Overweight horses and ponies often develop fatty tissue deposits along their body. When these fat pads develop along the upper curve of their neck, the animal is said to have a cresty neck. While fat pads are typically an indication of the type of diet and exercise an animal receives, sometimes they signal a different type of health issue.

Equine Metabolic Syndrome

Equine Metabolic Syndrome (EMS) is an endocrine disorder that is characterized by abnormal fatty tissue deposits found on the animal’s body. These fat pads can develop at any location on the body where fat naturally accumulates. In EMS affected animals, the fat pads are most commonly found at the:

• Crest of the neck
• Tail head
• On the prepuce and mammary regions.

Clinical signs of EMS include:

• Obesity and/or regional adiposity
• Insulin resistance (IR)
• Laminitis

The start of EMS is not specific, but the cause is referred to obesity and to genetic-predisposition, and seems to have the most impact on middle-aged animals. The University of Missouri reports that EMS horses are often described as easy keepers, animals that are able to easily maintain their body weight.

Cresty Neck Score

As part of the determination of EMS, a cresty neck score (CNS) may be given. The CNS utilizes a predetermined range of scores to describe an animal’s neck fat deposition. The score is used as a means to monitor changes in neck thickness which could indicate the progression of a physical disorder. The range of scores runs 0 to 5. Basic information taken from a CNS includes the following:

• Score of 0
• No visible crest, no palpable crest
• Score of 1
• No visible crest, slight palpable crest
• Score of 2
• Visually noticeable crest, fat deposited evenly
• Score of 3
• Crest enlarged and thickened, mounded appearance
• Score of 4
• Crest grossly enlarged and thickened, may have wrinkles
• Score of 5
• Fallen crest: Neck crest is massive and has shifted permanently to one side

Most breeds are affected by EMS, but some animals have a tendency to store more fat in their crest areas, for example:

• Draft horses
• Draft mixes
• Morgans
• Most ponies

Stallions typically maintain more of a crest than geldings or mares because fat in their neck is a characteristic that is indicative of the sex of an animal. The use of the CNS score should take into consideration the tendency, breed, and sex of the animal before assigning a score.

Diagnosis

Diagnosis of EMS requires a physical examination and laboratory tests. Since other conditions, such as Cushing’s disease and hypothyroidism, have symptoms similar to EMS, the diagnosis requires testing to rule out these disorders.
Diagnosing EMS may require:

• Examination for physical characteristics of EMS
• CNS
• Body Condition Score
• Abnormal fatty deposit distribution
• Radiographs of the feet
• Examination for laminitis which looks for:
• Abnormal hoof growth
• Dropped soles
• Separation of the hoof
• Unusual growth lines
• Glucose-tolerance testing
• Administration of glucose to measure insulin and glucose response levels
• The result of EMS will indicate high glucose and insulin levels
• Dexamethasone suppression test to rule out Cushing’s disease
• The result will be normal in EMS horses
• Thyroid test to rule out hypothyroidism
• The result in EMS animals will be within the normal range

Treatment

The most effective treatments involve limiting calories and increasing exercise. There is no medication designed to treat EMS.

Want to read more about equine related animal health issues? Contact your Covetrus representative today at 855.724.3461.

Sources:
https://cms.qut.edu.au/__data/assets/pdf_file/0009/329616/how-to-assign-a-cresty-neck-score.pdf
http://www.cvm.umn.edu/equinegenetics/ems/home.html
http://www.equinews.com/article/fat-pads-horses
http://www.equinews.com/article/cresty-necks-horses-possible-physical-sign-metabolic-issue