THANKS TO MODERN MEDICINE AND IMPROVED PREVENTIVE HEALTH PROGRAMS, HORSES ARE LIVING LONGER THAN EVER.
In fact, it’s estimated that senior horses – those 15 years of age and older – account for 20 to 30 percent of the entire horse population. And senior does not necessarily mean retired. Many horses remain active well into their golden years, both recreationally and competitively. Of the nearly 200 horses that competed at the 2012 Olympic Games, 17 percent were 15 or older. “Active longevity” is a testimonial to the benefits of improved preventive healthcare programs, better nutrition and dental care, updated parasite control strategies and relevant risk-based vaccines.
Senior horses have unique healthcare needs due to years of activity as well as physical and metabolic changes associated with aging. Diseases such as Cushings and Equine Metabolic Syndrome, issues such as missing and worn teeth and afflictions such as degenerative joint disease and arthritis require specialized care and attention.
Your senior horse’s best friend is his veterinarian. It’s much easier to correct problems such as weight loss, dental anomalies, and joint disease when they are identified and addressed earlier than later. For this reason, senior horses should be seen by a veterinarian at least once per year to have their teeth, joints and overall condition checked. Early detection – especially when it comes to cancer and endocrine diseases – is the key to a long, healthy life.
Key healthcare action items for senior horses:
- Annual physical examination including an ophthalmic exam, dental exam and soundness exam and body condition scoring
- Timely fecal egg counts in case your aging horse requires a change in deworming regimen.
- Bloodwork (CBC/Chemistry) for horses showing loss of condition without an obvious cause.
- Endocrine testing for Cushing’s and Equine Metabolic Syndrome in horses experiencing unexplained bouts of laminitis, changes in haircoat, increased drinking and urination, excessive sweating, increased appetite, muscle loss (especially along the topline), a potbellied appearance, and/or abnormal fat deposits.
Common problems seen in older horses are as follows:
While every horse owner should pay attention to their horse’s neurologic function, senior horse owners should especially watch out for Wobbler syndrome and Equine Herpesvirus Myeloencephalitis (EHM). EHM is the neurologic form of Equine Herpesvirus-1, and older horses may be more predisposed to this devastating disease. Wobbler syndrome can affect older horses through arthritic changes in the spinal column that, in turn, compress the spinal cord.
Other diseases that can affect your senior horse’s central nervous system are easily preventable through vaccination. These are Eastern Equine Encephalitis, Western Equine Encephalitis, West Nile virus and rabies.
To a lesser extent, senior horses may suffer neurologic deficits due to EPM, tumors or parasites that migrate to the brain.
If your horse shows signs of incoordination or clumsiness, call your veterinarian immediately. If you see a change in your horse that you’re not sure is normal, please call your veterinarian for a diagnosis. Depression, reluctance to eat and trouble getting up are all good reasons for a veterinary evaluation.
Perhaps there is no diagnosis more dreaded by horse owners than one of laminitis.
An inflammation of the laminae of the hoof wall, laminitis is a very painful condition that can have varying degrees of severity. The onset of signs can be slow and subtle or acute. In the most severe cases, the laminae are so inflamed that the third phalanx (aka the coffin bone) that is supported by these structures rotates and can penetrate the bottom of the sole. These horses experience extreme pain and spend the majority of their time lying down. Due to poor prognosis and poor quality of life, these horses are often times humanely euthanized.
Other cases of laminitis are not as severe and can be treated and managed with proper diet and corrective shoeing.
Signs of acute laminitis:
- Lameness, especially when a horse is turning in circles; shifting lameness when standing.
- Heat in the feet and increased digital pulses in the arteries supplying blood to the feet.
- Pain in the toe area when hoof testers are used.
- Reluctant or hesitant gait.
- Standing with the front feet stretched out in front to alleviate pressure on the toes and the hind feet positioned underneath the horse to support the weight.
- Puffy coronary bands with possible clefting.
Signs of chronic laminitis:
- Rings in the hoof wall that become wider as they are followed from toe to heel.
- Bruised soles.
- Widened white line with blood pockets and/or abscesses.
- Dropped soles or flat feet.
- Dished hooves, resulting from the heels growing faster than the rest of the hoof.
