Tobiano coat pattern

DNA test The DNA test verifies the presence of the chromosomal inversion. The Tobiano coat pattern usually involves some white...

€35.00

Sample Requirements

30 to 40 - hair roots - envelope or 5 mL - blood - K3 EDTA tube

Send your sample by regular mail or express delivery to:

Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal

Turnaround Time

2 to 5 working days

About the test

This DNA test detects the Tobiano (TO) chromosomal inversion, the dominant genetic variant responsible for the Tobiano white spotting pattern in horses. The test determines whether a horse is negative, heterozygous or homozygous for the Tobiano allele, providing valuable information for coat colour prediction and breeding decisions.

Why test?

Testing is recommended to:

Determine the horse's Tobiano genotype.
Identify heterozygous (TO/N) and homozygous (TO/TO) Tobiano horses.
Predict the likelihood of producing Tobiano offspring.
Support selective breeding programmes.
Combine with base coat colour testing (Extension and Agouti) for more accurate prediction of offspring coat colours.

How it works

🛒 Purchase the Test: Select and buy the test online.

📧 Receive Instructions: After payment confirmation, receive instructions for sample collection.

✨ Sample Collection: Your veterinarian collects hair roots or a blood sample.

📄 Download Submission Form: Download the printable submission form.

📮 Send Samples: Send your samples by regular mail or express delivery to:

Equigerminal Lab HIESE
Rua da Quinta do Sobreiro Nº25
3230-343 Penela, Portugal

📄 Receive Results: Get your result certificate by email.

Results

The DNA test verifies the presence of the chromosomal inversion and presents results as one of the following:

N/ – Non-tobiano horse.
To/N – Positive for the dominant Tobiano gene mutation, carrier of a single inherited copy of Tobiano. Horse’s base color may be modified to varying degrees by the Tobiano markings.
To/ – Positive for dominant Tobiano gene mutation, carrying two inherited copies of Tobiano. Will always pass Tobiano to foals. For breeding purposes, homozygous Tobiano horses are highly desirable as they are guaranteed to produce Tobiano foals regardless of their mate.

Additional information

The Tobiano pattern is characterised by smooth-edged white patches that typically cross the horse's topline, with white markings commonly present on all four legs. The head usually retains the base coat colour and is minimally affected by the Tobiano gene.

The Tobiano pattern results from a chromosomal inversion involving the KIT gene. While some homozygous Tobiano horses may show visual indicators such as "paw prints" or "ink spots," genetic testing is the only reliable method to confirm homozygosity.

FAQs

Which horses should be tested?

Any horse displaying a Tobiano coat pattern or intended for breeding where coat colour inheritance is important.

Does this test determine the horse's base coat colour?

No. The Tobiano test only identifies the Tobiano spotting pattern. Base coat colour should be determined using tests such as the Extension and Agouti DNA tests.

Why are homozygous Tobiano horses valuable for breeding?

Because TO/TO horses pass the Tobiano allele to 100% of their offspring, guaranteeing that every foal will inherit the Tobiano pattern.

Which samples are accepted?

The test can be performed using 30–40 hair roots or 5 mL of blood collected in a K3 EDTA tube.

When will I receive my results?

Results are available within 2 to 5 working days after sample arrival at the laboratory.