Hi everyone. I have two cats, a very large round tabby named Broccolli and a much smaller cat named Gargomel. We've had them both for about 2 years and they've been the best of friends since they met. They clean each other, eat together, sleep together, and play together. However, recently we were woken up at 1am a few days ago to find our bigger cat, Broccolli aggresively hissing and chasing the smaller one around. Our smaller cat, Gargomel was also growling and ran into a corner behind some cabinets and pee'd in the corner. (He's never had a litter box problem). Ever since then, they can't stand the sight of each other and we've had to keep them seperated, one in the living room and one in the bedroom. Their behavior toward us hasn't changed at all, they are both still loving and affectionate toward us but can't stand each other. What could have caused two cats who got along great for 2 years to suddently hate each other? Also, both our cats are neuteured so I'm not sure why Garogmel pee'd in the corner, he might have just been scared. If you have any advice or suggestions, pleasee pleasee help.