Mange continues to nag at the U.S. pork industry, according to a survey involving 10,452 hogs in 218 herds. A 28 percent infestation rate surfaced.

Still, it does reveal a drop in mange infestation when compared to a similar study in 1996, when 43 percent prevalence was found.

“However, if you’re the pork producer who is losing money because of mange, the reduced prevalence is of little consolation,” says John Melancon, DMV with Merial. “The real problem is that many pork producers don’t realize their herds are infested, because today’s mange levels are not easily detected by casual observation.”

Using Dermatitis Lesion Scoring, Melancon conducted the study at three processing plants, two in Minnesota and one in South Dakota.

Scoring conducted at the processing plant provides an effective indicator since there is a strong correlation to mange infestation. Hog carcasses are observed after slaughter and scalding at the processing plant, and then graded on a 0-3 scale:

  • 0 (no lesions)
  • 1 (mild localized dermatitis)
  • 2 (mild generalized dermatitis)
  • 3 (generalized or focal severe dermatitis)

Individual scores are used to determine the Average Dermatitis Score for that herd. A herd with an ADS of less than 0.5 is considered to be mange-free or not a problem. However, with 28 percent of the animals greater than 0.5, and 11 percent scoring between 2 to 3, profit loss can be serious, says Melancon.

Mange can be eradicated with a proper management program,” says Melancon.  “A 28 percent prevalence level is far too high given the tools available to pork producers today.”