Consists of testing blood samples for 7 blood group
and 10 biochemical marker systems. Uses of blood typing
- parentage verification
- paternity testing
- identification of individual horses in drug testing
cases or cases where horses with similar color and markings
may have been switched.
Traditional blood typing is used by the majority of breed
organizations. Blood typing consists of testing genetic
differences for nearly 40 different factors, including
red cell antigens and serum proteins. The sample
required consists of two tubes of blood - one collected
in anticoagulant, and one serum tube.
Red Cell Typing
Unlike the relatively simple human ABO system, the
horse has 7 systems, each of which contain a number
of specific “factors”. Because
of the variety of possible combinations, red cell
typing is very informative for parentage determination. For
each “factor” or red cell antigen that
we test for, we must develop our own specific “reagent” or
antibody to detect that factor. Our panel of
reagents is screened exhaustively for specificity
and reliability in our tests.
Both serum proteins and red cell proteins are tested
for variation (polymorphisms) by several gel electrophoretic
techniques. Ten different systems are tested
with these methods, and when combined with the results
of the red cell laboratory, provide a profile of an
individual horse that can be compared to the blood types
of its sire and dam. When there are no discrepancies
between the factors possessed by the sire, dam and
foal, we say that the “Parentage Qualifies”.
Important Notice about Blood Typing:
The UKAGTRL no longer offers regular full blood typing services. Red cell typing will only be performed during April and November. All red cell typing samples should be scheduled to arrive during either of those months, including those for blood donor horses.
Testing for biochemical markers (red top tubes) will also only be performed in April and November.
We will continue to offer serum screening for NI testing on an as-needed basis. Red cell typing of mares should be scheduled during April or November.
Please contact Dr. Kathryn Graves at firstname.lastname@example.org with any questions regarding blood typing.
BLOOD TYPING FOR TWHBEA HORSES
As of December 31 2012, the TWHBEA no longer provides contract pricing or kits for blood typing. BEFORE PROCEEDING PLEASE CONTACT THE TWHBEA to determine what is needed for your horse. If you must have a horse blood typed for parentage the lab recommends samples be mailed between April 1 to April 15, and November 1 to November 15. Requests for blood typing must be prepaid and submitted with the appropriate form.
You must submit a 10 ml draw red top tube AND purple top tube for each sample. DO NOT USE SERUM SEPARATOR tubes. If you prefer, the University has a limited supply of tubes available and can provide tubes and a mailer. The cost is $15.00 and must be prepaid and requested by sending a completed kit request form.
Requests for Red Top Tube conversions will also be processed only in April and November. Any vet will be able to supply a red top tube. Use the TWHBEA blood typing submission form (updated 9/14).
Payment may be made by MC/VISA or check payable to THE UNIVERSITY OF KENTUCKY. Results will be reported to TWHBEA. You will NOT receive results directly.
submission form -updated 1/30/15
TWHBEA submission form -updated 9/14
Instructions for Collecting Blood Samples
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Disease Prevention (Neonatal Isoerythrolysis, NI)
Hemolytic disease of the newborn, also known as neonatal
isoerythrolysis (NI), is a serious problem
in newborn foals whose red cell type is incompatible
with their dams’. A foal which inherits
a red cell factor from its sire that the dam does not
possess, is at risk for this condition which results
in the destruction of the foal’s red cells after
the foal is born and nurses the mare’s colostrum. There
is no in utero effect, since the antibodies
against the foal’s red cells cannot cross the
placenta. However, the colostrum is rich in antibodies,
and in mares that are sensitized to a red cell factor,
the colostrum can be deadly instead of protective. The
Blood Typing lab offers a serum screening service for
mares with a history of NI. A serum sample is
submitted within 30 days prior to the mare’s
due date. If antibody levels to one of several “high
risk” factors are elevated, it is essential to
prevent the foal from nursing its dam's colostrum,
and provide it with a substitute colostrum. In
addition, mares with a known history of NI can be crossmatched
to a stallion that does not have the red cell factor
to which the mare has become sensitized. That way,
the foal cannot inherit the factor from the sire, and
will not be susceptible to the mare’s antibodies.
Our NI testing program can prevent this problem by:
- crossmatching stallion and mare blood types or
- testing serum from the mare 30 or less days before
Testing submission form -updated 9/30/14
Instructions for Collecting Blood Samples
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DNA testing is available to generate DNA types and
perform parentage testing. We use a panel of 13 microsatellite
markers for standard testing. DNA can be extracted from
hair, blood or any tissue. DNA types and Blood types are
NOT interchangeable. We cannot perform a parentage analysis
on a foal that has been DNA typed but whose parents have
been blood typed. However, DNA types can be generated
from stored serum samples of horses that were previously
Testing submission form -updated 9/30/13
Instructions for Collecting DNA Samples
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Prediction of color can be important to breeders. We
offer 8 tests:
The A locus can be thought of as the gene that determines
if a horse is bay or black, although other genes come
into play. A horse that has at least one dominant "A" allele
will be bay if it also possesses at least one "E" allele.
