Breeder Information (Germany): As of January 2018, the Connemara Pony Interessengemeinschaft e.V. (CP-IG) and the Connemarapony Vereinigung e.V. (CPV) require that all foals are tested for HWSD, or that both of their parents have already been tested normal. More information is available in the information flyers provided by each club (available only in German). Special order forms are available for members of the CPV or the CP-IG.

Hoof Wall Separation Disease (HWSD)

→ Separation of the Hoof and Hoofwall

Symptoms:

  • Unstabile, brittle hoofwall
  • Inflammation of the hooves
  • Hoof pain

Information:

  • The first symptoms are commonly noticed within the first year.
  • As the hoofwall separates from the hoof, the horse can become lame.
  • Although some affected horses have minimal symptoms, the worst cases can require euthanasia because of severe pain.

Inheritance: autosomal recessive

→ The pony is only affected when both copies of the gene (hwsd/hwsd) have the mutation.  Ponies with only one copy of the mutation (N/hwsd) are clinically normal carriers.

The possible genotypes are:
N/N                   The horse is normal, and cannot produce HWSD-affected offspring.

N/hwsd            The horse is a carrier of HWSD, and can pass the allele on to approximately 50% of any offspring. If bred to another N/hwsd carrier, approximately 25% of the offspring will be normal, 50% will be carriers, and 25% will be affected.

hwsd/hwsd     The horse is affected with HWSD. If bred to a normal animal, 100% of the offspring will be carriers. If bred to a N/hwsd carrier, 50% of the offspring will be carriers and 50% will be affected.

Recommendations:
– Carriers may be bred to normal animals (N/hwsd x N/N) without any risk of producing affected offspring. The offspring should also be tested before breeding to determine if they are carriers or normal.

– Breeding two carriers (N/hwsd x N/hwsd) is not recommended due to the possibility of 25% of the offspring being affected.

– Affected animals (hwsd/hwsd) may only be paired with non-carriers (N/N) following a critical review of the breeding value of the animal

Test Information: This mutation test identifies a single base pair insertion in the SERPINB11 gene.

Finno, C.J., Stevens, C., Young, A., Affolter, V., Joshi, N.A., Ramsay, S., Bannasch, D.L.: SERPINB11 Frameshift Variant Associated with Novel Hoof Specific Phenotype in Connemara Ponies. PLoS Genet 11:e1005122, 2015. Pubmed reference: 25875171. DOI: 10.1371/journal.pgen.1005122.

 

Further Information is available on the OMIA website: Online Mendelian Inheritance in Animals.

Affected Breed:
Test #: H116
Samples: Blood, Hair
Special price: 30 € (net)
Combo-Package (HWSD+Identity test): 50 € (net)
Time required: 5-7 days