Your new foal is struggling to his feet and instinctively wobbling toward mom. You watch in anxious interest as she licks and nudges to encourage him–while he noses at her front leg, her flank, her buttock, and finally, DINNER!

The mare’s first milk is crucial for the foal’s survival. Colostrum contains several important ingredients to give him a good start. It serves as a gut stimulant to help pass his first bowel movements, and it contains a creamy fat that’s high in energy and easily digested to give him the calories he needs for strength and maintenance of body heat. A foal that gets right up and nurses within a couple hours is more vigorous and less apt to chill during bad weather than a foal that hasn’t nursed.

Especially important to the future health of the foal are the antibodies in colostrum. Those antibodies have been produced by the mare and accumulated in the colostrum in order to give the foal’s immature immune system a boost and protect him from the “bad bugs” in his environment. But some foals do not get an adequate amount. This is called failure of passive transfer.

Bonnie Barr, VMD, Dipl. ACVIM, of Rood and Riddle Equine Hospital located in Lexington, Ky., says if a foal is a little premature, his digestive tract might not be developed enough to absorb antibodies.

“Another reason (for failure of passive transfer) could be lack of oxygen during birth, which compromises the intestinal tract as well as other organs,” says Barr.

Foals that are slow to get up due to birth complications, angular limb deformities, or any other problems, might need help to ensure timely ingestion of the all-important antibodies.

Antibody Absorption

Most horse owners know that foals need colostrum soon after birth. Antibodies in colostrum stimulate systemic immune response, explains John Madigan, DVM, MS, Dipl. ACVIM, professor in the Department of Medicine and Epidemiology at the University of California, Davis. “There are activated immune cells that transfer right across the intestinal tract and trigger rapid development of the foal’s immune response,” he says.

The foal is born immune-deficient and must acquire temporary protection from disease (passive immunity) via the immunoglobulin type G (IgG) in his dam’s colostrum. He has a very short window of time in which to obtain that passive immunity while the membrane lining of his intestine is thin and permeable to allow antibodies (which are very large molecules) to slip through.

“Years ago we thought we had 24 hours to get colostrum into a foal,” says Charles Briggs, DVM, of Beckwith Veterinary Clinic in Edmonton, Alberta, Canada. “Then we realized that as soon as foals are born, this window starts to close down. It’s best to get colostrum into the foal within the first hour. Then if it’s average-quality colostrum, you know the foal got all the antibodies, whereas if it’s average and the foal takes four hours before nursing, there are probably some immunoglobulins he didn’t get. His ability to absorb them lessens as time goes on.”

Checking IgG Levels

Madigan says the amount of IgG a foal has ingested can be quantified with an IgG test so you can determine if the foal has obtained adequate antibodies. Barr says there are many stall-side tests available that are not expensive.

“The consequence of not checking, then ending up with the foal not having enough colostrum, can be serious; you could lose the foal,” she says.

“There are ways to check the mare’s colostrum, also, but you need a colostrometer to test specific gravity of the colostrum,” notes Barr. “We also use a special refractometer to look at the concentration of proteins. But that equipment may cost $200. You can just look at the colostrum to see if it’s thick and yellow. If it looks more like milk (thin and watery), it probably isn’t very good. And if a mare has been leaking milk prior to foaling, the foal might not get adequate colostrum.

“Some people don’t understand that even though (they have confirmed) the mare has good colostrum, the foal may not have gotten enough for some reason, or was unable to absorb the antibodies,” continues Barr. “His IgG level is still not adequate.”

Briggs says many people feel that if a mare leaks milk before foaling, her colostrum won’t be any good, and that she’ll have lost the antibodies. “Mares can leak a lot of clear, white, watery fluid prior to foaling without a problem, however, because the actual colostrum (with antibodies) is formed just before foaling,” he says. “She isn’t losing antibodies if she’s leaking fluid a week or so before she foals. Mares with large teats may leak a lot even up to three weeks before they foal, but this isn’t a big problem because if you look closely at that milk, it’s clear and white rather than thick, sticky, and yellow (colostrum). But if a mare actually leaks colostrum, check the foal’s IgG blood levels after he nurses to make sure he did absorb an adequate amount for disease protection.”

Philip Johnson, BVSc, MS, Dipl. ACVIM, ECEIM, MRCVS, professor of equine medicine and surgery at the University of Missouri, says tests for IgG levels in the foal are not perfect. “Very few tests we do will give 100% accuracy,” he says. “I often suggest that if a newborn foal isn’t doing well and you think you may be dealing with disease due to insufficient antibodies via colostrum, you don’t have to make a decision (whether or not to do a plasma transfusion) based on the test result. You can go ahead and give plasma (if there’s any question) along with antibiotics, no matter what the test says. If the foal is valuable and the veterinarian thinks the transfusion is indicated, do it to cover your bases.”

Alternate Sources of Colostrum

The best source of antibodies is colostrum from the foal’s own dam, since she will have developed antibodies specific to pathogens in the environment into which the foal is born.

“If you don’t have any stored colostrum, try to locate a source before your mare foals in case you need some quickly,” advises Barr. “Here in Lexington, the Thoroughbred Farm Managers Club has stored colostrum (a colostrum bank with donations from various farms), and we also store some here at Rood and Riddle, as do some of the other equine hospitals.”

You might want to call around ahead of time, checking with any large breeding farms in your area to see if they will sell you some colostrum if you need it.

“There are oral commercial colostrum products available, but I don’t use those,” says Barr. “I think some of them work, but there’s no substitute for the real thing. Colostrum has other good proteins (besides antibodies) necessary for gastrointestinal health.”

