The Coggins Test For [HORSES]

What is a Coggins Test For Horses?

If you own a horse, you have likely encountered the Coggins test. It is a straightforward test that takes around a week before you get the Coggins test results. So, what does this test mean, and why does your horse need it? For more details, please keep reading.

The Coggins test is a blood test conducted to detect antibodies to the Equine Infectious Anemia (EIA) disease. EIA is a virus that causes the affected horses to experience:

  • Intermittent to constant fever ranging from 100 to 105 degrees F.  
  • Rapid breathing.
  • Anemia (low red blood cell count). The horse’s blood may show a marked decrease in its red cell count. As a result, it usually appears thin and watery.
  • The horse could also have an irregular heartbeat and a jugular pulse.  
  • Sweating.
  • Weight loss, which is probably because the horse loses its appetite.  
  • Dependent Edema (stocking up). The horse may develop swelling, which is a sign of fluid collecting under the skin in the legs and underneath the chest.
  • Depression where the horse seems dejected and generally lazy.
  • Petechial hemorrhages where small blood-colored spots appear on the horse’s mucus membranes.

However, not all fevers are a sign of EIA. Some horses usually recover from the symptoms in less than 24 hours. The EIA virus is similar and related to the virus that causes HIV in humans. In this sense, horses that contact the virus carry it for life.

However, if your horse gets negative Coggins results, further testing is not necessary. This is because it will not become EIA positive except if it comes in contact with a horse with an unknown EIA status and develops a severe, feverish illness.

So, how long is a Coggins test for? Experts advise that you may have to perform the Coggins test annually if you plan to show or transport your horse.

You must be wondering, why Coggins? Well, the test was named after its developer, Dr. Leroy Coggins. Dr. Coggins was a veterinarian and a Ph.D. holder in virology. He researched African Swine Fever in Kenya in the 1960s and converted his findings to come up with the Equine Infectious Anemia test.

The first time the test was approved in the US by the FDA was in 1973. The good doctor lived in Cary, North Carolina, until Feb 2014, when he passed at the ripe-old age of 81.  

horse blood test

What Does Coggins Test For?

The Coggins test is performed to ensure that horses are not carrying the EIA virus. The virus is also known as swamp fever or mountain fever. It affects Equidae, including horses, zebras, donkeys, mules, and ponies. Additionally, experts report that the virus has a death rate of between 30 to 70%.

To conduct the test, your horse’s blood must be taken to a state-approved laboratory. So in what scenarios might you need to take the Coggins test?

  1. When you suspect one of your horses could be having the virus.
  2. Whenever you need to take your horse to a show.
  3. When you want to transport your horse across state lines, this is because other horse owners need assurances that their horses will be safe around your horse.
  4. In some states, you must produce a negative Coggins test result before you can sell it.

How is the Coggins Test Performed?

First, only licensed veterinarians are allowed to perform the Coggins test. The veterinarian draws blood from your horse and sends it to an accredited laboratory for analysis. Once the lab technicians receive the blood sample, they conduct the test to detect the EIA antibody.

The EIA antibody is a protein that allows the horse’s body to recognize the EIA virus. Therefore, this will only be present in blood from horses that have the EIA virus.

The horse owner will then receive either a positive (antibody present) or negative (antibody not present) test result through the veterinarian. These results are what are referred to as Coggins Papers. You will receive either a hardcopy or electronic copy of the results, which you should keep in the horse’s health records.

The results usually expire after one year. Here are the details contained in all Coggins tests:

  • Information about the owner such as name, address, and phone number.
  • Details about the stable including point of contact, address, and phone number.
  • Details of the veterinarian like name, clinic, address, and accreditation number.
  • Horse’s identifiable information such as name, breed registration number, barn name, breed, sex, age, color, permanent identification, and pictures.
  • Equine Infectious Anemia (EIA) test information including type, name of the lab that conducted the test, reason for testing, date received, date reported, and the results.  

Coggins Test Requirements of US States

Because of the infectious nature of the virus, states have several requirements that govern Coggins testing. For example, you need evidence of a negative Coggins test to be allowed to move your horse interstate and, in some instances, intrastate movement.

At the moment, all states in the United States of America require proof of a negative Coggins test for horses crossing a state line. For instance, Pennsylvania requires that all horses entering the Commonwealth should produce a negative Coggins from within 12 months before the requested date of entry.

However, foals aged six months and below accompanied by a dam with a negative test result are exempted from this requirement. Pennsylvania and several other states also have more requirements for interstate travel. For example, you will also need an up-to-date Certificate of Veterinary Inspection (CVI).

On the other hand, Maine requires that horses within its borders should have a Coggins test performed every three years. Moreover, horses entering and leaving the state must produce a negative Coggins test within one year of entry or departure date.

The state also demands that horses produce a certificate of veterinary inspection performed within 30 days of departure. Horses exporting to Canada must produce a negative Coggins test within six months of departure. Additionally, horses must have a Canadian Health Certificate within 30 days for entry into Canada.

These are just a few examples of the Coggins test requirement by states. It will help if you find out the destination state and home state requirements before you leave. This will ensure that you leave and reenter your state without facing challenges.  

Horse Health Check

What is Equine Infectious Anemia?

Equine Infectious Anemia is a blood-borne viral disease that affects Equidae. The horse industry is greatly concerned by this virus because it does not have a cure or vaccine at the moment. As mentioned earlier, horses having the virus display various symptoms and prognoses.

