skip to Main Content
+49 7071 565 44 850 Facebook

→ Nonfunctional immune system causes anemia and early death in foals


  • Diarrhea
  • Cough
  • Problems suckling
  • Infections
  • Anemia

General Information:

  • Antibodies that are usually produced after birth cannot be build by the impaired immune system.
  • At the age of 3 – 6 weeks, when the foal stopps suckling, maternal antibodies decrease in foals body and infections occur.
  • Anemia usually causes early death or euthanasia of the affected foal.
  • Estimated 10% of Fell ponies and 1% of Dales ponies are affected by FIS (data from UK breed societies).

Inheritance: autosomal recessive

→ Only animals with two copies of the genetic variant (fis/fis) are affected. Animals with only one copy (N/fis) are clinically normal carriers.

Possible Genotypes:

Genotype: The horse is:
N/N normal. The pony has no copies of the genetic variant causative for FIS and therefore cannot pass it on to its offspring.
N/fis a carrier. The pony is clinically healthy. The genetic variant causative for FIS will be passed on to its offspring with a probability of 50%.
fis/fis affected. The pony is affected and will not live long enough to reproduce.



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

Testinformation: This test detects a single basepair change in exon 1 of the SLC5A3 gene.

Fox-Clipsham, LY., Carter, SD., Goodhead, I., Hall, N., Knottenbelt, DC., May, PD., Ollier, WE., Swinburne, JE.: Identification of a mutation associated with fatal foal immunodeficiency syndrome in the fell and dales pony. PLoS Genet 7:e1002133, 2011. Pubmed reference: 21750681. Doi: 10.1371/journal.pgen.1002133.

Further information is available at Online Mendelian Inheritance in Animals.

Breeds affected:

Test #: H112

Samples: Blood, Hair

Price: 35 € (net)

Time required: 10-14 days

Back To Top