Diarrhea in Foals: Treatment and Control
By Siobhan McAuliffe, MVB, DACVIM, Foal Medicine Specialist
Part 3 in a 3-part series on diarrhea in foals
The cornerstones of therapy are maintaining hydration status and treating any underlying infections. Supportive care and adjunct therapies can also be useful.
Maintaining hydration status
In addition to the fluids and electrolytes that can be lost through diarrhea, many foals will decrease or stop nursing when they have diarrhea. The combination of decreased fluid intake and increased loss can rapidly lead to dehydration. Fluids and electrolytes can be replaced orally (using a nasogastric tube placed by the veterinarian) or by the use of intravenous fluids. Foals with severe diarrhea and dehydration may be difficult to treat at farm level and may require hospitalization.
Treating underlying infections
Viral infections have no specific treatment but in some cases antibiotics are administered to prevent bacteria moving through the wall of a compromised and inflamed bowel and gaining access to the blood stream This ‘bacterial translocation’ can make already sick foals even sicker.
Bacterial infections need specific antibiotic therapy. If you are in any doubt about the cause of your foal’s diarrhea a veterinarian should be called. The veterinarian can take samples of the foal’s feces for testing to determine the cause of the diarrhea and to determine if antibiotics are needed and, if so, what are the best antibiotics in each given case.
Foal heat diarrhea usually results in only mildly loose or slightly watery diarrhea. Foals with foal heat diarrhea rarely need treatment. However, sometimes they require oral or intravenous fluids to replace the fluids they have lost through the diarrhea.
It is important to make the foal feel as comfortable as possible and avoid any secondary problems. Loss of hair in the perineal area and irritation of the underlying skin is common in foals affected with diarrhea due to the constant contact with diarrhea. Cleaning the perineal area thoroughly, followed by careful drying and application of petroleum jelly two to three times a day, can prevent skin scald. This treatment prevents the diarrhea from contacting the foal’s skin and causing scalding.
There are many anti-diarrheal products on the market. Most of these are available ‘over the counter’, which means you do not need a prescription to buy them, although your veterinarian may advise you on what is best for your foal based on the suspected or confirmed cause of the diarrhea.
Pepto-Bismol™ can be given with the oral fluids (via nasogastric tube). Its bismuth subsalicylate has some antimicrobial effects and helps neutralize toxins and soothe the gut—reducing inflammation and secretions from the gut lining.
Bio-Sponge® is a di-tri-octahedral (DTO) smectite that binds to digestive mucus and adsorbs substances in the digestive tract such as endotoxins and exotoxins. Clostridia species produce such toxins, and the use of Bio-Sponge may be useful in these cases.
Neonorm™ Foal is a new, clinically-tested therapy for foal diarrhea. This botanically-derived product acts on the root cause of secretory diarrhea, electrolyte imbalance at the gut level. It is not a symptomatic absorbent, electrolyte or antibiotic. Neonorm Foal is available in paste form, acts locally in the gut, and is minimally absorbed systemically.
Control and prevention
The best prevention is cleanliness, good colostrum (making sure the foal gets adequate colostrum soon enough), and knowing whether or not you have problems on the farm and dealing with those. If a mare drips milk before foaling, she loses the important antibodies. Milk the mare and put the colostrum in the freezer to give to the foal with a bottle as soon as he’s born. A foal can also be given plasma in the first 48 hours if his IgG (one type of antibody) level is not high enough.
Biosecurity measures such as the use of gloves when handling and treating affected foals and the use of disinfectant footbaths on entering and leaving stalls can help curtail spread in outbreak situations.
Always avoid touching the umbilical area, don’t let your foal suck your fingers or clothes, and keep the stall very clean. When mares and foals are on pasture, it also helps to segregate them by age, rather than have young foals with older ones that might be shedding pathogens.
Any sick foal or adult should be isolated from others.
An equine rotavirus vaccine is available which is given to mares ahead of foaling to create antibodies in the colostrum. The mares receive three injections in late pregnancy to build peak immunity and strong antibodies in the colostrum.