Hog mange

Lice and mange mites are two common external parasites found on swine. Mange and lice infestations are increasing as confinement rearing increases, particularly mange. The crowding of animals promotes easier transmission.

Hog lice are nearly 1/4-inch long and large enough to be easily seen with the naked eye. They are often overlooked, however, because of the slate blue color which may resemble the skin of the hog. Lice are first noticed in small clumps inside the ears or in folds of skin about the neck. Another favorite location is on the inside surface of the legs near the body. These insects pierce the skin and suck blood causing the skin to become thick, cracked, tender and sore. Injury is more severe during the winter months, but lice can be found any time of the year. There can be 8 to 12 generations per year. Hogs in an unthrifty condition are usually more susceptible. Damage caused is primarily irritation. Hogs become restless and decrease feed intake. Lice can contribute to anemia in young pigs.

Hog mange is caused by tiny mites which burrow through the skin making thread-like tunnels up to one inch long. These mange mites are too small to be seen readily with the naked eye but are visible through a hand lens or reading glass. They cause hogs to rub and scratch. The skin about the eyes and ears and along the top of the neck and back becomes scaly, inflamed, scabby and eventually raw and cracked. The bristles also become stiff and stand upright, giving the animals a rough, unkempt appearance. Mange is highly contagious and may spread rapidly through a herd of hogs.

Wash yourself and clothing thoroughly after handling infested hogs. Mange-infested animals have a reduced growth rate, a reduced vitality and may have a high death rate. It takes three to six weeks from time of infestation until symptoms can be seen.

How to Apply

Spray hogs with a power sprayer or other equipment large enough to wet the animals thoroughly. Spray only on a warm, sunny day so that the animals will dry rapidly. Also spray pens, hog houses and bedding at the same time the animals are treated.

The amount of spray to apply to each animal depends on the size of the animal and thickness of hair. Spray thoroughly but avoid prolonged treating. There is some danger to swine when spraying them in winter. Instead, use a dust or granular insecticide when possible. However, if you must spray in winter, treat on a warm day; and if this is done in a barn, turn the animals out immediately to dry. Dusts are used as bought without further dilution. Apply carefully to louse infested areas and generally over the animal’s body.

Control Measures for External Parasites

Pest Problem	Insecticide Formulation	Method and Rate	Restrictions/ Remarks	Minimum Days from Last Application to Slaughter
Sarcoptes Mange and Lice	Malathion 57% EC Prolate 11.6% EC Atroban 11% EC (permethrin) Ivomec 1% Injection Ectiban 5.7% EC Ectrin 10% WDL Taktic (Amitraz)	Mix 2 qt/50 gals water Mix 2 qt/30 gals water 1 qt/50 gals water Use 1 pt of spray per animal. 1 ml/75 lbs 1 qt/25 gals water Mix 1 qt/50 gals water Mix 1 qt/50 gals water	None Do not treat pigs less than a month old. Do not spray food or water. Administered subcutaneously, only. Repeat after 14 days. Repeat in 14 days if necessary. Spray entire animal until wet.	0 1 5 18 5 1 1

EC = emulsifiable concentrate; WP = wettable powder; WDL = water dispersible liquid; D = dust

Housefly Control in Confined Hog Operations

Up to 1,000 houseflies can develop in one pound of hog manure. Houseflies cause little direct damage to hogs but are a nuisance and carry diseases. Good public relations is dependent on housefly control around swine operations. Depending upon environmental conditions, 6 to 20 days are required for one housefly life cycle in Arkansas. Spilled feed is a good fly breeding site.

SANITATION + SCREENING + INSECTICIDES = HOUSEFLY CONTROL

Sanitation

– Dispose of manure, spilled feed and bedding every 7 days during warm months.
– Keep manure either liquid (no breeding) or as dry as possible (less than 30 percent moisture) to help prevent
breeding.

Screens

– Flytight 14 to 16 mesh screens on doors and windows.

Insecticides

– See control suggestions in table.

Fly Control in Swine Barns (not on animals)

Insecticide Formulation	Method and Rate	Restrictions/Remarks
Revap (2 + 0.5) lbs/gal EC	12 T/gal water	Use 1 gallon of diluted spray per 500-1000 sq ft.
Malathion 57% EC (Cythion)	1 qt/12 gals water + 4 cups sugar	Animals may be present when spraying, but do not spray animals directly. Do not contaminate food or drinking water. Wet fly resting areas thoroughly.
Ectrin 10% WDL	1 qt/25 gals water	Never treat animals with the concentrate insecticide. Remove animals until spray dries. Repeat in 14 days if necessary.
Pounce 3.2 EC	4 oz/12.5 gals water Apply 1 gal/750 sq ft	None
Rabon 50% WP	1/2 lb/3 gals water	None
Atroban 11% EC	1 pt/10 gals water	Use 1 gallon of diluted spray per 750-1000 sq ft.

Hog mange

Protect Hogs from External Parasites

Potassium diformate as acidifier

Transitioning to Zero ZnO: The changes in diet formulation