However, severe symptoms are weight loss, fever, and disorientation. In some cases, horse owners have reported painful death. It is also important to note that many EIA infections are cases of asymptomatic carriers. These are horses that have the virus but show no signs or symptoms. This is one of the reasons why testing is essential.

Asymptomatic carriers are also called inapparent carriers. These horses usually have lower concentrations of the EIA virus in their blood than horses exhibiting clinical signs. Research suggests that only one out of six million horse flies is likely to pick up and spread the virus from asymptomatic horses.

Moreover, EIA is a lifelong disease, meaning that horses that test positive for the disease pose a significant risk to any other horses in their surroundings. As a result, EIA carriers have to be quarantined permanently. Experts advise that you should keep them at least 200 yards away from other horses. 

How is EIA Transmitted?

Fortunately, EIA is not infectious to humans. Moreover, it cannot be directly transmitted from horse to horse. Instead, the transmission of the virus occurs through the spread of blood from an infected horse to a non-infected horse.

Studies have revealed that EIA is mainly transmitted by biting flies. Horse and deer flies, also known as tabanids, are considered the most significant transmitters. The biting flies spread EIA by taking a blood meal from an EIA carrier and transmitting it to a non-infected horse.

It is nearly impossible to eliminate the blood-sucking insects around your horses. In this regard, there is always a chance that your horse could contract the virus or any other blood-borne disease. This is especially true if there is an infected horse in the vicinity.

Luckily, experts suggest that the virus does not live for long in the transmitting flies. It usually stays around 15 to 30 minutes. This implies that for a horse to infect the other, it should be nearby.

Besides that, EIA can be transmitted through contaminated equipment like needles and syringes. Additionally, there is a mare to foal transmission in-utero and through the natural breeding of mares and stallions.

These modes of transmission mentioned here above show that your horse doesn’t have to come into contact with an infected or carrier horse to catch the virus. Flies will come to your farm, meaning your horse is at risk even if it does not leave the farm.

How Can The Spread of EIA be Prevented?

When your horse gets a negative Coggins test result, that ensures that they don’t have the antibody for EIA at the time of testing. Nevertheless, experts advise horse farmers to keep implementing biosecurity measures as well as annual tests. Here are some preventive measures to consider:

  1. Since flies are the primary transmitters of EIA, you also have to employ fly management strategies to reduce the likelihood of infection. For instance, industry experts suggest that farmers should implement an integrated pest management (IPM) system. The system uses several targeted strategies to reduce the population of flies.
  2. Additionally, horse owners ought to prioritize their horses’ health and sanitation to help curb the spread of EIA. For example, before using a needle on your horse, it would help to ensure it is sterile. Likewise, suppose you are using a multi-dose vaccine bottle; ensure you use a sterile needle each time you puncture the bottle.
  3. When other horses visit your farm, their owners should provide proof of negative Coggins. Moreover, if new horses are entering your premises, quarantine them for a minimum of 14 days after they arrive. During the quarantine period, observe them for any signs of illness.
  4. Before you buy a horse, the seller should produce proof of a negative Coggins test. The same applies to horses you are considering for breeding.
  5. Additionally, the American Association of Equine Practitioners (AAEP) recommends that horse owners only participate in shows requiring negative Coggins test results.
  6. Experts also advise horse owners to evaluate their horses for signs of illness regularly. If you suspect that a horse has contracted EIA or any other virus, separate them from the rest to reduce the chances of transmission. After that, contact your veterinarian immediately.
  7. Disinfect surgical and dental equipment, bits, and lip chains thoroughly when using them between horses.
  8. When performing blood transfusions, ensure licensed veterinarians do it. The veterinarians should also use blood from confirmed EIA-negative donor horses.
  9. Ensure all wounds and cleaned and covered.

Why Should I Test My Horse For Coggins?

Testing your horse for the EIA virus is important because it ensures it does not spread to other horses. Moreover, as mentioned earlier, since there is no vaccine or treatment for EIA, horse owners must test their horses. 

Testing helps to identify infected horses and separating them from the other horses to prevent the spread of the virus.

The Implications of a Positive Coggins Test

Unfortunately, there is no specific treatment for the virus at the moment. Therefore, infected horses receive supportive treatment that includes fluids, non-steroidal anti-inflammatory drugs, and nutritional supplements. The treatment is usually used to help them through a feverish episode.

Whenever a horse tests positive for EIA, a second test is performed to confirm. So, what options does your horse have if it tests positive for the virus? You have two options:

Health form confirm


If you choose this option, your horse gets permanent identification by a tattoo or brand. It is then quarantined for life from other equine species within 200 yards. The quarantine must begin 24 hours after you receive official Coggins test forms.


This is the popular choice for many horse owners. With this option, you transport it to an accredited research facility or slaughterhouse.

The horses that interacted with the infected horse in your facility need to be tested every 30 to 60 days until there are no new cases. Experts also advise that you should quarantine infected horses as you monitor their situation.


Coggins in horses can be prevented if horse owners follow the stipulated guidelines. For example, getting a Coggins test each year is a must to help reduce the risk of EIA transmission. This is because most carriers are asymptomatic, and only testing can help to identify them.

Once you get a positive cognitive test confirmation, you are responsible for taking the available options to prevent the virus from spreading further. The two main options are quarantine or euthanasia. Many horse owners go for the latter as it is easier to implement.

Moreover, before you travel with your horse, ensure you find out about the documentation requirements for your state and the state you are traveling to. It is also advisable to participate in events that require a negative Coggins test result.

The bottom line is, when it comes to Coggins horse disease, prevention is essential. Therefore, follow the guidelines shared in this comprehensive piece to help keep your horses’ Coggins negative.