So today’s blog will start with pulling blood for IgG tests on foals!
One of the things that we always do with our foals at 9 to 12 hours after birth, is an IgG test. Foals are born with a functioning immune system, but it has not developed any antibodies. The main immunoglobulin (antibody) produced in the colostrum is gamma globulin (IgG) and the foal must receive that within the first 24 hours of life. But if the foal is slow to nurse, the mare has poor quality colostrum or has streamed milk for days prior to foaling, or if the foal is unable to absorb those antibodies, you may have a foal that has failed passive transfer. In order to be proactive, rather than reactive, one can easily pull an IgG test. If you know that a foal is low or has failed passive transfer at 9 to 12 hours post foaling, you still have approximately a 12 hour window to address the problem orally with another mare’s colostrum that is known to be good quality, or with a commercial product such as Seramune. We will then test again at 24 hours to insure that we have sufficient immune coverage. If at 24 hours, the reading is still low or passive transfer has failed, one can then address the problem with a transfusion.
There are several stall side tests available that cost as low as about $10. They can be purchased singly or in kits of 10 – obviously the more you buy, the lower the cost. Two of the most common are the Idexx Snap test and the Immuno-Chek G. The tests come with complete instructions, so I’m not going to go into detail on the entire process. But, both do require being able to pull blood a small amount of blood from the foal and is where many become a bit uncomfortable – attaining that sample of blood. Our goal here is to show you just how easy it really is to do! Indeed, I often end up doing it by myself – so the photos that accompany this Blog will show me doing exactly that!
The first thing is to either catch the foal when it is lying down as in the photo below, or you will have to lay the foal down. You "can" pull blood with the foal standing, but we have just found it much easier to do with the foal lying down and definitely easier to do if you are having to do this procedure by yourself!