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Sudden cat dominance over the other.

Discussion in 'Cat Training and Behaviour' started by Barda, Jul 12, 2019.

  1. Barda

    Barda PetForums Newbie

    Jul 12, 2019
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    Last night our two cats have become aggressive over each other. They have been living together fine for the past 6+ years until suddenly last night.

    One of the cats (cat 1) were sleeping on the bed while the other cat (cat 2) walked in. This is normally ok if cat 2 does not get on the bed. All of a sudden they started hissing and fighting each other. This went on all through the night.

    Now cat 2 is hiding in one of the bedrooms, while cat 1 is outside the door making sure she does not come out. Cat 2 that is inside the room will constantly hiss whenever she sees cat 1, but cat 1 does not seem to retaliate in any way.

    These cats have been living fine together for years and this sudden change has surprised us.

    Cat 1 is an incredibly affectionate cat towards humans, constantly wanting attention, but does not seem to care when giving affection to cat 2.

    What could be the cause for this sudden aggression and dominance.
  2. chillminx

    chillminx PetForums VIP

    Nov 22, 2010
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    Hello @Barda and welcome :)

    I don't think the hostility is due to a sudden desire of one cat to dominate the other. It could be redirected aggression, or could be due to one cat being ill or in pain, or could be due to one cat having picked up a strange scent on their coat or paws, making them smell like a stranger to the other cat. Cats are very scent-driven animals.

    If the cats go outdoors maybe one of them has been in a fight with another cat and has the other cat's scent on them.

    If they go outdoors maybe one cat has acquired an injury. Cats are very good at hiding pain, but it can show in unusual hostile behaviour at home. Have you noticed any changes e.g. in the eating patterns or litter tray use, of either cat ? If so then a vet visit may be required.

    If they are both indoor cats then it's possible one cat has seen through the window a strange cat in your garden. Your cat may fear the strange cat is trying to gain access to his core territory (your home) and hence he/she feels fear or aggression, which is being redirected at your other cat.

    It is possible one cat is feeling ill from an internal physical cause, nothing to do with outside influences. Illness can cause changes in an animal's scent, and in these circumstances could make one cat suspicious of the other. If one cat is unwell it may not be him/her who is being hostile, but could be the other cat reacting to the changed scent of the housemate.

    I had a similar situation in the past with my 2 female cats (sisters) who normally get on very well together. I took one of them to the vet and when I brought her home and let her out of the carrier the stay-home sister immediately attacked her and a vicious fight broke out between them. I had never had this situation arise before with any of my cats, past or present, so I was taken aback.

    I separated the 2 girls and kept them in different parts of the house overnight, then carried out lots of scent swapping the next day (take a soft cloth and wipe it around the neck and cheeks of one cat and then around the neck and cheeks of the other cat and then back again). I let the girls be together under supervision later that day, but any sign of aggression I separated them immediately. It took several days of careful supervision before they were fine with each other again.

    In my situation it was a vet visit which caused the falling out; in your case I don't know what it could be, but perhaps with a bit of detective work you may discover the cause.

    Whatever the cause it is important to prevent your cats from displaying any aggression to each other now by keeping them separate when appropriate. Cats being solitary predators are naturally suspicious of each other and even the relationship of housemates who are normally the best of friends can be seriously damaged if they fall out. Cats do not find it easy to 'forgive and forget' when another cat upsets them, and are skilled at bearing grudges against each other. In these circumstances the humans need to be the mediators.

    Running some plug in diffusers such as Feliway Friends and Pet Remedy may help calm the atmosphere. We use both these at the Shelter when a new cat comes in, and it does help calm things down.



    Pet Remedy contains valerian which is a natural calmer and relaxer.

    Or you could give both cats Beaphar Calming spot-on. It is a liquid placed on the back of the head. It takes a few hours to become effective and lasts for one week. If you gave both cats this before they next see each other it might help.


    Please let us know how things go. Good luck. :)
    #2 chillminx, Jul 12, 2019
    Last edited: Jul 12, 2019
    Ottery and sandy-cat like this.
  3. Ottery

    Ottery Cat Lady

    Jun 14, 2019
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    You say

    and yet

    So it sounds as if the peace was a bit fragile and depended on each 'knowing their place' and not upsetting the other.

    For some reason that has now tipped over into outright hostilities. It would be virtually impossible to pick apart why, so I agree you need to keep them separate and try the suggestions given by Chillminx.
    moomoowawa and chillminx like this.
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