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Nicole288 schreef:

Mak's babay staat

Whiz: Wat zijn er voor vorderingen bij Lady?

jeanette schreef:

Maar het wordt wel steeds spannerder Whiz

Citaat:

Neonatal isoerythrolysis (NI) means destruction of the foal's own red blood cells. The disease is characterized by signs of acute anemia.

Let's start by eliminating the use of the term RH factor. That is a human term. Red blood cells can carry antigens (markers) on their surface which in part determines a horse's blood type. There are 8 different blood groups with 32 different possible markers. Qa and Aa are the markers most frequently implicated in NI. Horses can be Qa-, Qa+, Aa-, Aa+. Negative means the marker is not there, positive means it is.

During late pregnancy mares are exposed to the blood of the foals they are carrying through the placenta. If the mare is negative, bred to a stallion that is positive and carrying a foal that got that + antigen from the sire her body will recognize these blood cells as "foreign" and start to form antibodies to kill the "foreigners" off. This will not affect the foal she is currently carrying but these antibodies will be with her for life. In subsequent pregnancies she could have an NI foal.

The following things are required for an NI foal...

1. The mare must have the antibodies to the antigen carried by the stallion (she has been sensitized to his blood type).
2. The foal must inherit the stallion's blood antigen.

If these 2 things happen then the foal will ingest colostrum containing antibodies to its own red blood cells. When it nurses and these antibodies are absorbed into its bloodstream the antibodies will proceed to attack and kill the foal's red blood cells leading to anemia.

Therefore every negative mare is at risk for producing an NI foal. Stallions must be tested to see if they are positive for any of the markers. Maiden mares are unlikely to have NI foals (unless they have received a blood transfusion in the past) because they need to have been pregnant before to have formed antibodies. NI is more common in mule foals because donkeys all carry a factor that is foreign to horses. Many breeders will cross negative mares with positive stallions because it's a breeding they really want. They must be sure to be present at birth to determine if the foal must be prevented from nursing. Don't forget that even with this cross there is a chance that the foal will inherit the mare's blood type and be fine.

Clinical signs in NI foals can appear from 5 hours to 5 days of age and vary depending on the severity and rapisity of onset of anemia. Signs can range from increased resp rate and lethargy to pale, yellow mucous membranes, increased heart rate, depression anorexia and collapse.

Treatment ranges from supportive care to repeated blood transfusions again depending on severity of anemia.