Need help with weight gain in old horse

I have a 30 year old Appaloosa named Shadow. When I took her in as a rescue she was severely underweight. So bad, that I had a friend tell me I would never get her back to a good weight and should put her down. She has gained over 100 pounds but just stopped gaining. I have her on Senior feed and worked up her rations but what else can I do to get her to gain some more weight? It seems like she got to a certain point in her weight gain and just stopped gaining.

I am having the same issue with a 20 year old gelding that lost weight due to severe colic and my 36 year old mare that lost it due to depression over loosing her pasture mate.

Teeth? Worms? Anemic? Kidney, liver function? What has the vet told you?

She has been wormed. He said her teeth aren't that bad but will need to be floated in the near future. She is healthy and said with how bad she was in the beginning she just might not gain anymore than what she has because of her age. I refuse to believe that and want to get her kinda chunky. Lol

I would get a fecal count done, rather than just deworm her. She looks wormy to me. Get her teeth done now, rather than in the near future. Then stick her face in a round bale and let her have at it.

What kind of senior feed? My friend's senior appy was on Purina senior and doing awful, but when she switched him to Triple Crown, he started gaining weight and improving.
Posted via Mobile Device

So what did the cbc say? I'm assuming you had blood work done as that is usually the first thing to check when a horse wont gain weight after of course getting their teeth done and being properly dewormed.