I'd still give the vitamin therapy.
If the tendon is slipped, then you should be able to feel that and usually the joint is swollen too.
Slipped tendon can be very hard to correct.
You may find the link below helpful...
I would get a bottle of B-Complex. Dissolve a 1/4-1/2 tablet in a tiny bit of water and give her the drops throughout the day until it's all gone.
Poultry Cell is a good pick me up and seems like a good punch for vitamins but if you read the label, that's per Fluid Ounce. So a couple of drops...
What vitamins?
I'd give her 1/4 tablet B-Complex daily, she needs to have some B2(Riboflavin) and B-Complex is a good way to get that into her along with other B Vitamins.
I'd keep her on a hard flat surface, so she can have purchase when she tries to walk. You can use puppy pads on the...