Low severity

Ringworm

Ringworm is a fungal skin infection (dermatophytosis) — not bacterial rain rot and not a tumour. It can look like a round, hairless, or scaly patch, often on the face, neck, girth, or where tack rubs. A photograph cannot diagnose ringworm. Diagnosis is a vet exam, often a scrape or fungal culture. The skin scan is a first look at the patch, not a verdict that your horse has ringworm, and there is no ringworm scanner.

Symptoms to watch for

A round, hairless, or scaly patch on the face, neck, girth, or where tack rubs

Broken hairs or a crusty ring that can look like rain rot but is not always on the back

More than one patch, or the same pattern on another horse on the yard

A person on the yard with a similar ring-shaped rash — ringworm can pass between horses and people

Itching is inconsistent; some horses rub, some do not

A change in size or number of patches is a reason to book a vet, not a photo verdict

Common causes

Dermatophyte fungi (Trichophyton, Microsporum) — fungal, not bacterial rain rot and not a tumour
Shared tack, rugs, or grooming kit that move spores from horse to horse
Young horses, or horses with a weakened immune system
Warm, humid conditions and close contact on a busy yard
Not the same as rain rot (bacterial) or sarcoid (a tumour) — those can look similar and need a vet

Prevention

Do not share brushes, rugs, or tack between an affected horse and the rest of the yard
Isolate a new horse with a patch until a vet has seen it
Wash and disinfect kit used on a suspect horse
Do not treat a photo, a round patch, or a scan result as a diagnosis
Skin photos can help you and your vet track a patch over time — they do not confirm or rule out ringworm

What to do

1
Book a vet visit for a new or spreading patch. Diagnosis is a vet exam, often a scrape or fungal culture, not a photograph.
2
Photograph the patch in good light and keep it on the horse's record so you and the vet can see change over time.
3
Do not share brushes, rugs, or tack, and do not start an antifungal cream from a photo guess.
4
Use a skin scan only as a first look at the patch to share, not as a ringworm test. There is no ringworm scanner.
5
If ringworm is confirmed, follow the plan your vet prescribes — that may include a scrape, a fungal culture, topical treatment, or isolation. Do not start a treatment protocol from a photo.
6
Keep the vet on the same page. Share what you see; do not treat a photo as a verdict.

When to call the vet

Pick up the phone if…

Schedule a vet visit if you find a round, hairless, or scaly patch, especially if more than one horse is affected or a person on the yard has a similar rash. Call sooner if the patches are spreading, painful, or the horse is dull or off feed. A photograph cannot diagnose ringworm. Diagnosis is a vet exam, often a scrape or fungal culture. Ringworm is fungal — not bacterial rain rot and not a tumour. The skin scan is a first look at the patch, not a verdict, and there is no ringworm scanner.