8 CCR 1201-19 Part 11 - Equine Viral Arteritis
11.1. Definitions
11.1.1. "Approved laboratory" means a
laboratory approved by the State Veterinarian to conduct official testing for
equine viral arteritis.
11.1.2.
"Book" or "booking" means the contracting or scheduling of a mare to be bred to
a stallion.
11.1.3. "Carrier" means
a stallion that has a positive EAV virus isolation test or polymerase chain
reaction (PCR) test from semen.
11.1.4. "EAV" means equine arteritis virus,
the organism that causes the disease equine viral arteritis.
11.1.5. "Equidae" means all members of the
genus Equus which includes but is not limited to horses, asses, hinnies, mules,
donkeys, burros, ponies, and zebras.
11.1.6. "EVA" means equine viral arteritis, a
communicable disease in equine resulting in abortion in pregnant mares, illness
and death in young foals, and potential establishment of the carrier state in
stallions.
11.1.7. "Isolated" means
the protocols to prevent the transfer of EAV through the appropriate
separation, movement controls, and biosecurity procedures approved by the State
Veterinarian.
11.1.8. "ISO
compliant microchip" means a microchip used to identify individual Equidae that
are compliant with the International Organization of Standardization and the
USDA's animal disease traceability requirements.
11.1.9. "Owner" means any person with the
legal right of possession or having legal control over any Equidae, and shall
include but not be limited to agents, caretakers, and other persons acting on
behalf of that person.
11.1.10.
"PCR test" Polymerase chain reaction test to detect EAV in samples.
11.1.11. "Semen" Secretion or ejaculate from
the reproductive tract of a stallion containing spermatozoa and seminal fluid
from the accessory sex glands.
11.1.12. "Sero-negative test mare" means a
mare that has been tested sero-negative (SN titer < :4) and has been
isolated from other horses for 21 days prior to being bred.
11.1.13. "Sero-negative" means a horse that
has tested negative (SN titer < :4) to a blood test for antibodies to
EAV.
11.1.14. "Sero-positive" means
a horse that has tested positive (SN titer >=1:4) to a blood test for
antibodies to EAV.
11.1.15.
"Shedder" or "shedding" means an Equidae has been determined to have EAV in its
body and has potential of transmitting the EAV to other Equidae.
11.1.16. "Stallion" means a sexually intact
male Equidae.
11.1.17. "Standard
insemination volume" means 10 ml of semen.
11.1.18. "Test breeding" means breeding a
suspect carrier stallion to 2 sero-negative mares a minimum of twice a day for
two (2) - to four (4) days in the same estrus period.
11.1.19. "Vaccinated" or "vaccination" means
an Equidae has been vaccinated with the approved EVA modified live virus
vaccine and the vaccination status has been kept current in accordance with the
manufacturer's recommendations.
11.1.20. "Vaccinated sero-positive stallion"
means a stallion that was sero-negative prior to being vaccinated against EVA
and which has a positive titer (>1:4) post vaccination.
11.2. General EVA Information
11.2.1. All laboratory samples pertaining to
this rule shall be submitted by an accredited veterinarian to an approved
laboratory.
11.2.2. It is
recommended that all breeding stallions be tested for EAV prior to use as a
breeding stud or collection for artificial insemination.
11.2.3. It is recommended that frozen semen
or semen from unknown stallions be tested negative by virus isolation or PCR
prior to being used for artificial insemination.
11.3. EVA Shedding Stallions
11.3.1. A stallion is considered to be a
carrier if any of the following apply: the virus can be cultured from his
semen, if the virus can be detected in his semen by PCR test, or if
sero-negative mares seroconvert to sero-positive status within 28 days
following breeding or insemination.
11.3.2. A stallion known to be a carrier
shall not be permitted to breed or be collected for artificial insemination
until the State Veterinarian determines that the stallion does not pose a risk
of transmitting EAV. In making this determination, the State Veterinarian shall
consider whether the requirements of Parts 11.3.2.2. and 11.3.2.3. of this
section will be complied with by the premises on which the carrier stallion is
located. The following restrictions shall apply to a carrier stallion that is
permitted to breed or be collected for artificial insemination:
11.3.2.1. The owner or agent of an EAV
carrier stallion shall notify in writing the owner or agent of a mare booked or
seeking to book a mare to that stallion that has been classified as an EAV
carrier. A written copy of the booking confirmation shall be sent to the State
Veterinarian.
