It is called neonatal isoerythrolysis (NI). It happens when the mare comes in contact with a previous foal's blood that is the same type as their sire's in the last few weeks of pregnancy. We don't know how or when this could have happened or with which foal as we do not typically blood type the foal and don't know which ones have her blood type and which ones have the stallion's. It does not happen very often, so I was fortunate that my vet had recently suspected the condition with another foal and was up to date and familiar with t
The worst part is that once the mare produces these antibodies, she will continue to do so with every pregnancy. We had the stallion, the foal, and the mare's blood analyzed and the result was that the mare would produce the antibodies to every horse blood type but her own - apparently unusual, so breeding her to other stallions would not solve the problem - not to mention that most stallion owners do not know the blood type of their horse anyway.
The danger to the foal only exists during the first 24 hours after birth. After that the mare stops producing co
After weighing this strategy and the quality of the foals the mare and stallion had produced (pictured here) in the last 4 years we decided that is was a small inconvenience to milk the mare and bottle feed the foal for 24 hours. So we thought! Future posts will detail the unforeseen problems we had with this year's foal. She is fine now - see post A New Filly


