For adrenaline junkie-type veterinarians, nutritional management isn’t nearly as satisfying or exciting as a good old-fashioned abscess, laceration or dystocia. That said, nutrition directly affects equine health, behavior, performance and welfare. Therefore, it could be construed as one of the most important aspects of horsekeeping.
“Surveys show that veterinarians rank highly as nutrition resources for owners, and nutrition experts strongly encourage general practitioners [to] perform a nutritional assessment as part of every horse’s routine physical examination,” said Catherine Whitehouse, MS, a nutrition advisor for Kentucky Equine Research.
The American College of Veterinary Nutritionists has an extensive list of competencies on its website (go to ACVM.org and search “equine competencies”). That organization stated: “Equine veterinarians should be able to perform the following functions competently upon graduation.” Even quickly perusing this list might be an eye-opening experience for veterinarians. The list includes assessing the horse, the feed and feeding management, recommendations and monitoring (and each topic has a list of six to 12 things that the veterinarian should be able to do).
Having deficiencies in some of these areas is understandable. As Whitehouse pointed out, “Veterinary students typically receive little nutrition training. Their basic nutrition education is generally covered in only one or two courses.”
Highlighting the importance of this part of equine practice, the April 2021 edition of Veterinary Clinics of North America: Equine Practice was devoted to equine nutrition. One of those articles, entitled “What would be good for all veterinarians to know about equine nutrition,” relayed data showing that most veterinarians had not recently (in the past year) participated in any nutrition continuing professional development, and that many veterinarians felt dissatisfied with the level of equine nutrition education they received in school (Harris and Shepherd, 2021).
“Limited nutrition-based continuing education resources and time are two culprits impeding dissemination of nutrition information,” Whitehouse noted. “While owners have the opportunity to ask for nutrition advice at routine care appointments, veterinarians often don’t have time to answer all of an owner’s questions at that one appointment. Nor do they have the opportunity to call them later to follow up.”
For those reasons—time and knowledge—equine veterinarians could benefit from the assistance of an equine nutritionist.
How to Partner with a Nutritionist
To demonstrate how veterinarians and nutritionists can effectively partner, let’s consider the following scenario:
Your patient is Darla, a 7-year-old Thoroughbred/warmblood cross mare. The owner has aspirations of starting to compete at the novice level of eventing within the next few months. The mare’s currently body condition score (BCS) is approaching 7 out of 9, but the owner thinks she is perfect.
The owner is wondering how much more she should feed her horse to meet her soon-to-be increased energy demands. How much concentrate and what kind? Does she need to add a ration balancer? Is there enough protein in the horse’s diet? How can she protect the horse from stomach ulcers? What supplements does she need, such as electrolytes, coat and hoof conditioners, joint supplements? The list goes on and on.
Here are some thoughts by two nutritionists on how veterinarians can begin to approach this situation.
Step One: A Complete Physical Exam
As stated above, nutrition is an aspect of medicine that directly affects horse health. It should therefore be treated with the same importance as a lameness examination. Thus, your first step in addressing nutrition-related issues needs to be a complete physical examination.
The full physical exam ensures the horse has no underlying conditions such as lameness, equine asthma, myopathy (e.g., polysaccharide storage myopathy type 1 or 2), an underlying endocrinopathy (such as equine metabolic syndrome or pituitary pars intermedia dysfunction, aka equine Cushing’s). Recognition of any of these (or other) underlying conditions will alter your approach to nutrition advice. For simplicity, let’s assume our horse, Darla, is sound without evidence of any underlying morbidities and has good dentition. With a BCS of 7, however, the horse is clearly overweight.
“This is not a surprising finding these days as the equine obesity epidemic mirrors that in humans,” said Whitehouse. “While broaching weight issues with owners who believe their horses are perfect can be challenging or even downright awkward, it’s important to address the elephant in the room for optimal equine health and performance.”
Excess condition/obesity is a leading nutrition-related concern, particularly in the leisure and sporthorse disciplines. Excess body weight, Whitehouse said, negatively affects joint health, fitness level and stamina, all of which Darla and her owner need in order to successfully compete even at a novice level.
Step Two: Body Condition
“The body condition scoring system most prevalently used for horses, developed by Dr. Don Henneke, revolves around both the visual and tactile appraisal of fat cover on six different anatomical areas of the horse: over the top of the neck, around the withers, down the back, around the tailhead, over the ribs and behind the shoulder. After evaluation of all six areas, a score from 1 to 9 is assigned,” said Jennifer Zoller, PhD, extension horse specialist in the Department of Animal Science at Texas A&M University.
Ideally, working horses should have a body condition score of 5.
“Darla has a BCS close to 7,” noted Zoller. “To reach her optimal BCS, we need to decrease the amount of energy in her diet. This can most easily be accomplished by reducing the amount of concentrate or supplements being provided or changing the type of concentrate to better meet her needs.”
In Whitehouse’s opinion, the three biggest barriers to weight loss are that owners: 1) do not appreciate how overweight their horses are; 2) have limited knowledge regarding the different categories of workloads (light, moderate, heavy, very heavy); and 3) do not know the nutrient requirements for those different categories.
