Pig lice (Haematopinus suis) are yellowish brown lice and measure 5mm long. They are very easy to spot and can be found around the head and neck and between the legs of the animal.. They are a constant irritant to the pig and will cause the pig to scratch up against gate posts and fences causing damage to the skin. A severe infestation can lead to anaemia and also cause the pig to become restless, slow its growth rate and affect its overall condition.
The adult female louse will lay 2-4 eggs daily for 20-30 days. The eggs are firmly cemented to the hair using a strong substance secreted by the louse. They take 10-21 days to hatch out into nymphs and then a further week or so to reach to adulthood. The whole process will take approximately 30 days.
Diagnosis will start with observing the pig in the first instance which will be seen to rub or scratch on a constant basis. The lice can be easy to spot on white skinned pigs but much more difficult to see on the darker varieties. However on closer inspection it may be easier to look for the pale egg cases which are usually situated behind the ear and on the neck.
If you suspect infection but can find no evidence of such then wait for a different time of the day and have another look. In warm conditions the lice will spread over the whole body and can be seen near the feet or inside the ears.
Pig lice are mostly uncommon today and are kept in check because people will treat their pigs for mange which destroys the pig louse at the same time.
Treating pig lice is very easy to do. However, you must ensure that any treatment is administered to the whole herd to break the cycle. This is especially important in the breeding herd because the sow will pass the lice on to her sucking pigs.
Treatment that can be administered:
Ivermectins - Given by subcutaneous injection and orally
Amitraz - Spray 0.06 percent amitraz, made by mixing 1 quart of 12.5 percent emulsifiable concentrate in 50 gallons of water. Use within six hours and cover feed during application.
Fenvalerate - Spray 0.05 percent fenvalerate, made by mixing 1 quart of 10 percent fenvalerate water dispersible liquid in 50 gallons of water
Deltamethrin - Has long lasting effects and is used as a pour on.
Always follow the instructions given for the proper administration and it may be helpful to note that any treatment given will not have any effect on the eggs. This means that about two to three weeks after administering the first lot of medicine you will have to treat the pigs again to make sure that you have killed any late hatchers.
http://www.thepigsite.com : Lice (Internet source accessed 16/02/10)
Skin Conditions in Pigs. Jenny Turton (Department of Agriculture 2001)