Fat Pads (Regional Adiposity) in Horses: Risk Factors, Causes & Treatment

Fat Pads & Obesity
Adipose Tissue
Assessment
Treatment

Fat pads in horses have become an increasingly common concern among owners and caretakers. Also known as regional adiposity, these patches refer to areas of fatty tissue that develop in certain locations on the horse’s body. Two common places for fat pads to develop are along the top of the neck and above the tail head. ^[1]

The formation of fat pads in horses is closely associated with general obesity and insulin resistance. It is also linked to a horse’s susceptibility to laminitis and a reduced recovery rate in laminitis cases. ^[2]

In addition to understanding the basics of body condition scoring, horse owners should be able to identify fat pads and signs of excessive weight gain in their equines. Monitoring your horse’s condition is important for making informed decisions about diet and management to support healthy weight control.

In some cases, underlying medical conditions can contribute to uncontrolled weight gain and regional fat deposits. Read on to learn more about equine fat pads and whether your easy keeper might benefit from veterinary or nutritional intervention.

Fat Pads in Horses

Fat pads in horses are localized areas of fat accumulation, often found in regions like the neck (cresty neck), along the ribs, around the tailhead, and over the shoulder area. These fat deposits are a common sign of obesity, but they can also be present in horses with normal overall body condition.

Fat pads are often a sign of conditions like Equine Metabolic Syndrome (EMS) and Pituitary Pars Intermedia Dysfunction (PPID, formerly known as Cushing’s).

Horses with EMS have insulin resistance, which is linked to excessive fat storage. Some horses with PPID are also insulin resistant. Therefore, horses with EMS or PPID with insulin resistance have a higher risk of being overweight or obese. ^[3]

Once fat pads have formed, they can be challenging to reduce, even with dietary changes and increased exercise. Persisting fat pads indicate ongoing metabolic issues that may require veterinary intervention.

General Obesity

Obesity in horses is a condition characterized by excessive accumulation of body fat. ^[1] It’s typically measured using a body condition score (BCS), where a score of 7 or higher out of 9 indicates an overweight or obese horse.

General obesity increases the horse’s risk of negative health consequences such as: ^[1]^[3]

Reduced athletic performance
Colic
Poor reproductive performance
Laminitis
Hyperlipemia during negative energy balance
Impaired thermoregulation
Osteochondrosis

Obesity and fat pads are a health and welfare issue in horses that often goes unreported or undetected by caregivers. ^[3] This is partly because weight gain can occur gradually, making it easy to miss until it reaches a problematic level.

Additionally, owners may not recognize the subtle signs of obesity, such as slight changes in neck or shoulder fat deposits, until more severe symptoms or health issues arise. ^[4]

Regular veterinary care and routine monitoring of body condition score can help owners identify and intervene when excess weight gain occurs.

Easy Keeper Breeds

Though any horse can become obese or develop fat pads, certain breeds are more prone to these conditions. These breeds are often considered “easy keepers“.

Easy keeper breeds include: ^[5]^[6]

Adipose Tissue

Both fat pads and general body fat are composed of adipose tissue, which consists of fat cells called adipocytes. These cells store energy in the form of lipids, which can be broken down and used for energy when needed.

However, adipose tissue does much more than just store fat — it is also an active endocrine organ. It produces and releases hormones and chemical messengers called adipokines that are involved in regulating metabolism, appetite, insulin sensitivity, inflammation, and other bodily processes. ^[2]

The primary type of fat in the body is white adipose tissue (WAT), found in subcutaneous fat, around internal organs, and within bone marrow. WAT cells can expand in size (hypertrophy) or increase in number (hyperplasia) when a horse consumes more calories than it needs.

