By: Dr. Eleanor Kellon
Vanishing, or poorly developed, toplines, is a very common complaint of owners. Successfully addressing it depends on finding the cause.
The obvious sign of a poor topline is prominence of the spinal vertebrae along the back. The tissues along the spine in the back should at least be even with the tips of the bones. The sacrum, at the highest point of the rump, should also be covered, as should the wings of the pelvis behind the flanks.
Muscle forms part of the tissues around these bones, but there is also a generous upper layer of fat both along the back and over the rump. The first cause of diminished coverage to be ruled out is weight loss. This is done by observing the body as a whole for weight loss. In particular, are the ribs less covered by fat? (There is no significant muscular coverage on the ribs.) Does the neck look thinner? If the horse has obviously lost weight in general, this probably accounts for the changes in the topline as well. A calorie count, evaluation of the digestibility of the diet and, if necessary, check for underlying disease states will locate the problem.
If weight loss in general is not the issue, decrease in the muscular mass is the problem. Reduced exercise may be part of the cause but is usually not enough to cause the bone to protrude unless the horse is very thin to begin with, with one exception.
Older horses can have several reasons for loss of topline. Sarcopenia of aging is loss in muscle mass as part of the aging process. This is one instance where exercise is actually the only treatment and lack of it the main cause. It can prevent and reverse sarcopenia of aging. “Long and low” exercise with the neck gently flexed is the most effective in rebuilding topline.
Poor topline development, and loss of muscle mass overall, may be related to Cushing’s disease, a benign pituitary growth with over production of hormones, including ACTH which controls cortisol secretion.
High cortisol causes poor utilization of glucose and breakdown of muscle tissue. To reverse this process, the horse needs to be started on pergolide.
Poor utilization of protein in the diet can come from poor chewing. This may occur in older horses even if a dental exam doesn’t show any particular problem. The solution here is to provide pellets or cubes rather than coarse hay. In low protein diets, poor utilization can also be related to insufficient intake of lysine and methionine, critical amino acids. Supplementing with 10 to 20 grams/day of lysine and 5 to 10 grams of methionine for the average size adult horse will show results in a few weeks if this is part of the problem.
When horses are in work and receiving adequate total protein, inefficient muscle metabolism can be the problem. This is particularly likely in young horses in training and any horse showing difficulty in bulking up and achieving training milestones involving speed, endurance or advanced movements.
In these situations, supplementing with leucine, the most abundant amino acid in muscle and also an important muscle fuel, often corrects both the topline and performance issues. In addition, metabolic efficiency can be supported with acetyl-L-carnitine, beta-alanine and betaine.
Muscle metabolism is complex, but research has shown where the weakest points may lie. Comprehensive support can make all the difference in both the top line and muscle appearance and function overall.
Uckele, maker of CocoSoya, features formulas that support improved toplines.
Tri-Amino helps maintain strong muscles, healthy weight, and supports a healthy topline with the three most essential amino acids. Lysine aids in bone health and immune function. Methionine plays a role in the synthesis of structural proteins, especially hooves and connective tissues, and hair and mane coat. Threonine aids in healthy immune function.
Muscle EQ: Muscle is your horse’s motor. Keeping it properly fueled nutritionally can help the horse reach his natural potential for speed and endurance, maintain smooth gaits, hold better bulk/definition and enjoy muscles that are able to properly relax after work. By targeting key nutrients you can ensure there are no preventable barriers to smooth, efficient muscular activity.
About Dr. Kellon
Dr. Eleanor Kellon, staff veterinary specialist for Uckele Health & Nutrition, is an established authority in the field of equine nutrition for over 30 years, and a founding member and leader of the Equine Cushings and Insulin Resistance (ECIR) group, whose mission is to improve the welfare of horses with metabolic disorders via integration of research and real-life clinical experience. Prevention of laminitis is the ultimate goal. www.ecirhorse.org
Uckele Health & Nutrition, maker of CocoSoya, is an innovation-driven health company committed to making people and their animals healthier. On the leading edge of nutritional science and technology for over 50 years, Uckele formulates and manufactures a full spectrum of quality nutritional supplements incorporating the latest nutritional advances. www.uckele.com.