How Often to Deworm a Show Pig: Two Products at Arrival, Then Every Six Weeks

The short answer: when your pigs come home, deworm them with two products, an ivermectin shot and a fenbendazole. Give the ivermectin shot again about 18 days later. After that, give a three-day fenbendazole treatment every six weeks through the end of the feeding period.

That is my whole schedule. If you typed this question into a search bar, the answer at the top of the page probably said monthly. Monthly is more often than a show pig needs, but if a date on the calendar helps you remember to get it done, deworming a little early will not hurt anything. I will show you below why the two schedules are closer than they look.

I have worked with show pig exhibitors as a veterinarian for more than 30 years, and winning show pigs are healthy show pigs. You picked the feed and you are at that feeder twice a day, but parasites eat first, and whatever they leave is what builds your pig. A wormy pig can look fine from the alley while part of every feeding goes to something else. That is growth you paid for and will not see in the ring.

My deworming protocol for show pigs, step by step

1. At arrival, once every pig is home: ivermectin and fenbendazole together. Wait until the last pig is in your show barn, then treat all of them. The ivermectin covers lice, mange and several of the internal worms. The fenbendazole is a full three-day treatment with Clean Sweep or another fenbendazole labeled for swine. Get the ivermectin dose from the label of the swine product you buy, or from your veterinarian. Injectable ivermectin for swine carries an 18-day withdrawal before harvest.
2. About 18 days later: a second ivermectin shot. The first treatment kills the lice and mites that are on him, but eggs that were already laid can still hatch afterward. The second treatment catches those before they are old enough to lay eggs of their own, and that breaks the cycle.
3. If mites come back: confirm it, then treat every pig on the place. Most skin trouble in show pigs is not mange, so get a skin scraping before you treat. I walk through how, and why, in Skin Problems in Show Pigs. If it is mites, either repeat the two-treatment ivermectin protocol or use Prolate every three days for a total of six treatments. Whichever you choose, treat every pig on the premises, not only the one you noticed. There is more on mites in The Facts About Mange.
4. Every six weeks, all the way through the feeding period: three days of fenbendazole. Six weeks after the arrival treatment, give him another three-day treatment of Clean Sweep at one scoop per 50 lb of body weight. Repeat it every six weeks until the feeding period is over.

Said in one breath: two products at arrival, ivermectin again at about day 18, then fenbendazole every six weeks.

Step 3 should be rare. Lice and mange mites spread from pig to pig and do not live long off one, so after the second ivermectin treatment a pig that never touches an infested pig should stay clean for the rest of the project. If they come back, look first at a new pig in the barn or nose-to-nose contact with someone else’s pig.

The arrival treatment lands in the same few weeks as your vaccination program, which I laid out in Show Pig Vaccination.

Why deworming at arrival does not hold by itself

Arrival deworming is the right first move. It clears the worms he brought home with him. The next morning, though, he walks back out onto the same ground, and whatever is in that ground is still there.

Swine roundworm eggs live in soil for decades. Not a season. Decades. When I was in school, my parasitology professor kept a vial of roundworm eggs on his shelf that were seventy years old and still infective. Seventy years in a jar, waiting on their next pig like they had nowhere else to be.

So if you are counting on clean ground because it has not had pigs on it since last year, do not. That dirt remembers. Whatever the last set of pigs left out there is still out there, waiting on the next one.

This is also why pigs and lambs get different advice. The stomach worm that matters most in sheep and goats needs grass to spread, so a lamb in a dry lot mostly stops picking up new worms. The pig roundworm needs no grass at all. Its eggs pass out in the manure, sit in the dirt or the pen until they are infective, and the next pig swallows them while he roots around. Lambs and goats get a different plan, which I wrote up in Deworming Show Lambs and Goats.

And a wormy pig can look right. Roundworm larvae do not stay in the gut. They travel through the liver and the lungs first, and in the liver they leave white scars called milk spots. You will not see any of that from the alley.

Six weeks, and the monthly advice you have read

You will see monthly recommended in a lot of places, from feed companies and extension services to the answer at the top of a search. It is a reasonable recommendation. As I wrote in my show pig medicine cabinet post, monthly is probably more than a show pig needs. If you have been deworming monthly, you have not done anything wrong.

