Copper toxicity-vs-hoof issue-vs-old age

I have a 10year old nanny Pygora who has been acting strangely for about 2 months. She appetite is decreased,she lays down a lot, and sometimes sits with her front legs up in front of her with her chest off the ground. Her hind leg hair is coppery. I read an article on copper toxicity in pygmys. I did dose her back in January with Copper in between a marshmallow. I have done this before with all my goats, and never had a problem. Her poop is fine, she moves slow. I have cut her hooves-no infection although her rear left leg is definitely skinnier than the right and she keeps it raised and kinda crossed over the right leg. Her dew claw on that left leg is long and crusty and feels hollow.
Any ideas?

 

Thank you all for the advice-going to see a vet!

 

No break in her foot or hoof. No worms-but I could have told them that. No other issues. SO they gave her antibiotics just to cover in case something was going on and some anti-inflammatory for what they think is just arthritis. She seems in better spirits but her leg still hurts. She was pretty freaked out about going to the vet and shook and was so out of it for a good 3 hours. Im watching her carefully. I love her and she is my absolute favorite goat. It does worry me that she won't even eat her treats just alfalfa and forage.