“Doc – What’s the Fuss About Some Disease Called C.E.M.?"
© A.J. Neumann, D.V.M.
published in The Draft Horse Journal, Summer 2000
Most of us who read the DHJ pay little or no attention to what might happen to our horses, should certain governmental agencies of the U.S. Dept. of Agriculture fail to be alert in performing their duties as required by law.
Having stated that, let me explain a little about what you have just read.
There are many diseases of livestock, including horses, which are found in some foreign countries. Were they to be introduced into our animal populations, they would utterly devastate and destroy our livestock operations.
livestock people have heard or read about foot-and-mouth disease, which infects cloven-hooved animals. It has been reported in the U.S. several times and has been stamped out by a vigorous control program, including quarantining animals in the affected area and slaughtering them. The disease, itself, can be
found endemic in many countries, including some in our own hemisphere. It is found in Mexico, where outbreaks occur from time to time, and the U.S. Department of Agriculture works with the Mexican government in controlling the disease. If it should spread into the U.S. and become established in the cattle,
sheep and hog populations, it would be devastating to the numbers of these species.
The same can be said for Venezuelan Equine Encephelomylitis or V.E.E., which appeared in Texas a few years ago, apparently coming from Mexico. It is a highly fatal disease of horses. Stringent steps were taken by state
governments to ban the import of horses from the stricken areas, and vaccination efforts were undertaken to produce immunity against the disease in those horses living in or near these afflicted areas. Often states will cooperate with the Federal government in the control or abolishment of these diseases when
they are introduced accidently from some outside source.
It is the job of certain agencies of the U.S. Department of Agriculture to monitor the presence of some of these diseases in foreign countries and to quarantine and test them in animals such as horses, imported into the United States. That is simply why
horses which are imported must spend a given amount of time undergoing testing and surveillance at quarantine areas so designated upon arrival in the States from some other point of origin. This fact is often resented by the purchaser of the quarantined horse or horses, since the period of quarantine may last
for many days or several months, depending on the animal’s origin and the disease-screening process.
Everyone involved in this process of quarantining a horse must realize that even though it is a lengthy and expensive one, it serves the best interests for the horse industry by possibly keeping out a disease
which could ruin the entire horse business.
As I have mentioned before, individual states also have laws regarding importation of horses into their territories. Occasionally states will pass laws, when the emergency arises, banning the importation of animals from other states where a disease is known to exist
in their stock.
There are some diseases of the horse, which are found in parts of the world, which we never want to import into the country. For any reason we do not want these conditions to become established in our own equine populations. To list a few, they are: Glanders; Dourine; African Horse Sickness;
and Contagious Equine Metritis or C.E.M.
A veterinarian in the course of a month’s time will receive a good many pieces of literature or bulletins from colleges of veterinary medicine, veterinary periodicals, and reports from various federal and state governmental agencies, all dealing with information regarding diseases and conditions of
animals, their treatment, and their occurrences in the states and country as a whole.
In the past several months there has been quite a bit of information released about Contagious Equine Metritis and its importance to the equine industry. This has been prompted by the very recent discovery of some
stallions with C.E.M., which were imported into this country, and a C.E.M. positive-test mare found at an approved C.E.M. quarantine facility in Florida. Apparently the infected mare had been test-bred by a stallion which had just recently been imported from Germany.
As a result, the state of Florida
has announced some additional testing on all breeding-age stallions and mares being imported from countries where C.E.M. is known to exist. This is in addition to testing being done at the Federal level at their own quarantine stations.
Contagious Equine Metritis (C.E.M.) is a true sexually
transmitted disease of the horse and ass family. It is generally held that there are only two other sexually transmitted genital infections of these species. One is a Klebsiella infection and the other a Pseudomonas infection of the genital tract.
C.E.M. is caused by a coccus-type bacteria sporting
the grand name Taylorella equigenitalis. This disease is found today in about 25 countries, including most nations of Europe. The very first outbreaks in 1977 appeared on stud farms in Ireland and England. Two outbreaks occurred in this country in 1978 and 1979. They were in Kentucky and Missouri, and, I believe,
involved Thoroughbreds which were traced back to carrier stallions which had been imported from somewhere in Europe. At that time very stringent methods were adopted by federal and state agencies, and the disease was eradicated. The U.S. has been free of the condition until these cases were discovered as the horses
entered quarantine facilities in the United States (federal) and Florida (state).
Most countries with C.E.M. have control programs in place which try to detect breeding animals which are infected and, therefore, prevent the disease from spreading. To our credit we have rigid import regulations and
quarantines for those horses coming from countries which are deemed not to be C.E.M.-free.