Six weeks is the schedule I give families. When I talk with them, I also tell them this: if doing it once a month helps you remember to get it done, it is not going to hurt anything to do it earlier. What causes trouble is the treatment that gets missed.

Here is why the two schedules are closer than they look. A roundworm egg a pig swallows today takes about six to eight weeks to become an adult worm laying eggs of its own. Deworm every six weeks or every four, and you remove most of what he picked up since the last treatment before it is old enough to put eggs back on your ground. Both schedules do that. Six weeks does it with fewer treatments.

Ivermectin and fenbendazole do different jobs

Plenty of families already know this, and the protocol above only makes sense once you do.

Ivermectin is a dewormer that also kills lice and mange mites. It covers several of the internal worms, and it is the only one of the two that does anything about the parasites on his skin.

Fenbendazole is the active ingredient in Safe-Guard and in Clean Sweep. It is broad spectrum on internal worms, which means it covers a long list of them. It does nothing at all for lice or mange.

Two worms separate them. Whipworm and kidney worm are not on the ivermectin label for pigs, and fenbendazole’s label covers both.

What it covers in a show pig	Ivermectin	Fenbendazole (Clean Sweep)
Large roundworm	Yes	Yes, including the larval stages in the liver and lung
Lungworm	Yes	Yes
Nodular worm	Yes	Yes
Whipworm	Not on the ivermectin label for pigs	Yes
Kidney worm	Not on the ivermectin label for pigs	Yes
Lice	Yes	No
Mange mites	Yes	No
Withdrawal before harvest	18 days (injectable)	None on the Clean Sweep label

So neither product covers everything. Ivermectin’s label leaves out whipworm and kidney worm, and fenbendazole leaves the lice and mange, which is why both go in at arrival. After the second ivermectin treatment the lice and mange stay handled unless a new pig brings them back, while the ground keeps handing him worms, so every treatment after that is fenbendazole.

The advice that gets passed around: rotate your dewormers. In the show pig groups you will see families told to rotate, ivermectin one round and Safe-Guard the next. I think rotating is unnecessary, and it is not productive. Ivermectin’s list of internal worms is shorter, so every round that is ivermectin’s turn leaves part of the worm load, whipworm and kidney worm included, untreated until the next round. Use each product for the job it does.

Clean Sweep: our fenbendazole, and how to feed it

Clean Sweep is our fenbendazole dewormer for pigs, the same active ingredient as Safe-Guard, in a meal that goes on his ration. Any fenbendazole labeled for swine will do the internal job on this schedule if you follow its label. The schedule matters more than the brand. Here is why we made ours the way we did.

One scoop per 50 lb of body weight, once a day, three days in a row. One level scoop is one ounce. Mix it into 1 to 6 lb of that pig’s ration. If his weight calls for a half scoop, round up to the next full scoop, so a 75 lb pig gets two.

That sentence cost me hours. Most medicated feed labels are written in milligrams per kilogram, with conversion charts, and I have watched capable people stand in their own alley with a scoop in hand, doing math and hoping they got it right. So I got on the phone with the regulators, round after round, and pushed for plain language until the bag said it in words a kid can follow. You should not need a PhD in pharmacy to deworm a pig.

Two habits make it work:

• Weigh him every time. He will be heavier at each six-week treatment, and the number of scoops goes up with him.
• Watch him clean it up. You are at that feeder twice a day anyway. On the three days he is on Clean Sweep, make sure he finishes, because a dose left in the feeder is a dose he did not get.

There is no withdrawal period. The label states plainly that there is no pre-slaughter withdrawal, so Clean Sweep can be fed right up to harvest. If you are close to a show and realize he is overdue, the calendar has not taken that decision away from you.

What the label covers. Large roundworm (Ascaris suum), including the larval stages in the liver and lung; lungworms; whipworm; nodular worms; small stomach worm; and kidney worm, adult and larvae. It is labeled for growing pigs, gilts, pregnant sows and boars, so a gilt project or a sow in the barn is covered too.

One bag deworms three show pigs for the whole feeding period on this six-week schedule, with the dose going up as they grow. If you are running three pigs or fewer, that one bag is the whole season. Monthly treatments go through it faster, so on a monthly schedule one bag may not cover three pigs.

It is for pigs only. Clean Sweep is labeled for swine, and we do not make a dewormer for lambs or goats. Do not put it in their feeder.