In EMS horses, hypertrophy is the primary form of expansion and can induce local inflammatory responses. ^[3]

White adipose tissue is specifically distributed throughout the body to serve various functions, including providing structural support, insulation, and acting as an energy reserve. ^[2] However, when excess lipid accumulates in fat cells, adipocytes can show signs of dysfunction including: ^[3]

Impaired function of the mitochondria and endoplasmic reticulum
Insulin resistance
Increased leptin secretion
Upregulated cortisol metabolism leading to overactivation of stress responses

These changes in fat cells can impact metabolism in the rest of the body, highlighting the importance of managing body fat to maintain metabolic health. ^[3]

Assessing Fat Distribution

Research shows that horse owners often tend to underestimate their horse’s weight or body condition score. They may also have varying perceptions of what an “ideal” body condition looks like based on the horse’s discipline or workload. As a result, owners might not realize that their horse is technically “obese” according to current medical standards. ^[4]

Researchers have developed various scoring systems to help owners and veterinarians assess a horse’s body condition. Each system has its pros and cons, particularly regarding the objectivity or subjectivity of the assessment. ^[2]

Objective assessments of body fat in horses include: ^[1]

Carcass evaluation
Ultrasonography of subcutaneous fat or total body water
Morphometric measurements

Subjective assessment methods include body condition scoring (BCS) and cresty neck scoring (CNS). ^[1]

Among the various adiposity assessments available, BCS and CNS are the most commonly used by both experts and owners. ^[6]

Body Condition Score

The Henneke Body Condition Scoring system was originally developed by the livestock industry for evaluating “flesh” in animals. However this 9-point scale has become the most commonly used assessment of body condition in horses today. The ideal Henneke score for a horse is between 4 – 6, depending on their physiological status and work. ^[7]^[8]

The BCS system evaluates externally visible or palpable fat at specific anatomical locations on the horse. While it cannot assess internal fat, it is considered a good predictor of total body fat, particularly when applied by experienced practitioners. ^[2]^[6]

However, BCS scores can vary depending on the observer, and inaccuracies may arise based on whether visual assessment or manual palpation is used. A thick hair coat can also make visual assessment challenging in some cases. ^[6]^[7]

Despite these limitations, many veterinarians continue to support the use of BCS as a valuable tool for identifying obesity and assessing health risks in horses. ^[6]

Cresty Neck Score

The cresty neck score (CNS) uses a 5-point scale to assess fat accumulation along the crest of the neck, above the nuchal ligament. Since fat in this area can be disproportionate to overall body fat, the CNS serves as an independent indicator of adiposity. ^[6]

More importantly, the CNS scale has been shown to correlate with measures of insulin sensitivity in ponies and some horses, but further investigation of this relationship is required. ^[#]^[10]

Cresty necks are scored as follows: ^[10]

Crest Score Scale
0	No palpable crest
1	No visual appearance of crest but slight filling felt with palpation.
2	Noticeable appearance of crest but fat deposited fairly evenly from poll to withers. Crest easily cupped in one hand and can be bent from side to side.
3	Crest enlarged and thickened so fat is deposited more heavily in the middle of the neck than toward the poll, giving a mounded appearance. Crest fills cupped hand and begins losing side-to-side flexibility.
4	Crest grossly enlarged and thickened and can no longer be cupped in one hand or easily bent from side to side. Crest may have wrinkles or creases perpendicular to the topline.
5	Crest is so large that it droops to one side (called a fallen crest).

Ideally, a horse should have a CNS of no more than 2. It’s important to note that horses with higher CNS scores may or may not be generally obese, though one study found a strong association between BCS and CNS scores. ^[11]

EQUIFATs

The EQUIFAT method of scoring is a newer 5-point scoring system. It uses both subjective and objective gradings to assess regional adipose tissue depots on the horse. EQUIFAT was developed to study the association between adiposity and risk of clinical conditions in live animals, during surgery, or in post-mortem examinations. ^[2]

The subjective portion of EQUIFAT involves assessing fat deposits on the rump, epicardial, omental, and mesenteric areas using specific descriptors. For example a score of 1 means there is no visible fat while a score of 5 means there is excessive adiposity. ^[2]

The objective portion involves assessing thickness scores of adipose tissue deposits in the nuchal crest and ventro-abdominal retroperitoneum (space behind the abdominal cavity). Again, scores range from 1 – 5. ^[2]

