The Fell pony immunodeficiency syndrome also occurs in the Netherlands: a review and six cases.

The abstract discusses a fatal syndrome in young Fell pony foals, related to immunodeficiency and severe anaemia, initially observed exclusively in the UK but now detected in the Netherlands as well.

Research Background

• The study focusses on a syndrome affecting young Fell pony foals. This syndrome, identified over the past decade, results in severe anaemia and immunodeficiency.
• Foals born with this condition appear normal at birth but show signs of deteriorating health between the ages of 2-4 weeks. The affected foals progressively lose their physical condition and become severely anaemic. Signs of immunodeficiency, a weakened state of the body’s immune system, are noticeable around 3-4 weeks old.
• It is important to note that the disease has a low occurrence rate (morbidity) but is always fatal (100% mortality rate), even with extensive treatment measures.
• Typically, affected foals do not live past the age of 3 months and are often euthanized to prevent suffering.

Understanding the Syndrome’s Genetics

• Researchers believe a single autosomal recessive gene is at the root of this syndrome. An autosomal recessive gene means both parents must carry and pass on the defective gene for the offspring to develop the condition. When an offspring receives the defective gene from each parent, they suffer from the syndrome, while the parents remain carriers without showing any signs of the disease.

Spread of the Syndrome

• Initially, this fatal condition afflicted foals in the UK exclusively. However, recent cases of the syndrome have been seen in the Netherlands, indicating that the disease is now spreading.
• Between June 2003 and August 2005, the Faculty of Veterinary Medicine in the Netherlands received six cases of Fell pony foals suffering from this fatal syndrome.