wooden tongue

Pictured here, a cow suffering from wooden tongue. Photo courtesy of Dr. Matt Miesner.

The expression “tongue tied” generally refers to someone who is reluctant to speak, but it might also apply to a cow with a certain type of infection in the tongue and throat area—a condition commonly known as wooden tongue.

The medical term for this disease is actinobacillosis and it is caused by the bacterium Actinobacillus lignieresii. This pathogen is commonly found in the environment and in the alimentary tract of cattle. According to Dr. Matt Miesner, clinical professor of livestock services at Kansas State University, this pathogen generally causes problems only when an injury to the tissues of the mouth or tongue enables the bacteria to enter these tissues.

The break in the tissues may be due to abrasions or punctures that occur when eating coarse feed, or lacerations on the side of the tongue caused by sharp teeth. Local infection of tissues at the base of the tongue causes acute inflammation, tissue death and results in pus discharge. The infection may spread to nearby lymph nodes. Those early signs are rarely observed, however. A person doesn’t notice the problem until the cow can no longer eat.

The tongue becomes sore and stiff, which interferes with chewing. The affected animal has trouble eating. You might notice that she’s not grazing with the other animals. If it is winter and you are feeding hay, you might realize that even though she comes up to the hay and pushes it around with her nose and tries to eat, she isn’t really eating. She may make chewing motions, however—looking as if she’s trying to get rid of a foreign object in the mouth. The tongue probably feels strange because it’s swollen and stiff. Due to the constant chewing, saliva may drool from the mouth.

If you restrain the cow and check her mouth, you might notice the tongue is enlarged and stiff, especially at the base. “The tip may be normal and it’s easy to feel the difference as you reach toward the back of the tongue,” says Miesner. Handling the tongue is painful to the animal. There may be lumps and ulcerations along the side of the tongue.

Since the cow has trouble eating, she starts losing weight. The weight loss is usually obvious within a few days. “She may also become dehydrated if the stiffness of the tongue makes it difficult for her to drink. Constant salivation and inability to swallow can lead to dehydration and generalized weakness, due to electrolyte loss in the saliva,” he explains.

In later stages of infection the tongue becomes shrunken, hard and immobile; the animal continues to have trouble eating. Enlargement of infected lymph nodes may interfere with swallowing, and may also cause loud snoring sounds when the animal breathes.


This infection responds well to iodides, which can be administered orally or intravenously. Potassium iodide can be given daily as a drench for seven to 10 days, but this treatment is time consuming and labor intensive and the animal may develop sensitivity to iodine. Sensitivity will be evidenced by excessive watering of the eyes, coughing, lack of appetite, and flaky skin (dandruff).

“It is simpler to just have your veterinarian give the animal one dose of sodium iodide (10 percent solution) intravenously, after which the signs of wooden tongue may dramatically resolve within a few days. Care must be taken to administer the IV slowly to avoid side effects (difficult breathing and rapid heart rate).

“Penicillin and several other broad-spectrum antibiotics are also effective, but iodides seem to give the best and most permanent results. People use various antibiotics, but sodium iodide is the standard treatment,” says Miesner.

“Intravenous sodium iodide infiltrates the tissues much better, to get rid of the infection. Some people worry about risk of abortion if the cow is pregnant, but this seems to be a very low risk. The warning about risk of abortion when treating pregnant cows is on the label, but the main reason it’s printed there is that this treatment hasn’t really been scientifically evaluated in pregnant cattle. We don’t know the level of risk, so the drug company is playing it safe and being cautious,” he explains.

Instances of abortion are rare, but even if there is a risk, most people go ahead and treat the cow. “My argument for doing this is that we know that if we don’t get the wooden tongue cleared up, the cow will starve to death, and then it won’t matter about the risk to her calf.” You need to first save the cow.

“Over decades of use, and administering multiple doses of sodium iodide to pregnant cows when they needed it, I haven’t found that it increases abortion risk, compared with the serious risks with this disease itself. Most veterinarians feel safe in using it for specific indications, especially when realizing that the problem they are treating is life threatening for the cow, and much worse than the risk of abortion from the sodium iodide. I still use caution when using sodium iodide for various less specific disease treatments,” says Miesner.

Sometimes a person needs to figure out a way to administer fluid and nutrients to the cow during the period of time she can’t eat or drink. Fluids can be given via nasogastric tube but feeding is more effective with a rumen fistula. “I’ve sometimes done surgeries to create a fistula in order to feed certain valuable individuals until the tongue regains mobility.

“Then we can put a feeding tube directly into the rumen to provide nutrition. This is easy on the cow; a small rumen fistula is not a major surgery and it’s easy to do. Then the cow can be fed through the tube until she can eat again. Some cases resolve in less than a week after you administer sodium iodide,” he says. — Heather Smith Thomas, WLJ correspondent

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