Club Lamb Fungus: What It Is, How It Spreads, and What Actually Works

You found it at evening chores. A crusty, raised spot up on the neck where the wool is short, about the size of a nickel, and it was not there last week. Maybe there are two of them now. And the first thing that went through your mind was not “is my lamb okay.” It was “the show is in three weeks.”

If that is where you are tonight, take a breath. Then let me walk you through what this thing actually is, because almost everything that goes wrong with club lamb fungus goes wrong in the first week, and it goes wrong because nobody explained it.

What club lamb fungus actually is

Club lamb fungus is ringworm. Not a worm, and not really a rash. It is a fungal skin infection caused by a group of organisms called dermatophytes, and the ones that show up in club lambs are usually in the Trichophyton family.

These fungi live on keratin, which is the protein your lamb’s skin and wool are built out of. That is the whole story of the disease in one sentence. The fungus is not attacking your lamb the way a bacteria does. It is eating the outer layer of skin and the base of the wool fiber.

Understanding what happens next is what lets you read a lesion instead of guessing at it. The skin under attack responds by releasing fluid. That fluid dries on the surface into the crust you can see and feel. Then, once the fungus has finished the keratin underneath it, the crust lifts and falls off, taking the wool with it and leaving bare skin behind.

And the fungus does not stay put. It works outward in a circle. It finishes the keratin in the middle, moves to the ring of fresh skin just outside it, and does the same thing again. That is why a spot that started the size of a dime is the size of a silver dollar two weeks later, and why you will see rings inside of rings on a lesion that has been going a while. The live fungus is always out at the edge, not in the middle. Remember that, because it decides where you spray.

It got the name “club lamb fungus” because in the early 1990s it started tearing through the club lamb circuit specifically, and it has been on that circuit ever since. It is not a sign of a dirty barn or a bad feeder. Some of the best-kept lambs in the country get it.

If you run show cattle alongside your sheep, the same family of organism is behind ringworm in show cattle, and the protocol below is the one we use there too. The season and the barn conditions differ enough to be worth reading separately.

Why it hits show lambs and not the flock out in the pasture

This is the part worth understanding, because prevention lives here.

A dermatophyte cannot get established on healthy, intact skin very easily. It needs a way in. On a club lamb, we hand it four at once, and every one of them is something we do on purpose.

• Close shearing. Slick shearing a lamb takes off the wool that was shading and protecting the skin, and the blade leaves behind thousands of tiny nicks and abrasions you cannot see. That is the door.
• Washing. A show lamb gets bathed on a schedule no pasture sheep will ever see. Shampoo does not know the difference between dirt and the natural oils on the skin, so it takes both. Those oils are not just grease. They are part of the skin barrier, and they help hold the normal population of organisms that lives on healthy skin and takes up the space an invader would want. Wash often enough and you are left with a drier, barer surface and a changed skin microbiome sitting on top of it. That is a far easier surface for a fungus to get a foothold on than the one nature set up.
• Shared equipment, and your own hands. Clipper blades, combs, chutes, blowers, blankets and tubes, wash racks, trailers. Dermatophyte spores are tough. They live on a blade, in a blanket, in the bedding of a trailer for months, and they move animal to animal without either animal ever touching. And so do you. Working an affected lamb and then walking down the line to the next one is one of the most common ways this gets through a barn, and it is the one nobody counts because it does not feel like equipment.
• The circuit itself. Jackpot, jackpot, county fair. Lambs from twenty different farms sharing air, wash racks and tie rails, most of them freshly sheared, most of them hauled and stressed.

Shearing, washing, sharing and stress. That is the recipe, and the show circuit serves all four.

Notice that none of this is a mistake you are making. Clipping and washing are not optional, they are how you present a lamb, and nobody is telling you to stop. It is just worth knowing that good fitting takes down two of the skin’s own defenses, because that is exactly the gap you want to be filling back in.

One more thing that catches families off guard: the incubation period runs roughly one to four weeks. So the spot you found tonight was picked up at the show before last, not at the one you just came home from. By the time you see it, the exposure is old news. That is exactly why prevention has to be a habit and not a reaction.

