOTES ON INTER CAT CONFLICT

Cats maintain social harmony by maintaining distance. They can prevent aggression in this way. There are go away signals such as staring, spraying etc. Most cats will spread themselves round an area with careful distances between each other. Within large groups there are often smaller family groups so a colony of 10 cats is really two groups of three and one of four.
Because they are not pack animals, they do not have the many appeasement signals used by dogs. Therefore aggression can become serious very rapidly. There are no signals to slow down aggression. Thus keeping a safe distance is vital. Scent messages help define territory or reveal who is passing by and when. Domestic cat groups are dysfunctional by their nature. There are no kittens to rear (feral groups sometimes share kitten nursing). They are usually not related, ie not a family group. They gender is mixed - ie they are not a group of related females, as they would be in a feral cat colony. The actual territory is imposed upon them, rather than chosen by them - ie an indoor group may not have enough safe distance or the territory may be unclear because of the cat flap in intruding strange cats.
Moreover rescue cats may have had different genes (ie be naturally more or naturally less sociable) and different upbringings (which also affects sociability). Domestic cats vary in shape and colour - unlike cats in the wild - thus making recognition less easy. Finally neutering affects faeces and urine odours and probably flank odours so that the smells are not natural.
There may be too many cats in one house - more than five makes conflict much more likely. And there may be too many cats outside. Suburbs often have a lot of pet cats. There is competition for latrine areas and sometimes competition for food (neighbouring cats raid through the cat flap or visa versa). Bullying and intimidation may occur without fighting.
The home environment may not be suitable. There may not be enough litter trays (one for each cat and one over). They may be sited so that one cat can be ambushed by another - they should be sited in different locations. There may not be enough feeding locations. Cats don't enjoy eating close to one another and if their relationship is bad, it's stressful for them.
There may be not enough beds (more than one per cat) or not enough safe high places to hide. High places reassure cats better than low ones. Slippery floors or unsuitable location of cat beds don't help.
Cats that have lived together happily, can sometimes have a breakdown in their relationship. Sometimes an outside intruder (another cat, a dog, or a fox) frightens the cats so much they they turn their anger on each other.
If the cats are indoor cats, they may see the intruder through the window and then attack each other. Group dynamics can also change when a new cat joins the household. Or when a mother cat starts chasing away a grown-up kitten. Or when a cat is pregnant or nursing kittens. Or even when two cats are housed separately in a cattery and then brought back together again. Sometimes time (ie pregnancy is over etc) will put this right.
Sometimes the cause is smell. Cats identify friend and foe by smell rather than by sight - this makes sense to a twilight hunter. Friends smell of each other and of the home territory. This is produced by rubbing on each other or by grooming. Cats rub on humans to mix scents.
One cat is taken to the vet and comes home smelling of the vet and is therefore identified as a foe. Or one cat goes out and gets a different smell on it (ie like horse manure) and comes home smelling like an unfamiliar enemy.
The major difficulty is that cats don't have a range of appeasement behaviours like dogs do. Within a group (pack) of dogs there are many ways the subordinate dog can deflect aggression or just make up to the top dog - submissive urination, rolling over, etc.
But with cats, if they have failed to prevent aggression, there is no way to turn if off. Once a fight has taken place, then both cats are more likely to fight a second time. So it is VITAL to act as soon as possible to make the cats feel better. Do not let bad feeling develop.
Aggressive play can take place which looks bad but isn't too serious. Ie. play attacking with some hissing and loose fur. But sometimes the victim cat ends up terrified, and permanently unhappy. The severity of the aggression must be judged by the unhappiness of the victim.

IS THE VICTIM SUFFERING?
1. Does the victim need veterinary treatment?
2. Are there wounds -- bitten ears, broken skin, blood etc?
3. Is one cat spending less time in the house because it is afraid to enter?
4. Is the victim spending its time hiding somewhere like under the bed?
5. Is the victim no longer grooming itself?
6. Is the victim too frightened to eat when the other cat is in the same area?
7. Is the victim too fearful to use the litter tray?
8. Is the victim no longer willing to approach you, because of fear of being attacked by the other.
9. Do you come back into the house to see signs of conflict?
10. Is the aggressor patrolling an area of the house so that the victim only has a small area of living space?

