Problems with cats using litter boxes

[alovewithin]

We adopted a new cat in March; Bruin. I had the usual open litter boxes. Miss Bruin likes to pee right at the edge. So when she would go her feet would be inside the litter box and her tail would be over the edge. Some urine would be in the box but most was on my carpet. Cali took this as an act of war and she started marking places around the litter box. I cleaned my carpet and the areas around it. I purchased storage containers that was easy for them to jump in and out of. (this was back in may)

That took care of that problem. The new problem is I have them on Science diet or blue buffalo. (June started this food instead of what i would get at walmart or Purina one) It made Cali more regular which is awesome. She used to go two days and it was firm. She started going #2 every day like clock work. Just recently it started getting soft at the end and she gets it on herself. She also can poo like she used to in these boxes. She used to balance herself on all fours on the corner of the box. (All feet on the edge none in the litter) Now she basically goes standing she doesn't angle her butt down a lot.

Cali also has been licking the base of her tail on the side. She is a little pudgy. This was at the beginning of the month. I took care of it with neosporin and vicks so she wouldn't lick. It healed and the hair grew back. Then Monday she has started licking again. I'm thinking its because she cant reach her butt to clean it. I wiped her butt since she can't. I applied neosporin and vixks to deter licking Monday night. I haven't reapplied since Tuesday and I haven't noticed her licking the spot open since.

I got a calming collar at the beginning of the month. Cali was marking outside the box again. The collar took care of her pee marking. I noticed her being more stressed. Bruin seemed to be pushing her buttons. Bruin is 2 Cali is 10. Bruin just wasn't leaving Cali alone. The collar calmed Cali down also worked for Bruin. I honestly feel it took her back to her old personality. The one she had before I adopted Bruin. I got the collar about the same time she was licking.

Sorry this got long. I'm just at a loss. so I guess ideas for the soft stool, licking, and pooping on herself?