An equine nutritionist can help by providing a favored BCS chart to review with owners (don’t just hand it to them!).
Zoller recommended the body condition score chart from Texas A&M AgriLife Extension. Kentucky Equine Research also offers a downloadable body condition score chart. Go to KER.com and search “body condition score chart.”
Step Three: Strip Down the Diet
This owner is super enthusiastic and wants to dress up her horse’s ration, adding all sorts of “extras.” Encourage your owners to go back to the basics: forage.
“The foundation of any horse’s diet, regardless of activity level, should be forage. It’s by far the most important component of a horse’s diet,” said Zoller.
According to Zoller, not only can forages provide many of the necessary nutrients a horse requires, they can also:
- help reduce the incidence of ulcers;
- improve gut health (the intestinal microbiome);
- support dental health; and
- reduce the incidence of negative behaviors such as cribbing, weaving, etc.
“Unless there are exceptional circumstances, most horses need an absolute minimum of 1% of their body weight per day in forage on a dry-matter basis,” emphasized Whitehouse.
For Darla, a horse we know is over-conditioned, Whitehouse recommended feeding between 1.5 and 1.8% of her body weight in moderate-quality grass forage.
Darla probably weighs about 1,400 pounds. Feeding 1.8% of her body weight in forage is 24 pounds of forage per day. This approach assumes you have accurately estimated the horse’s body weight and that the owner is actually weighing the hay using some sort of scale. Counting flakes or “guesstimating” forage weight is not sufficient. For body weight estimations, use a weight tape or one of the available body weight calculators such as the University of Minnesota’s Healthy Horse App. (You can download it from Apple or Android app stores.)
You also need to consider the quality of hay being offered. You don’t want to offer less than about 1.5% of body weight in forage, but if the horse—like Darla—needs to lose a lot of weight, then the horse needs a lower-quality hay.
“Forage quality refers to the digestible energy or nutritional value of a hay,” Whitehouse said. “Lower-quality hay is higher in fiber and often harvested at a later stage of maturity so it has lower digestibility and is therefore lower in calories.”
Zoller added, “When comparing types of hay—bermudagrass hay to alfalfa, for example—certainly the alfalfa is going to be higher in nutrient value and thus would be termed higher quality. That is not to say that the bermudagrass hay is bad—simply that the horse will get more nutrients from the alfalfa. Feeding a bermudagrass hay is perfectly acceptable, and bermudagrass hay is prevalently fed to horses in my home state of Texas as well as many other areas across the U.S.”
It is important to appreciate that not all horses require high-quality forage, but all horses do require hygienic forage. A lower-quality hay is less nutritious but still must be free from mold and dust.
While recommending a moderate-quality forage for Darla is appropriate, Zoller noted that selecting forage is always a balance between need and availability. An equine nutritionist can help you find a reputable producer in your area.
Zoller said, “While veterinarians are capable of sourcing hay, time constraints, the size/area of their practice, etc., can certainly have a big impact on their ability to locate appropriate forage. Local extentsion agents can be great resources to both veterinarians and horse owners as they typically have knowledge of hay producers in the area. Many county offices also have forage sampling equipment available, and often county agents can assist in the sampling and forage analysis interpretation.”
Step Four: Concentrate on Concentrates
Many owners do not appreciate that their horses are overweight. This problem is compounded by the fact that many owners view and feed their horses as elite athletes when in fact the horses are not! As a result, owners want to feed concentrate feeds when their horses do not require the extra energy.
“In the scenario above, I would estimate Darla’s workload to currently be light, about one to three hours per week of light riding, maybe moving more toward moderate, which is three to five hours per week of moderately strenuous exercise,” Zoller said.
Darla, being overweight and not performing at a particularly taxing level, does not require concentrate feed, but the owner is likely going to ignore this advice and offer one anyway.
“A ration balancer can be an acceptable option for the owner that insists on providing pellets,” said Zoller. “Ration balancers are formulated to provide additional protein, vitamin and minerals. They are typically lower in energy than most complete concentrates, which is ideal for Darla.”
Whitehouse added, “A balancer is a great way to supply quality protein (amino acids), vitamins and minerals, especially if a lower-quality hay is being offered.”
Zoller encouraged vets to educate owners on the positive aspects of forage rather than focusing on concentrates. “Horses are designed to be continuous grazers of forage, and forage alone can certainly meet the needs of horses at maintenance and light activity,” she said.
Additional Ways an Equine Nutritionist Can Help
Darla was a pretty straightforward example of feeding a horse that is overweight but otherwise healthy. But even the slight modifications in diet recommended above will make a huge impact on her performance and health.
Even with this simple example, the benefits of using an equine nutritionist can easily be appreciated. For more complicated situations, such as horses with insulin dysregulation/resistance, equine metabolic syndrome, tying-up or a gamut of other nutrition-related conditions, your nutritionist can provide a wealth of valuable information.
“We have the time and expertise to conduct a detailed nutrition consultation to understand the current diet and how the horse is being managed,” said Whitehouse. “With this information, we can then suggest an appropriate diet based on evidence-based recommendations that take any underlying medical conditions into consideration. The veterinarian-nutritionist team is vital in treating nutritionally related diseases.”