What it looks like, and what it gets confused with

Classic club lamb fungus shows up on the head, ears, neck, top of the shoulder and along the back, in the areas that got sheared shortest. What you see is usually:

• A raised crust of dried fluid, rough to the touch. These are not warts, and they are not a growth of any kind. It is your lamb’s own skin weeping under the fungus and that fluid drying on the surface.
• Wool that pulls away easily from the spot, and bare skin where the crust has already lifted and fallen off
• A round lesion that keeps getting bigger, often with rings inside of rings. That expanding circle is the fungus working its way outward through fresh keratin, and it is the most useful thing you can look at. A spot that is growing week over week is an active spot.
• Not much itching, and usually a lamb that otherwise acts completely normal

And here is where families get in trouble. There are several different things that sometimes get confused with this, and they are treated differently. Sore mouth (orf) is a virus and shows up around the lips, nose and muzzle. Staph dermatitis is bacterial and tends to be pustules rather than dry crusts. Dermatophilosis, what most people call rain scald or wool rot, makes paintbrush-looking scabs down the back after wet weather. Mites itch, hard, and in lambs and goats the ones you are most likely to run into are heel mites.

I have watched a lot of families treat one of these for two weeks with the wrong thing before anybody asked what it actually was. That is two weeks you do not get back before a show.

Get a diagnosis. It is not optional here.

Call your veterinarian and get the lesion looked at. There are two reasons and they both matter.

First, you need to know which of those four things you have, and you cannot tell reliably by looking, especially early. Your vet can do a culture or send a PCR, which is the only way to be certain. One honest note while we are here: the black light trick you may have heard about does not work for this. That test only picks up a different fungus, and the Trichophyton species that cause club lamb fungus generally do not fluoresce at all. A dark spot under a Woods lamp does not clear your lamb.

Second, your vet may reach for something stronger than what is in this article. Lime sulfur dips and miconazole are what the veterinary literature supports most strongly for dermatophytes, and if your lamb has widespread lesions or a show that is close, that conversation needs to happen now rather than after two weeks of doing it yourself.

Everything below is barn management that works alongside your veterinarian’s plan. It is not a substitute for it.

It goes both ways, so protect your kid

This is the part I will not soften. Club lamb fungus is zoonotic. It transmits to people, and it transmits to kids handling lambs constantly and with their arms bare.

It usually shows up on forearms, hands, neck and face as a red, scaly, expanding ring. It is annoying, it is treatable, and it is entirely avoidable.

• Long sleeves and disposable gloves any time somebody is working an affected lamb
• Wash hands and forearms thoroughly afterward, every time
• Do not share towels, and wash barn clothes separately in hot water
• If a ring shows up on a person, that is a call to your family doctor, not a barn problem

Tell the kids why. In my experience they are better about it than the adults once somebody explains it.

The two jobs, and why one product cannot do both

Here is the framework that makes the rest of this simple. Working a fungus problem on a show lamb is two separate jobs, and people fail because they only do one.

Job one is the surface. Reduce what is living on the skin and on everything the lamb touches. That is an antiseptic job, and that is what chlorhexidine is for.

Job two is the skin itself. A dermatophyte gets in through skin that is dry, abraded and run down, and on a show lamb we are actively producing that skin every time we clip and every time we wash. Skin that is well supported, with a healthy barrier and a healthy population of the normal organisms that live on it, is a much harder surface to colonize. That is a nutrition and skin-support job, and it is what Provilli is for.

Put plainly: the shampoo takes the oils and the microbiome off, and Provilli improves the skin microbiome, which is how you put that back. That is the whole reason it belongs in the same bottle as the antiseptic instead of being a separate thing you get around to.

Chlorhexidine works on what is on the lamb. Provilli works on the lamb. Neither one does the other’s job, and honestly, that is why they go in the same bottle so well.

Those two jobs are the whole program when you are preventing. When you already have an active infection, a third layer goes on top of them, and I will walk through exactly how that stacks in the treatment section below.

The mix

One quart sprayer. Into it:

• 1 ounce of Provilli
• 1 ounce of 2 percent chlorhexidine solution
• Fill the rest with water

Shake it before every use. Provilli is an emulsified product and it will want to separate a little sitting on a shelf.

That is the whole recipe. It costs a little over three dollars a quart in Provilli, it takes about a minute to mix, and it is the same bottle whether you are preventing or treating. What changes is how often you use it and what else you do alongside it.

Provilli is esterified medium chain fatty acids in an emulsified liquid. Used topically it supports healthy skin and a healthy skin microbiome, which is the surface your lamb defends himself with. It is also labeled as a grooming aid and every ingredient in it meets FDA standards and is GRAS, so it is not something exotic you are putting on an animal that is going to be shown and eventually eaten.

