Ivermectin for Pigs: Uses, Dosing & Side Effects

This information is for educational purposes only. Never give your pet any medication without your veterinarian's guidance. Dosing, frequency, and safety depend on your pet's specific health profile.

Ivermectin is a macrocyclic lactone antiparasitic used in pigs to treat certain internal worms and external parasites. In swine medicine, it is commonly available as an injectable product and, in some settings, as a medicated feed formulation. It works by disrupting nerve and muscle function in susceptible parasites, which leads to paralysis and death of the parasite.

For pigs, ivermectin is most often used as part of a broader parasite-control plan rather than as a one-size-fits-all dewormer. Your vet may recommend it for pet pigs, miniature pigs, feeder pigs, or breeding stock depending on the parasite involved, the pig's age and weight, and whether the animal is entering the food chain.

Because pigs are a food-animal species, label directions, route, and withdrawal times matter. That means your vet should guide product choice, dose, and timing. Extra-label use in food animals has legal and safety limits, and withdrawal intervals may need to be adjusted by your vet when use falls outside the label.

In pigs, ivermectin is used to treat and control several important parasites. FDA and veterinary references list activity against gastrointestinal roundworms, lungworms, kidneyworms, lice, and mange mites. In practical terms, that means your vet may use it when a pig has poor thrift, coughing linked to parasite burden, itching from lice, or crusting and scratching caused by sarcoptic mange.

One of the most common reasons your vet may recommend ivermectin in pigs is sarcoptic mange. Mange can cause intense itching, rubbing, skin thickening, and reduced comfort. Merck also notes ivermectin use in swine for Sarcoptes scabiei, and miniature pet pig guidance lists ivermectin for most helminth infections, with repeat treatment often needed for mange.

Ivermectin is not the right answer for every parasite problem. Resistance patterns, housing conditions, manure management, and reinfection risk all matter. Your vet may pair treatment with skin scrapings, fecal testing, environmental cleaning, or herd-level parasite planning so the medication fits the actual problem.

Always use ivermectin exactly as your vet directs. In swine references, a common labeled injectable dose is 0.3 mg/kg given subcutaneously. Merck also lists 0.3 mg/kg SC repeated in 2 weeks for swine mange, and for miniature pet pigs notes 0.3 mg/kg PO, IM, or SC, with repeat dosing in 10 to 14 days for sarcoptic mange. Oral dosing may be less effective for mange than injection in pet pigs, so route matters.

Feed formulations have different directions. Merck lists 0.1 to 0.2 mg/kg in feed for 7 days in swine, but medicated-feed use depends on the exact approved product, concentration, and indication. Never substitute one formulation for another on your own. Injectable ivermectin, feed premix, and products labeled for other species are not interchangeable dose-for-dose.

Your vet will calculate the dose from your pig's current body weight, intended route, and treatment goal. Underdosing can reduce effectiveness and may contribute to parasite resistance. Overdosing raises the risk of toxicity. If your pig is a food animal, ask your vet for the exact meat withdrawal time for the product and regimen being used, and keep treatment records.

Most pigs tolerate ivermectin well when it is used at the correct dose, but side effects can happen. Mild problems may include temporary injection-site discomfort, brief stress during handling, or reduced appetite for a short time. Merck notes that injection can cause signs of discomfort in miniature pet pigs.

More serious reactions are uncommon at labeled doses, but ivermectin toxicity can affect the nervous system. Signs may include lethargy, weakness, stumbling, tremors, dilated pupils, depression, trouble standing, or breathing changes. Merck notes that toxic reactions generally require doses far above normal, but neurologic and respiratory depression are the major concerns when overdose occurs.

See your vet immediately if your pig seems weak, collapses, has tremors, cannot rise, or develops breathing trouble after treatment. Also call your vet if itching, coughing, poor growth, or skin disease does not improve, because the problem may be reinfection, resistance, or a different diagnosis.

Ivermectin can interact with other medications that affect how drugs move through the body or how the nervous system responds. In general, your vet will be more cautious if your pig is receiving other macrocyclic lactones, sedating drugs, or medications that may alter P-glycoprotein transport. These interactions are discussed more often in dogs and cats, but the principle still matters when your vet is building a treatment plan.

For pigs, the most important practical issue is often not a classic drug-drug interaction but a formulation and food-safety issue. Combining products without veterinary guidance can increase the risk of dosing errors, duplicate parasite coverage, or residue problems in food animals. Medicated feed combinations also have specific approvals and label limits.

Tell your vet about every product your pig receives, including dewormers, medicated feed, supplements, and any off-label livestock products. That helps your vet avoid overlap, choose an appropriate withdrawal interval, and decide whether ivermectin is the best option for this parasite problem.