Jack Won’t Go In The Box

In case you didn't know, I am a huge animal lover. 

I have four cats, Jack, Oliver, Frances and Gracie.  They are my life, I love them so much!

I got Jack, Oliver and Frances together as babies in the Spring of 2012, and I got Gracie in November 2013, also as a baby kitten.  So, before Gracie came along, the three kitties got along great, and were all wonderfully behaved.  Once I adopted Gracie, they were reluctant to accept a new cat to our home.  It took about a month for them all to warm up to her, but now they are have for the most part, and Gracie likes them back.

So, here's the problem.  Jack is having a difficult time using the litter box.  He uses it just fine for #1, but not so much for #2.  This didn't start happening until I got Gracie, and it used to be once in a while, but now, it's almost every day.  Jack is only almost 2 years old, so I don't think he's sick, but I do think he is trying to tell me something.  He seems completely fine, content, happy, playful, I don't see any change in him whatsoever...the only change is that we got another cat, so I kind of think the addition of Gracie is his reason for him going outside of the box.

I have added another litter box just in case he just wasn't happy sharing a box.  I also have tried moving the boxes to different locations, that didn't change anything.  I haven't changed up the food or litter, so it's not that.  I just can't figure out what the problem is!!

I think my next move will be adding yet another litter box, so I'll have 4, one for each kitty. If that doesn't work, than it is going to have to be time for a trip to the vet.

Any animal lovers out there that have experienced anything like this?  I'd love any suggestions on what I should do!