The most effective way to treat mites on pigs is a two-dose injectable treatment spaced 14 days apart, combined with thorough cleaning of pens between doses. Nearly all pig mite infestations are caused by a single species, Sarcoptes scabiei var. suis, which burrows deep into the skin and causes intense itching, weight loss, and stress. The good news is that with the right approach, you can completely eliminate mites from your herd.
Recognizing a Mite Problem
Mite infestations in pigs are tricky because many cases are subclinical, meaning the pig carries mites without showing obvious skin lesions. The earliest sign is usually excessive scratching and rubbing against pen walls, feeders, or any rough surface. Over time, you may see thick, crusty skin forming inside and around the ears, then spreading to the head, neck, legs, and flanks. The ears are the mites’ preferred starting point, and heavy infestations there can look like a buildup of dark, flaky debris inside the ear flap.
Secondary bacterial infections often develop where pigs have broken the skin through constant rubbing. If you notice red, raw patches or oozing sores alongside the scratching, mites are a likely culprit. Weight gain slows noticeably in infested pigs. One study found that simply eliminating mange from growing pigs increased their average daily weight gain by 12%.
To confirm the diagnosis, a skin scraping from inside the ear (the pinna) is the standard method. Your vet will scrape a small area, place the material under a microscope, and look for mites or eggs. Because mite numbers can be low even in infested animals, a negative scraping doesn’t always rule out the problem. Blood tests that detect antibodies to the mite are also available for herd-level screening.
Injectable Treatment: The Standard Approach
The most widely used treatment is ivermectin, given as a subcutaneous injection in the neck at a dose of 300 micrograms per kilogram of body weight (1 mL per 75 pounds). This is the cornerstone of most mange eradication programs. A single injection kills active mites but not all eggs, so a second injection 14 days later is essential. That 14-day gap is carefully chosen: it’s the time needed for surviving eggs to hatch into adults that the second dose can kill.
Doramectin is another injectable option in the same drug family, and it works the same way. Both products have a persistent drug level in the pig’s system that continues working for days after injection, but neither kills mites instantly. Plan on about one week before the drug fully clears mites from a treated animal. During that week, keep treated pigs away from untreated animals and clean facilities to prevent reinfestation.
Successful eradication programs typically follow this pattern: treat every pig in the herd twice at a 14-day interval, and simultaneously clean and disinfect the housing between treatments. Research comparing different approaches found that two whole-herd treatments with ivermectin, combined with pen cleaning, reliably eliminated mange. Some herds that skipped the environmental cleaning needed a third treatment round to achieve the same result.
Topical Treatments
Spray-on or pour-on products can work when injection isn’t practical. Amitraz-based sprays are one option that has shown effectiveness in clinical trials, typically clearing mange within about five weeks when applied on day one and again on day seven. Phosmet, an organophosphate compound, has also been used as a topical treatment for growing pigs with good results.
The challenge with topical treatments is coverage. Mites burrow into the skin, so the product needs thorough, even application across the pig’s entire body. Spraying a large, uncooperative pig thoroughly enough to reach every skin fold is harder than giving a single injection, which is why most commercial operations prefer the injectable route.
Neem Extract as a Natural Alternative
If you’re looking for a more natural option, neem fruit extract has shown genuine promise. In a controlled trial on grower pigs, a 25% concentration neem fruit extract (mixed with water) performed comparably to a commercial amitraz spray. Pigs were sprayed on day one and again on day seven. The amitraz cleared clinical mange by week five, while the 25% neem extract took about six weeks. Lower concentrations (5% and 10%) were significantly less effective, so concentration matters.
Neem works in a dose-dependent way, meaning stronger preparations kill more mites. It offers a cheaper, safer alternative for small-scale or organic operations, though it requires more patience than conventional treatments.
Treating Breeding Stock and Piglets
Sows are often the source of mite transmission to newborn piglets. The most effective prevention strategy is treating sows before they farrow. The recommended window is 7 to 14 days before the expected farrowing date. In a controlled study, a single ivermectin injection given to pregnant sows seven days before farrowing was 100% effective at preventing mite transmission to piglets, with no negative effects on litter size, birth weight, or pre-weaning survival.
The production impact is real. Piglets born to treated sows grew faster, gaining an average of 541.5 grams per day compared to 518.4 grams per day for piglets from untreated sows. That difference adds up quickly across a litter and a growing period. Gilts should also be treated 7 to 14 days before breeding and again 7 to 14 days before farrowing.
Cleaning Pens and Housing
Mites are permanent parasites of pigs and don’t survive long away from a host. They’re sensitive to drying out, so environmental contamination is generally a minor concern, with one important exception: if you’re moving new pigs into a pen that housed infested animals shortly before. Eggs, however, can survive in the environment for a long time, which is why the 14-day retreatment interval exists.
Between your two treatment rounds, empty the pens completely, pressure wash all surfaces, and apply a disinfectant. This removes eggs and debris from cracks and crevices where mites may have been shed. Herds that combined treatment with environmental cleaning achieved eradication more reliably than those that relied on drug treatment alone. Pay special attention to farrowing crates, rubbing posts, and any rough surfaces pigs regularly contact.
Meat Withdrawal Periods
If you’re raising pigs for meat, you need to observe withdrawal periods after treatment. For injectable ivermectin, the withdrawal period is 18 days before slaughter. For ivermectin given as a feed premix, it’s 5 days. These timelines ensure no drug residues remain in the meat. Mark your calendar on the day of the last injection and count forward carefully. Different products have different withdrawal windows, so always check the label of the specific product you use.
Preventing Reinfestation
Once you’ve cleared mites from your herd, keeping them out is straightforward. New pigs are the primary source of reinfestation. Quarantine any incoming animals for at least two weeks and treat them with ivermectin before introducing them to the rest of your herd. Since subclinical infestations are common and hard to spot visually, treat all new arrivals regardless of whether they appear clean.
In a whole-herd eradication effort, every pig on the property must be treated at the same time. Leaving even one untreated animal creates a reservoir that will reinfest the rest. If you have pigs in multiple buildings or pastures, coordinate treatment so all animals receive their first dose within the same day or two, followed by the second dose 14 days later across the entire herd.