cat sudden pissy fits

I have 2 cats - The older one is Dorito and the younger is Static whom we've had for almost 3 years. They love each other and have never had any problems until Nov. 24... out of nowhere my boyfriend and I hear Dorito let out this deafening scream and then see her and Static run like hell out of our room. Dorito turns around and is hissing/screaming/meowing with her ears back and all crouched down at Static... This has NEVER happened before. Static is confused and keeps trying to get close to Dorito but it looks like a fight is going to start so we seperate them thinking Doritos just having a pissy moment... it wasnt just a moment. She wouldnt calm down and would barely let us touch her. I noticed the window was open and thought that maybe there was another cat out there that freaked Dorito out... so I close the window and grab Static. I notice she has a slight urine smell to her furr... I figured thats what had Dorito all fussy so me and the boyfriend give her a bath. This seems to calm Dorito a little. So we wash Dorito too and after a few hours of drying off, they seem to be okay with eachother but now Static is apprehensive of Dorito because shes afraid of being yelled at. So the passed few days went by great with very few growls between the two... and then tonight... the boyfriend and I come home and out of nowhere, Dorito hisses/screams/meows with her ears back at Static. I sniff Static and she smells clean and theres no obvious signs of what could have set this off again.... I am SO confused right now. Her piss fits literally come out of NO where and shes never done anything like it before.. I feel bad for Static because she wants to get close to Dorito and she cant. Shes all sulky about it like a repremanded child. Can someone please help me? There have been no changes around or to the cats. No new people or furniture... no change in diets or litter box... I just dont understand it. :(

The first thing I'd recommend is a trip to the veterinarian and a full checkup for both cats, particularly bloodwork and - for Dorito - a neurological examination. Sometimes hissy-pissy outbursts that come out of nowhere can have a physical cause. Since a physical problem can be life-threatening, it is best to eliminate medical issues first, then worry about a behavioral issue. (I'm assuming here that both cats are spayed and kept indoors. If not, you should correct these situations at once.)

If your veterinarian gives both cats a clean bill of health, the best thing you can do is make sure both cats have plenty of space, then let them work it out on their own. Cat fights are generally noisy but not lethal. The screaming sounds awful, but remember if that mouth is busy yelling it isn't biting.

Make sure the litterbox is scooped daily and changed fairly often. You might want to consider a second litterbox if you don't already have two. Remember to take fresh stool samples to your vet, and if you can get a clean urine sample that will also help the vet with his/her diagnostics. Be sure to mention that urine smell to the vet, it could indicate a bladder infection or other physical problem.

Also, think hard about when the problem started. Did anything change in your apartment during the week leading up to the first explosion? Sometimes something as insignificant as a new piece of furniture, new cleaning product, new perfume or new brand of cat food can rock the very foundations of a cats universe. Remember that your apartment is their whole world, something that is barely noticable to you could be earthshaking to the cat.