Feeding the Senior Horse

When feeding your senior horse, there are several important factors to keep in mind that can change their dietary requirements.

Dental Condition

Number one is the status of your horse’s teeth. You may have heard the term “expired” teeth when your veterinarian is examining your horse’s mouth. This term refers to the fact that horses’ teeth become worn down over time with all the grinding of their feed and can even wear all the way down to the gum line. These expired teeth can no longer effectively grind forage into the small pieces necessary for a horse to gain nutritional value.

The lack of effective grinding can also predispose horses to choke and impaction colic from swallowing long pieces of hay. As a result, we often recommend starting our senior horses on more processed diets, such as hay pellets, hay cubes, or complete senior feeds. These forage alternatives are already processed into smaller particles, making it much easier for the horses to digest. It is recommended to soak these types of feed in water to reduce the risk of choke. When soaking feed, it is recommended to use a ratio of 2:1 (water to feed), especially if the feed contains beet pulp, and allow it to sit for 30 minutes or even longer if the water is cold. The mash should ideally end up with an oatmeal-like consistency.   

GI Changes

In addition to the teeth, there are some age-related changes to the rest of the GI tract that can affect feeding protocols. There is an overall reduction in the absorption of nutrients in a senior horse due to changes in the microbiome and scarring of the intestines. Supplementing with a probiotic, such as Platinum Performance GI or Arenus Assure Guard Gold, can help regulate the microbiome and improve nutrient absorption.

Senior horses are also less efficient at digesting crude protein, meaning that their dietary protein requirement is higher – it is often recommended to feed 12-14% crude protein to older horses, as opposed to the 10-12% recommended for younger horses. Geriatric horses often tend to require more highly digestible fiber sources, such as beet pulp, to keep them healthy. It is important to keep the crude fiber content of their diet over 10% to meet their physiologic needs.

Regardless of age, horses require approximately 1.5 – 2% of their body weight in dry matter per day – whether that’s mainly hay or almost completely comprised of processed feeds, we need to make sure they are receiving the appropriate amount for their weight. Weighing your scoops of grain is very helpful in determining if your horse is getting enough food. For example, a 1000 pound horse being maintained entirely on Purina Equine Senior requires anywhere from 15 to 17 pounds of feed per day depending on their activity level per the label recommendations.

Metabolic Status

A third piece of the puzzle is the horse’s overall metabolic status. Older horses are much more likely to have PPID, or Cushing’s disease, which can make it difficult for them to maintain good body condition, even in the face of good nutrition. These horses need to go on the appropriate medication, Prascend, to allow them to thrive and keep weight on.

On the flip side, horses with EMS (Equine Metabolic Syndrome or Insulin Resistance) often struggle to get weight off. It is important for these horses to be kept on a diet low in non-structural carbohydrates to prevent large fluctuations in glucose levels and elevated insulin levels that can predispose them to laminitis.

Determining if your horse has a metabolic disorder involves running blood work that checks the levels of various enzymes and hormones within the system. ACTH (adrenocorticotropic hormone) is the hormone we look at in Cushing’s disease. In some cases, a horse may have a normal baseline ACTH level but still have Cushing’s disease. If there are clinical signs consistent with Cushing’s disease (muscle atrophy, weight loss, delayed shedding, etc.) your veterinarian may recommend a second test called a TRH stim test to more definitively determine if your horse has Cushing’s disease. Equine Metabolic Syndrome is characterized by insulin resistance, leading to elevated insulin levels, and often elevated glucose levels as well, which are reflected in the bloodwork.

For more information on these metabolic syndromes as well as other conditions that can affect senior horses, please visit our other blog articles:

Each horse ages differently, so it is important to have regular check-ups with your veterinarian to make sure you are meeting all their nutritional needs. Contact us at any time to schedule a check-up and nutrition consult!

Hang on now Doc, is my horse really that chunky?

Sometimes when we as horseman see our horses on a routine basis, it can be easy to overlook that thickened, cresty neck or the fat pads that have developed on either side of their tail head.  We recognize that it has been quite a while since we’ve been able to palpate any evidence of their ribs, but what other physical indicators do we use as veterinarians to assess the body condition of our patients?  With the significant increase in metabolic laminitis cases seen on a national level, now more than ever, it is important to ensure our horses remain a healthy weight. 

