Quarantine facilities...the mere name implies isolation and horses with infectious diseases for which there are no cures. In reality, quarantine facilities are the first line of defense to protect horses in the United States from such diseases. Horses in these facilities usually are healthy, and regulated quarantine limits and testing make sure that they stay that way until they are released into the general population. Quarantine facilities are necessary to ensure that diseases exotic to this country are not introduced from other countries. Horses coming into the United States are required to undergo testing for a number of infectious diseases that occur in other parts of the world. This serves to protect our "naive" population (meaning our horses have not been exposed to that disease, have no resistance, and are not protected by vaccination or other means) from potential exposure to these diseases.

For this article, we will focus on one such disease, contagious equine metritis (CEM), to illustrate the importance of quarantine and explain the procedures involved. CEM, which is sexually transmitted in horses, does not occur in the United States. Our government and horse owners want to keep it that way. Mares and stallions which are imported into this country must be quarantined for other diseases, then undergo a separate quarantine and be tested for CEM before they are allowed into the general equine population.

With the breeding season at hand, you will need to become familiar with CEM quarantine procedures if you are planning on importing mares or stallions into this country.

What is CEM, and what are the signs of this disease? Where are the available quarantine facilities? How do you decide on which one to use? What is the cost of quarantine? The answers to these questions and more are in this article.

What Is CEM?

Contagious equine metritis is a venereal disease of horses caused by the organism Taylorella equigenitalis. This bacterium can cause endometritis (inflammation of the lining of the uterus) and subsequent resorption of the embryo. Rarely is the bacterium the cause of abortion in mares. Stallions do not develop clinical signs of disease, but they can serve as carriers and transmit the disease to mares. Mares which develop signs of disease most commonly have a thin, grayish-white vulvar discharge about 10 days after breeding to an infected (carrier) stallion. The clinical signs of disease will resolve even without treatment, but a percentage of mares remain asymptomatic carriers of the organism, as do some stallions.

A significant problem with this disease is the difficulty of detecting carrier stallions and mares. Carriers will appear clinically normal, yet harbor the bacteria within their genitourinary tract. During breeding they can pass the organism to a previously uninfected and susceptible individual. This organism can also be transmitted through infective semen, so using artificial insemination for breeding can give rise to a false sense of security. Before semen can be imported from a CEM-affected country, such as Germany, however, the donor stallion must be put in quarantine, where he is sampled and cultured for the presence of the CEM bacterium. The cultures are sent to a laboratory that is approved by the USDA, and if the results are negative then the stallion's semen can be collected, and the fresh or frozen semen may then be imported into the United States.

The only outbreaks of CEM in this country were in Kentucky in 1978 and in Missouri in 1978 and 1979. The former was devastating to the Thoroughbred breeding industry's economy in Kentucky. Luckily, the outbreak was contained, and the United States still is considered CEM-free. Since the disease still occurs in many European countries, there are strict guidelines that mares and stallions imported from those countries must follow in order to be allowed into this country.

Federal Quarantine

Before a horse can enter this country, it must have an import permit, a health certificate from the country of origin (signed by a veterinarian), and a negative CEM culture taken within 30 days of import (for mares and stallions). If allowed into the country, all horses must be placed in federal quarantine at a USDA animal import center, which usually lasts two or three days. In the United States, there are four ports of entry for horses coming into this country--Los Angeles, Calif.; Newburg, N.Y.; Miami, Fla.; and Honolulu, Hawaii.

Each horse brought into this country must pass through one of these USDA facilities. During that time, the horse will be tested and observed for clinical signs of illness resulting from "exotic" diseases such as dourine, glanders, piroplasmosis, or more common diseases such as influenza. After quarantine, the mares and stallions over 731 days of age (two years) which are new to our country must undergo CEM quarantine at a separate facility.

CEM Quarantine

CEM quarantine facilities must be approved by the U.S. government. Twenty states have approved facilities--Alabama, California, Colorado, Florida, Georgia, Kentucky, Louisiana, Maryland, Montana, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and Wisconsin. These facilities accommodate horses during a quarantine period that can be as short as two weeks, or as long as three weeks or more.

