Cat attacked me after outdoor scare. Why is he now hissing more?

If your mom found a cardboard box on the street and brought it, it likely had strange smells. This may have caused Oliver to act aggressively, it's called redirected aggression. Something set him off, possibly a smell from another cat, but since he couldn't attack that cat, he went after your mother. Aggression can be hormonally related, as intact male cats are territorial. I'd have him neutered. Best of luck.

Keep them separated for the time being. Oliver may need a few days to reacclimnate to Minnie. If she allows, a bath may remove any residual outdoor scents that could be upsetting Oliver. Pheromone products such as Feliway spray may decrease his anxiety/aggression as well.

While he may be curious about the outdoors, it sounds as though walks may be quite stressful for him. You might try some other ways to enrich his environment. Many cats enjoy window perches where they can view the outdoors. Catwalks, [hammocks](https://www.petco.com/shop/en/petcostore/product/catastrophicreations-deluxe-cat-playplace-hammocks ) or wall perches inside also give them an interesting new perspective on their surroundings. [Interactive toys](https://www.petco.com/shop/en/petcostore/product/petstages-catnip-chase-track-cat-toy) and [scratching posts](https://www.petco.com/shop/en/petcostore/category/cat/cat-toys/cat-scratcher-toys) are also very helpful in keeping a cat's environment interesting and keeping them content. If Leo is acting this way on walks, I would not continue to take him outside. It's not worth the stress to either of you. I think you can find a number of other ways to keep him happy and occupied inside! Thanks for asking PetCoach!

Hello. Your cat may have experienced some minor trauma or even an unpleasant event outside. I have seen cats chased by dogs & even dive bombed by angry jays that would come into the house & sulk. And you never rule out some medical reason like a fever. If your cat continues to act strangely or unwell, refuses to eat or drink, please have him examined by your veterinarian as soon as convenient. Thanks for using Petco Pet Education Center, formerly Petcoach.

I'm sorry to hear that your going through this. In my mind, the two possibilities is that your niece did something that scared/upset Ollie or was even just near him when something scary happened so he associated the event and her. Cats can remember things like that for a incredible amount of time and have what seems like a wildly disproportionate reaction. This whole process can happened without us even realize we've done something scary. The second thing I would be worried about is that Ollie is ill or uncomfortable in some way -- such as starting to have more arthritis if he's an old guy or having an intestinal bug, etc. From a practical standpoint, I would recommend separating Ollie for the next visit or two and slowly reintroducing them at the following visit. It might be worth a quick vet visit to make sure everything is medically normally. Then, let Ollie have ALL of the control over how much he and your niece interact, she shouldn't approach him at all or even reach for him. You'll have to judge if this particular child can follow that level of rules - totally depends on the kid at her age. Finally, since it sounds like her feelings are very reasonably hurt by this change in behavior, I'd recommend explaining that we think he doesn't feel very good and wants to hang out by himself for a little bit.

That is very unusual and sounds scary! There could be a few reasons for this behavior. Sometimes there could be pain or a medical condition causing a change in behavior. Since Oscar can't talk and tell you what is happening, I recommend to have him examined by the veterinarian to be safe. Sometimes this behavior is related to the stress of seeing another cat outside. For some cats, this causes frustration and they can then exhibit bullying type behavior to other pets or people within the house. If the veterinarian thinks this is behavioral, there are a few things you can do. Try enriching the environment. Here is a great article about cat's instinctual needs: https://www.petcoach.co/article/why-every-cat-needs-a-place-to-climb/ Use a Feliway diffuser, set aside 30 minutes a day for vigorous play (really get him moving) and/or switch the food to Royal Canin Calm. If he is the only cat in the household, you may try feeding him out of a food puzzle. Hide food for him to find. Do not use these last two mentioned options if you have other cats. Provide a stand or resting place by a window so he can look outside. You may also try clicker training him for positive behavior. Here is a link about training cats: https://www.petcoach.co/article/can-i-train-my-cat/ Wash all windows and doorway exteriors where a cat may be spraying outside. Try to drive out the cat if possible. You may also need to block the window where you think Oscar may be viewing the cat most frequently. Most cats response best to combination therapy. The veterinarian can also prescribe medications which can help with aggression/stress. I hope this helps and please feel free to post any additional questions.

I am sorry to hear about Memphis. Sometimes cats will react to a stressful situation by transferring their frustration/aggression to those nearby. I would be sure your kitty has a safe area at home where he feels like he can hide/get away if wanted and he can easily access his food/water/ and litterbox for the next few days. I would consider picking up a Feliway pheremone diffuser such as this one which releases pheremones which can be calming to anxious kitties. I would also consider a calming supplement such as Composure or Zylkene. Your vet may carry these or you can order them online or find them in some petstores https://www.petco.com/shop/en/petcostore/product/vetri-science-composure-feline-bite-sized-chews