As a veterinarian, the first indication that I may be dealing with a horse in metabolic crisis is not their enlarged abdominal girth but instead is the thickened, hardened appearance to their crest.  The crest is the region directly under the horse’s mane along the topside of their neck.  A normal crest palpates soft, fluctuant, and homogenous to the surrounding tissue and muscle.  The crest on a horse in metabolic crisis becomes hardened, like the density of cauliflower.  The crest can also become wider and more visually pronounced in severe cases.  As the metabolic disease process progresses, horses can develop regional adiposity, also known as the accumulation of fat pads throughout their body.  These pads of adipose tissue most commonly develop behind the shoulder blades on either side of the withers and on either side of the tail head.  In severe cases, adipose pads can develop along either side of the thoracolumbar spine and in the girth region.    A horse of a healthy weight has no evidence of regional adiposity, with rib coverage that allows for palpation of each individual rib but not the visual distinction of each rib. 

Body condition scoring in horses is commonly done using the Henneke System.  This scoring system was developed in 1983 and has been accepted throughout the international equine industry as a standardized means to assess adiposity in horses.  The scores range from 1 to 9 with a score of 1 being associated with extreme emaciation and a score of 9 correlating to extreme obesity.  Below is an outline of the individual scores:

Poor: Grade 1 – Extreme emaciation; no presence of fatty tissue, all bony prominences including withers, shoulder blade, dorsal spinous processes, ribs, pelvis and sacrum are all clearly visible.

Very Thin: Grade 2 – Emaciated; slight tissue cover over bony prominences but withers, shoulder blade, dorsal spinous processes, ribs, pelvis and sacrum are all clearly visible.

Thin: Grade 3 – Slight accumulation of adipose tissue; bony prominences are no longer clearly discernible; some fill over withers, shoulders and throughout the neck, ribs still visible.

Moderately Thin: Grade 4 – Ridge of spine and withers are still visibly pronounced, ribs still visible, some accumulation of adipose tissue over the shoulders and through the neck and tail head region. 

Moderate: Grade 5 – Spine and ribs cannot be visibly differentiated although ribs can be palpated, tail head is soft and squishy; withers, shoulders and neck are smooth and rounded.

Moderately Fleshy: Grade 6 – slight crease down the spine, tail head is still soft and squishy, regions of adipose accumulation are present on either side of the withers and through the crest, most ribs can still be palpated but not all of them.

Fleshy: Grade 7 – a crease is present along the spine, the ribs have fat filling between them, tail head is still soft, regions of adipose accumulation are pronounced through the crest and on either side of the withers. 

Fat: Grade 8 – a definite crease is present along the spine (aka. “drainage ditch”), it is difficult to feel any ribs, soft adipose tissue surrounds the tail head, the neck/crest is quite enlarged and there is adipose accumulation on the inner aspects of the hind limbs as well as behind the shoulder blades.

Extremely Fat: Grade 9 – the “drainage ditch” collects water when it rains, there is bulging adipose accumulation on top of the ribs, behind the shoulders, through the crest and on either side of the tail head.  Accumulated abdominal fat is also present on the underside of the flank. 

To confirm your horse is in optimal health, it is important to be able to accurately grade your horse’s body condition.  An ideal range is between 4-6, depending on the breed and usage of your horse.  If your horse falls outside of this range, it is important to discuss the nutritional components of your horse’s diet with your veterinarian to decrease the risks associated with equine obesity and ensure your horse isn’t deficient in necessary nutrients. 

Caring for Your Senior Horse

At what age is a horse considered geriatric or senior? Does owning a senior horse mean that he must eat a feed labeled as a “senior” feed? As always, the answer is, it depends. Our horses are living longer lives than ever, thanks to an evolving understanding of the needs of geriatric horses and our ability to provide high quality care. There is no set age cutoff as to when a horse is considered geriatric, but most experts agree this can be around age 20. However, age is just a number, and many horses are still active and competing into their twenties, while others are happily retired. The main issues we see in our older horse population include dental disease, altered dietary needs, metabolic disease/PPID (Cushings), and arthritis.

