Controlling and Eliminating Mange Mite Infections in Pigs

My piglets have mites. What can I do to treat the mites and the pigs' skin damage, and how can I avoid future infestations?
First, we need to determine whether you are in the middle of a "lousy" circumstance or a "mitey" major problem. People frequently mix mites and lice, but if you understand the distinction, it's simple to tell the two apart: Lice may be seen with the naked eye, whereas mites require a microscope. Skin scrapings and microscopic examination, skin biopsy, or even treatment response can all be used to diagnose mite infestations, but a hog-lice infestation can be simply identified by inspecting the pig's skin. Pigs can be infected with both parasites at the same time.

Lice vs Mites
Unlike other livestock lice, which are typically troublemakers in the winter, hog lice appear to be perfectly content to be a problem in the summer, while mites can be a nuisance at any time. Both parasites have life cycles that are fully dependent on their host. They are primarily transmitted by contact with diseased animals, as well as infected bedding or habitat. If you didn't have an issue before and now do, it's likely that you brought in an infected animal or that your pigs came into contact with one.

Microscopic mange mites crawl into a pig's skin, depositing eggs and inducing irritation and itching in the host. The eggs hatch within a few days, and the entire process from egg to egg-laying adult takes around two weeks. Although most mites and eggs stay on the host, some can infect the environment, particularly bedding. Mites can live for many days in the environment, but when temperatures rise, they die in a matter of days. All animals in contact with one another and/or having access to the same environment should be treated at the same time; a second and perhaps third treatment will be required to eliminate any mites that emerge after the first treatment. Wait a week following treatment before transferring pigs to uninfected facilities or allowing them to interact with uninfected swine. Permethrins can be used to eradicate mites in the environment, but they also harm beneficial insects, so exercise caution.

Hog lice are huge for lice—adults are 1/4 inch long—and dark, preferring to live on a pig's bottom as well as in armpits, skin folds, and ears. They can also be spotted moving on the heads and backs of infected animals, or connected and sucking blood. Adult female lice lay eggs known as nits, which are firmly attached to the host's hair and plainly seen.

Depending on the environment, eggs hatch in two to three weeks, and the life cycle lasts another two weeks. The entire life cycle occurs on the infected animal, as lice can only survive a few days without a host. Lice, like mites, irritate their hosts, producing itching, reddish skin, secondary skin injuries, anxiety, and weight loss; they can also transmit certain infections. As with mites, a second or possibly third treatment will be required to kill nymphs and adults that emerged from eggs following the initial treatment.

Treating Pig Lice and Mites.
Over-the-counter medications are available to treat lice and mange in pigs. When administered as directed, injectable ivermectins and topical permethrins are effective against both parasites. It is important to note that treated swine should not be slaughtered until five days after permethrin treatment, or 18 days if an ivermectin medication is used. Always adhere to prescription label guidelines for slaughter withholding times and dosing.

Unless your pigs are secondarily infected, their skin should heal quickly once you eradicate their parasites and they quit excoriating themselves when scratching. Clean severe scratches and wounds with a livestock disinfectant soap twice a day, washing thoroughly. If sores or injuries persist, consult a veterinarian. Avoid using topical drugs since they often impede rather than accelerate healing. Using an approved fly spray can help prevent flies from troubling unhealed lesions.

If feasible, remove diseased pig bedding and leave the area vacant for several weeks before reintroducing clean bedding and housing pigs—the longer the better. If you effectively treated all affected pigs, retreated once or twice, removed bedding, and let any mites or lice in the surroundings to die, you should be able to move on from this episode.

Prevent another infestation.
To decrease the risk of reintroducing lice or mites into your herd, keep it closed or meticulously inspect new recruits for visible lice as well as the irritated skin, blisters, and itching associated with mange mites. To be safe, your veterinarian may recommend prophylactic mite treatment for new herd members. However, keep in mind that using an ivermectin medication for external parasite management accelerates the development of internal parasite resistance to this class of dewormers. In most herds, ivermectins are still quite effective against internal parasites of pigs, therefore don't endanger their efficiency by using them excessively for exterior parasite control. Use topical permethrins initially, as long as they are still effective.

Now is an excellent moment to plug quarantine pens. Isolate herd additions for one to three months downwind and downstream from the main herd, looking for signs of disease or parasite problems. If you reside in a region with feral hogs, take extreme care to avoid any contact or environmental overlap between them and domestic pigs, as they can spread mites, lice, and other significant problems to your herd.