Foal immunodeficiency syndrome

Veterinary advice should be sought before applying any treatment or vaccine.

Foal Immunodeficiency Syndrome

Fell Pony Syndrome

Foal immunodeficiency syndrome (FIS), formally known as fell pony syndrome, is a fatal autosomal recessive disease that affects young foals. Foals with FIS appear normal at birth, but soon develop a profound anemia which causes them to start to weaken 2 to 8 weeks later. The anemia is caused by the complete absence of B lymphocytes in the circulation or tissues which has an affect on their ability to produce their own antibodies.

The first reported case of FIS was in a Fell Pony in 1996. In 2009, a confirmed case of FIS was seen in a Dales pony foal. A mutation associated with FIS in both the Fell and Dales Pony breeds was identified in 2011. Other at risk breeds of FIS are the Clydesdale, Highland Pony, Exmoor Pony, Welsh Pony, and colored horses and ponies.

Symptoms

Weight loss
Lethargy
Failure to suck
Pale mucous membranes
Nasal discharge
Watery diarrhoea
Coughing
Rapid heart rate

Diagnosis

  • History
  • Clinical signs
  • Physical exam
  • Genetic test

Support

Therapies

Supportive therapy, however the syndrome is ultimately fatal to the foal.

Prognosis

Poor, there is usually 100% mortality by the time the foal is 3 months old.

Scientific Research

General Overviews

Age Range

Young foals 3-4 weeks of age of the Fell Pony breed