Fucosidosis is a metabolic disorder resulting from an inherited lack of the enzyme alpha-L-fucosidase, and is inherited as an autosomal recessive trait.

This disease affects English springer spaniels, and is more common in the UK and Australia, although it is still seen in North America and Europe as well.

Lack of this enzyme means that complex sugars and glycoproteins that have a terminal fucose sugar cannot be broken down, and these substances accumulate inside cells.

This accumulation is most important in the cells of the brain and in nerve cells, as it interferes with their normal function, and is what causes the clinical signs seen with this disease.

Clinical signs are normal seen in young adults, from 1 – 4 years of age.

The most commonly seen signs include incoordination, loss of balance, ataxia (wobbly gait), a loss of learned behaviour and a change in temperament, depression, and visual and/or hearing loss.

There may also be a difficulty in swallowing food, or regurgitation due to oesophageal dysfunction.

The condition is progressive over a number of months, and is eventually fatal.

The disease can be diagnosed by measuring alpha-L-fucosidase levels in the blood, however there is a DNA test available which allows for rapid diagnosis as well as screening of breeding animals to prevent affected animals being produced.

There is no cure for fucosidosis, and it cannot be treated successfully.