* What is HYPP?
* ApHCC Genetic Disorders Bylaw
* ApHCC HYPP Policy & Procedure
* ApHCC Approved Laboratories for HYPP Testing
What is HYPP?
In 1986, veterinarian Jon Naylor (BVSc'75(Bristol), DiplACVIM'81
(Diplomate), PhD'84 (Pennsylvania), ACVN'88 (American College)) was one
of the researchers who discovered a new disease of Quarter horses,
Hyperkalemic Periodic Paralysis (HYPP). In 1992, Prof. Naylor and his
colleagues proved that the disease is a genetic condition and that all
known cases of HYPP have descended from one Quarter horse sire,
Impressive. At the University of California at the Davis School of
Veterinary Medicine, Dr. Sharon Spier was also researching HYPP. In
November of 1992, following a presentation at the Association of Equine
Practitioners meeting, Dr. Spier announced that in her research all
horse found with the disease were descendants of the Quarter Horse
In simple terms, Hyperkalemic Periodic Paralysis (HYPP) is a muscular
disease caused by a hereditary genetic defect which affects the muscle
cells' balance of sodium and potassium.
"Horses with HYPP can experience unpredictable attacks of paralysis
which, in severe cases, can lead to collapse and sudden death. The
cause of death usually is cardiac arrest and/or respiratory failure.
The disease is characterized by intermittent episodes of muscle tremors
manifested by generalized of localized shaking, trembling and weakness.
Occasionally, episodes are accompanied by respiratory noises resulting
from paralysis of the muscles of the upper airway (larynx and pharynx).
In cases of mild attacks, muscle tremors may be so subtle as to be
detectable only by an experience clinician performing EMG testing."
from Current Facts About Hyperkalemic Periodic Paralysis (HYPP)
Disease, Sharon J. Spier, DVM, PhD University of California at Davis
School of Veterinary Medicine, Department of Medicine.
For further information please contact:
University of Saskatchewan
University of California at Davis
ApHCC Genetic Disorders Bylaw
ApHCC BYLAWS, SECTION XI - UNACCEPTABLE BREEDING AND/OR CHARACTERISTICS
C. Genetic Disorders
1. Effective 01 January 2000, any horse applying for
identification or registration in the Register of Appaloosa Horses and
carrying a known and/or identified genetic disorder, including, but not
limited to, HYPP (Hyperkalemic Periodic Paralysis) and SCID (Severe
Combined Immunodeficiency), shall only be eligible for entry into the
Register of Appaloosa Horses upon receipt by the ApHCC of Application
for Pedigree Registration/Identification and veterinary verification
that the horse is a gelding or spayed mare.
2. Effective 01 January 2002,any horse applying for identification or registration in the Register of
Appaloosa Horses and carrying a known and/or identified genetic
disorder, including, but not limited to, HYPP (Hyperkalemic Periodic
Paralysis) and SCID (Severe Combined Immunodeficiency), shall be denied
identification or registration with the ApHCC.
3. Any ApHCC applicant or registered horse may
be required, at the sole discretion of the ApHCC, to undergo testing to
screen for any genetic disorder. Such testing will be performed by an
ApHCC Authorized Representative, at the owner's expense, and the
findings noted on the horse's certificate.
4. Failure of an owner to comply with a
request of the ApHCC for such testing will result in the rejection of
the Application for Pedigree Registration/Identification or withdrawing
of registration/identification status of the horse. Such non-compliance
may further be subject to review by the ApHCC Law Review Committee.
ApHCC HYPP Policy & Procedure
Hyperkalemic Periodic Paralysis (HYPP)
Bylaws, Section XI C. Genetic Disorders
A) HYPP Testing of Registered Horses
1. Any HYPP test results of a registered horse,
issued prior to 1 June 2000 will be accepted by the ApHCC
2. Any HYPP test results of a registered
horse, issued after 1 June 2000 will be accepted by the ApHCC if issued
by an ApHCC approved laboratory.
3. A "registered" horse as referred to in items A) 1. and 2. may be:
* An Appaloosa for which an ApHCC Certificate of Registration or Certificate of
Pedigree was issued prior to 1 January 1999
* An Appaloosa for which an ApHCC Certificate of Identification has been issued.
* All Appaloosa horses for which an ApHC (Moscow, Idaho) Certificate of Registration
has been issued and which horses do not have Arabian parents or unknown parents
* All Quarter Horses for which an American Quarter Horse Association Certificate of
Registration or Appendix Certificate or Canadian Quarter Horse
Certificate of Registration has been issued
* All Thoroughbred horses for which a Jockey Club, Kentucky, or Canadian
Thoroughbred Society Certificate of Registration has been issued.
B) HYPP Testing of Unregistered Horses
1. An unregistered horse may be HYPP tested prior
to application for pedigree registration with the ApHCC provided the
following procedures are followed:
* At this time, testing must be completed at the
University of Calgary, Animal Genetics Laboratory, Vita-Tech Canada, or
* Samples must be collected and submitted by a veterinarian who must identify the animal, label the
specimen, and sign the submission form.
* The veterinarian must use an Equine Infectious Anemia (EIA) Serum Test and Report form (Agriculture Form
for Coggins) completely filled in and signed by the veterinatian but
marked at the top: FOR HYPP (this reminds you that the sample was sent
for HYPP and not for EIA (University of Calgary Animal Genetics
Laboratory does not do Coggins tests)
* Two copies of the Equine Infectious Anemia submission form (FOR HYPP) shall accompany the specimen. One
copy will be returned with the lab report.
* Should the owner choose to apply for
ApHCC registration, the completed Application for Pedigree Registration
form, required photographs, registration fees, AND the copy of the HYPP
report including the copy of the EIA form returned from the lab shall
be submitted to the ApHCC.
ApHCC Approved Laboratories for HYPP Testing
* As of 24 May 2000, only the University
of Calgary Animal Genetics Laboratory, Vita-Tech Canada, and Maxxam Equitest have
been ApHCC approved for testing of unregistered horses. Research is
underway to determine if other laboratories performing HYPP testing
will utilize the Equine Infectious Anemia form (FOR HYPP) for
identification purposes when testing unregistered horses.
* As of 28 March 2000, the following laboratories have been ApHCC approved for HYPP testing of registered
o University of Calgary Animal Genetics Laboratory, Calgary, Alberta
o Maxxam Equitest, Guelph, Ontario
o Vita-Tech Canada, Markham, Ontario
o University of California, Davis, California
o Stormont Laboratories, Woodland, California
The horse's registration number must be included on the submission forms as well as the results of the HYPP test.