If you answer yes to any of these questions, this is serious aggression. If it has access to out doors the victim will soon leave home. My own feeling is that if you answer yes to more than three questions, you must rehome one of the cats. The victim is leading a life of almost constant fear. It is just not fair on the victim to expect it to live in this way. It is selfish to let this state of affairs continue.

METHODS OF IMPROVING A RELATIONSHIP WHICH IS NOT TOO BAD.
1. Do not punish them when fighting. If you do, they will associate the other cat with the fear and pain of punishment. Ignore minor scuffles, because otherwise they will stage fights to get your attention or wake you up in the morning! (I know this one!!). Never force them to be close.
2. Reduce competition. Make sure there are plenty of cat beds, scratching posts, a litter tray for each cat AND one extra, lots of feeding bowls in different locations and lots of water bowls in different locations. If the cats live in separate territories within the house, make sure there are litter trays and feeding bowls in both areas.
3. Get each cat to associate the scent of the other with nice things like treats. Wash your hands, then stroke cat A round the chin and cheek area (where the scent glands are). Then stroke this scent on to the cat B, meanwhile feeding it a treat. Then visa versa. The idea is that both cats associate the scent of the other with nice food.
4. If the cats have separate sleeping areas, swap bedding from one to another.
5. If there is an area you wish them to share (like the bed), call them to this area and give them treats only when they are both in the area and close to each other.
6. Give them titbits at times when you see them sharing a sofa or a windowsill etc. The idea is to reward them for closeness.
7. If they are indoor cats, or both spend a lot of time in one room, install a Feliway Diffuser which will make the general atmosphere more relaxing. Relaxed cats are less aggressive.
8. Guard against intruders or frightening wildlife by blocking off the sight of these, closing the cat flap permanently, or installing a magnetic cat flap so only the household cats can use it. This is important, because if the cats are attacking each other because of intruders/wildlife this will often end up in a genuinely bad relationship between them.
9. If a vet's visit triggered the aggression, take both cats to the vet's surgery just for a trip and make sure vet smells are wiped over both. (Explain this to your vet!). I have come across one pair of cats, where this put back the old loving relationship! Next vet visit make sure both cats are taken even if only one is sick.
10. Make sure there are plenty of hidey holes - cardboard boxes with holes are cheap - where cats can retreat if ambushed. Put in high shelves to cats to retreat to and look down from. Make sure routes to food or litter trays have these retreat areas so that a cat isn't ambushed on a piece of open ground. This can be done in the garden too. Lots of scratching posts.

ACCEPT A DISTANT RELATIONSHIP
Cats can sometimes work out a relationship which is remote but not abusive. They may live in different parts of the house, or in different rooms, with separate litter trays. If this is an acceptable relationship to them, and neither cat seems to be suffering, then it should be acceptable to you. Accept their decision.

SETTING UP SEPARATE AREAS. Here are some ideas.

1. Put a cat flap in the garage, install bed etc. and make one of the cats an outdoor cat. If the situation has been caused by taking a stray into the house, this will be a sensible solution. The stray is homed but out of doors. Separate living arrangements may not be a humane solution. It depends on the circumstances. Forcing a pampered cat to live in the garage, for instance, would be cruel, but it would not be cruel to let a stray (used to living rough) become the garage cat.
2. For cats that are used to collars… Install a magnetic cat flap into the airing cupboard/wardrobe/spare room. Let the victim have a bolt hole to itself. Install bedding and litter tray there. This will only work if the aggression is not too severe. If it is severe, the poor cat may simply live in the cupboard all the time.
3. Keep cats in separate areas with separate cat flaps. To be fair, you will have to divide your time between the two areas. Work out a timeshare arrangement in the garden so that one lot of cats is never out there when the other is.
4. Stop hassling during meals. Feed the bullied cat inside an upturned stout cardboard box, with a hole made in it. This prevents the bully cat from shouldering the bullied one out or staring menacingly. REHOMING This may cause you pain and suffering but may be the only way to relieve the pain and suffering of the victim cat. Truly caring owners should be prepared to do this. In the UK the Cats Protection are a good rescue shelter. Before handing over the cat make inquiries about their euthanasia policy. Find a neighbour who will take the cat on. Some cats truly blossom when they live alone.