The International Dilute Register

Dilutes Australia Ltd International dilute register for dilute horses and ponies living outside Australia

Registration and Membership Applications

The International Dilute Register has been established for the purpose of registering dilute horses and ponies residing outside Australia.  It is owned and maintained by Dilutes Australia Ltd, Australia's largest national dilute registry.  The register currently offers registration for all horses and ponies that carry a genetic coal colour dilution gene, irrespective of size, parentage, breed or type.  

The currently recognised equine coat colour dilution genes are:

Cream - denoted as Cr

Cream dilutes red pigment but has no effect on black pigment and in single copy produces the single cream dilutes - palomino, buckskin and smoky black.  

Palomino - cream on chestnut

Buckskin - cream on bay

Smoky Black - cream on black

Cream in double copy (CrCr) dilutes both black and red pigment in the skin and coat to create the double cream dilutes - cremello, perlino and smoky cream.

Cremello - double cream on chestnut

Perlino - double cream on bay

Dun - denoted as D

Dun is a primitive gene and although it is considered a dilution gene, dun is actually the original, or primitive, state of a gene called the TBX3 gene.  Therefore it is not, unlike the other genes, a mutation in and of itself.  Rather, all non-duns are caused by 2 mutations to this gene.

Red dun (chestnut dun)

Bay dun

Grulla (black dun)

Silver - denoted as Z

Silver dilutes black pigment but has no visible effect on red pigment.  There is no visible difference in colour between heterozygous silvers and homozygous silvers.

Chestnut carrying silver

Bay silver

Black silver

Champagne - denoted as Ch

Champagne dilutes all base colours and affects both skin and hair pigment.  There are subtle differences in tone between heterozygous and homozygous champagnes.

Gold - champagne on chestnut

Amber - champagne on bay

Classic - champagne on black
(photo courtesy of Susanne Hoffmann)

Pearl - denoted as Prl or Pr

Pearl is the newest dilution to have been discovered but has likely been around for a long time, mistaken for champagne or even double cream.  It is a mutation in the same gene as cream so it's impossible for a horse to be homozygous for cream and carry pearl OR be homozygous for pearl and carry cream.  One copy of pearl is not visible, 2 copies creates a champagne lookalike and one copy with a copy of cream creates a double cream lookalike.

Homozygous pearls

Double pearl on chestnut
(photo courtesy of Carolyn Shepherd, ICHR)

Double pearl on bay
(photo courtesy of Paco Marti, Spain)

Double pearl on black

Heterozygous pearls

Heterozygous pearl on chestnut
(photo courtesy of Carolyn Shepherd, ICHR)

Heterozygous pearl on bay
(photo courtesy of Smooth Running Peruvian Pasos, NZ)

Heterozygous pearl on black
(photo courtesy of Smooth Running Peruvian Pasos, NZ)

Pearl / cream composites

Pearl & cream on chestnut
(photo courtesy of Valle del Sol)

Pearl & cream on black
(photo courtesy of Smooth Running Peruvian Pasos, NZ)

IDR Non Solid Dilutes

The IDR also registers dilutes that carry coat pattern genes (tobiano, frame , Lp / PATN, splash, sabino and other white spotting genes as well as dilute roans.

Ownership requirements

The owners of all dilutes being registered in the IDR must be current financial members of the Company. Should an owner cease to be a financial member, the registration of all horses registered in his or her name will be suspended until such time as said owner rejoins the association, at which time the registration of all horses registered in his or her name will be reinstated

DNA requirements

All horses / ponies being presented for registration as dilutes with the IDR may be required to undergo DNA testing if it is determined by the registrar that there is not sufficient physical evidence of dilution.

Sufficient evidence includes any one or more of the following criteria:

  • proof of homozygous parentage for a partiuclar dilution gene
  • production of dilute progeny from non-dilute partners 
  • obvious dilute characteristics.

Standard of Excellence

All dilutes being considered for IDR registration shall meet the standards of conformation (breed characteristics being irrelevant) prescribed by the Board. To be considered for IDR Registration a dilute  must meet the required conformation standards prescribed by Board and be a genetic dilute. 

Palomino Click here to see photos illustrating the various shades.