Mange

Causal agent	Sarcoptes scabiei var. suis
Age group	Affects all age groups, although sows and growing pigs most often exhibit the characteristic clinical signs
	World wide distribution with some 70% or more herds infected
Life cycle
	Eggs are laid in the skin of the pig. The female lays about 1 to 3 eggs a day and the adult female lives for about a month, therefore some 30 to 40 eggs are laid per female. Most of the eggs are laid in the soft tissues of the inside of the ear. There may be as many as 18,000 mites per gram of ear skin.
	The eggs hatch out in about 5 days
	The larvae molt to the nymph, which molt to the adult in 10 to 15 days. The life cycle remains on the pig at all times
Clinical signs
	Scratching
	Piglets may be uncomfortable and have intermittent body scratching
	A few weeks later the weaned and growing pig demonstrate persistent itching and rubbing
	Ear wax increases, sometimes forming plaques
	Chronic lesions may occur with thickened skin, hair loss and abrasions, especially behind the ear and tail head.
Mange mite microscopic view		Itchy pig		Examination of the ear reveals lots of wax
Areas of hair rubbed off around the face			Chronically infested thickened skin

Infectivity
	The disease is spread through pig to pig contact and through pigs coming into contact with infested buildings
	The mite is able to survive 21 days off the host in ideal situations. The warmer and drier the conditions the shorter the survival time.
	The pig mange mite does not live in other hosts
Economic Importance
	Economic importance varies depending on infestation, but a loss of 10% growth rates is not unusual in moderate to severe infestations. Mange will weaken the pig and is an added stress. Note the constant rubbing causes damage to buildings
Diagnosis
	Examination of ear wax and scrapes from the skin of the inner ear. However, individuals may be necessary to examine to find evidence of the mite to confirm the diagnosis. Absence is very difficult to ascertain
	An ELISA test is being developed
	Examination of the skin of finishing pigs in the slaughterhouse
	The problem may be more apparent in the cooler months
Skin score 1		Skin score 2	Skin score 3
Treatment
Control	Use avermectins via various routes. Note failure to adequately treat large boars is a common reason for failure to provide adequate control
Eradication	Where possible mange should be eradicated from units. Need to purchase animals from mange free farms
Common differentials
	Sows may scratch when exposed to cigarette smoke or perfumes including after shaves
	Forage mites in straw/bedding
	Other causes of skin hypersensitivity / allergy
	Skin may be thickened with parakeratosis or dry and scaly with deficiencies of essential fatty acids
Zoonotic Implications
	There are no significant zoonotic implications