Nathan Luszcz
Well-Known Member
Just as a FYI...
So many of the people here either breed or own stallions I thought this would be important to post.
The following is excerpted from the Colorado Department of Agriculture, and is viewable complete here.
"The purpose of this rule regarding equine viral arteritis (EVA) is to protect the equine industry of the state of Colorado. Clinical disease due to EAV infections is a reportable disease to the Colorado State Veterinarian. Equine Viral Arteritis (EVA) is a contagious disease of horses caused by the equine arteritis virus (EAV) EVA is of special economic concern because it can result in abortion in pregnant mares, illness and death in young foals, and establishment of the carrier state in stallions. The import control policies of most countries currently deny entry to carrier stallions and EAV-infective semen because of the associated disease risks. It is important to enable the ability to require testing of some horses prior to vaccination to demonstrate that antibody titers are due to vaccination rather than natural infection. The vast majority of Colorado have never been exposed to the vurus; therefore, the risk of spread of infection in Colorado is significant."
My second-to-last paragraph describes the vaccination process for stallions. This middle section describes the disease (feel free to skip to the end )
EVA presents just like flu or rhino with depression, snots, and a minor fever. Just like flu and most strains of rhino, it's not a big deal for most animals. They get sick, get over it, and move on with life. However, it's extremely contagious, spreading rapidly if presented with the chance. The infected animals shed the virus copiously for approximately 21 days. Nose-to-nose contact is the largest method of transmission, but feces and urine in the infected animal are also contagious. Stallions infected with EVA have a 50% chance of becoming a carrier animal, shedding the virus in their semen (and therefore possibly in their urine, since the stallion eliminates extra spermatozoa and fluids in their urine). Mares bred to these stallions have a 98%+ chance of getting infected. If a pregnant mare (not a just bred mare) is infected with EVA, they have a very, very high chance of aborting their foal. This is a huge concern all over the US with the major outbreak this past breeding season in New Mexico. Semen from this single infected stallion was shipped nation-wide, mares were bred, then those mares cause secondary infections causing hundreds of abortions and a huge problem.
This disease is not new; on the contrary, the vaccine has been available commercially for several decades, and the disease identified for even longer than that. There are minor outbreaks every decade or so. This past one was devastating due to the increased travel and use of shipped semen from these carrier stallions.
It is said that the majority of Standardbred horses have been exposed to EVA sometime in their life (with upwards of 70% being sero-positive). Many STB stallions are carriers. However, for some reason that is not understood, STBs do not seem to react to the disease. It is suspected that the STB strain of the virus has mutated and isn't the same as the older disease. This new outbreak IS the older strain and causes major abortions everywhere it goes.
There is a test for EVA. It is a very simple blood test that tests for the presence of antibodies. Horses that test positive are said to be "sero-positive". That means that they have been exposed to the disease sometime in their life and have formed antibodies against it. All EVA vaccinated horses will test sero-positive for the remainder of their lives. This is not a big deal for a horse that is not a stallion. Adult geldings and mares get over the disease quickly and usually easily. Foals can die if they are infected at an early age, but that's not all that unusual for any disease outbreak.
Stallions who have reached sexual maturity are susceptible to be carriers. They harbor the virus in their accessory sex glands (the ampula, prostate, seminal vesicles, and BU gland) and shed it constantly in their semen. The virus requires testosterone to maintain its presence, so castrating the stallion will kill the virus in their bodies. Carrier stallions are 100% healthy and are not affected in any way from the virus being harbored in their bodies. If a stallion tests sero-positive, you must then test the semen to see if they are a shedder. If they are a shedder, you must make the choice to tell all of your potential clients that your horse is EVA positive so they can make (very simple) arrangements to avoid spreading the disease, take the horse off the market as a breeding horse, or geld the stallion. It is not ethical to continue breeding the stallion without telling the mare owners he is a shedder.
There is a vaccine available for this disease. Given to mares or geldings, they can still get EVA but the incubation time drops from 21 days of potential spreading to 3 days, and a lot less virus being shed in their mucus and urine.
ALL STALLIONS SHOULD BE VACCINATED. To do this you need to ask your vet to purchase the vaccine (they must get permission from their state veterinarian before Fort Dodge will sell the vaccine). Then you do a blood test on the stallion to confirm that they are negative. WITHIN 10 DAYS of drawing the blood, and after the lab confirms they are negative, the vet must come out and vaccinate the horses. It's a simple vaccine, just like any other spring shot. The stallion then builds antibodies and is protected. The best time for this vaccine is now; in November or December, before the breeding season. They also require an annual booster. The initial vaccination is reportable to the state vet; they must be informed that a stallion was vaccinated.
As far as I know the disease hasn't spread across the mini population, but they can harbor the disease just as well as a full sized horse, so its important for the welfare of the whole equine species to attempt to limit or even wipe out the disease. There are concerns about exporting both horses and semen, but TB's routinely are exported for the fall breeding season and all countries, including Australia, accept them with proper proof of status and vaccination. Consult your vet, and learn what you can! This disease is important to be aware of and to address in your herds.
Ug, I wrote all this in MS Word, but apparently " and ' don't translate here, lol. Edited to correct.
