Attacks Owner After Seeing Another Cat

[FoodLady]

Two of my cats have done this to me. I checked with my vet - she calls it "displaced aggression". Your furball wants to defend his territory and since he can't get to that other cat, takes it out on the closest animal/person. My vet suggested not touching my kitty or otherwise trying to distract her because that can make the situation worse. They're so focussed on the interloper that they turn on you. Just leaving my cat alone and/or leaving the room has worked best for me.
Good luck!

[G535]

My cat's the same, I just leave him to it, doesn't take him too long to settle down again. After all these cats are invading "his" territory and he's frustrated because he can't get at them.

[Sonia59]

Peppito does the same. I have never tried to distract him with a toy but it's a good idea, I will try next time, as it appears impossible to touch him when he is over-stimulated.

[orangegirl]

My cat does this also. A friend of mine had her hand really stratched up after another cat got into her apartment and her indoor cat attacked her. She had to go to the emergency room and everything. They say that some cats do it tho and it is not abnormal. Ouch!

[Maya & Inka's mommy]

I would distract him with a toy. If this doesn't work, keep the spray-bottle ready: everytime he bites, spray water on him.

But like I said, I would try the "gentle" trick-with-toy first