 

Photo Courtesy PugnoM on Flickr

Dental Changes

The ideal time to begin focusing on your horse’s regular preventative veterinary care is when he is young. Horses receiving regular preventative care, especially veterinary dentistry, preserve their teeth longer and can age more gracefully. Waiting until signs of dental disease or difficulty chewing are observed often indicates advanced disease and more limited treatment options. Most horses benefit from yearly dentistry, which includes a thorough sedated oral exam with a dental speculum, light source, and mirror. A thorough oral exam is vital to accurately assess, document, and treat any issues.

Horses suffering from abnormal dental wear, cracked or missing teeth, or severe periodontal disease may require more frequent care. Even though horse teeth are described as “long rooted,” they do eventually wear out, so proper care ensures the longest possible life of the tooth. Common dental issues in older horses include fracture of cheek teeth, complete expiration or wearing out of cheek teeth, loose/painful teeth, and periodontal disease. The incisors can also be affected by similar conditions.

Staying on top of your senior horse’s dental care helps ensure that he gets what is needed from his diet. Sometimes severe dental disease and impaired chewing ability necessitates eliminating hay from the diet entirely. Complete feeds are formulated specifically for horses that can no longer chew hay effectively. These diets have greatly improved the quality and length of life for senior horses with compromised teeth.

Nutritional Changes

Nutrition recommendations for the geriatric horse are formulated around maintaining an ideal body condition. In the geriatric horse, this can be complicated by difficulty chewing, poor teeth, metabolic disease, and decreased ability to digest fiber and protein. For older horses in good weight and with adequate dentition, little dietary change may be required. For older horses who have difficulty maintaining weight and/or compromised teeth, complete feeds as mentioned above can help. These feeds are high in easily digestible fat, fiber, and protein, and are designed as easy-to-chew. They are formulated to replace hay entirely for those horses that can no longer adequately chew hay.
Adding water to soften the feed can reduce the risk of choke and ensure additional water intake. Feeding recommendations are often listed as pounds of feed per day depending on whether the horse is also eating hay, so it is important to weigh out your horse’s portion so that any necessary adjustments can be made more accurately.

Metabolic Changes

A curly haircoat and muscle loss over the back aren’t just signs of aging- They can indicate a common underlying condition: equine pars pituitary intermedia dysfunction, more commonly known as PPID or Cushings disease. This is a treatable (but not cureable) condition that is very common in geriatric horses, resulting in hormonal imbalances and symptoms such as delayed shedding, curly hair coat, muscle loss over topline, increased drinking and urinating, personality changes, and increased susceptibility to infections and laminitis. Diagnosis is made by a blood test as well as by history and clinical signs. Management involves daily administration of pergolide (Prascend) tablets, which help restore normal hormone levels and alleviate the clinical signs of the disease.

Equine Metabolic Syndrome (EMS) is a separate metabolic condition, but it sometimes occurs in conjunction with PPID. EMS horses typically show signs of being an “easy keeper”- cresty neck, regional fat deposits behind the shoulders and at the tail head. Horses with EMS are more susceptible to laminitis and usually have a higher baseline insulin level than normal. EMS horses are managed with strict attention to diet (minimizing sugar and starch) and exercise to help them maintain a lean body weight.

Joint and Muscle Changes

Just like us, aging horses suffer from daily aches and pains. An examination with your vet can help identify major and minor issues and

Photo Courtesy nikki_tate on Flickr

determine what treatment plan works best for you and your horse. Many options are available to keep our old horses comfortable.
Nutraceuticals (supplements) are very popular, although many of these products lack proof of efficacy and ingredients. More researched options include medications such as adequan (administered intramuscularly) and Legend (administered intravenously). These medications help provide the components necessary to keep joints healthy.

Joint injections target individual joints to reduce pain and inflammation and improve mobility. Non-steroidal anti-inflammatories such as Equioxx are also helpful, along with acupuncture and chiropractic care. Stable management is equally important- maximum turn out time allows horses to move at will, and monitoring herd dynamics ensures that older horses are not prevented from accessing food and water. In addition to these considerations, regular veterinary and farrier care will help your senior horse enjoy his golden years with you.

