Why Is My Horse Losing Weight?

Common causes, and when to ask your vet for help

Quick Answer

Weight loss can be linked to diet, dental problems, parasites, or an underlying health condition
Gradual weight loss despite adequate feeding is always worth investigating with your vet
Sudden or rapid weight loss, especially with other signs, needs prompt veterinary attention
Your horse’s age, workload, and dental history all give useful clues to the cause

Common Causes of Weight Loss

01 Insufficient feed or forage

Not enough forage or hard feed for the horse’s workload, age, or condition can be linked to gradual weight loss over time.

02 Dental problems Common in older horses

Sharp edges, missing teeth, or other dental issues can make chewing forage difficult, and may be linked to weight loss even when plenty of feed is available.

03 Parasite burden Worth checking

A high worm burden can be linked to poor weight gain or weight loss, particularly in younger horses or those on an irregular worming routine.

04 Gastric ulcers

Stomach ulcers can be linked to reduced appetite, mild colic-type signs, and weight loss, and are relatively common in horses in regular work.

05 Chronic pain

Ongoing pain, such as ongoing lameness or low-grade discomfort, can be linked to reduced appetite and gradual weight loss.

06 Underlying illness Older horses

Conditions such as PPID (Cushing’s), kidney or liver disease, or other chronic illness can be linked to weight loss despite normal or increased appetite.

Sudden vs Gradual Weight Loss

Sudden / Rapid

Often linked to acute illness, severe parasite burden, or pain that’s putting the horse off its feed. Mention the speed of change to your vet.

Gradual

Often linked to dental issues, low-grade parasite burden, or an underlying condition such as PPID. Still worth investigating even if it’s slow.

Contact Your Vet Immediately

Rapid weight loss alongside lethargy, fever, or diarrhoea
Weight loss alongside repeated colic signs
Complete loss of appetite for more than a day
Weight loss in a pregnant mare or a foal

These combinations can point to a more serious underlying problem that needs prompt assessment.

When to Contact Your Vet

Noticeable weight loss over a few weeks despite normal feeding
Weight loss alongside a dull coat, lethargy, or behaviour change
Difficulty chewing, dropping feed, or quidding (dropping partly chewed hay)
Weight loss in an older horse, even if gradual

How Pet Med Direct Can Help

Once your vet has identified the cause of weight loss, ongoing support may include a tailored worming programme, dietary supplements, or other products recommended for your horse’s specific needs.

Some treatments require a valid veterinary prescription. Pet Med Direct can only supply prescription medicines after the prescription has been checked. Always follow your vet’s advice and the directions on the medicine label.

Frequently Asked Questions

How quickly should I be concerned about weight loss?

If you notice a clear change over a few weeks, or it’s happening despite normal feeding, it’s worth speaking to your vet rather than waiting to see if it continues.

Can stress cause weight loss in horses?

Yes, stress from a change in routine, travel, or a new environment can sometimes be linked to a temporary reduction in appetite and weight.

Does age affect weight loss risk?

Older horses are more prone to dental wear and conditions such as PPID, both of which can be linked to weight loss, so regular vet and dental checks become more important with age.

How often should my horse’s teeth be checked?

Most horses benefit from a dental check at least once a year, though your vet or equine dental technician can advise on frequency based on your horse’s age and history.

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This this article is for informational purposes only and does not constitute veterinary advice.
If you are concerned with your dog’s health, please consult a qualified veterinarian.