During that time, the horses will be rigorously tested to ensure they are not harboring the organism that causes CEM. This is accomplished in mares by culturing sites where the organism likes to reside (such as the clitoral fossa and clitoral sinuses). Samples are taken from those sites on the mares three times during the first week of quarantine (usually Days 1, 4, and 7). After all of the cultures are taken, the same areas are washed with 2% chlorhexidine (an anti-bacterial solution) and treated with an anti-bacterial ointment such as nitrofurazone for five consecutive days. At the end of the treatment period, the mare is released if she has had three negative cultures for the CEM organism--which usually takes around two weeks. However, if any of the cultures are positive for the CEM organism, the mare is quarantined for an additional period during which she is treated, and the entire testing procedure is repeated.

Stallions at quarantine facilities initially are cultured from several sites, including the urethral fossa and sinus, the terminal urethra, the prepuce, and the shaft of the penis. If these cultures are negative, then the stallion is test bred to two mares. After the breeding, the test mares are cultured on post-breeding Days 3, 6, and 9. Between Days 20 and 45 post-breeding, a blood sample is taken from the mares and tested for antibodies against the CEM organism using the complement fixation test.

The stallion's quarantine period can be variable, from four weeks to two months or longer. The variability is due to the test mares--the mares must be in season (heat) in order to be receptive for breeding. The mares can be short-cycled using hormones ahead of time so they will be ready to breed shortly after the stallion's arrival. A monetary deposit is required for this to be performed. Furthermore, during the cold winter months in some areas, it is difficult to achieve standing heat in the mares.

Finding A Quarantine Facility

Once you have decided to purchase and import a stallion or mare then a CEM quarantine facility must be chosen. What is the best way to find one? According to William Barnes of the William Barnes Agency, a company that specializes in the international shipment of horses, it often is easiest to leave that decision up to the shipping agent.

The shipping agents are very familiar with the paperwork required for importation and arranging transportation for the horses, as well as with most of the CEM facilities available. They often decide on the facility that best meets your horse's needs.

There are several factors to consider when deciding upon the quarantine facility. The top priority is quality of care of the horses within the facility, according to Barnes. The second factor is location. Some owners want to be able to visit their horses at the facility, so they desire a facility close to home. The third factor concerns show horses whose owners want or need the horse to remain in work during the quarantine period. This can be especially important for stallions, which can be in quarantine for many weeks.

Some people choose a facility based solely on the ability to exercise a horse during quarantine. One such facility I recently visited is Runaway South in Wellington, Fla., which has a jump field and dressage ring that can be used by the quarantined horses in order to keep them fit during the quarantine period.

The last factor, but certainly not the least, is the cost.

Why Do Quarantine Facilities Cost So Much?

CEM quarantine facilities are expensive. Charges for CEM quarantine run between $1,400-$5,000 for a mare and $5,000-$8,000 for a stallion. The costs are high because of several factors:

1) Board for two to six weeks, perhaps longer. Most facilities charge board on a daily basis, so the quicker the horse can leave quarantine, the less expensive the board bill.

2) Veterinary-related costs. A licensed and accredited veterinarian must perform the culturing procedures on the horses and supervise the test breeding of stallions. He or she must be available in case the horses become ill during the quarantine period. The veterinarian on duty might vaccinate the horses for diseases that occur in our country, such as rabies, rhinopneumonitis, and strangles.

3) Laboratory costs. The diagnostic laboratory used to carry out the necessary tests charges for each culture that is submitted. For a mare, that might be only nine samples. For a stallion, the number of samples is greater. Nine samples (sometimes more) from the stallion initially followed by a minimum of six samples prior to breeding and six samples after breeding for each test mare. The complement fixation antibody test must be run on each of the test mares prior to breeding and again 20-45 days after breeding the two test mares. Furthermore, mares and stallions often are tested for other diseases while in quarantine, such as equine viral arteritis.

So, you can see that while the facilities seem expensive, your money is going toward paying board, veterinary-related costs, and laboratory costs.

CEM quarantine has been very successful in keeping this potentially devastating disease out of our country. So overall, it is a small price to pay for keeping all of our horses healthy.

CEM is just one of the diseases we want to exclude from our U.S. horse population. Temporary rules can be enacted that regulate movement of horses from specific countries and areas based on reported occurrences of disease. Communication is important among countries on a governmental level and among veterinary research institutions. Control of disease with the least interference to equine movement--and the best health of the quarantined animals--is the goal of import quarantine.

About the Author

Christina S. Cable, DVM, Dipl. ACVS

Christina S. Cable, DVM, Dipl. ACVS, owns Early Winter Equine in Lansing, New York. The practice focuses on primary care of mares and foals and performance horse problems.

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