The prevention protocol

Prevention is where this is won, because the incubation math means you are always working a month ahead of what you can see.

1. Spray after every clipping and after every bath. This is the single highest-value habit on the list, and it covers both doors at once. Clipping opens thousands of small abrasions you cannot see. Washing strips off the oils and the microbiome that were defending the skin. Either one leaves your lamb more exposed than he was that morning, so the spray goes on at the end of both jobs. Mist the short-wool areas well, work it in with your hand, and let it dry.
2. Spray coming home from every show. Not the day you find something. The day you unload. Assume every jackpot exposed him, because the incubation period means you will not know for weeks either way. That trip home is worth a thought on the inside of him as well, and we cover worms and coccidia in show lambs and goats separately, because the parasite that costs families the most does not announce itself either.
3. Twice a week through show season as a baseline. Neck, shoulders, back, wherever the wool is shortest. It takes about a minute at chores.
4. Put your eyes on the skin at every feeding. You are already out there morning and night. Part the wool on the neck and shoulder and actually look. Catching one spot beats catching nine.
5. Disinfect the equipment, not just the lamb. Blades and combs between animals, every time, no exceptions. Blankets and tubes washed hot. Chutes, stands and trailer wiped down with a disinfectant. If you skip this step, you will reinfect a lamb you just cleaned up, and you will not understand why nothing is working.
6. Do not share clippers. I know how that lands at a jackpot when somebody’s blades go down. It is still the fastest way this moves.
7. Mind the order you work them in, and wash your hands between lambs. If anything in your barn is questionable, that lamb gets handled last, every chore, every time. Your hands move this as reliably as a dirty blade does.

The treatment protocol

You found a spot, your veterinarian has confirmed what it is, and you are working it.

1. Isolate that lamb. Separate pen, separate equipment, and work him last at every chore so you are not carrying it down the line on your hands and boots.
2. Leave the scabs alone. This is the instruction people ignore, and it is the one that costs them the most. Do not pick at the crusts, do not scrape them, do not scrub them off, and do not go after them with a brush or a comb. I know how badly you want that spot gone. Working a scab tears the skin underneath it, and torn skin is one more door for the fungus and an open invitation for a bacterial infection on top of the fungal one you already have. It also puts infective material on your hands and your equipment. Spray it, let it be, and let the crust release on its own when the skin under it is ready.
3. Spray the lesions and a wide margin around them. Wider than you think, and this is the step people shortchange. The live fungus is out at the advancing edge of that circle, working into skin that still looks completely normal to you. If you only treat the crust in the middle you are treating the part that is already finished. Get well out past the visible edge, every time.
4. Let it air dry. Do not blow it out. Just walk away and give it time. Two reasons, and both of them matter. A blower on a lamb with active lesions is broadcasting infective material into the air of your barn, onto your other lambs, your equipment and your kid. And blowing takes the solution back off before it has had any contact time, which is most of what you were trying to accomplish. This is one of the few times in a show barn where doing nothing for a few minutes is the correct move.
5. Once it is dry, top it with your treatment of choice on the affected areas. MTG, fluid film, a lime dip, whatever you and your veterinarian have settled on. That goes on the lesions themselves, and it is the layer doing the work of actually killing the fungus. Follow the directions on whatever you are using.
6. Then leave it sit. Do not wipe it, do not rinse it, do not blow it. These products work by staying in contact with the skin, so contact time is the whole point. Every time you take it back off early you have started over.
7. Run that sequence twice a day. Spray, air dry, top, leave it. It is not complicated, but it only works in that order.
8. Keep going after it looks better. The skin closes up before the fungus is gone. Stay on it for two full weeks past the last visible lesion, or as long as your veterinarian tells you.
9. Keep spraying the healthy lambs on the prevention schedule the whole time, because the exposure already happened.
10. Strip and disinfect the environment while you treat. Bedding out, pens and panels disinfected, blankets washed hot, blades disinfected after every single use. Spores outlive your treatment plan by a wide margin.

Where a lot of this thinking came from

I want to tell you about a set of lambs, because they are the reason I think about this problem the way I do.

Way back when we were first developing PreVent, I bought a set of lambs that had been disqualified at a fair and sent home over fungus. Nobody wanted them. That is how I got them. I hauled them home and I worked on them with nothing but immune modulators. No secret dip, no miracle in a spray bottle. I wanted to see what an animal’s own immune system would do with this problem if somebody actually fed it.