So many of the people here either breed or own stallions I thought this would be important to post.
The following is excerpted from the Colorado Department of Agriculture, and is viewable complete here.
"The purpose of this rule regarding equine viral arteritis (EVA) is to protect the equine industry of the state of Colorado. Clinical disease due to EAV infections is a reportable disease to the Colorado State Veterinarian. Equine Viral Arteritis (EVA) is a contagious disease of horses caused by the equine arteritis virus (EAV) EVA is of special economic concern because it can result in abortion in pregnant mares, illness and death in young foals, and establishment of the carrier state in stallions. The import control policies of most countries currently deny entry to carrier stallions and EAV-infective semen because of the associated disease risks. It is important to enable the ability to require testing of some horses prior to vaccination to demonstrate that antibody titers are due to vaccination rather than natural infection. The vast majority of Colorado have never been exposed to the vurus; therefore, the risk of spread of infection in Colorado is significant."
My second-to-last paragraph describes the vaccination process for stallions. This middle section describes the disease (feel free to skip to the end )
EVA presents just like flu or rhino with depression, snots, and a minor fever. Just like flu and most strains of rhino, it's not a big deal for most animals. They get sick, get over it, and move on with life. However, it's extremely contagious, spreading rapidly if presented with the chance. The infected animals shed the virus copiously for approximately 21 days. Nose-to-nose contact is the largest method of transmission, but feces and urine in the infected animal are also contagious. Stallions infected with EVA have a 50% chance of becoming a carrier animal, shedding the virus in their semen (and therefore possibly in their urine, since the stallion eliminates extra spermatozoa and fluids in their urine). Mares bred to these stallions have a 98%+ chance of getting infected. If a pregnant mare (not a just bred mare) is infected with EVA, they have a very, very high chance of aborting their foal. This is a huge concern all over the US with the major outbreak this past breeding season in New Mexico. Semen from this single infected stallion was shipped nation-wide, mares were bred, then those mares cause secondary infections causing hundreds of abortions and a huge problem.
This disease is not new; on the contrary, the vaccine has been available commercially for several decades, and the disease identified for even longer than that. There are minor outbreaks every decade or so. This past one was devastating due to the increased travel and use of shipped semen from these carrier stallions.
It is said that the majority of Standardbred horses have been exposed to EVA sometime in their life (with upwards of 70% being sero-positive). Many STB stallions are carriers. However, for some reason that is not understood, STBs do not seem to react to the disease. It is suspected that the STB strain of the virus has mutated and isn't the same as the older disease. This new outbreak IS the older strain and causes major abortions everywhere it goes.
There is a test for EVA. It is a very simple blood test that tests for the presence of antibodies. Horses that test positive are said to be "sero-positive". That means that they have been exposed to the disease sometime in their life and have formed antibodies against it. All EVA vaccinated horses will test sero-positive for the remainder of their lives. This is not a big deal for a horse that is not a stallion. Adult geldings and mares get over the disease quickly and usually easily. Foals can die if they are infected at an early age, but that's not all that unusual for any disease outbreak.
Stallions who have reached sexual maturity are susceptible to be carriers. They harbor the virus in their accessory sex glands (the ampula, prostate, seminal vesicles, and BU gland) and shed it constantly in their semen. The virus requires testosterone to maintain its presence, so castrating the stallion will kill the virus in their bodies. Carrier stallions are 100% healthy and are not affected in any way from the virus being harbored in their bodies. If a stallion tests sero-positive, you must then test the semen to see if they are a shedder. If they are a shedder, you must make the choice to tell all of your potential clients that your horse is EVA positive so they can make (very simple) arrangements to avoid spreading the disease, take the horse off the market as a breeding horse, or geld the stallion. It is not ethical to continue breeding the stallion without telling the mare owners he is a shedder.
There is a vaccine available for this disease. Given to mares or geldings, they can still get EVA but the incubation time drops from 21 days of potential spreading to 3 days, and a lot less virus being shed in their mucus and urine.
ALL STALLIONS SHOULD BE VACCINATED. To do this you need to ask your vet to purchase the vaccine (they must get permission from their state veterinarian before Fort Dodge will sell the vaccine). Then you do a blood test on the stallion to confirm that they are negative. WITHIN 10 DAYS of drawing the blood, and after the lab confirms they are negative, the vet must come out and vaccinate the horses. It's a simple vaccine, just like any other spring shot. The stallion then builds antibodies and is protected. The best time for this vaccine is now; in November or December, before the breeding season. They also require an annual booster. The initial vaccination is reportable to the state vet; they must be informed that a stallion was vaccinated.
As far as I know the disease hasn't spread across the mini population, but they can harbor the disease just as well as a full sized horse, so its important for the welfare of the whole equine species to attempt to limit or even wipe out the disease. There are concerns about exporting both horses and semen, but TB's routinely are exported for the fall breeding season and all countries, including Australia, accept them with proper proof of status and vaccination. Consult your vet, and learn what you can! This disease is important to be aware of and to address in your herds.
Ug, I wrote all this in MS Word, but apparently " and ' don't translate here, lol. Edited to correct.
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