We do not sell ivermectin or Prolate, so those come from your veterinarian or your usual supplier.

The Clean Sweep label also says this, and I agree with it: consult your veterinarian for assistance in the diagnosis, treatment and control of parasitism.

When to call your veterinarian

Call before you start, and call when something does not fit the picture.

• Before the arrival treatment, for the ivermectin dose on the exact product you bought. I do not print the dose here on purpose, because products differ. The same goes for Prolate if you end up needing it.
• When you think mites are back, before you treat anything.
• When a pig eats well and does not grow, or his skin and hair go dull and rough. Worms are one possible reason, and there are several others.
• When he scours, especially with blood or mucus in it. A heavy whipworm load can do that, and so can diseases that need a completely different treatment.
• When a cough does not clear up. Roundworm larvae pass through the lungs, but a pig fresh off a sale has plenty of other reasons to cough.
• When you need to treat close to a show with anything that carries a withdrawal time. Ask the question out loud and write the answer down.

The short version

Two products at arrival, ivermectin again at about day 18, and three days of fenbendazole every six weeks after that, because the ground keeps supplying worms all season.

The day you finish a treatment, count six weeks forward and write the date on the feed room wall. If you are not sure where your pigs are on the schedule, call us and we will work it out with you. That is free, and it does not depend on whether you buy Clean Sweep from us.

Frequently asked questions about deworming show pigs

How often should I deworm a show pig?
Every six weeks, after an arrival protocol. When your pigs come home, treat them with both an ivermectin and a fenbendazole, and repeat the ivermectin shot about 18 days later. Then give a three-day fenbendazole treatment every six weeks through the end of the feeding period. Monthly, which you will see recommended in a lot of places, is more often than most show pigs need, but if a monthly date helps you remember to get it done, deworming a little early will not hurt anything.

Is it OK to deworm a show pig every month?
Yes. Monthly is more often than a show pig needs, but it will not hurt him, and if a monthly date is what keeps you on schedule, use it. Six weeks is enough because a roundworm takes about six to eight weeks to go from a swallowed egg to an adult laying eggs, so either schedule clears most of them before they can put eggs back on your ground. The real risk is a treatment that gets skipped.

Is ivermectin enough to deworm a show pig?
No. Ivermectin covers lice, mange and several internal worms, but whipworm and kidney worm are not on the ivermectin label for pigs. Fenbendazole is labeled for both and covers a broad list of internal worms, but it does nothing for lice or mange. That is why I use both at arrival and fenbendazole every six weeks after that.

Can I use ivermectin for pigs?
Yes. Ivermectin is labeled for swine, and it is half of my arrival protocol, repeated about 18 days later to break the lice and mange cycle. Use a product labeled for swine and get the dose and withdrawal time from that label or from your veterinarian. Injectable ivermectin carries an 18-day withdrawal before harvest, so check it against your show calendar if you ever need to treat late in the season.

Do I need to deworm if my ground has been empty for a year?
Yes. Swine roundworm eggs live in soil for decades. My parasitology professor kept a vial of roundworm eggs that were seventy years old and still infective. Whatever the last set of pigs left on that ground is still there, and your pig walks back out onto it the morning after you deworm him.

Is there a withdrawal period on pig dewormers?
It depends on the product. Clean Sweep has no withdrawal period. The label states there is no pre-slaughter withdrawal, so it can be fed right up to harvest. Injectable ivermectin for swine carries an 18-day withdrawal. Read the label on whatever product you use, write the date down, and do the same for Prolate.

What is the best dewormer for pigs?
No single product covers everything a show pig can carry. Fenbendazole covers a broad list of internal worms, including whipworm and kidney worm, which are not on the ivermectin label for pigs, and it is what I use every six weeks. Ivermectin is the one that handles lice and mange, so it goes in with fenbendazole at arrival. Clean Sweep is our fenbendazole, one scoop per 50 lb of body weight once a day for three days, with no withdrawal period.

Can I use Clean Sweep on my show lamb or goat?
No. Clean Sweep is labeled for pigs only, and True North does not make a dewormer for sheep or goats. Their worm problem works differently too, because the stomach worm that matters most in sheep and goats needs pasture to spread. Our article on deworming show lambs and goats covers what they need.