Reprinted from Howtodressage.com
If you notice a tiny tuft of hair sticking up in your horse’s coat, you’ll probably assume it’s a fly bite, or perhaps your equine has been rubbing himself on the fence. However, when a small collection of tufts appears and seems to be spreading, you could be looking at a case of ringworm.
So, what is ringworm, how is it treated, and how much downtime will your horse need?
We give you the answers to these questions and many more in this comprehensive guide on how to identify and manage ringworm in horses.
What is ringworm?
Ringworm is not actually caused by a worm at all but by a dermatophyte fungus of which there are several species.
The species of fungi that trigger ringworm in the horse are primarily Trichophyton and Microsporum. Unfortunately, both these fungi can infect other animals, too, including people and dogs.
Ringworm is not necessarily a seasonal problem, although most outbreaks generally occur during the fall and winter when horses are stabled for longer periods.
Because the condition is highly contagious, large yards where grooms care for multiple horses are especially at risk.
Symptoms of ringworm
When a ringworm infection starts, you usually notice a few tiny, innocent-looking tufts of hair sticking up, often on the horse’s neck.
As the infection takes hold, you might notice small raised spots underneath the tufts of hair.
The hair falls out, and the spots become scaly and scurfy, sometimes forming a dry, crusty scab. The lesions can be itchy and sore, often causing horses to rub and scratch themselves on fencing or field shelter door frames.
The infection is spread readily through mutual grooming between horses turned out in a group or stabled animals via shared grooming tools, tack, etc.
Unfortunately, although the majority of horses are happy in themselves, many rub away the hair over the affected area in response to the skin irritation that the fungus causes. That can result in weeping or bleeding skin, which may then become infected, especially during the summer months when flies are very active.
In severe cases, the hair follicles in the skin may be permanently damaged, causing the hair to grow back white. However, most cases are self-curing once the fungus has been eradicated, and the hair grows back normally, within a few weeks.
How is ringworm spread?
Ringworm is highly infectious and spreads rapidly via direct horse-to-horse contact or indirectly through contact with shared grooming tools and tack, rugs, bedding, fencing, food bowls, mangers, and stable doors.
You can be responsible for spreading the fungal spores, too, on your clothing or hands.
As is the case with many diseases, very old, very young horses, and those with immunosuppression issues due to the use of certain drugs are more likely to catch ringworm. That’s because their immune systems are generally less effective than strong, healthy animals that are fit and in their prime.
However, once a horse has had ringworm, he will develop a degree of immunity to the particular fungus responsible, and he will, consequently, be less likely to contract the condition again in the future.
That said, the reproductive spores that the ringworm fungus produces are able to survive for very long periods of time, sometimes lurking in woodwork, old rugs, and even in the depths of deep litter beds. That means that cases of ringworm can appear months or even years after treatment has eradicated an outbreak.
The first signs of ringworm can take between six days and six weeks to appear following contact with the fungus.
How is ringworm diagnosed?
Although the skin lesions that ringworm causes are pretty characteristic of the disease, they can sometimes be mistaken for other skin complaints such as folliculitis and rain scald (dermatophilosis).
Your vet will confirm the diagnosis by taking skin scrapings for analysis.
The ringworm fungus is found in the damaged hair shafts and may be cultivated in the laboratory to positively identify the species that’s involved.
That can be helpful in cases that are slow to resolve. However, most horses recover quickly and, if left untreated, self-cure within six to 12 weeks.
Ringworm treatment
As mentioned above, most cases of ringworm will self-resolve without any treatment. However, because ringworm spreads so readily and quickly, most owners prefer to treat the problem right away.
Also, horses with ringworm are not permitted on competition yards and are not allowed to travel abroad.
First of all, isolate all infected horses.
Secondly, withdraw any immunosuppressant medication from horses that are showing symptoms of ringworm. That gives the horse’s body more chance to fight off the infection quickly.
