What is Greasy Pig Disease?

The disease is a skin infection caused by bacteria named Staphylococcus hyicus, which is commonly found on the skin of pigs. The oozing of serum from the damaged skin makes the surface greasy, hence the name. Outbreaks of the severe form of the disease cause high mortality and survivors are often poor doing pigs that have to be culled. Pigs with damaged skin due to fighting, mange, etc. are prone to getting the disease.

Why is Greasy Pig Disease on the Increase?

Producer surveys show that the number of cases of greasy pig disease in Ontario is increasing. This is possibly because:

• More producers (30 per cent of those surveyed) moving away from routinely clipping needle teeth, which can result in more skin damage due to fighting.
  
  
• S. hyicus has developed antimicrobial resistance, which results in ineffective treatment of the disease. Many producers surveyed expressed disappointment regarding response to treatment.

How is it Currently Treated

• About 70 per cent of the respondents reported that they routinely use topical treatments to control the disease, with mineral oil alone or in combination with an antibiotic such as novobiocin, or they use an antiseptic such as iodine.
  
  
• Over 50 per cent of the respondents reported they use an injectable antibiotic, either alone or in conjunction with a topical treatment. The popular antibiotic choice was penicillin.

Other Findings

Skin scrapings and skin swabs were collected from six pigs from each of seventeen farms.

• 60 per cent of the samples showed positive for S. hyicus and 40 per cent of the samples showed positive for S. aureus
  
  
• All 66 isolates of S. hyicus cultured from skin swabs showed resistance to penicillin and ampicillin and about 70 per cent of the isolates showed resistance to ceftiofur (Excenel®). All three antibiotics belong to the same drug family, the beta-lactams. The resistance pattern was similar to S. aureus.

Take-Home Messages

Greasy pig disease is unlikely respond to injections of penicillin or any of the beta-lactam antibiotics due to antibiotic resistance.

Alternative approaches such as topical treatments and vaccination need to be explored.

Good sanitation, lowering humidity, minimising wounds, eradicating mange and minimising non-essential mixing of pigs are essential to prevent the disease.

Early application of antiseptics to wounds can also help prevent infection and reduce the chance of greasy pig disease.

April 2010