Foal Immunodeficiency Syndrome (FIS)

Fell Pony Syndrome, now known as Foal Immunodeficiency Syndrome as it can affect other breeds, is a fatal and untreatable condition which causes severe progressive anaemia and a deficient immune system, making foals particularly susceptible to infection. There has been some breakthrough news on the testing for this disease, which you can read more about here.

 What are the signs of Fell Pony Syndrome?

Fell Pony Syndrome is a disease that is passed when an uninfected horse comes into contact with infected material, be that directly from an infected horse or a handler/breeder who has come in contact with an infected horse. The disease in foals is fatal, but not through its own effects – instead it lowers the immunities of the affected foal so that infections can take a hold with less resistance, meaning a more dangerous effect overall, as the viruses can become stronger whilst incubated within the horse.

Because the immune system is weakened drastically, the disease can easily be mistaken for a variety of other things. As it only affects foals, you can be forgiven for believing your foal has endoparasites or some other form of minor infection when it begins to seem ill or act differently. At the first signs of any illness, you should seek the advice of a vet, even if you believe you have not come into contact with an infected subject. Once the horse begins to show muscle wastage, apathy and lethargy, the disease has progressed and unfortunately this means your pony does not have much time left.

Because of the untreatable manner of this disease, the only means to combat it are through prevention. You should keep your stables clear and clean from any material brought in from foreign bodies, such as any visitors that have had contact with other pony. You should also not go into your ponies’ vicinity if you have recently been in contact with a pony that was untested or had FIS. Through these safety measures you can avoid giving this disease to your foal before it is old enough to resist its effects by itself.

Secondly, breeders need to focus on how they can aid pony breeding stocks by avoiding any mating pairs that have a chance, or at least a higher than average chance of producing a foal with FIS. Now that a testing scheme is available here in the UK, breeders can ensure their stock is safe from passing on this disease. Both Fell and Dale ponies have depleted numbers around the world and here in the UK, so any means of protecting them should be taken.

If you’re at all concerned by your pony’s well-being, or have any fears about the health of your pony, do not hesitate to ask your vet for advice.