skip to Main Content
+49 7071 565 44 850 Facebook



 → Accumulation of cerebrospinal fluid in a foal’s brain.

Instructions for ordering:

  1. Enter the information of the first horse for which you want to order the test
  2. Add to cart
  3. Go to cart to check out, or
  4. Enter the information for a second horse
  5. For sample collection follow the instructions here.
  6. You can use this template to send in hair samples.
  7. Please also send the completed order form together with the samples.

For a breeder or veterinarian discount please contact us before ordering.

Any information you include here is optional, but will be included on the certificate of results (except “Additional info”).

Enter the name of your animal
Enter your animal's date/year of birth
Enter the breed name
Enter the registration number if known
Enter the microchip number
Is there anything else you would like to tell us about your horse? Reason for testing, symptoms etc.?

General Information

  • Accumulated fluid exerts pressure on brain and skull.
  • Affected foals are usually stillborn.
  • Can lead to complications during birth → endangers mare.


  • Enlarged skull

Inheritance and Genotypes

→ Hydrocephalus is an autosomal recessive hereditary disease, meaning that horses with only one copy of the genetic variant (N/hcp) are clinically normal carriers while horses with two copies of the genetic variant (hcp/hcp) are affected.

Genotype: The horse is: Effects:
N/N normal. The horse does not have any copies of the genetic variant causative for Hydrocephalus and therefore cannot pass it on to any offspring.
N/hcp a carrier. The horse is clinically normal. The genetic variant causative for Hydrocephalus will be passed on to its offspring with a probability of 50%.
hcp/hcp affected. The horse is affected and will not live long enough to reproduce.


  • Carriers may be bred to normal animals (N/hcp 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/hcp x N/hcp) is not recommended due to the possibility of 25% of the offspring being affected.


Ducro, B.J., Schurink, A., Bastiaansen, J.W., Boegheim, I.J., van Steenbeek, F.G., Vos-Loohuis, M., Nijman, I.J., Monroe, G.R., Hellinga, I., Dibbits, B.W., Back, W., Leegwater, P.A.: A nonsense mutation in B3GALNT2 is concordant with hydrocephalus in Friesian horses. BMC Genomics 16:761, 2015. Pubmed reference: 26452345. DOI: 10.1186/s12864-015-1936-z.

Further information is available at Online Mendelian Inheritance in Animals.

Back To Top