Why would a male horse kill a foal? What causes sudden foal death?

I am so sorry to hear about Fred! Unfortunately, the only way to know what caused Fred's death with any certainty would be a full autopsy by a veterinarian or a veterinary pathologist. In terms of diarrheal diseases in young goats, the cause is typically parasites. Scouring, aka profuse diarrhea, is a common cause of death in young sheep and goats. It can cause rapid dehydration, intestinal bleeding, and nutritional imbalances. My advise to you would be to alert the people from whom you received Fred to see if they have any other animals that might be sick. They should be warned about what is happened, and might even offer to help pay for an autopsy. If you have any intentions of doing this, Fred's remains need to be kept cool in a refrigerator (or if the only option, a freezer). If there is any diarrhea still around on your property, I would bring some of this in to your veterinarian and have it tested for parasites (including coccidia, a very parasite in young goats). Once again, I am very sorry that Fred is gone. I hope you are able to figure out what happened.

Very hard to speculate what could have happened. She may have colicked and died of a twisted gut. She could have had a serious worm burden, or had a tumor, a defective immune system. If she was freshly dead, you could have had a post mortem done. Without a post mortem, I am afraid, one can only speculate on the cause of death.

Horses need to pass the afterbirth within 1 hour or the placenta is considered retained. This can lead to serious infections of the uterus or reproductive tissues. Please call your vet right away because it is important that she have an examination. They can be sure that she passed the complete placenta or they will flush her out and administer antibiotics.

Poor Molly! It sounds like she's very sick. Mucus dripping from her nose could be caused by a severe respiratory infection, a problem called choke which is caused by food blocking the esophagus, or some other type of illness. Her lack of appetite and weight loss may be related to this, or could be due to a separate problem. Regardless, if she hasn't eaten in several days, this is an extremely serious problem - she may die without prompt veterinary care, so I would recommend calling an equine vet out to come and see her immediately. He/she can do a complete exam and some diagnostic testing if needed to help determine what's wrong and get her started on appropriate treatment. The foal should start to become used to you the more you are around - feeding and handling Molly, etc. Over time, he will become less afraid and you can begin gently handling him as well. Go slowly and take your time to earn his trust.

Not necessarily. It is a matter of genetics. Horses with light colored coats typically have light or blue eyed foals. You may see a darkening of eye color as the foal ages but this doesn't always happen.

With all the information you have provided, this situation sounds very suspicious of a Barber Pole Worm infection, also known as haemonchus contortus. It is a parasite that infects the digestive tract and feeds off the the sheep's blood. Sheep can become anemic and die very quickly. My recommendation is to have your veterinarian perform fecal sampling on your herd. If eggs are present in the feces for this parasite your veterinarian will need to reassess your parasite control program.

I am so sorry. Unfortunately there is a reason for kittens being pushed away by mom, or being separated: They usually have some birth defect and nature is cruel. It would take away energy and strength from the other kittens if it was to be raised or needed extra care. So there is a very high possibility that this kitten had a serious defect and therefore did not make it. There is also a reason for cats having up to three litters a year: Kitten mortality is high, especially in "the wild", so they have up to 18 kittens/year to make sure some survive. Again, I am very sorry you lost this baby.