My family bought these two cats that are sisters about 6 months ago that were
FIV positive. Luckily, they are both fine. However one sister is still very
sick looking, much skinnier and more sensitive to food. The sisters always
got along great and got along well with our dog as well. This past week we
got them both fixed at the same time. When they arrived home the sicker one
won't even be in the same room with either the cat or the dog and will hiss
and growl at them. She won't eat in the same room with the cat so we have
been feeding them in different rooms. Our other cat is acting fine and
doesn't seem to have a problem with its sister or the dog.

Is there any suggestions on how to get the two cats and the dog to get along
again?

It would be greatly appreciated.