This disease, where it flourishes, is very economically devastating to the equine industry. It happens like this: an infected stallion, who, by the way, shows no symptoms of the ailment, will breed a mare. Two
to ten days later the mare will have developed an infection of the vagina, the cervix, and the lining of the uterus. These are known as vaginitis, cervicitis, and endometritis, respectively. The mare will also exhibit at this time a very nasty so-called muco-purulent discharge.
Of course when this
happens, the conception rate plummets, as much as 50 percent or more. Some mares will recover on their own and conceive upon a later breeding. Other mares may show little or no signs of the infection, but will probably be infertile for a while.
In any case, many of these so-called recovered mares
will be carriers of the ailment for several months or longer. The clitoral sinuses and fossa will harbor the infection for a long period of time, and these mares will show no clinical symptoms of the disease.
The diagnosis of the condition is based upon recovering the causative bacteria from the
cervix, uterus, endometrium, or the clitoral sinus or fossa. Collection and growth of the bacteria are not easy procedures, so there is some room for a margin of error. With the present culture techniques it is feared that some carriers may slip through the net and go undetected.
the bacteria which are circulating in the blood can be detected by any one of several serological tests. However, these tests are not 100 percent accurate, so they seem to have a limited value, especially in diagnosing the chronic carrier.
Another test to detect the presence of the causative
bacteria, using a polymerase chain reaction, may be the best yet. It has only recently been approved.
At the present time all horses imported into the United States from countries with C.E.M. are quarantined. Three negative samples taken seven days apart from the endometrium, clitoral fossa, urethral
fossa, and cervix, for the presence of T. equigenitalis, are required. At least one set of samples must be taken from the quarantined mare at the time of estrus.
The pregnant mare is kept in quarantine until she delivers. Upon delivery she must have three negative culture samples at seven day
intervals, the same as other mares, in order to be released from quarantine.
Stallions from countries with a C.E.M. problem must be quarantined upon arrival in the U.S. for at least 45 days. Cultures are taken from three areas: the prepuce, urethral fossa, and the urethra. They must test negative for
the causative bacteria.
In addition to the above cultures, the stallion is required to breed three mares, and they, in turn, must have negative cultures on the three different occasions taken seven days apart. For the trial mares this same procedure as described previously for the quarantined mares.
Now, one can understand why the authorities in Florida were disturbed and announced additional testing requirements for all breeding-aged stallions and mares imported into Florida from countries affected by C.E.M. No one in his or her right mind wants an infected stallion or mare to slip through the tests and be dumped
out into our horse populations.
Florida’s C.E.M. emergency rule, which has been put into place, requires imported mares to have additional testing over and above the federal tests. Not only are there more tests, but there are also more culture locations. Also, the post-breeding test of most mares has
been extended from 15 to 21 days.
In addition, C.E.M. serological testing must be done on the first three mares bred to stallions after their release from quarantine.
With this emergency rule in place and operational it should make the possibility of a carrier mare or stallion much
less likely to slip through the screen undetected.
I decided to write this article for two reasons, the first being that I wanted to demonstrate how some of our governmental agencies are working hard to protect the livestock industry, including the horse business. We often do not realize what a
responsibility the men and women who work in these agencies have resting on their shoulders. A mistake on their part could cost, in this case the horse industry, millions, if not billions, of dollars in losses.
Many draft horse breeders today are entering the “warm-blood” market, and raise
draft-Thoroughbred or draft-Morgan or draft-Quarter Horse crosses, to name a few. Even though many animals of the draft breeds are not imported, I am sure there are plenty members of the so-called “hot blood” breeds that are. So a draft breeder could get caught up with C.E.M. by purchasing an imported stallion or
mare of some “hot blooded” breed.
The second reason is that in the last two months I have just clocked 18 phone calls and letters, mostly from subscribers to the DHJ, who have asked about C.E.M. Among the 18 received is a page from the Florida Market Bulletin by the Florida Department of Agriculture
and Consumer Services with the following headline: “Disease testing increased–Florida moves to protect horse industry.” Then there follows a discussion of C.E.M. Well, guess who sent it. None other than Mr. Lynn Telleen, the editor of the DHJ!
I will say, I had most of the reading and research done
for this article when his letter arrived.
I hope I have answered most, if not all, of your questions about Contagious Equine Metritis. And it’s sure great to report that there are some real dedicated government employees out there watching out for the horse and mule industry!