Ultrasounds

Ultrasonography is another method for measuring adiposity in horses. This technology can be used to measure rump-fat thickness and depth of adipose depots at specific sites on the horse. Ultrasound of adiposity at the base of the neck has proven especially useful as it can be correlated with elevated plasma insulin and leptin concentrations. ^[1]

While ultrasonography may provide useful measurements of regional adiposity, researchers aren’t sure if this is the best way to predict total body fat in horses. ^[2]

Total Body Water & Bioelectric Impedance

Another measure of adiposity is total body water. This method is based on the principle that water is distributed in all parts of the body except fat. To measure this, researchers infuse labelled water called deuterium oxide into the blood and measure its dilution. ^[8]

This technique is used to calculate the total body water and fat free mass to then calculate fat mass. This method is very technical and limited to a research or clinical setting. ^[8]

Another technique for assessing body composition in horses is bioelectric impedance. ^[12]^[13] This method measures the resistance of body tissues to the flow of a small, harmless electrical current. It is used to estimate body fat and muscle content based on the principle that muscle conducts electricity better than fat tissue. ^[14]

However, estimating body fat content using bioelectrical impedance is not yet considered reliable, with large variability in individual animals. ^[14]

Morphometry

Morphometry involves measurements of different areas of the horse’s body to estimate obesity. These measurements often include: ^[11]

Height at the withers
Body length (from point of shoulder to point of buttock)
Girth circumference
Waist circumference (coinciding with umbilicus)
Neck circumference
Neck length
Neck crest height

In particular, girth to height ratio may indicate animals that are overweight. ^[1]

Treatment

Diet and exercise are the primary methods for managing fat pads and general obesity in horses. However, successful management requires a long-term weight loss plan that requires consistent effort and discipline from the horse owner. ^[3]

It’s highly recommended to seek guidance and supervision from a veterinarian and equine nutritionist when implementing a weight loss plan for your horse.

Diet Plan

Horses that consume more energy than they require are prone to weight gain and the development of fat pads. Therefore, reducing calorie intake and/or increasing physical exercise are key strategies for treatment. ^[3]

Removing Grains

Grain-based feeds should be removed from the horse’s diet to eliminate excess calories and sugars. Avoid feeds that contain high starch or sugar ingredients such as corn grain, wheat grain, or molasses.

The primary reason for reducing starch and sugars in the diet is to minimize the insulin response to meal intake. Meals that are higher in sugar and starch trigger a higher insulin response than those that are lower in sugars and starch.

This is particularly true for easy keeper breeds such as Andalusians and ponies, whereas hard keepers such as Standardbreds have a lower insulin response to the same sugar intake. ^[15]

Therefore, eliminating excess grains to reduce sugar intake is especially important if your horse belongs to an easy keeper breed, particularly if they are overweight or have regional fat pads.

If you feel your horse needs a carrier to consume supplements, you can consider low starch and sugar options such as beet pulp or timothy cubes/pellets.

Adjusting Forage Supply

Another significant source of calories and sugars in your horse’s diet is pasture. Reducing or eliminating access to pasture is an effective way to lower digestible energy (DE).

Pasture is typically very palatable and encourages high intake, with some studies showing pasture dry matter intake of up to 5% of body weight. ^[16] This level of intake can easily lead to weight gain and fat accumulation.

To support gradual weight loss, remove overweight horses and ponies from pasture and provide appropriate-quality hay and a vitamin and mineral supplement. ^[3]

Ideally, hay should have a low hydrolyzable carbohydrate (HC) content (sugar and starch). This can be determined by sending a hay sample for analysis. Hay with an HC of 10% or less is best for overweight, insulin resistant horses. ^[3]

If the HC of the hay is higher, it can be soaked in cold water for 60 minutes to reduce sugar levels. ^[3]

Your veterinarian or nutritionist may also recommend restricting hay to 1.5% of the horse’s ideal body weight. A slow feeder, small hole hay net or grazing muzzle can be used to extend foraging time while regulating forage intake. ^[3]

However, it’s important not to over-restrict forage intake. Without access to forage for prolonged periods, horses are prone to developing stereotypic behaviors, such as cribbing or wood chewing, and gastric ulcers.

