Scabies is a skin disease caused by an external parasite (mite) which is characterized by severe swelling that affects the growth of pigs.
Alternative names: Sarcoptic mange, Sarcoptes scabiei, scabies
Mange is a parasitic skin disease caused by Sarcoptes scabiei. It is not common to find scabies caused by Demodex phylloides in swine. Sarcoptic mange (sometimes called scabies) is the most common and important one because it is irritating and uncomfortable for swine, causing a lot of scratching and damaging of their skin. It significantly reduces the growth rate and feed conversion efficiency. The life cycle of the mite is direct and takes 14-15 days to complete a cycle from adult to adult. The mite dies quickly outside the pig (from hours and up to 15 days), in most conditions, in less than five days. It is important to keep this in mind for its control. If a farm is free of mange, it is one of the diseases easiest to avoid, because it can only be introduced to the farm by animals carrying the organism. However, once introduced into the farm, it tends to remain endemic if measures are not taken.
In case of an acute disease:
- They shake their ears.
- They scratch continuously against the walls of the pen. About three to eight weeks after the initial infection, the skin becomes sensitive to the protein of the mite, and animals can develop an intense allergy resulting in small red pimples covering their entire skin.
- There is a severe itching that causes the animal to scratch to the point of producing blood.
- Small red pimples all over the skin.
In case of chronic disease:
- Thicker lesions appear, similar to asbestos in the ears, on both sides of the neck, elbows, the front side of the hock and the dorsal side of the neck.
- Its presence affects the efficiency of feed conversion and daily gain, especially if the infective burden is large.
Causes / Contributing Factors
- Mites spread directly from pig to pig, either through skin contact or contact with recently contaminated surfaces.
- The boar helps to keep the infection in the farm because it is constantly in direct contact with the skin of breeding females and remains as a chronic carrier.
- If pigs are housed in groups, the spreading is easier.
- Pigs recently purchased.
- Pens used continuously.
- If no control measures are taken or no treatment is given it will result in a serious illness.
It is confirmed by demonstrating the presence of the mite. Scrapings are taken from suspicious skin lesions and especially from inside ears. A teaspoon is the ideal tool to get out material from inside the ear. This material can be placed on a piece of black paper; leave it there for ten minutes. Mites from scabies may be visible by the naked eye; they are round and only 0.5 mm in length. There is also an ELISA test available to perform blood samples, although its use is not common.
Scabies is an expensive disease, not only because of its economic impact on pigs, but also the cost and need for repeated treatments and damages to the farm’s equipment.
- Examine breeding animals looking for chronic injuries. Identify these animals so that they receive special treatment. These chronic lesions, which are mainly found in the ears, behind the elbow and limbs, can be difficult to eradicate and remain a constant source of infection.
- If evident in ears, cover them three times a day, once every 10 days, 1 ml of phoxim or spraying with 1% benzyl benzoate. If they are found in skin, rub lesions with amitraz every 10 days.
- Treat all breeding animals (gilts, sows and boars) with phoxim. Repeat treatment 10-14 days after. Alternatively use ivermectin or injectable doramectin, or ivermectin in feed every 4-6 months.
- Treat pigs the day of their weaning with phoxim using an oral dosing or give an injection of ivermectin. Alternatively medicate the pre-starter with ivermectin for 7 days or put it in water during the first five days post-weaning. The second is better if you use a water tank attached to the bowl type drinker. Ivermectin has given good results when dipping animals in it.
- The treated pigs should be moved to clean pens that have been sprayed with a parasitic substance such as amitraz and left empty for at least three days, preferably five or six.
- If scabies is active at the beginning of the growth period, add ivermectin in feed for seven days.
- There are effective eradication programs using injections of Ivermectin or Doramectin as well as to clean and fumigate every pen and corridor.