Q and A: Prevention and Early Detection of Neonatal Isoerythrolysis
The prevention and early detection of Neonatal Isoerythrolysis (NI) should be a routine part of your breeding and foaling checklist. In this article, we address common questions we receive for this easily preventable condition.
What is neonatal isoerythrolysis and how can my foal get it?
Foals are not born with NI. It develops in the first week of life and results from consuming antibodies from the dam’s colostrum that damage the foal’s red blood cells. The foal then begins producing antibodies of his own and mass destruction of his red blood cell occurs.
How serious is NI?
Left untreated, NI can be severe and even fatal.
How does a mare develop antibodies against her foal’s red blood cells?
Your mare must be bred to a stallion with an incompatible blood type (see below for how to easily prevent this). If the resulting foal has an incompatible blood type and his blood gets into her bloodstream, her immune system will create antibodies against his blood.
How does a foal’s blood get into the mare’s bloodstream?
A placental hemorrhage during pregnancy, or from an injury during foaling, are common ways for a foal’s blood to get into her bloodstream. (Antibodies from a foaling injury would not jeopardize her current foal, but could impact her offspring in future years.)
Are there other ways my mare can develop antibodies?
Yes, if she receives a blood transfusion or other blood-based products.
Why are the antibodies potentially deadly?
Red blood cells serve a range of purposes, including carrying oxygen throughout the body. In addition, ruptured red blood cells damage the kidneys and the brain. Fortunately, prevention and early detection are both successful interventions.
Can any breed of horse get NI?
Yes. It can develop in all breeds, but is more common in certain purebreds, including Friesians and Thoroughbreds. We are also starting to see it more frequently in warmbloods.
Do mares and stallions carry NI?
No, mares and stallions do not carry NI. It develops only in foals who drink the colostrum from a mare with antibodies.
How do I Prevent NI?
The first step to preventing NI should be taken before you breed, with a blood type and antibody screen for your mare to check for any issues, as well as assess compatibility with the stallions you are considering.
Where can I get my mare blood typed?
The University of California at Davis (UC Davis) offers blood typing tests. Visit this link for all of the details:
Are the Iron Spring Farm stallions blood typed?
Yes. All of the Iron Spring Farm stallions’ results are available on their individual stallion pages on the ISF website. We can also email you the reports for review with your veterinarian. In addition, UC Davis keeps our stallions’ information and can work with mare owners to assess any compatibility issues.
Do you blood type your mares?
Yes. We blood type our Friesian mares and encourage all Friesian mare owners to do the same.
What other steps can I take to prevent NI?
Test your mare for antibodies before she foals. Our Friesian mares are tested for antibodies 1-3 weeks prior to due date.
My mare developed antibodies last time she foaled. What should I do?
If your mare developed antibodies in a previous pregnancy or during foaling, she’s likely to produce them again, so knowing your mare’s history is essential. Talk with your veterinarian about this situation.
What do I do if my mare does have antibodies?
Fortunately you can easily prevent your foal from receiving the antibodies by not letting him have a drop of his dam’s colostrum. Work with your veterinarian to take the necessary precautions. Steps include milking off your mare’s colostrum and providing your foal with colostrum from a donor mare that is free from antibodies. Your veterinarian will let you know when it’s safe for your foal to nurse from his dam, usually after 48 hours.
While NI is a potentially deadly disorder, it’s easily preventable.
Disclaimer:
All content provided by Iron Spring Farm is general and for informational purposes only. Content may also not constitute the most up to date information. Nothing in this content is intended to constitute veterinarian advice or to serve as a substitute for consultation with a veterinarian. Always seek the advice of your veterinarian or other qualified provider with any questions that you may have about the treatment and care of your horse.
Any reliance that you place on the information provided is strictly at your own risk and Iron Spring Farm, its officers, employees, representatives, and agents, hereby disclaim any and all liability to any party for any direct, indirect, implied, punitive, special, incidental, consequential or other damages arising directly or indirectly from access to or use of any content provided to the maximum extent permitted by law.