Finally, commence the treatment that is prescribed or recommended by your vet.
Most forms of ringworm treatment entail bathing the infected areas with a specific anti-fungal solution. However, you may need to try several different products before you find one that is effective.
Before treating the site, you’ll need to remove all scabs, debris, and scurf that would otherwise protect the fungus from the effects of the medication.
To do that, you’ll need to gently exfoliate the affected area with a toothbrush or nylon scouring pad. In cases where the skin is raw, the scabs may need to be left alone until the first few treatments are complete.
Topical treatments are generally left in situ and not washed off. Leave the infected area open to the air, and do not place dressings over it.
Once you’ve completed the course of treatment, the lesions should have stopped spreading, and the skin will appear healthy. New hair grows through pretty quickly once the infection has gone.
In very severe cases or where there’s an outbreak among a group of horses, griseofulvin powders may be prescribed for administration in the feed for up to 14 days. Griseofulvin takes up to six weeks to be effective and is often prescribed for use in conjunction with topical skin treatments.
Stay safe!
Ringworm can infect other animals, including humans.
At all times, when handling or treating affected horses, their associated tack, rugs, etc., wear disposable gloves and washable overalls.
When you’ve finished, remove your gloves and overalls, place them in a bin bag, and seal it. Destroy the gloves, and wash the overalls on a hot wash cycle.
Do not take your dog with you to the yard during a ringworm outbreak.
How to prevent the spread of ringworm
Prevention is definitely better than cure when it comes to ringworm:
Step 1: Immediately isolate all affected horses in a quarantine block.
Step 2: Thoroughly disinfect all tack, grooming tools, and rugs that have been in contact with infected horses.
Step 3: Disinfect gates and fences in paddocks where infected animals have been turned out.
Step 4: The horses’ bedding must be removed and burned, and the stables thoroughly cleaned and disinfected, including all doors, mangers, and woodwork.
Step 5: Place a bucket of disinfectant and some hand sanitizer outside the quarantined horses’ stables, and be sure to dip your boots and disinfect your hands each time you leave the box.
Step 6: Lockdown the yard until at least six weeks after the appearance of the final case. That means no horses may leave or be brought onto the premises, and only essential visitors are permitted in the yard.
Clean-up top tip!
Hire a steam cleaning machine or power washer!
Steam-clean or power-wash all surfaces, including field shelters, stables, transport, lorries, and trailers.
Set the pressure washer at a pressure of less than 120psi to avoid producing aerosols that could spread the fungal spores through the air.
After the storm
After the ringworm outbreak is under control, remain vigilant.
Remember that ringworm can remain dormant, only to reappear many weeks or months after the main event.
Although previously infected horses will have some immunity, and reinfection tends to be less severe if the same fungus is responsible, it’s still a nuisance, especially on very large yards.
There are a few steps that you can take to protect your horses from ringworm in the future:
Place all new horses in quarantine for at least six weeks.
When out competing or training, don’t allow contact between your horse and others.
Use a separate grooming kit, rugs, feed bowls, and tack for each horse in the yard.
Make it part of your regular routine to disinfect saddle cloths, grooming kits, feed bowls, and rugs.
If you hire a horsebox from an off-yard supplier, disinfect the horse compartment before use.
Use sanitizer when handling horses that you don’t know. That can prevent you from contracting ringworm, as well as minimizing the likelihood of you passing it on to your horse.
Although taking all these steps might seem like a time-consuming hassle, that’s nothing when compared with the inconvenience, expense, and competition downtime you’ll go through if your yard is hit by an outbreak.
In conclusion
An outbreak of ringworm may not present a danger to you or to your horses, but it is a real nuisance, as it means you’re grounded until the condition is eradicated.
Prevention is definitely better than cure where ringworm is concerned. So, be vigilant and isolate any animals that are showing symptoms right away.
Take great care not to inadvertently spread the disease among other horses in your yard by following the tips given in this guide.