Actinobacillosis

Also called wooden tongue

Description

This is an infection in the tongue caused by Actinobacillus lignieresii, the same bacterium that often causes soft-tissue abscesses in the mouth. This pathogen is commonly found in the digestive tract of cattle and generally causes problems only when there’s injury to the tissues of the mouth or tongue that enable bacteria to enter.  

Local infection of the tissues with this particular pathogen causes acute inflammation, tissue death and pus discharge.  The infection may spread to nearby lymph nodes.

Some animals with wooden tongue develop multiple abscesses around the head and jaw.  In some instances a case of wooden tongue might be mistaken for lumpy jaw, because of the abscesses and difficulty eating.  

An animal with wooden tongue has a very firm, hard tongue which interferes with chewing and makes it difficult to move the tongue--which hinders ability to eat. Since a cow eats by pulling feed into her mouth with the tongue, she can’t eat very well with this condition and loses weight.

The tip of the tongue may protrude from the mouth if it is swollen; the cow can’t pull it back in. Sometimes there is drooling of saliva because the cow can’t keep her mouth closed. If you examine the tongue, it is very large and firm.

The affected animal may be standing around and not grazing with the other animals. If you are feeding hay, she may come to the hay and push it around with her nose, trying to eat, but she isn’t really eating. She may make chewing motions, 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 constant chewing, saliva may drool from the mouth.
 
If you restrain the cow and check her mouth, the tongue is enlarged and stiff, especially at the base. The tip may be normal and you can feel the difference. 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 loses weight. The weight loss is usually quite noticeable within a few days. She may also become dehydrated if the stiff tongue makes it difficult to drink. Constant salivation and inability to swallow can lead to weakness due to electrolyte loss in the saliva.

In later stages of infection, without treatment, the tongue becomes shrunken, hard and immobile. Enlargement of infected lymph nodes may interfere with swallowing, and may also cause loud snoring sounds when the animal breathes.

In diagnosis, wooden tongue is sometimes mistaken for bony lump jaw (infection in the jawbone) because of the abscesses and difficulty eating; some animals with wooden tongue develop multiple abscesses around the head and jaw. But if an animal with wooden tongue has abscesses they are just in the soft tissue and not in the bone.

Wooden tongue can be treated with antibiotics and halted. The tongue can then remodel and the animal recovers.  

Signs

    Drooling, tongue hard and sore, may protrude from the mouth, inability to eat, weight loss, sometimes abscesses around the head.

Causes

A break in the tissues allows bacteria to enter, and may be due to abrasions or punctures when eating coarse feed, or lacerations on the side of the tongue caused by bad teeth.

Prevention

The best prevention is avoidance of coarse or sharp feed. This may be difficult, however, if cattle are on fall and winter pastures and consuming coarse feeds after softer forages are gone. It’s not always possible to monitor what cattle are eating or chewing on.

If you find an animal with wooden tongue, you can isolate her to keep her from spreading the infection. It’s always wise to isolate any animal that develops wooden tongue, and treat it quickly. Otherwise the animal may contaminate pasture and feeding areas with pus discharges.

Treatment

This infection is in the soft tissue of the tongue (and not in bone), so it can be more easily treated with antibiotics. The causative organism is sensitive to penicillin and tetracycline so these animals can be successfully treated, recover and do well. Long-acting oxytetracycline (LA-200 or LA-300) works well because you get longer coverage and don’t have to treat every day.

The infection also responds well to iodides, which can be administered orally or intravenously. Potassium iodide can be given daily as a drench for 7 to 10 days, but this treatment is time consuming and labor intensive and the animal may develop sensitivity to iodine. The sensitivity will be evidenced by excessive watering of the eyes, coughing, lack of appetite, and flaky skin (dandruff).  

It is often simpler to have your veterinarian give the animal one dose of sodium iodide (10% solution) intravenously, after which the symptoms of wooden tongue disappear in 24 to 48 hours. 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 quicker) and most permanent results.

Intravenous sodium iodide infiltrates the tissues better, to get rid of the infection. Some people worry about the risk of abortion if the cow is pregnant when giving the iodide solution, but this seems to be a very low risk, and most people go ahead and treat the cow. It’s more important to get the wooden tongue cleared up; otherwise 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.

Most veterinarians feel safe in using sodium iodide in pregnant cows, especially since the problem they are treating is life threatening, and much worse than the very low risk of abortion from the sodium iodide.

Sodium iodide given IV is very effective in treating wooden tongue and can also help in some cases of bony lump jaw, putting the bone infection into remission for a while. The pathology of wooden tongue and lumpy jaw is similar—so people often give sodium iodide for lumpy jaw, along with an antibiotic that might penetrate that area. The good news about wooden tongue compared with lumpy jaw is that the animal will recover from wooden tongue with proper treatment. Some cases resolve in less than a week after the sodium iodide is administered. By contrast, a cow with lump jaw will generally relapse.

 Sometimes it’s necessary 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. Veterinarians can surgically create an opening into the rumen to feed a valuable individual until the tongue regains mobility. A feeding tube can be put directly into the rumen to provide nutrition through the tube until she can eat again.