My Horse is Losing Condition, Why?

Unexpected weight loss, resulting in poor body condition, endangers your horse’s health. With the support of your veterinarian, the underlying cause can be diagnosed and a management plan developed to promote safe weight gain and healthy body condition. 

Sudden or chronic weight loss is detrimental to horse health. There are a number of reasons why your horse may be losing weight and determining the cause on your own is often challenging.

Involving your veterinarian from the outset is recommended. They will perform a full physical examination, including dental exam, and may take blood and manure samples for analysis. In some cases, further testing may be required to rule out a health problem.

Your veterinarian can also assess your horse’s diet. Poor quality roughage, including your own pasture, may be linked to your horse’s weight loss. Your veterinarian will be able to offer guidance on analysing the quality of your pasture and hay with laboratory testing.

Five Common Causes of Weight Loss

For those horse owners who want to learn more about the common causes of unexpected weight loss, we’ve outlined the top five below. Your knowledge of what’s normal for your horse will help your veterinarian determine the reason behind your horse’s weight loss.

  1. Stress

 Particularly for the highly strung horse, stress may contribute to unexpected weight loss.

A sudden change in environment, diet, training, or the occurrence of a health problem, can affect your horse’s appetite. Together, stress and decreased feed consumption may trigger the formation of gastric ulcers, resulting in pain and further perpetuating the issue of weight loss.  

  1. Intestinal Parasites

 With inefficient worming, intestinal parasites may proliferate and lead to malnutrition problems.

Intestinal parasites can wreak havoc on your horse’s health if not kept in check with regular worming. When allowed to increase to large numbers, these parasites compete for the nutrients present in your horse’s feed and cause damage to the lining of their gastrointestinal tract. 

  1. Dental Problems

 Poor dental health, including difficulty chewing, may play a role in unexpected weight loss.

 Of the various issues that can occur, sharp enamel points are often implicated in weight loss. Caused by uneven wear, missing or misaligned teeth, the immense pain may force your horse to chew awkwardly, drop food while eating or avoid some foods, such as roughage, altogether.  

  1. Illness or Disease

 Chronic diseases can deplete your horse’s appetite or impact on their digestion.

 Liver and kidney disease cause physiological damage to these vital organs, often resulting in weight loss. Some cancers are known to produce inflammatory hormones which may affect digestion, in turn, decreasing your horse’s appetite and leading to weight loss. 

  1. Diet

 An inadequate diet, low in calories or vital nutrients, may deplete body condition.

The importance of a well-balanced, forage-first diet cannot be underestimated. For horses with high caloric needs, such as young, growing horses, lactating mares and performance athletes, a diet insufficient in energy, protein, vitamins and minerals may contribute to weight loss.


  • Dr Louise Cosgrove

    The founder of Exclusively Equine Veterinary Services, Louise is driven to support horses in their recovery from injury or illness. A graduate of the University of Queensland, with international equin...

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