They may also shown signs of increased stress such as aggression towards each other. Horses should not be fed less than 1.5% of ideal body weight in forage and should not go more than five hours without access to forage. ^[17]

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Balancing the Diet

Forage-based diets are critical for all horses to support digestive health and mental well-being. However, forage alone does not supply enough vitamins and minerals, leaving your horse with several nutrient deficiencies. The deficiencies will be further exacerbated if forage intake is restricted.

Research has shown that supplements including magnesium, chromium, and short-chain fructo-oligosaccharides (a prebiotic) improve insulin sensitivity in normal horses or EMS horses fed a high starch challenge. ^[18]^[19]^[20]

To fully balance the diet, a comprehensive vitamin and mineral supplement that does not supply significant calories should be used. If you are restricting forage, you may also need to add protein or amino acids to the diet.

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Physical Exercise

Increasing physical exercise is recommended for obese horses to help them lose weight and improve insulin resistance. Research shows that increased physical activity can increase insulin sensitivity. ^[3]

Exercise also helps prevent muscle loss in horses and may have anti-inflammatory benefits. ^[3]

For horses with insulin resistance or obesity, the following exercise protocols are recommended: ^[21]

For horses with no clinical laminitis or lameness, exercise no for more than 30 minutes at a low to moderate intensity at least 5 times per week.
For horses with a history of clinical laminitis but whose hoof lamellae are stable and fully recovered, exercise for no more than 30 minutes at low intensity on soft ground at least 3 times weekly. Be sure to watch for any signs of returning lameness and modify accordingly.

As the horse loses weight and gains fitness, exercise intensity, frequency, and duration can be gradually increased. Consult with your veterinarian and a qualified trainer to develop an appropriate exercise program for your horse.

Medications

Pharmaceutical drugs are generally not the first approach for addressing obesity or fat pads in horses. However, certain medications may be beneficial for horses at risk of laminitis or those experiencing weight loss resistance despite dietary modifications. ^[3]

Medications that may be used to treat obesity and regional adiposity in horses include: ^[3]^[22]^[23]

Levothyroxine sodium (Thyro L): Aids in weight loss and may increase insulin sensitivity. The recommended treatment is 3-6 months (until the desired body weight is achieved) at a dose of 0.1 mg/kg. The dose is gradually tapered by half over two weeks before discontinuation.
Metformin hydrochloride: Commonly used in human medicine, this drug is now used for horses as well. It reduces hepatic glucose production, improves insulin sensitivity, and enhances glucose transport in insulin-sensitive tissues. Metformin may be effective in treating Equine Metabolic Syndrome (EMS) and is administered at 15-30 mg/kg, typically 30-60 minutes before feeding.
Sodium-glucose co-transporter 2(SGLT2) inhibitors: These drugs, such as canagliflozin, increase glucose loss into urine by the kidneys. This reduces insulin levels in the blood which helps prevent laminitis. However, some horses might develop high blood lipids while on these drugs.

These medications should always be used under veterinary supervision and in combination with proper dietary and exercise modifications. ^[3] Consult your veterinarian for an appropriate treatment plan tailored to your horse’s needs.

Summary

Some horse breeds are more prone to developing excessive fat pads or regional adiposity. These fatty deposits are strongly linked to general obesity but can also occur independently. If you suspect your horse has excessive fat pads or general obesity, it’s essential to have them evaluated by a veterinarian as soon as possible.

Excessive fat pads are linked to several equine health issues, including insulin resistance and laminitis.
Fat pads can be assessed using equine adiposity scoring systems like BCS or CNS, but it’s best to have this done by a veterinarian or qualified equine nutritionist, as owners may underestimate these scores.
Excessive fat pads and general obesity can be managed with diet, exercise, feeding adjustments, and, in some cases, medication.