Goat with Arthritis

I have an elderly pet milking goat with arthritis. I have been giving her arthritis herb and comfrey for 10 days, but instead of getting better, I have noticed that she is worse. Today she didn't seem to be able to bend her back legs at all, but although they were stiff before, she could bend them.This may be due to the weather. It is very hot and on the few cooler days we have had she seemed to be a bit better. As a precaution, I will stop both herbs. Do you think one or the other could be making things worse? What do you think would be best for the goat?
P.S. I'm not sure of the botanical name for arthritis herb. It has small roundish leaves and it was recommended that people take 2 of these small leaves a day.

Unfortunately (or fortunately!) there are many herbs used in arthritis so it difficult to guess to which herb you are referring. Did you pick the leaves yourself? If so, best to use a reliable botanical identification book so you know exactly which herb you are harvesting. Also, odd that you mention your goat is better during cooler weather as a cool and damp environment often exacerbates arthritic pain. Herbs often used for this ailment include: Turmeric (Cucurma longa), Celery (Apium graveolens), Parsley (Petroselinum crispum) and Burdock (Arctium lappa). I have also heard of apple cider vinegar employed at one tablespoon vinegar to one and a half pints of water added to drinking water three times a week as helpful in arthritic conditions.
You may also want to look at your goat's diet to see if a change would be beneficial. Try to ensure the feed is free of chemicals, wheat, sugar and any member of the Nightshade (Solanaceae) family (potatoes, etc.) as these can trigger allergic responses that exacerbate arthritic symptoms. In addition, ensure any pasture used by goats is well-drained and free from herbicides, pesticides and chemical fertilisers.