A few years ago, I looked out my kitchen window one holiday morning and saw a newborn foal running outside of a fence line. The foal had been born to my neighbours’ mare, a maiden mare, and they were out of town. The mare had rejected the foal and wasn’t interested in any of my attempts to get them back together. She also had little colostrum (the first, antibody-rich milk that foals need to drink early in life to survive). To make a long story short, I ended up doing a field transfusion, collecting blood from another horse on the farm to give to the foal, to provide it with those much-needed antibodies. The donor horse was healthy and I didn’t know of any disease issues in the area, so I was pretty confident that there wasn’t a significant risk of disease transmission, but you never know. Ideally, equine blood donors are screened for infectious diseases, particularly equine infectious anemia (EIA), since EIA is a rare but nasty disease that can be spread by blood.

When I started to read a report the other day about a transfusion-associated EIA infection in a German foal, my first thoughts were "that’s bad," followed by my ever-optimistic side thinking "well, maybe it was an emergency transfusion and it was a bad but unavoidable consequence" or "maybe it the donor was properly screened but was infected with the EIA virus after it’s last test" (the latter situation is an ever-present risk when you are screening donors in advance (days, weeks or months) of collecting the blood for transfusion, since test results only tell you what their status was at the time of testing).

Unfortunately, it didn’t take long to see that this wasn’t an unfortunate or relatively unavoidable infection. Rather, I can only interpret this as stunning negligence.

Here’s the story

  • On August 2, EIA was confirmed in a 3-month-old foal in North Rhine Westphalia. When the foal was two days old, it had a septic joint (and probably an overall deficiency in antibodies) and was treated with a plasma transfusion, which is a pretty standard procedure in such a case.
  • EIA antibodies were then detected in the donor.
  • Since 2009, 20 other horses had received plasma from this horse. Four have been confirmed as infected, and horses that live with these infected animals have been quarantined until test results are back. Positive horses are typically euthanized because they pose a lifelong risk of transmission of the virus to other horses.  The four positive horses in this case have been euthanized (and presumably the foal as well).

So, this wasn’t some random emergency field transfusion, or a donor that got infected after testing. It appears that this donor has been used for years with no testing, despite the fact that it’s well known that EIA transmission is a risk from blood transfusions and the virus is present (albeit rare) in Germany. While there are no standards of care for equine blood transfusions (as opposed to dogs), EIA testing is a standard recommendation in anything I’ve seen written about equine blood donor programs (click here for one example). Sometimes you get put into situations where testing can’t be done in time for logistical reasons, but I can’t see how anyone would not test horses that are to be used for a formal donation program or repeated transfusions. Failure to do low cost and easy EIA screening of that donor horse has resulted in the deaths of multiple horses, with the potential for even broader secondary transmission of this virus to additional animals.