11.3.2.2. A carrier
stallion shall be housed, handled, and bred or collected for artificial
insemination in a facility isolated from non-shedding stallions.
11.3.2.3. A carrier stallion shall be bred to
a mare(s) that:
11.3.2.3.1. Have been
vaccinated against EVA at least twenty-one (21) days and not more than 1 year
prior to being bred; or
11.3.2.3.2.
Has an existing EAV titer from vaccination or natural exposure to EAV, if the
serological test for EVA was performed prior to date of
breeding.
11.4. Sero-Positive Non-shedding Stallions
11.4.1. A stallion may be considered to be a
'vaccinated sero-positive stallion' if a blood sample collected within 10 days
prior to administration of an approved vaccine was negative (SN titer < :4)
for antibodies to EAV. See Section VIII for recommended vaccination
protocols.
11.4.2. It is required
that a sero-positive vaccinated stallion that did not have an EVA negative test
prior to vaccination comply with one of the following testing procedures to
ensure that the stallion is not at risk of transmitting the virus:
11.4.2.1. A standard insemination volume
(10ml) of semen should be collected and either virus isolation tested for EAV
or evaluated using a PCR test; or
11.4.2.2. The stallion should be bred to two
(2) mares negative for EAV antibodies. The two (2) mares should have blood
collected for an EVA test twenty-eight (28) days after breeding or artificially
inseminated from two ejaculates, separately collected.
The sero-positive stallion would be considered a non-carrier if the semen virus isolation tested, semen PCR or test-breeding results are negative.
11.4.3.
A stallion may be considered a 'non-vaccinated sero-positive stallion' if the
stallion has seroconverted following a natural exposure to the virus. It is
required that a non-vaccinated sero-positive stallion be tested as outlined
below prior to breeding to ensure that he is not at risk of transmitting the
virus.
11.4.3.1. Semen should be collected
and either tested by virus isolation or evaluated using a PCR test for EAV;
or
11.4.3.2. The stallion should be
bred to two (2) mares negative for EAV antibodies. The two (2) mares should
have blood collected for an EVA test twenty-eight (28) days after breeding or
artificial insemination.
11.4.3.3.
The sero-positive stallion will be considered a non-carrier if the semen by
virus isolation, PCR, or test breeding results is negative.
11.4.4. A stallion previously classified as a
carrier stallion may be re-classified as a non-carrier stallion if the
following criteria are met:
11.4.4.1. During
the first breeding season following the stallion's classification as a
non-carrier, the first five (5) sero-negative mares bred or artificially
inseminated using semen collected from separate ejaculates from this stallion
shall be test negative to a blood sample collected for an EVA test twenty-eight
(28) days after breeding or artificial insemination.
11.4.4.2. During the second breeding season,
the stallion shall be bred to two (2) mares negative for EAV antibodies that
will be tested twenty-eight (28) days after breeding or have its semen
collected and be virus isolation negative for EAV or have the semen tested
negative by PCR for EAV. If the semen virus isolation test or PCR test and
blood samples are negative for EAV, there shall not be restrictions placed on a
future breeding season.
11.4.5. The final determination that a
stallion is not an EAV carrier shall be made based on scientific procedures
described in this section and approved by the State Veterinarian. Until this
determination is made the stallion shall be considered as an EAV
carrier.
11.5.
Requirements for Breeding Mares to a Carrier Stallion or Inseminating Mares
with Known EAV Infected Semen
11.5.1. The
following guidelines are required when breeding mares to a carrier stallion or
inseminating mares with known EAV infected semen.
11.5.1.1. If a sero-negative mare is to be
bred to a carrier stallion for the first time.
11.5.1.1.1. It is required that the mare be
vaccinated a minimum of twenty-one (21) days prior to the first breeding or
artificial insemination by an EAV carrier stallion and subsequently isolated a
minimum of twenty-one (21) days after the first breeding or artificial
insemination.
11.5.1.1.1.1. During isolation,
the mare shall be physically separated from other Equidae in a separate
isolation area approved by the State Veterinarian or designated
personnel.
11.5.1.1.1.2. After the
isolation period, the mare may move without
restriction.
