Goats get CL (caseous lymphadenitis) when bacteria enter their body through a break in the skin. The bacterium responsible, Corynebacterium pseudotuberculosis, needs a wound or abrasion to establish infection. It cannot penetrate intact skin on its own. Once inside, it travels to the lymph nodes and forms thick, walled-off abscesses filled with a greenish-white pus that is highly contagious to other goats.
How the Bacteria Gets In
The most common entry point is a skin wound. Any cut, scrape, or puncture gives the bacteria an opening. In a farm setting, this includes injuries from shearing, ear tagging, tail docking, castration, and routine handling. It also includes the smaller, less obvious injuries goats pick up from barbed wire, exposed nails, rough feeders, and thorny browse.
The bacteria can also enter through mucous membranes, such as the lining of the mouth. A goat eating from a contaminated feeder or hay rack that an infected goat has rubbed against could potentially become infected this way, especially if it has any sores or irritation in its mouth.
Where the Bacteria Comes From
The single biggest source is pus draining from an open abscess on an infected goat. When a CL abscess ruptures, either on its own or because it was lanced, it releases a massive load of bacteria into the environment. That material gets on bedding, fencing, feeders, water troughs, the ground, and anything else nearby. A healthy goat with even a tiny scratch that contacts contaminated material can become the next case.
People can also spread it. Anyone who handles an infected goat or touches drainage material can carry bacteria on their hands, clothing, and equipment to the next animal. Shearing tools are a classic route: the blade nicks the skin and deposits bacteria from a previously shorn infected animal directly into the wound.
The Bacteria Survives for Months
What makes CL so difficult to eliminate from a herd is the organism’s hardiness. It can survive on wood surfaces and in bedding for up to two months, and in soil for eight months or longer at normal environmental temperatures. That means a pen where an abscess ruptured six months ago can still be a source of infection, long after the sick goat has been removed. Wooden fence posts, barn walls, hay feeders, and dirt lots all act as reservoirs.
This environmental persistence is why cleaning up after an abscess rupture matters so much. The bacteria isn’t fragile. It waits.
External vs. Internal CL
Most goat owners first notice CL as a visible lump under the skin, usually near a lymph node. Common locations include under the jaw, in front of the shoulder, in the flank area, and above the udder. These external abscesses grow slowly over weeks, eventually becoming firm, round swellings that may rupture on their own.
CL also has an internal form, where abscesses develop on lymph nodes inside the body, particularly those near the lungs. Internal CL is harder to detect because there’s no visible lump. Affected goats may lose weight gradually, produce less milk, or simply fail to thrive without any obvious external sign. Some goats carry internal infections for years without showing clear symptoms, quietly shedding bacteria and exposing herdmates. This makes internal CL a hidden driver of spread within a herd.
Common Scenarios That Spread CL
- Buying an infected animal: A new goat with no visible abscesses can still be carrying the bacteria internally or in an abscess that hasn’t surfaced yet. Introducing it to your herd without quarantine and testing is the most common way CL arrives on a clean farm.
- Shared equipment: Borrowing grooming tools, milking equipment, or handling chutes from another farm can bring contaminated material home.
- Contaminated housing: Moving goats into a pen or barn previously used by infected animals puts them at risk, especially if wooden surfaces haven’t been thoroughly disinfected.
- Abscess rupture in a group setting: A single abscess bursting in a communal pen can expose every goat in the group. The pus contaminates everything it touches, and any goat with a minor wound is vulnerable.
Reducing the Risk
Prevention starts with keeping the bacteria out of your herd. Quarantine new animals for at least 30 days and have them tested before they join the group. Inspect them carefully for any lumps, particularly around the head, neck, and shoulders.
On the farm, reducing injury opportunities makes a real difference. Walk your fencing and housing regularly and remove anything that could cut or scrape: exposed nails, broken wire, splintered wood on feeders. Every wound you prevent is one less entry point for the bacteria.
If you do have a goat with a suspected CL abscess, isolate it immediately. The goal is to prevent that abscess from rupturing in a shared space. If an abscess does burst, all contaminated bedding and soil should be removed and the area disinfected. Any pus or drainage material is extremely infectious and should be handled with gloves and disposed of carefully, not left on the ground.
A vaccine does exist for CL. Studies on its conventional formulation show it can protect around 95% of vaccinated animals against infection. However, the vaccine does not cure animals that are already infected, and it’s primarily used as one part of a broader control program rather than a standalone solution. It’s most useful in herds with a known CL problem, where reducing new infections over time is the goal.
Because the bacteria can survive in soil for the better part of a year, eliminating CL from an infected herd takes sustained effort over multiple seasons. There’s no quick fix. The combination of testing, culling or isolating positive animals, vaccination, environmental cleanup, and strict biosecurity is what gradually brings a herd back to clean status.