A horse that is homozygous recessive for "a",
that is "aa", will be black if it also possesses
a "E" allele. All black horses are "EE
or Ee and aa". WHY TEST- If a horse is homozygous
for "e", it will have a sorrel or chestnut
base coat regardless of what genes it carries at the
A locus. Thus a chestnut horse may be able to produce
blacks if it carries an "a" allele and is bred
to another horse carrying the "a" allele and
a "E". If a person has a black horse and wants
to know if a breeding to a chestnut horse will produce
a black, the black horse needs to tested for the E locus
and the chestnut horse needs to be tested for the A locus.
A black horse that tests homozygous for "a" must
also be homozygous for "E" to produce 100%
We now offer the test for the mutation responsible for the Champagne factor in horses. The mutation was discovered here at the University of Kentucky. The Champagne gene is a dilution gene often confused with the Cream dilution gene. Unlike horses carrying a single Cream gene, Champagne horses have pink skin which becomes mottled in exposed areas such as the muzzle. Also Champagne foals are born with blue eyes that later darken to hazel or brown. A true black horse can mask the presence of the Cream gene, but a black horse carrying the Champagne gene is generally a chocolate color. There is no added effect if a horse carries two copies of the Champagne gene, whereas the homozygotes for the Cream gene create a more dilute horse with pink skin (cremellos and perlinos). Therefore the ability to test for the Champagne gene can distinguish homozygotes from heterozygotes, as well as more clearly determine the genotype of dilute pigmented horses.
The cream gene, designated Cr, is a dominant dilution
gene that causes a reduction in red pigment in the body
hair and mane and tail hair. It acts on any base color-
therefore a sorrel horse that inherits one copy of the
Cr allele is palomino (ee, Cr/cr), a sorrel that inherits
a Cr from each parent is Cr/Cr and is a cremello (ee,
Cr/Cr). A bay horse that inherits a Cr allele from one
parent is a buckskin (E/-, Cr/cr), while one that is
homozygous for Cr is a perlino (ee, Cr/Cr). True black
horses can mask the presence of the Cr gene, so it is
possible for a black horse to produce palominos or buckskins.
Cream is a different gene than Dun, which is also a dilution
gene. In general, dun horses have a dorsal stripe. WHY
TEST- Owners of a black horse with a palomino or buckskin
parent may want to determine if the horse carries an
unexpressed Cr allele. Horses carrying the champagne
gene may be confused with horses carrying the Cr gene-this
test will verify if the horses indeed possess the Cr
allele. It will also determine if a dun or gray horse
may also possess a Cr allele.
E locus (red gene)
The Extension locus is another gene related to color,
and determines whether a horse has black “points” as
in the bay coat color pattern (the mane, tail, legs
and tips of the ears are black). The allele responsible
for this pattern is designated as E, the capital letter
indicating it is dominant. The alternative
allele, e, is recessive, and when a horse has two copies
of this allele, as in ee, the horse lacks black pigment
in the extremities, as in chestnut horses. For
owners of a bay or black horse that want to know if
that horse is homozygous for the Extension locus, and
thus will always have offspring with black points,
a DNA-based test is available.
We now offer the test for the mutation causing the gray phenotype. Gray is caused by a dominant mutation, therefore a gray horse has at least one copy of the gray gene. Gray causes a horse to progressively lighten as it ages, regardless of other color genes the horse possesses. The ultimate effect is that the horse will become totally white or flea-bitten gray. The skin remains black unless the horse has other genes that result in pink skin. The test is useful to determine if a horse with two gray parents is homozygous for the mutation, or if a horse has such a dilute phenotype that it is difficult to determine if it also has the gray mutation.
Sabino is a Paint color pattern that is variably expressed
and can range from white stockings and a blaze to white
leg and face markings and extensive white spreading
up from the belly into the body area. The mutation
we detect is indicative of the Sabino1 gene. Homozygous
sabinos may have more extensive white than heterozygous
horses. There is more than one sabino gene so that
a horse that appears to have the sabino pattern may
test negative for the Sabino1 gene. So far all horses
that test positive for Sabino1 have the sabino pattern.
Silver Dapple (Z)
The Silver Dapple mutation results in a chocolate colored horse that has a lighter mane and tail. It is most commonly found in pony breeds and gaited horse breeds such as the Rocky Mountain Horse. The mutation requires the presence of at least one E allele to be expressed. Therefore genetically black or bay horses alone express it if they carry one or two Z alleles. A chestnut horse (ee) may carry a Z allele, but there is no effect on color. It is thought that horses homozygous for the Z allele have a whiter mane and tail than the heterozygotes.
The lab offers testing to determine homozygosity for
the Tobiano (spotted) gene. Since the tobiano color
pattern is valued and is dominant, horses that possess
two copies of the gene (homozygous) are of special
value to breeders, as ALL their offspring will inherit
the tobiano color pattern. We no longer perform the
serum protein test based on blood types due to its low
reliability. Instead, the University of Kentucky Animal Genetic Testing Lab is proud to offer the most reliable test for the Tobiano spotting pattern yet developed. Dr. Samantha Brooks of the University of Kentucky discovered an inversion on chromosome 3 that appears to be 100% concordant with the presence of the tobiano pattern. This test replaces the former double marker test previously offered. Please be advised that Tobiano testing reports will reflect this change.
