have you had her teeth checked?
If she’s dropping enough weight to worry you, it’s time to take her to the vet.
If she is experiencing uncontrolled weight loss and lack of energy you need to call the vet out. Getting the weight back on is important, but even more so is finding the underlying cause and taking care of that.
Has her teeth recently been floated. when she eats do you notice her dropping a lot of extra feed or even slobbering? I would have a vet. check her out to be safe and find out what is going on with her. I’d be afraid of her getting down. Good luck and I hope everything turns out ok!
I would definitely have her teeth checked. Good luck!
That much weight loss that fast sounds serious. You really should call the vet.
The first places to look are teeth and worms, and fix either that needs fixing. Next, you could have a vet do bloodwork to see if anything is going on. I did this with my old pony who was losing weight, and the vet found nothing specific, but did find an elevated white blood cell count, indicative of some kind of infection, so we put him on some antibiotics.
Once you work out what might be the cause, you can experiment with her feed. Switching to senior feed made a huge difference with my pony. You can also try things like added corn oil, beet pulp, rice bran, etc.