As always, if you have any questions about caring for your senior horse, please contact your veterinarian who can offer a personalized plan to help keep your geriatric horse happy, healthy, and comfortable well into their senior years.

Equine Metabolic Syndrome and all it Entails

By Dr. Allison Hartman

 

the-hoof-473095_1280Laminitis has been a bane of horseman and farriers since the horse was first domesticated.  As our medical knowledge and diagnostic abilities have evolved, so has our understanding of the contributing factors of this disease process, including Equine Metabolic Syndrome.  Equine Metabolic Syndrome is a term that’s been thrown around the equine community for the past few decades, but what does it mean?

 

What is EMS?

 

Equine metabolic syndrome (EMS) is a condition most commonly characterized by an inability to properly metabolize carbohydrates. The disease has been known by many names, including hypothyroidism, peripheral Cushing disease and pre-laminitic syndrome. Today, we know that Equine Metabolic Syndrome is characterized in horses, ponies and donkeys by obesity, regional deposition of fat, and systemic insulin resistance.Shetland_pony_dalmatian2

 

Insulin is an important hormone that allows the cells to obtain glucose from food.  Without insulin, or a proper response to insulin, cells cannot utilize glucose, regardless of how much food the horse is fed.  This starvation process at the cellular level pushes the horse into a stressed state (characterized by elevated cortisol levels) where the body is encouraged to hold on to as much fat as possible, making weight loss next to impossible in these horses.  In addition, glucose deprivation in the laminae of the horse’s feet can lead to laminitis.
How is it Diagnosed?

 

When we suspect a horse may have EMS, we will recommend bloodwork to confirm our suspicions as well as guide us in the proper treatment of your horse.  Horses with EMS may also have concurrent Cushing disease, which has been shown to be a contributing factor to the initial development of EMS.  It is important for us to understand the underlying metabolic factors that are contributing to your horse’s case in order to provide the most efficacious recommendations both medically and diet.

 

The key values we assess when running blood work for EMS include:

  • ACTH: When elevated, this value can be indicative of Equine Cushing’s Disease.
  • Insulin: Elevated levels of insulin indicate insulin resistance.
  • Leptin: This is a secondary value, used to ascertain the validity of elevated Insulin. When leptin is elevated in addition to elevated insulin, EMS and IR (insulin resistance) are valid diagnoses.
  • Glucose: When both ACTH and insulin are elevated, glucose can help differentiate the primary disease process.

 

What Can You Do About It?

 

Horses that are merely overweight but not actively laminitic should be put on a low starch diet, comprised of hay with less than 12% non-structural carbohydrates fed at 1-1.5% body weight.  (in this example, a 1000lb horse should be fed 10-15lbs of hay per day).  Their forage diet can be adequately balanced using either a ration balancer or a specifically formulated low starch feed.  These horses also benefit from routine exercise as an additional aid for weight loss.

 

In those patients that are actively laminitic, exercise is not recommended but the same dietary recommendations apply.  In addition, if your horse is diagnosed as insulin resistant (IR), metformin is a beneficial medication used to increase tissue sensitivity to insulin.  Horses with IR are comparable to humans with type 2 diabetes, in that they produce adequate amounts of insulin, but their body simply fails to respond appropriately.  Metformin is a medication commonly used in humans with IR and its efficacy in equine IR cases has been confirmed both in laboratory and field studies.

 

pony-2472424_1920Another option to stimulate weight loss in EMS horses is levothyroxine, commonly sold in the equine community as Thyro-L.  Thyro-L functions by increasing the rate of the horse’s metabolism to further stimulate weight loss.  It is important to understand that Thyro-L has no direct impact on the laminae of an actively laminitic horse and instead works indirectly over a longer period of time.

 

EMS is a frustrating disease for practitioners, clients and patients alike.  The more we understand of the disease process the better our chances at restoring metabolic equilibrium and preventing further deterioration of the laminae.  If you suspect your horse may have EMS, talk to your vet about appropriate diagnostic measures.