RESEARCHERS ARE STILL WORKING TO DISCOVER HOW AND WHY LAMINITIS HAPPENS, BUT WE DO KNOW SEVERAL RISK FACTORS, INCLUDING:
- Increase in carbohydrates (horse gets into the feed bin or too much time on new, green grass or clover).
- Mechanical overload (a horse with an injury such as a fracture will bear more weight on the uninjured leg, thus predisposing it to laminitis).
- Certain disease conditions such as Cushing’s Disease (PPID).
- Severe, systemic bacterial illnesses (e.g., septic metritis in a post partum mare or a horse with Potomac Horse Fever diarrhea) that result in release of toxins into the blood stream.
If you are concerned about laminitis, talk with your veterinarian right away as early intervention is the best chance for a positive outcome. Therapy for laminitis can vary, but includes pain medication, anti-inflammatory drugs and proper foot support. Icing the affected feet is a very effective therapy during acute stages of laminitis. Chronic cases of founder require teamwork between your veterinarian and farrier (sometimes one and the same individual!) to provide proper trimming and shoeing as indicated by radiographs and clinical signs.
Senior horses (15 years or older) can be at an increased risk of developing laminitis due to hormonal imbalances such as PPID (Cushing’s disease) or Equine Metabolic Syndrome.
Maintaining a proper body condition score and having routine veterinary examinations play an integral role in helping prevent laminitis.
A lifetime of galloping, jumping, turning, trail riding and just daily routine exercise can take its toll on a body. Muscle and joint problems are one of the most common disorders in senior horses and are often compounded by conformation faults, degenerative conditions or underlying endocrine diseases.
Did you ever wonder why old horses often look swaybacked? As horses age, they lose muscle mass – both as part of the aging process and due to reduced exercise and conditioning. The ligaments that support the back also weaken, making the withers appear more prominent. Underlying, untreated endocrine diseases such as Cushing’s disease can accentuate this muscle loss and swaybacked appearance.
You may also notice dropping of the fetlocks in your old horse, especially in the hind legs. This may be a result of degeneration of the suspensory ligaments. It’s more common in certain breeds and can be made worse by late-stage pregnancy in older broodmares.
As always, if your older horse is starting to have a more difficult time just getting around, call your veterinarian for a full workup.
Degenerative joint disease
As horses age, so do their joints and all of the structures associated within the joint, especially the cartilage. Cartilage damage is the hallmark of degenerative joint disease (DJD) in the senior equine.
Joint cartilage can become damaged due to overuse, a traumatic joint injury, infection or normal, age-related wear and tear. Cartilage has a very limited ability to regenerate and heal, which is why DJD is not reversible and usually progressive. However, through the use of modern medicine, DJD can be diagnosed and managed so that many senior horses can live a more comfortable, longer life.
Diagnosis and treatment
DJD can show up as varying degrees of lameness. A thorough physical examination by a veterinarian – including a lameness evaluation – will help determine which joint or joints are affected. This exam might include radiographs (X-rays) and/or an ultrasound. These tests will help determine the severity of the DJD and the proper course of treatment and future management.
TREATMENT FIRST FOCUSES ON ADDRESSING THE MOST LIKELY CAUSE (E.G., IMPROPER SHOEING, POOR HOOF/PASTERN AXIS) AND THEN MANAGING PAIN AND PREVENTING PROGRESSION OF JOINT DAMAGE. YOUR VETERINARIAN MIGHT PRESCRIBE ANY COMBINATION OF THE FOLLOWING:
- Physical therapy.
- Corticosteroids (either systemic or intra-articular).
- Nonsteroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone or Banamine.
- Chondroprotective agents such as sodium hyaluronate (HA), polysulfated gycosaminoglycans (Adequan) or other nutraceuticals.
- Regenerative therapy such as platelet rich plasma (PRP) or stem cell therapy
With proper care and treatment, senior horses with DJD can remain pasture sound or even rideable well into their 20s and 30s.
Liver and kidney
If your older horse had previous bouts of infectious disease or a history of certain drug therapy throughout his life, he may be at increased risk for chronic kidney and/or liver disease. If this is the case, proper hydration and nutrition are essential. Fluids are especially important in older horses that are being administered short- and long-term medications as most drugs are metabolized and excreted through the kidneys. If kidney or liver disease is detected, certain drugs may need to be avoided, or the dosages adjusted accordingly, since the horse’s metabolism is often altered.
