Diarrhea is one of the leading contributors of neonatal death in both humans and animals. Of the many pathogens that can cause diarrhea, rotavirus is the most important single cause of neonatal diarrhea, worldwide.
To that end, equine rotavirus commonly leads to diarrhea in foals less than six months of age. Transmitted through fecal-oral contamination, foals often become infected with the virus when they lick contaminated surfaces.
A large number of rotavirus particles are shed in fecal matter, but only a small number of particles are needed to cause infection. Once the foal has contracted rotavirus, damage to the lining of the intestines occurs, which inhibits digestion and absorption of food.
Until recently, this illness was caused solely by rotavirus group A (RVA), mainly affecting foals around six months of age. With RVA, fatalities occur mostly in foals less than three months of age. However, in 2021, a novel equine rotavirus B pathogen was detected in farm outbreaks in Kentucky, posing an even bigger challenge to farm owners and veterinarians. This strain affects foals as young as 2-5 days old, causing diarrhea and dehydration.
Veterinarians have found that it is especially prevalent in February and March and, as one might expect, these younger foals are often more severely affected than older foals.
Infected foals may shed the virus in their feces for up to ten days, and horses without symptoms may shed the virus for up to eight months! This is what makes rotavirus in horses highly infectious, often leading to farm-wide outbreaks.
Interestingly enough, most adult horses have rotavirus antibodies, indicating a previous exposure or infection.
Symptoms of Rotavirus in Foals
The main symptoms of rotavirus in foals include:
- Watery diarrhea;
- Reluctance or failure to nurse (anorexia);
- Abdominal distension due to gut inflammation; and
- Colic due to gut stasis.
Rotavirus damages villi, the fingerlike projections of epithelial cells in the horse’s small intestine that aid in digestion and absorption of nutrients. This damage reduces the foal’s ability to digest milk and also creates conditions in the gut that allow pathogenic bacteria to flourish, which may lead to other health problems.
The foal can become rapidly dehydrated as they lose fluids and electrolytes through diarrhea and lack of nursing. Electrolyte imbalances that occur as a result can be fatal.
Common complications that can occur with rotavirus include gastric reflux, gastric ulcers, pyloric stenosis (swelling of the muscle between the stomach and intestines), duodenal stenosis (narrowing in part of the small intestine), as well as stomach rupture, which is fatal.
In older foals, aged 75-120 days, diarrhea tends to be the only symptom and it is usually mild and self-limiting, requiring minimal veterinary intervention. Adult horses are not adversely affected by rotavirus.
Diagnosing and Treating Foal Rotavirus
Rotavirus is diagnosed by identifying the virus through enzyme linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction (RT-PCR) assays.
With that said, once it has been detected on a farm, all foals with symptoms should be treated as if they have the disease.
The good news is that early detection and treatment of rotavirus can often lead to a quick recovery in the affected foal. However, because the disease is so contagious, preventing spread to other horses on a farm can present quite a challenge.
Primary treatment of rotavirus focuses on supportive care and intravenous fluid therapy to rehydrate the foal. Other treatments may include gastrointestinal protectants and probiotics. Extremely young foals may be placed on prophylactic antibiotics to help prevent gut bacteria moving through the compromised gut wall and infecting a joint (septic arthritis).
While antibiotics don’t necessarily shorten the duration of the illness, they can help with gastrointestinal inflammation and reduce translocation of bacteria that may result in septic arthritis and other bacteria that might adversely affect a compromised foal.
How to Prevent Rotavirus in Foals
Prevention, both on an individual and farm-wide basis, is the best strategy with equine rotavirus. If an outbreak has already begun, sick foals should be separated from other foals on the farm and staff that handle infected foals should maintain strict biosecurity protocols. Because the virus can persist in the environment for months, manure from infected horses should not be spread on pastures.
Pregnant mares can be vaccinated to increase their foal’s antibodies to the virus; however, there is currently only a vaccine for rotavirus A and it should also be noted that, even in vaccinated mares, there is still a chance that the foal can become infected.
IgY Antibodies and Equine Rotavirus
In the early 1990s, researchers proposed that immunoglobulin Y (IgY) from chicken egg yolk antibodies could be given orally to provide specific treatment for rotavirus diarrhea in both children and animals.
Since that time, a number of studies have been performed and results have shown that IgY significantly reduces the severity of diarrhea in treated subjects when compared to a control or placebo group. Researchers have also concluded that oral IgY is safe to give to neonates.
Many researchers have also recognized the advantages of chicken egg yolk IgY when compared to antibiotics, vaccines, and oral immunotherapy.
As opposed to pharmacological drugs, IgY has a number of benefits, including that it:
- Has no toxic tissue residues;
- Avoids environmental contamination that can occur with synthetic chemical drugs;
- Does not induce pathogenic microorganism resistance;
- Is highly specific in its reactivity and controls only targeted pathogens without affecting normal bacterial flora;
- Has a potentially broad spectrum of uses against various viruses, bacteria , and fungi; and
- Does not cause adverse side effects like synthetic drugs can.
Fullbucket’s Foal Kick Start Paste, which contains these life-saving IgY antibodies, is a highly concentrated product designed to get newborn foals off to a healthy start.
The antibodies in this product help protect foals against Rotavirus, Salmonella, E. Coli, Clostridium, Coronavirus and Lawsonia. With additional essential vitamins, Foal Kick Start is designed to boost gut and immune function during those first 24 critical hours of life.
Most importantly, Foal Kick Start Paste can aid in the prevention of equine rotavirus. It can also be used as treatment in conjunction with other therapies.
Don’t wait! Foal Kick Start is ideally used in the first 24 hours of a newborn foal’s life.
Order yours today to protect your vulnerable newborn and give them the best start possible.
Chicken Egg Yolk Antibodies (IgY) for Treatment of Rotavirus
Photo by Nick Fewings on Unsplash