Thank you for your question.
I am most concerned about the state of your goat. If she is taut like a balloon (and probably sounds like a steel drum when you flick the distension), then I would be concerned that she has bloat. This time of year, despite the varied diet then I would be concerned that she is selectively grazing (possibly due to dental disease) and likely been eating more grain then her hay. The problem with bloat in these guys is that the distended stomach can put a lot of pressure on the rest of the organs of the body. Bloat is painful (and we can see grinding teeth and depression) and if she is severely bloated it can be fatal if left untreated. If this animal wasn't in an emergency state, I would want you to first remove the her from feed. Avoid giving water to a goat who has ingested large quantities of grain, because water will add to the fermentation rate and cause the grain to expand. Wait maybe 12 hours before you give water - once she has had roughage to help stimulate the rumen. If she can stand and walk, you can try to drench her with a quarter of a pint cooking oil down her throat and then exercise the her (through walking) and massaging of the sides. This most often will cause the built up gas to escape through the mouth or rectum. Once you have gotten the goat relieved of the gas, one treatment option is to give a small amount of sodium bicarbonate (~1 tbsp) mixed in a small amount of warm water or molasses.
If she is too weak to get up, then I would advise having your vet evaluate her now. And if need be, the vet will be able to stomach tube her to release the gas, use a trochar or operate if she is that bloated. The vet will also be able to administer pain relief to make her more comfortable and evaluate her teeth (since this is likely a trigger).
I hope this information is helpful. Please let me know if you have any further questions. If you have no further questions, I would be grateful if you would press the wee green accept. Happy holidays, Dr. B.