Fat lump behind the saddle on your horse: what now?

What exactly is a fat lump?

A fat lump is a benign accumulation of fatty tissue directly under the skin, medically referred to as a lipoma. They feel soft and moveable, have a clearly defined border and are usually painless to the touch. In horses they occur most commonly in older animals and in ponies or crossbreeds that put on weight easily, such as cob types and Fjords. The size ranges from a golf ball to a fist. Behind the saddle — roughly between the back of the saddle tree and the loins — this is an awkward location, because the sloping skin there comes into direct contact with the seat and the rear saddle-tree points.

Fat lump or something else? Here is how to check

Not every swelling behind the saddle is a fat lump. Pressure damage (a so-called saddle sore or bursitis) also feels soft but is often warm and painful. An abscess is harder, warm and can cause a fever. A fat lump is cool, moves freely and causes no pain under light pressure. Not sure? Record the size of the lump in the horse profile in EquiSight — a photo with a date stamp helps you and your vet to see whether the swelling is growing. Measuring is simple: use a ruler and note the diameter in centimetres.

When should you call the vet?

In these situations, veterinary advice is not a luxury:

• The lump is larger than 5 cm or is growing quickly (noticeably larger within 2 weeks).
• The swelling feels hard, warm or painful to the touch.
• Your horse shows behavioural changes: standing hunched when being saddled, refusing, unwillingness or a hollow back.
• The skin over the lump is damaged, has a wound or hair loss.
• Your horse has recently received a knock or fall on that spot.

Effect on saddle fit and riding

A fat lump of more than 3 cm behind the saddle can literally disrupt the saddle fit. The seat tilts forward, the rear saddle-tree points sit higher and uneven pressure distribution develops. You may notice this when a horse moves irregularly, tightens its back or has difficulty with rearward movement. With a fat lump, always have a certified saddle fitter come for a recheck. Sometimes a soft pad or a different saddle is sufficient; in other cases the owner, together with the vet, opts for surgical removal under local anaesthetic, a relatively straightforward procedure with a short recovery time (on average 7–10 days of stable rest).

Diet and weight as a risk factor

Fat lumps occur more often in horses with a high Body Condition Score (BCS). A score of 6 or higher on Henneke's 9-point scale is associated with increased fat distribution on the neck, ribs and back. Structured roughage based on bodyweight (on average 1.5–2% of bodyweight per day) and restriction of sugar-rich grass are effective measures. Use the calendar in EquiSight to schedule weight checks every 4 weeks and use EquiCoach for personalised nutritional advice based on your horse's weight and activity level.

Daily checks: how to build the routine

• Always run your hands along the back before saddling up — any noticeable changes are quickly felt this way.
• Photograph new swellings immediately and save them in the horse profile with the date and size.
• Check the saddle for symmetrical sweat patterns after each training session.
• Schedule a saddle-fitter check every 6 months, more frequently if your horse loses or gains weight.
• Record behavioural changes during riding in the EquiSight logbook function, including small things such as pinned ears or tail swishing.