Goats with knots under their ears, on their flanks, or about their chests have a 70% probability of being infected wth the bacterium which causes Caseous Lymphadenitis (CL) abscesses.
What Is CL?
Recurring (chronic) lymph node abscesses in goats are caused by the organism corynebacterium pseudotuberculosis. These abscesses can be both external and internal and can be slow to develop, sometimes taking months or years to become visible. The western and south-central parts of the United States have historically demonstrated a higher incidence of CL than the rest of the country. However, the increasing popularity of meat goats and the transportation of them from one area to another has provided fertile ground for transmission of this disease to all goat breeds. No goat breed is exempt from contracting this disease.
Dairy goats have had a higher incidence of CL than meat breeds, primarily because the penned method of raising dairy animals gave rise to easier transmission of the bacterium from goat to goat. However, the use of dairy does as recipients for Boer embryos has facilitated the spread of CL, and crossbreeding dairy animals with meat goats has taken it a step farther.
First reported in Oregon many years ago, Caseous Lymphadenitis is now a world-wide problem which continues to baffle scientists striving to find either a prevention or a cure . . . neither of which currently exists.
Infection occurs primarily through wounds caused by head butting, punctures, and shearing. However, ingestion, inhalation, or penetration through intact skin are also possible, though less likely. Internal abscesses cause major health problems. The disease can affect the lungs, liver, and kidneys, respiration may become rapid and difficult, and infertility can result from scrotal abscesses in males. Udder abscesses in females can seriously deplete milk production. External abscesses are most common under the ears in the head and neck region of the goat's body, while internal abscesses usually appear most often in the lungs. In decreasing percentages of frequency, external abscesses are found under the ear, on the shoulder, on the flank, and in the udder/scrotum areas.
Females contract CL at about the same percentage rate as do males. Wethers display a lower incidence of the disease, perhaps because they are generally terminal animals. The high infection rate in older animals confirms that the organism can be acquired at any time and that exposure increases with age.
All abscesses on goats are not necessarily CL abscesses. The bacterium actinomyces pyogenes also produces a fast-growing nodule, but it contains a smelly, greenish pus. A simple and inexpensive test can be done of blood samples to determine the bacterium causing the abscess. Most nodules . . . as high as 70% . . . . . are CL abscesses. It is highly contagious and spreads through a herd rapidly.
Why Is Caseous Lymphadenitis (CL) Considered A Problem In Meat-Goat Herds?
Unthrifty goats are not desirable in any meat-goat herd. Unhealthy animals are not productive, and unproductive goats cost producers' money.
Breeders who let abscesses burst and infect the ground have created for themselves a very long-term problem. CL can survive temperatures of 50 degrees F. below zero! Some evidence exists that it is less survivable in hot, dry climates, but studies are not advanced enough to reveal at what temperature and how long the weather must remain very hot and dry to eliminate CL in the soil once it is there. Recent research indicates that the bacterium survives better when mixed with dirt, hay, and feces and when it comes into contact with wooden rather than metal troughs, posts, fences, and feed bunkers.
CL is chronic (recurring) and incurable. Existing vaccines are effective only on sheep. If these vaccines are used on goats, not only will they provide no protection against the disease but they will also cause painful leg swelling which lasts for days. Autogenous vaccines --- vaccines made from a particular herd's infectious material --- are of very questionable effect.
How Should An Outbreak of CL Be Handled?
Create a "sick pen" dedicated solely to CL-infected goats; use it for nothing else. Immediately remove an infected animal from the herd and place it in isolation in the "sick pen." NEVER let the abscess burst on its own and contaminate pen or pasture. When the abscess begins to feel soft or the hair starts coming off its center, prepare to open the abscess and remove the exudate.
Gather the following supplies: disposable latex gloves for all persons involved, a #10 disposable scalpel, a 3 cc Luer slip syringe (no needle required), paper towels, 7% iodine solution, a rectangular shallow pan, a gallon of bleach, and a plastic bag into which the paper towels, exudate, and used gloves can be placed. It is also wise to have a hard-sided container (like an old Band-Aid can) into which the scalpel and Luer slip syringe can be placed for disposal.. Before entering the "sick pen," pour the bleach into the shallow pan and place it outside the pen for use as a "shoe bath" when exiting the pen. This should help prevent the spread of CL bacterium to other areas if by chance it adheres to the soles of your shoes.
