Canine Fucosidosis | Animal Genetics



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Canine Fucosidosis (Fc)


Canine Fucosidosis (Fc) is an autosomal recessive disorder found in English Springer Spaniels that affects the dog's ability to produce the enzyme alpha-fucosidase. This enzyme deficiency prohibits the normal breakdown and metabolism of complex polysaccharides from within the cells. Instead, these compounds build up in the cells and diminish the cell's ability to function properly. Accumulation of these compounds in the brain and nervous systems gives rise to the outward signs of the disease.


The disorder affects dogs between 18 months and 4 years of age. Clinically, the disease is characterised by a decrease in central nervous system functions. Signs can include loss of learned behavior, change in temperament, blindness, loss of balance, deafness and weight loss. From the onset of symptoms, the disease will progress quickly and is fatal.

Because fucosidosis is a recessive disorder, the dog must have two copies of the defective gene (one from each parent) to suffer from the disease. A dog that carries one copy of the mutation does not exhibit any symptoms. However, they can still pass on a copy of the mutation to any offspring. If two carrier dogs produce a litter of puppies, each pup has a 25% chance of being affected by Fucosidosis.

Acceptable Sample Types:

Animal Genetics accepts buccal swab, blood, and dewclaw samples for testing. Complimentary sample collection kits are available and can be ordered at Canine Test Now.

This Test Is Relevant For the Following Breeds:

  • English Springer Spaniel


Animal Genetics offers DNA testing for canine fucosidosis. The genetic test verifies the presence of the recessive fucosidosis mutation and presents results as one of the following:

Fc/Fc Affected The dog carries two copies of the mutant gene and is homozygous for fucosidosis. The dog is affected by canine fucosidosis and will always pass a copy of the mutation to its offspring.
n/Fc Carrier Both the normal and mutant copies of the gene detected. Dog is a carrier for the canine fucosidosis mutation and can pass on a copy of the defective gene to its offspring.
n/n Clear Dog tested negative for the fucosidosis mutation and will not pass on the defective gene to its offspring.