Sometimes horse owners give an oral antibody product to a foal even if the mare has plenty of colostrum, but this might interfere with the foal getting antibodies from the mare, says Johnson. The permeability of the gut wall begins to change as soon as antibodies are absorbed in order to protect the animal against absorption of bacteria. If the first antibodies absorbed are from your commercial product, then the foal might not be able to absorb much from his dam’s colostrum.

“The foal ideally needs to get colostrum from his own dam,” says Johnson. “So using a commercial product should only be something to consider if a mare doesn’t have any colostrum. But in our experience here, the commercial products are not very good at getting antibody levels very high in foals. We see a fair number of foals come in with infections, even though they had a commercial product.”

Helping Mother Nature

Several years ago, Madigan began recommending hand-feeding of colostrum very soon after birth, even before the foal gets up. “This was based on evidence that foals, during the process of seeking the udder, can acquire bacteria that go into the intestinal tract and cross what we call the open gut,” he says.

“On a farm where we experienced a salmonella outbreak, we began this process of getting colostrum into foals before they nurse the mare, along with washing the mare down and having a clean udder before the foal nurses,” says Madigan. “After a mare passes her placenta, there’s a lot of contamination. Mares defecate in stage two labor. There’s bacteria on her and on the afterbirth. Having a clean udder for the foal to nurse is very important. Once the mare is cleaned up, we milk out two to eight ounces.

“While the foal is still lying there, starting tongue movement and sucking motions, we feed him with a bottle,” explains Madigan. “He may have tried to get up a time or two, but hasn’t gained his feet. We found that these foals take a bottle very readily before they stand up.”

Once they’ve actually tried to stand, they have too much mental focus on getting up and might not be as cooperative. But the suckle reflex is very strong right after birth and foals will readily suck a bottle that’s offered before they get up.

Madigan cautions horse owners to be careful in trying to feed a foal that doesn’t have strong willingness to suck. “Weak foals without a good suckle reflex should not be bottle fed,” he advises. “They may aspirate some of the milk (down the windpipe), setting the stage for pneumonia.”

Sucking a bottle does not confuse a foal or keep him from going ahead in his urge to find the udder.

“At that stage, they don’t know where that milk came from; it merely stimulates them to want to get up and find more,” says Madigan. “So this was part of our treatment (prevention) strategy to protect foals from early infection with salmonella, and it was very effective.”

When a foal is born, it’s a race between the pathogens and the antibodies. Feeding the foal colostrum before he starts licking the mare’s hind legs or the stall walls gets colostrum into the gut ahead of the bacteria. It stimulates systemic immunity quickly and also gives a local coating of the gut, providing antibodies to combat the pathogens ingested during udder seeking.

“It has been shown in experimental models in other species that absorption of antibodies from colostrum inhibits bacterial translocation,” says Madigan. “Colostrum provides a local antibody, IgA, which stays in the gut (besides the IgG molecules that are absorbed into the bloodstream). The IgA stays there to give protection. There is enough evidence in experimental literature to say that colostrum prevents and reduces bacterial translocation in foals.”

Briggs says he doesn’t think it is necessary to use a bottle and nipple.

“Since he may still be lying down, I just milk the mare and use a 10 cc syringe to put it into the side of the foal’s mouth after letting him suck my finger,” says Briggs. “If he’s lying down, I tilt him up so he’s not lying flat. A lamb nipple doesn’t always work well because it’s not very firm, and the milk may just dribble out the side of the mouth.

“With your finger, however, you can put a little pressure on the roof of the mouth and that tends to stimulate the foal to suck,” Briggs says. “You can use your finger to get more sucking action as you squirt the milk into the side of his mouth.”

Milking the mare as soon as she gets up, and feeding colostrum to the foal before he gets up, ties in nicely with imprinting, if you choose to do that.

Robert M. Miller, DVM, who first publically taught the technique of imprinting, says he now includes advice with his instructional videos that give directions on milking the mare and feeding the foal during the imprinting process, while the foal is still lying down. He also recommends using the new mare milking device (see sidebar on page 66) to make this task easier.

Take-Home Message

Foals need colostrum, and they need it as soon after birth as possible. Some veterinarians advocate milking the mare and feeding the colostrum to the foal even before the foal can stand and start rooting around for the udder. That milk-seeking process can cause the foal to ingest bacteria before the colostral antibodies have a chance to offer protection.

MILKING THE MARE

It’s easy to milk the foaling mare and give the foal two ounces (60 cc) or more of colostrum. “Then you’ve got your bases covered and the foal can take all the time he needs to get up and nurse on his own,” says Charles Briggs, DVM, of Beckwith Veterinary Clinic in Edmonton, Alberta. “You can get colostrum into him, give him an enema, and go back to bed!”
“After the mare foals, there are certain things you are doing such as making sure the foal is breathing and the navel stump is disinfected, but after the mare gets up it’s easy to milk her and get some colostrum into the foal,” he says.

Milking by hand can be a challenge, however, if you haven’t done it before. “A lot of people think a mare has teats like a cow, but this isn’t true,” says Briggs. Each teat draws milk from two quarters. If you are milking with your fingers, envision each teat as having a front half and back half. If you stroke your thumb against the rest of your fingers, you tend to get more milk. “I put my fingers behind the teat and use my thumb to pull down the milk from each of the cisterns. Mares’ udders are a little tender at this time; if you try to milk them the same way you would a cow, stripping the teat downward, this makes the teat sore and they get cranky. It’s better to put your hand firmly against the udder so the mare gets used to it being there, then gently start moving the milk out of the udder