Mange

The mange mite is a burrowing mite that feeds on the lymph underlying the pig's skin. It causes stress in the pig which is often reflected as scratching, restlessness, tail biting, bar biting and excessive noise.

The economic effects of mange infestation are quite serious. In finishing pigs, mange can reduce food conversion rates by 10 percent and daily liveweight gain by 20 percent. The effects of mange on breeding stock are not as serious. Yet most control programmes concentrate on the sow and boar. This is because the sow is the initial reservoir of infection for the newly born piglet.

Most treatments for manage are only effective for 7 to 14 days. Suppose a sow enters the farrowing house with mange. One litter of infested piglets can infect the entire finishing herd over time.

The transmission of mange is mainly by pig to pig contact, however, other vectors include clothing, footwear and animal hosts such as cats and dogs. Further to this the mange mite and its eggs may survive outside the host for up to 2 to 3 weeks.

A breeding pair of adults and their offspring can produce up to 60,000 to 70,000 mites over a two-month period.

If we are only treating the breeding herd, have we ignored the fact that there may be mange in the feeding herd? If so, has it ever been treated.

Bearing in mind that the mange mite can survive outside the pig and can establish itself so rapidly, it is conceivable that in time it can become established in the feeding herd.