Humans can contract Caseous Lymphadenitis; a skin lesion exposed to the bacterium is an invitation to this highly-contagious organism. Draft a dependable, strong helper to hold the goat down. Cover exposed body parts with clothing and put on the disposable gloves. Enter the "sick pen" and place the goat on its side on the ground. Cut into the abscess perpendicularly to the goat's body . . . NOT at the base or at the top of the abscess . . . taking care not to allow the contents of the abscess to squirt on you. A "ripe" abscess oozes material the general consistency of toothpaste. Using paper towels, squeeze the abscess until all of the pasty content is out and a bloody liquid begins to appear. Apply pressure from several directions, since most abscesses are comprised of several chambers closed off from each other. (This is why antibiotics are not effective; the medication cannot reach the encapsulated abcess.) A second incision is occasionally required.
Flood the interior and the exterior of the incision with 7% iodine, using a 3 cc luer-slip syringe. Be careful to keep the iodine from running into the goat's eyes, ears, nose, or other orifice near the incision. Bag all infected materials tightly, step into the shoebath as you leave the pen to prevent the spread of the bacterium, and prepare to burn all items which came into contact with the infected exudate. Use Betadine Surgical Scrub on all exposed parts of your body and change clothes and shoes before going on to your next task.
Keep the infected goat in isolation until the wound completely heals. Repeat the above-outlined procedure several times over the next three to five days, as needed, because an abscess tends to fill up again . . . although usually with less and less exudate . . . until it quits draining and begins to heal. With really large and complicated (multi-chambered) abscesses, it is advisable to soak a piece of gauze in iodine and place it inside the incision, with a bit of the gauze hanging out of the cut, so that you can pull it out the next day and re-work the abscess. This will prevent the incision from healing over, so you won't have to cut the animal again.
Infected areas should be thoroughly cleaned of all contaminated materials. The top two inches of dirt should be removed from the barn, shed, or pen areas, and a solution of tri-sodium phosphate or similar detergent should be applied to the ground. Agricultural lime should be generously spread and allowed to remain in the soil.
What Are The Challenges to Eliminating CL In Meat-Goat Herds?
Caseous Lymphadenitis is extremely resistant to antibiotic therapy because the thick caseous pus is encapsulated in a tough fibrous capsule which antibiotics cannot penetrate. The abscesses usually develop slowly and contain a cheesy, dryish, white pus. The smell is unmistakable. Lab testing on blood samples is the only diagnostic tool currently available, and tests on goats under six months of age are very unreliable. Active, runny, open abscesses are most accurately testable. Older lesions don't shed enough of the baceterium to be readily detectable. The incidence of "false negatives" is high, particularly in goats displaying no visible evidence of abscesses. This is one good reason NOT to buy goats at commercial auctions; you are usually buying someone else's problems.
Dr. Michael D. Piontowski, DVM, Senior Staff Veterinarian at Colorado Serum, who provided this writer with much of the information contained in this article, advises that a CL vaccine for goats is "in the works" but is still a long, long way off.
Why Should CL Be Eliminated From Meat-Goat Herds?
Quality breeding stock cannot have abscesses or any other disease. And slaughter goats with abscesses will certainly bring less money to the producer.
The meat-goat industry . . . an industry in which animals can be produced in large quantities and with goats big enough to permit cuts for the grocery store's meat case . . . is in its infancy. Supply cannot meet demand, even now. However, if we don't police ourselves and keep all diseases, including CL, out of our products, some other entity like the USDA or the American media will do it for us.
CL is "zoonotic," which means that it CAN be transmitted to humans. The incidence is quite low, but that will be irrelevant if television or the print media elects to present a "documentary" on CL in goat meat. No definite link between "mad-cow disease" and illness in humans was ever made in Britain, but many cattle raisers had to destroy thousands of animals anyhow. The public outcry had to be quelled.
If producers permit zoonotic diseases to remain in their goat herds, then the American public will likely never begin to eat goat meat on a large scale, despite its low-calorie, low-fat characteristics which make it the ideal healthy meat. Our fledgling industry will be stopped cold in its tracks.
Today there is no adequate method available to get control over and properly manage Caseous Lymphadenitis (CL) in a goat herd. If a goat contracts CL, cull that animal from your herd. CL should be considered a "terminal" disease in a meat-goat operation.
