CL in goats stands for Caseous Lymphadenitis, a chronic bacterial infection that causes abscesses in the lymph nodes and sometimes in internal organs. It’s caused by the bacterium Corynebacterium pseudotuberculosis, and once it enters a herd, it’s notoriously difficult to eliminate. The disease is one of the most common reasons goats are culled from herds worldwide.
How CL Spreads
CL spreads primarily when pus from a ruptured abscess contacts another animal’s skin, especially through cuts, scrapes, or shearing wounds. The bacteria can also be inhaled or swallowed. What makes CL so persistent is the organism’s ability to survive outside the body for long periods: up to 2 months on surfaces like bedding and wood, and up to 8 months in soil. If an abscess ruptures in a pasture, that ground remains contaminated for most of a year.
Shared equipment is another major route. Feed bunks, stanchions, shearing tools, and fencing that contact drainage from an abscess can carry the bacteria to the next animal. Flies can also transfer infected material between goats. A single introduction, whether from a new purchase or contaminated equipment brought from another farm, can seed an outbreak across an entire herd.
External vs. Internal Forms
CL shows up in two distinct ways, and the difference matters for both detection and prognosis.
The external (superficial) form is the one most goat owners notice first. Firm, round swellings appear at lymph node sites, most commonly around the jaw, behind the ears, in front of the shoulder, in the udder area, or in the flank. When cut open, these abscesses contain thick, greenish-white pus with a characteristic “onion ring” layered appearance. In one study of superficial cases, the lymph nodes near the throat were affected most often (about 41% of cases), followed by the mammary lymph nodes (31%) and prescapular nodes near the shoulder (16%).
The internal (visceral) form is harder to detect and more dangerous. Abscesses develop on internal organs or deep lymph nodes, most frequently in the respiratory system. In studied cases, 85% of animals with the visceral form had lesions in their lungs or the lymph nodes surrounding them. The liver, kidneys, and brain can also be affected. Goats with internal CL may show chronic weight loss, coughing, labored breathing, or general wasting without any visible lumps. This form tends to appear more often in older animals and can go undiagnosed for a long time.
Diagnosing CL
The most reliable way to confirm CL is to culture the bacteria from abscess material. Any time you find a lump on a goat, it should be treated as potential CL until proven otherwise by lab results.
Blood testing can also identify infected animals, including those without visible abscesses. The ELISA blood test performs well for screening herds, with specificity rates above 98% in goats, meaning false positives are rare. However, no blood test catches every infected animal, especially those in early stages of infection before the immune system has mounted a detectable response. The best approach combines physical examination (feeling for lumps at common lymph node sites) with blood testing to catch both obvious and hidden cases.
Managing Infected Goats
There is no reliable cure for CL. Antibiotics don’t penetrate the thick-walled abscesses effectively, so management focuses on preventing spread to healthy animals. The practical steps matter enormously here.
Any goat with an abscess should be isolated immediately from the rest of the herd until the abscess has completely healed and the cause has been identified. If you need to lance an abscess, do it over a hard surface like concrete that can be scrubbed and disinfected, or over a disposable tarp. Never lance an abscess in a pasture or dirt pen. All drainage material, including gloves, gauze, and any covering material, needs to be burned or double-bagged and discarded.
Goats showing respiratory symptoms or unexplained weight loss in a herd with known CL should also be separated, since these signs can indicate internal abscesses that are shedding bacteria into the lungs. Many producers choose to cull animals with confirmed CL, particularly repeat offenders or those with the internal form, because chronically infected goats serve as ongoing reservoirs of infection.
Preventing CL in Your Herd
Biosecurity is the most effective tool against CL. New animals should be quarantined in a separate pen and tested twice, 30 days apart, before joining your herd. Ideally, you’d also confirm the herd of origin has tested negative. Purchase and maintain your own shearing and hoof-trimming equipment rather than borrowing or sharing tools between farms. Disinfect feed bunks, milking equipment, and stanchions regularly.
Fly control matters more than many producers realize, since flies can carry bacteria from draining abscesses to open wounds on other goats. If an abscess does rupture in a pasture, rest that area for at least 8 months before using it again.
Vaccines exist but offer incomplete protection. Products available in different countries combine killed bacteria with toxoid components, but their performance in goats specifically has been inconsistent. Some vaccines also carry notable side effects, including injection-site abscesses (which can be confused with CL itself), fever, and reduced milk production. Vaccination can slow the spread of infection at the flock level and reduce internal lung lesions, but it won’t prevent all new infections or eliminate the bacteria from already-infected animals. It works best as one layer of protection alongside strong biosecurity practices, not as a substitute for them.
Economic and Production Losses
CL takes a real financial toll on goat operations. Visible abscesses lower an animal’s market value and can make goats unsaleable entirely, particularly in markets where buyers expect visually healthy animals. At slaughter, infected carcasses may be partially trimmed to remove affected tissue, reducing the amount of usable meat. In severe cases, entire carcasses are condemned and rejected for human consumption. The disease also reduces reproductive efficiency and can damage hides and fiber quality in fiber-producing breeds.
Can Humans Get CL?
CL is a zoonotic disease, meaning it can occasionally infect people, though it’s uncommon. A review of cases from Australia documented human lymph node infections caused by the same bacterium, mostly in people with occupational exposure to sheep and goats. Some patients experienced prolonged illness or recurring symptoms. The risk is highest when handling draining abscesses without gloves or when contaminated material contacts broken skin. Wearing disposable gloves, washing thoroughly after handling suspect animals, and avoiding contact with abscess contents are straightforward precautions that significantly reduce your risk.