Symptoms of an Insulin‑Resistant Horse

Insulin resistance in horses shows up through a combination of metabolic, behavioral, and physical changes. Signs of insulin resistance in horses include obesity (difficulty losing weight), abnormal fat deposits (a cresty neck), laminitis, and increased appetite. Symptoms can vary in severity, and some horses show only a few early clues before progressing.

🐴 Symptoms of an Insulin‑Resistant Horse

🔥 Common & Recognizable Signs

• Abnormal fat deposits
  • Cresty neck - fat deposits along the neck crest, 
  • Fat pads over tailhead, shoulders, sheath/udder
• Generalized obesity, difficulty losing weight (despite eating less)
• Laminitis (mild to severe)
• Recurrent or chronic
• Subclinical signs such as short, choppy gait or sensitivity on hard ground

💧 Metabolic & Systemic Signs

• Increased thirst
• Increased urination
• Increased hunger
• Low energy

🧬 Muscle & Body Condition Changes

• Muscle wasting or loss of topline
• Poor overall body condition despite fat deposits

👁 Other Physical Clues

• Puffy or swollen areas above the eyes (fat accumulation)
• Reproductive issues (irregular cycles, reduced fertility)

🐎 Behavioral or Performance Changes

• Reduced stamina
• May show reduced performance levels, lethargy, or general irritability
  

🧪 How Vets Confirm Insulin Resistance

• Resting insulin levels
• Combined glucose–insulin test
  

If your horse is diagnosed with insulin resistance, management typically involves dietary changes, increased exercise, and sometimes medication. A low-starch, high-fiber diet is often recommended, along with regular exercise to help manage weight and improve insulin sensitivity.