Hoof Wall Separation Disease (HWSD)


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Hoof Wall Separation Disease (HWSD)


Hoof Wall Separation Disease or HWSD is a condition that has been identified in Connemara ponies and horses that have been crossed with Connemara ponies. HWSD is an autosomal recessive disorder that  causes the hoof wall to easily break and crack. All four feet will be affected by the disease. Damage can be seen in affected ponies as young 2-3 weeks of age. In rare cases some affected ponies develop less severe form of the disease. This is due to the fact that the mutation is not fully penetrant. In very few case the disease can be managed but in other case the ponies must be euthanized. Studies estimate that in the general population the percent of horses carrying a single copy of the disorder is around 15%.

Unfortunately, there is no cure of HWSD. As the condition worsens, the foal will begin to develop severe infections, as well as suffer from increasing pain and discomfort.

HWSD is an autosomal recessive trait, meaning a foal can only be affected if the foal inherits the disease from both parents. Parents that are carriers do not have any symptoms associated with HWSD. However, they will pass on a copy of the defective gene to their offspring 50% of the time. If breeding two carriers the foal has a 25% chance of being affected and a 50% chance of being a carrier.

Breeds Affected:

Testing for Hoof Wall Separation Disease (HWSD) is valid for Connemara Pony and horses that have been crossed with Connemara ponies.

Test Results:

Animal Genetics offers DNA testing for Connemara Pony. The genetic test verifies the presence of the recessive HWSD Gene and presents results as one of the following:

Hoof Wall Separation Disease (HWSD):

HD/HD Affected The horse carries two copies of the HWSD mutation and is homozygous for HWSD. The horse is affected with the HWSD genetic disorder associated with your breed.
n/HD Carrier Both the normal and mutant alleles were detected. Horse tested heterozygous for HWSD and is a carrier of the HWSD mutation associated with your breed.
n/n Clear Horse tested negative for HWSD and does not carry the HWSD gene mutation. The horse will not pass on the defective gene to its offspring.

    Submit a Sample for Testing:

    To submit a sample for testing please click on ORDER and download a sample submission form. Then follow the sample collection and submission instructions.


    Cost per sample is $45.00. Please see our Equine Fee Schedule for all equine testing rates.