Hoof Wall Separation Disease (HWSD)
→ Separation of the Hoof and Hoofwall
- Unstabile, brittle hoofwall
- Inflammation of the hooves
- Hoof pain
- 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.
|Genotype:||The horse is:||Effects:|
|N/N||normal.||The horse has no copies of the genetic variant causative for HWSD and therefore cannot pass it on to its offspring.|
|N/hwsd||a carrier.||The horse is clinically normal. The variant will be passed on to its offspring with a probability of 50%.|
|hwsd/hwsd||affected.||The variant will be passed on to its offspring with a probability of 100%. All offspring will be carriers (N/hwsd).|
- 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.