Color Testing submission form and Sample Collection -updated 4/13
to Color Gene Testing
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Disease Mutation Testing
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We offer 4 tests: Junctional Epidermolysis Bullosa (JEB); Overo Lethal White Syndrome (OLWS); Myotonia; Dwarfism.
Junctional Epidermolysis Bullosa (JEB)
JEB is a condition found in American Saddlebreds and certain other light breeds of horses. It results in a lethal skin condition in affected foals. The foals must inherit the mutation from both parents. A test to identify carriers is now available. The mutation was discovered at the University of Kentucky Animal Genetic Testing Lab with support from the American Saddlebred Horse Association. The mutation for the Saddlebred form of JEB is different than that for the Belgian Horse JEB. We offer only the Saddlebred JEB test. Carriers can be safely bred as long as they are not bred to another carrier. Cost: $50 from blood or hair samples.
JEB affected foal.
Photo courtesy of the American Saddlebred Horse Association.
Overo Lethal White Syndrome (OLWS)
This is so named because affected foals are all white or near white at birth and have improperly formed rectal tissue resulting in death or requiring euthanasia at a few days of age. It is caused by a mutation that in the heterozygous form results in a frame overo pattern. Therefore the color pattern is very desirable for Paint or Pinto horse breeders. There are no health effects for carriers. However if two carriers are bred 25% of the foals on average will be homozygous for the mutation and will be affected. Although most common in Paint horses and Quarter horses, the mutation has been found in Tennessee Walking Horses as well.
An inherited neuromuscular disorder has been identified in New Forest ponies (Wijnberg ID et al., 2011) which is caused by an autosomal recessive mutation in the CLCN1 gene. Carriers of the mutation appear normal, but when two carriers are mated there is a 25% chance that an affected foal will be produced. Affected foals have abnormal muscle activity and spend more time than usual laying down and also exhibit gait abnormalities. In cooperation with Dr. Cord Drögemüller in Switzerland, the University of Kentucky Animal Genetic Testing Lab is offering this test. Please see the submission form for instructions on submitting a sample.
Disease Mutation submission form and Sample Collection -updated 4/4/13
ACAN Dwarfism Mutations in the Miniature Horse
Four mutations in the ACAN gene have been found in Miniature Horses associated with a dwarf phenotype by John Eberth, MS, working in the lab of Dr. Ernie Bailey here at the University of Kentucky. It is important to test breeding stock for these mutations because at least one of these mutations is lethal in combination with any of the other mutations causing early pregnancy loss. Care must also be taken in breeding two horses together that are carriers for Dwarf mutations, as the presence of two mutations in any combination will lead to early abortion or live foals with a range of physical ailments associated with the dwarf phenotype. Some of these physical ailments seriously affect the health of the horse and include breathing problems, malformed mouths which lead to eating difficulties, and abnormal bone growth leading to chronic soundness issues.
Horses carrying only one of the mutations are normal in appearance, exhibiting the desired stature and proportions the Miniature Horse should possess. There are four identified mutations, designated D1, D2, D3 and D4. The normal copy of the gene is designated as N.
The following table summarizes the effects of the various mutation combinations:
|Examples of Normal Phenotypes
|Examples of Dwarf Phenotypes
||D1/D1 Dwarf (aborted)
The genotypes D3/D3 and D4/D4 have unknown effects, as no samples with these genotypes have been found so far.
D1 and D2 were the most common mutations found in the pilot study. Since D1 is lethal in combination with any of the other mutations, it is recommended that D1 carriers (N/D1) only be bred to horses that do not carry any other Dwarf mutation.
Testing: Hair samples may be used for the DNA test for these mutations. Please see Hair Sample collection instructions on the submission form. Make sure there are plenty of hairs with bulbs submitted if more than one test is requested. Fees: Full panel of all four mutation tests: $150; any test individually: $40 each.
Dwarfism Mutation submission form and Sample Collection - 1/30/15
Canine DNA genotyping and parentage testing is available
using the new ISAG (International Society for Animal
Genetics) panel of microsatellite markers. Samples
may be submitted as blood or cheek swabs. Testing
is for $40 per dog. Discounts are available for litter
typing and additional sire testing. Please contact
Dr. Graves at 859-218-1193 or email@example.com.
Canine DNA submission form -updated 4/20/13
Instructions for Collecting Cheek Swab Samples
Boston Terriers - the dog on the left has early onset juvenile cataracts.
Hereditary Juvenile Cataract Mutation
The University of Kentucky Animal Genetic Testing and Research Lab is now officially licensed by the Animal Health Trust to offer testing for the HSF4 gene mutation.
The cost of the test is $45.
To request a kit of buccal brushes and a submission form, please contact
Dr. Graves: firstname.lastname@example.org.
Guide to Juvenile Cataracts in Dogs and the HSF4 Test
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