Those lambs became part of the original research behind PreVent.

Here is what I want you to carry out of that. Everything in this article up to this point happens on the outside of the lamb. The chlorhexidine works on the surface. Provilli works on the skin. Your topper works on the lesion. All of it matters and none of it is optional. But the outside is not what finishes this. The animal does.

Think about the levers you actually have on any health problem in a barn. There are four. Management, vaccination, treatment, and the immune system. And the first three all run through the fourth, because a vaccine needs an immune system to answer it and a treatment needs one to finish up behind it. The immune system is the only one of the four that nobody budgets for. It is the lever everybody leans on and nobody feeds.

That is the whole idea those lambs put in my head, and it is why the TrueGlo line is built on PreVent rather than on something that just makes hair shine. For a show lamb, TrueGlo or TrueGlo CR is where that lever gets fed, daily, in the feeder. It supports gut health and immune function, and it goes alongside the topical program rather than instead of it. Both species-appropriate for sheep, and worth saying plainly: the Turbo and Turbo Shag versions are show pig products, so those are not the ones you want for a lamb.

I am not going to tell you that a feed supplement is the answer to a fungus. Go back and read the treatment section again, because that is the work. What I will tell you is that the lamb doing the healing is the one variable in this whole article that most families never think to support, and it is the one I spent years of my life on.

What to expect, honestly

Dermatophyte infections are slow. Skin turns over slowly, wool grows back slower than that, and no honest person is going to tell you a lamb clears up in a weekend. What you are looking for over two to four weeks is the boring good stuff: no new spots showing up, and the existing circles holding still instead of growing. Measure the edge, do not judge the middle. A crust that lifts off is the normal course of the thing and does not tell you much on its own. A lesion that has stopped getting bigger is the sign you are winning.

The bare patches fill back in last, and they may not fill in before your show. That is worth knowing early so you can plan, and it is one more argument for treating prevention as the real work.

Now the part nobody wants to read, and I would rather you hear it from me tonight than from a vet at a check-in gate. A lamb with an active lesion does not go to a show. Not until it is healed and the wool is starting to come back.

That is not primarily a rule book answer, although most shows and fairs do inspect for skin lesions and plenty of lambs get turned away at the gate. It is that an active lesion is contagious to every lamb on that tie rail and to every kid handling them. Hauling him is how one spot on one lamb becomes a problem in twenty barns, and those are your friends. Nobody wants to be that trailer.

The wool is your signal. Skin that has quieted down but is still bare has not finished. Wool starting to fill the patch back in is what tells you the skin underneath actually recovered.

Read that timeline backward and you have the honest argument for everything in the prevention section. Wool does not hurry. If a lesion found today can cost you a show six weeks out, then the minute you spend spraying on the weeks when nothing appears to be wrong is not the cautious option. It is the only one that works on the calendar you actually live on.

The short version

Club lamb fungus is a keratin-eating fungus that gets in through skin we have just clipped and washed, and it moves around the circuit on shared equipment. You will see it about two to four weeks after the show that gave it to him. It transmits to your kids, so gloves and sleeves. Get a real diagnosis before you treat, because three other things look just like it.

Then run the two jobs. Chlorhexidine for what is on the lamb, Provilli for the lamb’s own skin, one quart bottle, an ounce of each. Spray after every clipping, every bath and every haul home, disinfect your blades like it matters, and put your eyes on the skin at every feeding. When you are treating an active spot, the order is spray, air dry, top with your treatment of choice, and leave it sit.

And do not forget the animal underneath all of it. The chlorhexidine, the Provilli and your topper all work on the outside; the lamb is the one who finishes this, which is why the immune system is worth feeding on purpose.

Know the hard line going in too: a lamb with an active lesion does not go to a show, not until it is healed and the wool is coming back. Wool does not hurry, which is the whole reason prevention is the real work.

That is not a miracle. It is a minute at chores, done on the weeks when nothing appears to be wrong. Which is exactly when it is working.

Questions about whether this fits your program? Reach out. We are glad to talk it through, no sales pitch.

Frequently asked questions about club lamb fungus

What is club lamb fungus?
It is ringworm in sheep, a fungal skin infection caused by dermatophytes, usually Trichophyton species. The fungus feeds on the keratin in the skin and wool. The skin releases fluid in response, that fluid dries into the crust you see, and the crust falls off once the fungus has finished the keratin under it, leaving a bare patch. The lesion then expands outward in a circle, which is where the name ringworm comes from. It earned the name club lamb fungus because it spreads heavily through the club lamb show circuit.

