How to Test for Dun Factor in Horses

The dun color gene in horses is a dominant gene, so it can't skip a generation. In order for a horse to test positive for the dun gene, one parent must also carry the gene. Dun is classified as a "dilute" gene, meaning it will dilute the base color of a horse. A sorrel or red horse carrying the dun gene would be a red dun. Instead of a vibrant red color, a red horse with the dun gene appears more of a peach color. As of 2010, the UC Davis School of Veterinary Medicine was the only facility offering the dun factor test.

Things You'll Need

Two color pictures labeled with your horse's name
Three-generation pedigree for your horse with colors and patterns listed
Hair sample with the root balls attached from at least one parent of your horse

Instructions

- 1
  Go online to vgl.ucdavis.edu and click on "Services."
- 2
  Click on the "Horse" icon.
- 3
  Scroll halfway down the page and click on the dun zygosity form icon.
- 4
  Log into your existing account or make a new account at the prompt.
- 5
  Fill in all requested information on the online submission form and then hit "Save."
- 6
  Enter your method of payment (either an online payment or check enclosed) and print the testing submission forms.
- 7
  Attach two color pictures (with the horse's name on the back of each picture) of the horse you are testing to the testing form.
- 8
  Attach to the sample form a three-generation pedigree, with all colors and patterns listed, for the horse being tested.
- 9
  Pull about 30 hairs (with the root ball attached) from your horse's sire or dam's mane or tail; immediately place the sample in a plastic zip lock bag.
- 10
  Attach the hair sample bag to the parent sample form with the parent horse's name clearly identified on the form.
- 11
  Mail all forms, hair sample bag, pedigree, pictures and payment to:
  
  Veterinary Genetics Laboratory
  
  One Shields Ave
  
  Davis, CA 95616-8744