High severity

Quittor (Collateral cartilage infection)

Quittor is infection of the collateral cartilage of the coffin bone — a chronic draining tract at or above the coronary band, not thrush in the frog, not white line disease in the wall, and not an ordinary hoof abscess. A photograph cannot diagnose quittor. A still cannot tell quittor from a coronary-band wound, gravel, a hoof abscess, or canker. Diagnosis is a vet exam, often probing or imaging. The hoof scan is a first look at the coronary-band drain / hoof, not a verdict that your horse has quittor, and there is no quittor scanner.

Symptoms to watch for

A draining tract, sinus, or wet spot at or just above the coronary band — often one side of the foot

Swelling, heat, or pain over the coronary band or the side of the hoof

A tract that closes, then opens and drains again over weeks or months

Lameness that comes and goes, or a horse that is short on that foot when the tract is active

Discharge that can look like an abscess breaking at the coronary band (gravel) or a simple wound

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

Common causes

Infection and necrosis of the collateral (ungual) cartilage of the distal phalanx (coffin bone)
A puncture, abscess, or trauma near the coronary band that reaches the cartilage — the wound is a clue, not a diagnosis
Wet, heavy, or chronically bruised feet that let infection sit in cartilage that has a poor blood supply
Not thrush (frog sulci), not white line disease (inner wall), not an ordinary hoof abscess, not canker, and not a simple coronary-band wound — a still cannot tell those apart, and those need a vet

Prevention

Pick out all four feet every day and look at the coronary band, not only the frog and the white line
Provide dry standing and protect the coronary band from kicks, punctures, and chronic wet bruising
Keep a regular farrier cycle and treat coronary-band wounds as a vet job, not a wait-and-see photo
Do not treat a photo, a coronary-band drain, or a scan result as a diagnosis
Hoof photos can help you and your vet look at the coronary-band drain — they do not confirm or rule out quittor, and they cannot tell quittor from a coronary-band wound, gravel, a hoof abscess, or canker

What to do

1
Book a vet visit if you find a draining tract at or above the coronary band. Diagnosis is a vet exam, often probing or imaging — not a photograph.
2
Do not dig, syringe, or pack the tract yourself. A still cannot tell quittor from a coronary-band wound, gravel, a hoof abscess, or canker.
3
Photograph the coronary-band drain / hoof 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 coronary-band drain / hoof to share, not as a quittor test. There is no quittor scanner.
5
If quittor is confirmed, follow the plan your vet prescribes — that may include imaging, surgery to remove necrotic cartilage, or antibiotics. 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 draining tract at or above the coronary band, if the same spot keeps opening, or if the horse is short on that foot. Call sooner if the horse will not bear weight, the limb is suddenly very swollen, or the horse is dull or off feed. A photograph cannot diagnose quittor. A still cannot tell quittor from a coronary-band wound, gravel, a hoof abscess, or canker. Diagnosis is a vet exam, often probing or imaging. Quittor is infection of the collateral cartilage of the coffin bone — not thrush, not white line disease, and not an ordinary hoof abscess. The hoof scan is a first look at the coronary-band drain / hoof, not a verdict, and there is no quittor scanner.

Get a first look at the coronary-band drain / hoof

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.