How does club lamb fungus spread?
Mostly on shared equipment and on your own hands rather than nose to nose. Clipper blades, combs, blankets, tubes, chutes, wash racks and trailers all carry the spores, and the spores survive in the environment for months. You are a vector too. Handle a lamb with an active lesion and then go put your hands on a healthy one, and you have just moved it yourself, which is why an affected lamb gets worked last and why you wash up in between. Show lambs are also far more susceptible than pasture sheep, because close shearing creates small abrasions the fungus needs to get established and repeated washing strips away the natural oils and the skin microbiome that would otherwise defend the surface.

Can humans catch club lamb fungus?
Yes. It is zoonotic and it shows up on people as a red, scaly, expanding ring, typically on the forearms, hands, neck or face. Wear gloves and long sleeves when handling an affected lamb, wash thoroughly afterward, and see your family doctor if a ring appears on a person.

How do I tell club lamb fungus from sore mouth or staph?
You often cannot by eye, and that is why a diagnosis matters. Sore mouth is a virus that concentrates around the lips and muzzle, staph dermatitis produces pustules rather than dry crusts, and rain scald makes paintbrush scabs down the back after wet weather. Your veterinarian can culture the lesion or run a PCR. A black light is not a reliable test here, because the species that cause club lamb fungus generally do not fluoresce.

What do you put on club lamb fungus?
The barn-level mix we use is one ounce of Provilli plus one ounce of 2 percent chlorhexidine solution in a quart sprayer, filled with water, applied twice daily to the lesions and a wide margin around them. The chlorhexidine is the antiseptic. Provilli supports healthy skin and a healthy skin microbiome so the skin itself is a harder surface to colonize. Talk to your veterinarian first, because widespread cases or a show that is close may call for lime sulfur or miconazole.

Does Provilli treat club lamb fungus?
Provilli is a nutritional supplement and grooming aid, not a medication, and we are not making a treatment claim with it. Diagnosing and treating a fungal infection is your veterinarian’s job, and Provilli goes alongside that plan rather than instead of it.

What it does is work on the skin. Provilli improves the skin microbiome, and that matters more on a show lamb than most people realize, because the clipping and washing that come with fitting are exactly what take that microbiome down. Customers who have added Provilli to their treatment routine also tell us they get wool back faster than they used to.

Worth knowing, since people ask: medium chain fatty acids are not a new idea. They have a long history in the research literature as antifungals, and that body of work is part of why we build with them.

Can I still use MTG or fluid film on a lamb with club lamb fungus?
Yes, and that is exactly how the treatment routine is built. The chlorhexidine and Provilli spray goes on first, over the lesions and a wide margin around them. Let it air dry on its own, and do not use a blower, which strips the solution off before it has worked and blows infective material around your barn. Once it is dry, put your MTG, fluid film or lime dip on the affected areas and leave it sit, because these products work by staying in contact with the skin. Talk to your veterinarian about which one fits your case.

Should I stop washing my show lamb?
No. Washing is how you present a lamb and nobody is suggesting you quit. Just understand what a bath costs you. Shampoo strips the natural oils and disturbs the skin microbiome that were helping defend the skin, which leaves a barer surface behind. The answer is not to wash less, it is to put that support back at the end of the job, which is why the spray goes on after every bath.

How long does club lamb fungus take to clear up?
Plan on two to four weeks of consistent work before you can call it, and keep treating for about two weeks past the last visible lesion or as long as your veterinarian directs. Wool fills the bare patches in last and may not be back before your show, which is the strongest argument there is for running the prevention protocol year round.

Can my lamb still be shown?
No. Not until the fungus is healed and the wool is starting to grow back. I know that is not the answer you were hoping for, and I am not going to soften it. An active lesion is contagious, to every lamb on that tie rail and to every kid handling them, and hauling him is how a barn full of families ends up with the same problem three weeks later. Wool starting to fill the bare spot back in is your signal that the skin has actually recovered, not just quieted down. On top of that, most shows and fairs inspect for skin lesions at check-in, so a lamb who should not go often does not get in anyway. Read the health requirements for every show you plan to enter, but understand the real standard is the one above, not whatever the rule book happens to say.