Wooden TongueThe ConditWooden tongue is a well-defined disease of the soft tissues of the mouth region in adult cattle.
It is caused by Actinobacillus lignieresii, part of the normal bacterial flora of the upper digestive tract. The bacteria usually invade the skin through a wound or minor trauma caused by sticks or straw or barley awns.
The disease is fairly acute, with swelling in the affected part, under the jaw and in the regional lymph nodes. The clinical symptoms are excess salivation, difficult mastication and inappetance. The condition is seen either as an outbreak in several animals simultaneously or as an individual case in a single animal, often in association with a diet change.
In cattle, ‘wooden tongue’ is the most commonly recognised, acute presentation of actinobacillosis, but the bacteria can affect soft tissues anywhere in the gastrointestinal tract (including the rumen and reticulum) and may present as a chronic condition of up to six months duration. Additionally, cutaneous actinobacillosis has been reported where it is important to differentiate this condition from cutaneous lymphosarcoma.
Methods of Control and Prevention
Avoiding rough grazing, soil-contaminated silage, and “weedy” hay/haylage or straw for cattle feed usually prevents trauma to mucosal membranes in the mouth.
In the case of an isolated incident in an individual animal the best approach to prevention and control is to isolate and treat the animal at the first sign of symptoms. The animal should not be brought back into the main herd until all symptoms have disappeared as they are a potential source of infection to the rest of the herd.
In an outbreak, it is important to identify the causative factors to the predisposing lacerations in the mouths of the affected animals. This is likely to be a feed source that, once identified, should be removed. Again, isolation of affected animals and effective treatment early are the best control measures to prevent further spread. If there is an outbreak of cutaneous actinobacillosis, rough objects in the environment (such as feed barriers) should be removed or modified to prevent skin abrasions allowing bacterial entry.
As the causative bacteria do not survive more than 5 days in the environment and are present in the mouths of healthy cattle, the removal of the predisposing feed source is adequate to control the disease within a herd. If the problem persists, it is important to look for further sources of predisposing factors and eliminate them.
Treatment wooden tongue is usually successful if started early. However, if treatment of classic wooden tongue is started more than two weeks after the first symptoms and the animal has lost a lot of condition, the treatment is less likely to be successful and humane slaughter should be considered. However, treatment of cutaneous actinobacillosis has been successful even in cases of long standing (up to 6 months).
A veterinarian should always be involved if treatment for wooden tongue is attempted. Antibiotics are very efficacious and should be the treatment of choice for this condition. Treatment with penicillin and streptomycin combinations have been successful, but may need to be continued for 2-3 weeks duration for complete resolution of long standing cutaneous disease.
The Condition and Welfare
Classic wooden tongue is painful and distressing for the animal. Early examination of any symptoms indicating excess salivation and difficulty in mastication is important to enable early treatment and minimal suffering.
Removal of predisposing feed or grazing is also important from the animal welfare point of view, in order to prevent further cases.
Good Practice based on Current Knowledge
When dealing with individual animals with wooden tongue, or with outbreaks of the disease, it is good practice to:
- Examine early any animals with “mouth” symptoms (excess salivation, difficulty in mastication etc.) and contact a vet as soon as the condition is suspected.
- Isolate the animal and initiate a course of treatment immediately for successful results.
- Always attempt to identify the predisposing factor (feed or grazing) and eliminate it immediately, even when only one animal is affected
Guidelines on the Disease during the Conversion Period
There are no particular measures necessary for the conversion period or an Animal Health Plan if the farm has not suffered from the condition recently or at all.
If the farm has experienced recurrent outbreaks of wooden tongue, it would be advisable to incorporate guidelines for prompt treatment and control into an Animal Health Plan. Identification and exclusion of the predisposing feed or grazing should be included in the conversion plan.
