Boars continually grow tusks that pose a safety hazard to human handlers and other pigs.
To remove the danger, tusks are sometimes trimmed once or twice a year.
Tusks can be removed using hoof nippers or bolt cutters. Less frequently used – but the recommended method – is orthopedic wire is used as a “saw” to cut off tusks.
Tusks are generally trimmed very close to the gum line without the use of painkillers or sedation.
The majority of boar tusks have pulp extending above the gum line. The pulp contains nerves. Therefore, trimming may cause pain and leave the tusk open to infection.
A research study was conducted in Ontario to learn more about the structure and the presence of nerves in the pulp (soft tissue) of the tusk. See Figure 1 for a cross-sectional view of the boar tusk.
The mandibles of 51 cull boars were collected from a commercial slaughter plant (Figure 2), which contained 102 tusks. Tusk length, pulp exposure and gum condition were assessed using a scoring system.
Of the 102 tusks examined, 51% were assigned scores of 2 or 3, which are associated with pulp chamber exposure; 44% also had scores associated with moderate to severe gum inflammation, indicating that tissue irritation/inflammation may be linked with trimmed tusks (See Figure 3, Figure 4, and Figure 5).
Analyses performed on seven intact tusks following decalcification showed that the tusk pulp chamber, on average, extended to the level of the gum line. In four of the seven tusks, the pulp chamber extended beyond the gum line. Figure 1 illustrates the location of the gum line in relation to the tusk.
Sections of five tusks examined for the presence of nerves revealed that all five contained nervous tissue. In general, nerves were most common at the tusk base.
In two of the five tusks, nerve fibers extended beyond the gum line. Further research needs to focus on differentiating between autonomic nerves (which control the blood vessels) and sensory nerves (which detect pain or pressure) within boar tusk pulp tissue.
Researchers concluded that boar tusks do have nerves. Tusk trimming can expose the pulp which contains the nerve and contribute to the development of gum inflammation.
As a result, researchers recommended avoiding or reducing tusk trimming. Consider housing and transporting boars individually to avoid the need to trim tusks.
If tusk trimming must be done, cut the tusk about an inch beyond the gum line to avoid cutting into the pulp chamber, they suggest.
Researchers: K. Bovey, J. DeLay and T. Widowski, all of the University of Guelph; and P. Lawlis, Ontario Ministry of Agriculture, Food and Rural Affairs. Contact Widowski by phone (519) 824-4120 (ext. 52408), fax (519) 836-9873 or e-mail twidowsk@uoguelph.ca.