I have two black and white "tuxedo" cats, both female, ages six (Tux) and five (Sweet Pea). Two weeks ago, Tux went through surgery to remove a fibrosarcoma tumor in her side. The tumor was quite large and the incision is about 10 inches long (she's a big cat: 21 lbs.). Ever since Tux's surgery Sweet Pea hasn't been so sweet: growling and hissing at Tux whenever she sees her and even growling and swatting at my husband and I. I figured that maybe it was an attention thing but we have been giving them equal attention as we always do (except for when we had to give Tux her medications, which stopped three days ago). Tux's scar is pretty much healed up (her stitches were removed this past Tuesday), however it will take a while for all of her hair to grow back. Tux's behavior towards Sweet Pea hasn't changed, there is no ill will that I have witnessed. Has anyone experienced this before? Will this behavior fade away? I'm flabbergasted because they were the best of friends.