Newborn Foal: Why the IgG Test Matters in the First Days
Short answer
The foal IgG test checks whether a newborn foal took in enough antibodies from its mother's first milk. It helps a vet spot a weak start early and decide what to watch.
By Pashupatinath Vet Lab Share
The foal IgG test checks whether a newborn foal has taken in enough antibodies from its mother's first milk. A foal is born with almost no protection of its own, so this blood test helps a vet spot a weak start early. Your vet chooses the right time to take the sample and reads the result with the foal's condition.
Why does a newborn foal need its mother's first milk?
A foal is born into a world full of germs, yet its body has very little defence ready. Unlike some animals, a mare cannot pass antibodies to her foal through the womb. Antibodies are small proteins that help the body recognise and fight germs. The foal must get them from colostrum, the thick first milk.
In the first hours of life the foal's gut can move these proteins straight into its blood. This ability does not last, and it fades as time passes. A foal that is slow to stand, slow to find the udder or too weak to suckle can miss the chance, even when the mare has plenty of milk. A mare that drips milk before foaling may also lose part of her colostrum.
What does the foal IgG test show?
IgG is the main antibody found in blood. The Foal IgG (Passive Transfer) Test measures how much IgG the foal has. Vets call the hand-over of antibodies from mare to foal "passive transfer". If the foal took in too little, the problem is called failure of passive transfer.
The report shows a reference range next to the result, and your vet reads the result against it. A low result does not mean the foal is sick today. It means the foal is more open to infection, so your vet may watch it closely, repeat the test or plan other steps. The sample is a small amount of blood taken by your vet.
Which foals are checked early?
Vets often think of this test when a foal:
- was slow to stand or to find the udder
- was born early, or looks small and weak
- has a mare with little milk, a mare that dripped milk before birth, or a mare that will not let it suckle
- has a damp navel, a swollen joint or a fever
- comes from a farm where earlier foals fell sick
A foal that is lying down, will not suckle or feels cold needs a vet at once. Do not wait for a lab result before calling.
Which other tests help a young foal?
A foal that looks unwell is often checked for inflammation. Equine Serum Amyloid A (SAA), called SAA, is a protein that rises in the blood when the body is inflamed, and it can rise quickly. In a foal it may help a vet judge whether an infection is starting, together with the physical examination.
A Complete Blood Count (CBC) counts red cells, white cells and platelets. Changes in the white cells may indicate that the body is fighting a germ. A newborn's normal values differ from an adult horse's, so your vet compares the numbers with what is expected for a very young foal.
Some stud owners prefer to book mare and foal checks together. The Mare & Foal Check Pack groups such checks into one visit. The exact list is confirmed when you book, and your vet can add or remove tests.
What can the IgG test not tell you?
The test shows the antibody level at the time of sampling. It does not show whether the foal already has an infection, and a foal with a good result can still fall ill for other reasons.
Only a registered veterinarian can read the result together with the birth history, the foal's suckling, its temperature and its behaviour, and then decide what to do next.
Read next
SAA is explained in more depth in Equine SAA: The Inflammation Marker in Horses, including what a raised result may and may not mean. If a young horse develops swollen glands under the jaw or a runny nose, Strangles in Horses: How the Lab Confirms It describes how that infection is confirmed.
Testing in Bhopal
For a foal in Bhopal, ask your vet to draw the blood, then call or WhatsApp +91 88175 01118 to arrange free collection from the stable. The lab is at C-200, C Sector, Shahpura, Bhopal, and it confirms the method, sample needs and reporting time when you book. A stud outside Bhopal can send the sample by courier or bus parcel through its vet.
This article is general information and does not replace a veterinarian’s advice. Please talk to a registered veterinarian about your animal’s signs, tests and treatment.