High severity

Lyme disease (Borrelia)

Lyme disease is a tick-borne infection (Borrelia burgdorferi). Owner-reported signs are often shifting lameness, stiffness, or a horse that looks sore or off — but those signs are not unique to Lyme. It is not ordinary lameness, not PPID (Cushing’s) stiffness, and not shivers. A photograph cannot diagnose Lyme disease. A still cannot tell Lyme from other shifting lameness, sore feet, or ordinary stiffness. Diagnosis is a vet exam plus bloodwork, not a photo. The gait scan is a first look at the movement to share with a vet, not a Lyme test, and there is no Lyme scanner.

Symptoms to watch for

Shifting lameness — the horse is off, then seems better, then off again — a reason to book a vet, not a photo verdict

Stiffness that can look like sore feet or ordinary work stiffness — a still cannot tell them apart

Reluctance to go forward, or a horse that looks sore after rest — a clue, not a diagnosis

May look normal in a still; the first sign is often a change in the way they move — that is a vet visit, not a photograph

A gait that can look like other shifting lameness, sore feet, ordinary stiffness, or PPID-related stiffness — a still cannot tell them apart

A still photo is especially weak here: this is not a lesion you can point at — a reason to book a vet, not a photo verdict

Common causes

A tick-borne infection with Borrelia burgdorferi — exposure and bloodwork are clues, not a photo diagnosis
Not ordinary lameness, not sore feet, and not ordinary stiffness — a still cannot tell Lyme from those
Not PPID (Cushing’s) and not shivers — those are different problems and need a vet
A still cannot tell Lyme from other shifting lameness, sore feet, or ordinary stiffness — those need a vet exam plus bloodwork

Prevention

Check for ticks after turnout in endemic areas, and book a vet if the horse is newly stiff or shifting lame rather than waiting on a photo
Do not work through a new shifting lameness or unexplained stiffness hoping it will settle — that is a vet visit, not a photo
Do not treat a photo, a still of a lame stride, or a scan result as a diagnosis
Do not treat a photo, a blood-test printout you read alone, or a scan result as a diagnosis
A gait clip can help you and the vet look at the movement — it does not confirm or rule out Lyme, and it cannot tell Lyme from other shifting lameness, sore feet, or ordinary stiffness

What to do

1
Book a vet visit if the horse is shifting lame, newly stiff, or looks sore without a clear hoof or joint cause. Diagnosis is a vet exam plus bloodwork — not a photograph.
2
Do not treat a still of a lame stride as a verdict. A still cannot tell Lyme from other shifting lameness, sore feet, or ordinary stiffness.
3
If you record a gait clip, film walk and trot on a hard, level surface from the side — that is a video, not a still, and it is a first look to share, not a diagnosis.
4
Use a gait scan only as a first look at the movement to share, not as a Lyme test. There is no Lyme scanner.
5
If Lyme is confirmed, follow the plan your vet prescribes. 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 the horse is shifting lame, newly stiff, or looks sore without an obvious hoof or joint cause, or if the horse looks normal at rest but the hitch appears when you ask them to walk and trot. Call sooner if the horse will not bear weight or is in obvious pain. A photograph cannot diagnose Lyme disease. A still cannot tell Lyme from other shifting lameness, sore feet, or ordinary stiffness. Diagnosis is a vet exam plus bloodwork, not a photo. The gait scan is a first look at the movement, not a Lyme test, and there is no Lyme scanner.

Get a first look at the movement

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

Scan the gait

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

Educational content only. Not a substitute for veterinary advice.