11.5.1.2. Mares that have been vaccinated
against EAV or have been bred to an EAV carrier stallion within the previous
two (2) years may be re-bred to a carrier stallion but should be isolated for a
minimum of twenty-one (21) days after breeding as noted above.
11.5.1.3. When a mare bred to a carrier
stallion is returned to the premises of origin within 21 days of breeding, it
shall be in a transport vehicle or trailer by herself or with other
sero-positive Equidae. Upon returning to the premises of origin, the transport
vehicle or trailer and equipment used to move the mare must be immediately
cleaned and disinfected according to procedures approved by the State
Veterinarian.
11.6. Actions for Newly Diagnosed
Sero-positive Stallions
11.6.1. A stallion
infected with EAV during the breeding season shall immediately cease breeding
or immediately cease having semen collected for artificial insemination or
semen collected and stored for future use. Since EVA is a reportable disease in
the State of Colorado, the State Veterinarian must be immediately notified in
the event of clinical EVA disease demonstrated by a positive laboratory test on
serum or semen. An owner or agent with a mare booked or bred to a stallion that
became infected with EAV during the breeding season shall be immediately
notified in writing by the stallion's owner or agent. A copy of the written
notification shall be sent to the State Veterinarian. A stallion infected with
EAV during the breeding season shall be classified as an EAV carrier and shall
be handled according to the requirements of this rule. Following the stallion's
classification as a carrier, the State Veterinarian may reclassify the stallion
as a non-carrier in accordance with this rule.
11.7. Equidae Vaccinated Against EVA
11.7.1. Following are the recommendations
that will provide for a more effective program for mares or stallions to be
vaccinated for EVA in Colorado:
11.7.1.1. The
Equidae owner's facility should have a premises identification number
(PIN).
11.7.1.2. The mare or
stallion receiving EVA vaccine should have an ISO compliant microchip implanted
according to USDA's animal disease traceability requirements.
11.7.1.3. That mares be tested for antibodies
to EAV prior to an initial EVA vaccination.
11.7.1.4. Testing for antibodies in blood of
mares be submitted to an approved veterinary laboratory.
11.7.1.5. A certificate documenting the mare
has been vaccinated be sent to the State Veterinarian within seven (7) days of
the vaccination date.
11.7.1.6. The
EVA vaccination certificate for mares should be on a form prescribed by the
State Veterinarian.
11.7.1.7. The
prior negative EVA test and vaccination of intact colts between 6-12 months of
age and of adult teaser stallions.
11.7.2. Following are the requirements for
mares or stallions to be vaccinated with EVA vaccine in Colorado:
11.7.2.1. Testing of stallions for antibodies
in blood or evidence of EAV in semen shall be submitted to an approved
veterinary laboratory.
11.7.2.2.
Stallions vaccinated for the first time against EVA shall be test negative to a
blood sample collected by an accredited veterinarian prior to
vaccination.
11.7.2.3. Stallions
vaccinated for the first time against EVA shall have the EVA vaccine
administered by an accredited veterinarian within ten (10) days after the
sample collection date.
11.7.2.4. A
certificate documenting that the stallion has been vaccinated shall be sent to
the State Veterinarian within seven (7) days of the vaccination date.
11.7.2.5. The EVA vaccination certificate for
stallions shall be on a form prescribed by State Veterinarian.
11.7.2.6. All Equidae vaccinated for the
first time against EVA shall not have direct exposure to an EVA affected animal
or a pregnant mare for twenty-one (21) days after vaccination.
11.7.2.7. A vaccinated stallion shall not be
used for breeding or artificial insemination within twenty-eight (28) days
after vaccination. A vaccinated mare shall not be bred within twenty-one (21)
days of vaccination.
11.8. EVA Test Mares
11.8.1. An EVA test mare shall be isolated
from the other Equidae and under the supervision of the State Veterinarian if
the mare becomes:
11.8.1.1. Clinically
affected with EVA after breeding or artificial insemination; or
11.8.1.2. Sero-positive after breeding or
artificial insemination.
11.8.2. An isolated mare shall be released
from isolation by the State Veterinarian after:
11.8.2.1. Twenty-eight (28) days in isolation
and providing test results are negative; or
11.8.2.2. The spread of EAV is no longer a
risk, whichever is longer.
Notes
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