In response to the pregnant question, my sister in law bought a horse that had not been gelded yet, he was gelded by the vet within 2 weeks of her getting him, but apparently it was 2 weeks to late lol. All of our horses are "fixed" with the exception of mama horse. Am considering when she is fully recovered to see if the vet can fix her so we don't have any more accidents from new horses being bought. We have almost 100 acres of land that all the horses share, and as I said in my comment on the other post, I married into the family and land so I don't really have a say in how they are separated. We do have separate fields, but we generally keep them all together except in cases such as mine. For now we have mama and baby colt alone in a pasture with the barn because it has stalls and is set up for close dealings with them. Thanks again for being so nice and responding to my concerns!
Thank you for writing about your horse. This seems like a very serious situation. It is not good when a horse is so weak that she falls down, and is so thin. I would immediatly recommend a call to your vet to have him/her come take a look at your mare. There could be a variety of reasons that she is losing weight and falling because of her weakness. The vet would need to determine if the situation is a medical one, or the mare is just not getting enough nutrition. Pregnancy and nursing can take a lot out of a mare. During this time, nutrition requirements are different than if she were not pregnant/nursing. As well, there could be a problem with her teeth, and they would need "floating" by the vet. He could also determine her age by looking at her teeth. If she is elderly, her nutrition requirements would be different as well. In addition, the growing foal will have its own nutritional requirements. It is getting close to the time that the foal will need to be weaned, anyhow.
How did the Mama horse "become" pregnant again? Do you have a stallion on your property? It would be advisable to have any stallion gelded. You can talk to your vet about that as well. It is something that can be done in the field. Also, there are low-cost gelding clinics available, depending on where you live, or assistance with financing for that. If you need more information, please let me know.
Please let me know how the mare is doing.