As a highly contagious disease, the equine rotavirus is thought to infect around fifty per cent of foals if and when the disease is present in their area. Unlike the canine rotavirus which can be transmitted to humans, the equine rotavirus is species specific and known to only really affect young foals. Currently, death is rarely an occurrence following infection from this disease with the exception of very severe cases. Upon entering the digestive system, the rotavirus replicates and thus damages the lining of the intestines. It is young foals under the age of six months that are more susceptible to contracting the equine rotavirus especially if the mother has not been vaccinated.
Equine rotavirus is generally transmitted orally by ingesting infected faeces. Symptoms include diarrhoea which results in dehydration and also depression. Fortunately, the equine rotavirus is not considered a zoonotic disease which means it does not affect humans. Mares should be vaccinated since vaccinating foals is dangerous due to their weaker immune systems.
Transmission occurs through direct contact with infected faeces. If the animal eats or simply licks the faeces then the rotavirus may be transmitted. An entire herd can become infected by the virus as a result of just one infected faeces. After infection, foals can shed the virus for as longs as ten days. Therefore infected foals should be kept away from other young horses. In order to prevent or reduce transmission as much as possible adequate hygiene is vital. Bleaches do not destroy the equine rotavirus although other strong disinfectants can be recommended by the owner’s vet.
The milder form of the disease presents itself with the foal having soft faeces. This usually occurs in this form if the foals are approximately two months of age. As it damages the intestinal lining, the equine rotavirus reduces the ability for the cells to absorb water and other materials. The disease can progress in this way so that the young foal experiences runny, water-like diarrhoea. This can result in dehydration and the foal will become depressed following infection of the equine rotavirus. Younger foals, before they are around two weeks old, are most severely affected. Extreme dehydration or an imbalance of important electrolytes can actually cause death although this is fairly uncommon.
Treatment and Prevention
There is no medical cure against the equine rotavirus and so only supportive therapy can be used as a form of treatment. IV fluids are replaced in cases where dehydration is present and occasionally probiotics are administered. Extra nutrition and electrolytes may also be administered intravenously or tubed into the stomach via the nose.
Vaccination of mares used for breeding is encouraged so their colostrum contains the relevant antibodies to prevent the spread of this the equine rotavirus in foals. This is because foals are unable to produce the correct antibodies in time to destroy the virus following their immune systems being stimulated by the vaccine, and so can still become ill after infection. During pregnancy the mares can be vaccinated every month following the initial one at eight months and the last being at ten months, thus decreasing the number of foals infected by the rotavirus. Additional, mares can be given annual booster vaccines.
Diagnosis and Prognosis
Diagnosis can be made from the symptoms although faecal matter can be tested for the virus. Foals are rarely fatally affected by the equine rotavirus although severe cases of dehydration and mal-absorption can lead to death.