High severity

Canker (Hoof canker)

This is hoof canker of the frog and sole — chronic proliferative pododermatitis — not oral canker and not avian canker. A photograph cannot diagnose canker. A still cannot tell canker from thrush, white line disease, proud flesh in the foot, or a hoof abscess. Diagnosis is a vet exam, often biopsy. The hoof scan is a first look at the frog/sole, not a verdict that your horse has canker, and there is no canker scanner.

Symptoms to watch for

Soft, white, frond-like or cauliflower-like tissue on the frog or sole that can look like crabmeat and bleeds easily

A frog or sole that is ragged, moist, or growing extra horn instead of a firm, dry frog

A smell or discharge that can look like thrush in the frog sulci

Lameness that may be mild at first, or a horse that is short on that foot when the tissue is sore

Tissue that starts in the frog sulci and can spread over the frog, sole, or heel bulbs

A change in the frog, sole, or soundness is a reason to book a vet, not a photo verdict

Common causes

Chronic proliferative pododermatitis of the frog and sole (often anaerobic) — the cause is not settled, and a still cannot name it
Wet, dirty, or chronically packed feet that let abnormal frog/sole tissue sit — the standing is a clue, not a diagnosis
Can appear even in horses that are shod and kept clean — hygiene is not a verdict
Not oral canker, not avian canker, not thrush (frog sulci infection), not white line disease (inner wall), not proud flesh in the foot, and not a hoof abscess — a still cannot tell those apart, and those need a vet

Prevention

Pick out all four feet every day and look at the frog and sole, not only the white line or coronary band
Provide dry standing and keep the frog and sole from sitting packed in wet mud or manure
Keep a regular farrier cycle and treat a frog or sole that is growing soft, frond-like tissue as a vet job, not a wait-and-see photo
Do not treat a photo, a ragged frog, or a scan result as a diagnosis
Hoof photos can help you and your vet look at the frog/sole — they do not confirm or rule out canker, and they cannot tell canker from thrush, white line disease, proud flesh in the foot, or a hoof abscess

What to do

1
Book a vet visit if you find soft, frond-like, or crabmeat-like tissue on the frog or sole. Diagnosis is a vet exam, often biopsy — not a photograph.
2
Do not cut, burn, pack, or treat the frog or sole yourself from a photo guess. A still cannot tell canker from thrush, white line disease, proud flesh in the foot, or a hoof abscess.
3
Photograph the frog/sole in good light and keep it on the horse's record so you and the vet can see change over time — a first look to share, not a diagnosis.
4
Use a hoof scan only as a first look at the frog/sole to share, not as a canker test. There is no canker scanner.
5
If hoof canker is confirmed, follow the plan your vet prescribes — that may include debridement, topical care, or biopsy. 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 soft, frond-like, or crabmeat-like tissue on the frog or sole, if a 'thrush' spot is spreading or bleeding, or if the horse is short on that foot. Call sooner if the horse will not bear weight, the foot is suddenly very painful, or the horse is dull or off feed. A photograph cannot diagnose canker. A still cannot tell canker from thrush, white line disease, proud flesh in the foot, or a hoof abscess. Diagnosis is a vet exam, often biopsy. This is hoof canker of the frog and sole — not oral canker and not avian canker. The hoof scan is a first look at the frog/sole, not a verdict, and there is no canker scanner.

Get a first look at the frog/sole

Scan the hoof in HorseCare. 5 free scans this month, then Pro.

Scan the hoof

5 free scans this month, then Pro. Scans run in the HorseCare app.

Educational content only. Not a substitute for veterinary advice.