Porcine sarcoptic mange

Porcine sarcoptic mange, also known as pig mange or scabies, is a skin disease caused by mites. It is widespread in Australia. Pig farmers can treat and control mange in existing herds, or establish mange-free herds.

The disease substantially reduces the performance, including growth rates (up to 12%), in infected pigs.

Feed conversion ratio (FCR) (the kilograms of feed required to produce a kilogram of pork) is increased, and mange can predispose the pig to other skin disorders.

Scientific name

Sarcoptic scabies var suis

Cause

The mite Sarcoptic scabies var suis

Other names

  • Pig mange
  • Pig scabies

Distribution

Widespread in Australia.

Hosts

Pigs

Life cycle

  • Female mites lay eggs as they burrow under the skin
  • Eggs hatch and mature mites develop in 10-15 days
  • Adult mites and eggs can survive for a few days outside the pig, contaminating the pig's environment

Affected animals

  • pigs

Symptoms

The signs of sarcoptic mange include:

  • skin lesions (damage) usually starting around the ears and head, but can spread over the whole body
  • intense irritation causing itching, rubbing and an allergic response in young pigs
  • early lesions appear as small red patches on the skin
  • chronic mange develops with rubbing and thickening of the skin and crusts in the ears - mostly in boars and sows.

Impacts

  • Often more severe than pork producers realise
  • Reduces growth rate and feeding efficiency of affected pigs, especially in weaners and grower pigs
  • Damages the pig's skin from rubbing and scratching, predisposing the pig to other skin diseases, particularly bacterial infections
  • Alters body condition from continual skin irritations caused by chronic mange which may adversely affect breeding efficiency

How it is spread

  • Mange-infested sows infect their suckling piglets in the farrowing house
  • Mites spread rapidly when pigs are in close contact

Risk period

Sarcoptic mange is more severe during the cooler months.

Monitoring and action

  • Sarcoptic mange 'scoring' is conducted on pigs following slaughter (minor dermatitis may be from other causes besides mange)
  • The Pig Health Monitoring Scheme routinely performs 'scoring' on marketed grower pigs
  • Mites can be seen under the microscope in deep skin scrapings and crust from the ear canal of affected live animals
  • Multiple skin scrapings may be needed for detection

Control

Chemicals can control sarcoptic mange and prevent pig herds from reducing their performance.

Always follow the manufacturer's directions for use, storage and instructions for withholding period.

Using spray chemicals

The pig's body must be totally wet, especially:

  • the inside of ears and legs
  • around the head
  • under the belly
  • areas covered by crusts.
  • use personal protection equipment (PPE)
  • record all treatments, date, product, dose.

You could dip small pigs, for example at weaning, in a drum containing the chemical.

Eggs are not killed by the chemical. In an infested herd, spray the whole herd twice, 7-10 days apart, to kill any mites that have hatched since the first treatment.

You might need to spray severely affected herds again.

Chronically affected animals may not respond to treatment and may need to be culled.

Using pour-on products

Apply to the pig's backline. Use a small portion of the measured dose to apply in the ears and onto body crusts.

Using injectable treatments

Injectable treatments are registered for treating sarcoptic mange in pigs, and are also effective against internal parasites such as worms.

Planning treatment

Piggeries should follow a treatment program:

  • treat boars every 2-3 months as they are in constant contact with sows
  • treat sows/gilts before farrowing to restrict spreading mange mites to piglets
  • treat piglets at weaning and during the growing period as required
  • prevent contaminating the pigs' environment by using chemical sprays to kill the mite in pens
  • use protective clothing when using chemicals.

Planning treatment may:

  • eradicate (completely remove) the mange mite from the herd
  • establish and maintain a mange-free herd.

For the most effective treatment program, consult your veterinarian.