I have 2 female cats that are about 18 months old. Neither have been spaded yet, but they are indoor cats only; they have never been outdoors. They don't seem to be able to gain any weight. They act healthy, very playful, coats are shiny, but they are so skinny you can see the back bone and feel their rib cages. They've been checked for worms and it was negative.
What can be done for this? Will they gain weight after they are spade?
Yes, they will gain some weight after being spayed. Vetcare