The kidneys rely on a good blood supply in order to perform their function of removing toxins from the blood stream and maintaining electrolyte and fluid balance within the body. While specific drugs and diseases can harm the kidneys directly, any condition that results in hypotension (drop in blood pressure) and/or dehydration can jeopardize kidney health and impede its ability to perform its vital functions.
For example, a horse with severe diarrhea can become very dehydrated, which in turn causes a decrease in blood pressure and decreased blood perfusion to a variety of organs, including the kidneys. Fortunately, this form of kidney impairment is usually reversible with proper fluid therapy. Other causes of kidney disease include certain drugs, including some commonly used nonsteroidal anti-inflammatory drugs (i.e., NSAIDs), and antibiotics (e.g., tetracyclines and aminoglycosides such as gentamicin); a variety of toxins including those contained in some plants (e.g., wilted red maple leaves, wild onions, bracken fern); over-supplementation with certain vitamins (e.g., vitamins K or D); bacterial infection; and, on rare occasion, kidney/ureteral calculi (stones).
Some non-specific signs of underlying kidney disease include:
- Excessive water consumption.
- Changes in urination.
- During early stages of kidney disease, horses may urinate larger amounts of dilute urine.
- During end stage renal failure, urine production may decrease, resulting in fluid retention.
Diagnosis and treatment
Blood work frequently reveals elevations in blood urea nitrogen (BUN) and creatinine. BUN is a byproduct of protein metabolism, and creatinine is a byproduct of muscle metabolism. Blood work may also reveal changes in electrolyte balance and possibly protein levels. Chronic kidney disease can result in weight loss and can even have an effect on normal red cell production, resulting in anemia. Your veterinarian may recommend to ultrasound the kidneys or perform a biopsy in order to diagnose the disease.
Therapy will depend on the underlying cause of kidney disease. Chronic cases that have gone undetected for a long time are often more difficult to reverse. Good nutritional management is essential. For example, excessive protein intake should be avoided in horses with chronic renal failure.
End-stage liver failure in horses is rare, but it can occur. There are many ways a horse can acquire liver disease:
- Toxic: Ingesting certain plants, including alsike clover, panicum grasses and plants that contain pyrrolizidine alkaloids (e.g., Senecio, Amsinckia).
- Infectious: A variety of bacteria can result in inflammation of the liver (hepatitis) and bile ducts (cholangitis). Choleliths (bile stones) are often related to chronic infection.
- Inflammatory: Neoplasia (cancer) and granulomatous disease.
- Metabolic: Hepatic lipidosis.
Liver disease is frequently associated with jaundice – yellow discoloration of mucous membranes including the gums, nasal mucosa and the sclera (whites of the eyes). Acute liver disease may be associated with neurologic signs, while chronic or end-stage liver disease, regardless of the cause, is often associated with weight loss, poor appetite and lethargy. Some causes of liver disease such as choleliths (bile stones) that cause blockage of the bile ducts are a cause of colic. Hepatitis due to bacterial infection is often accompanied by fever.
Diagnosis and treatment
If your veterinarian suspects liver disease, he or she may use a number of diagnostic tests:
- Lab work to evaluate liver-specific enzymes and triglyceride concentration.
- Liver function tests.
- Ultrasound evaluation of the liver to look at overall liver size and detect dilated bile ducts, masses such as tumors or evidence of fibrosis.
- Liver biopsy for culture and microscopic examination.
Treatment will vary greatly depending on the cause, but good nutrition and adequate hydration remain essential.
Just like people, aging horses frequently experience an increased incidence of heart disease. These diseases are often accompanied by cardiac murmurs of varying intensity.
Your veterinarian may first detect a cardiac murmur during a physical examination, and can further diagnose heart disease through an EKG or echocardiography. Your senior horse could have leaky or compromised heart valves (such as mitral and aortic valvular insufficiency), which can increase the workload of the heart and make it harder for your horse to tolerate exercise. Talk to your veterinarian if you’re noticing that your horse becomes easily fatigued or out of breath sooner than before.
Since many senior horses can have problems with their eyes, it’s important to include an annual ophthalmic exam in your horse’s physical. That way, your veterinarian can detect progressive changes before they compromise your horse’s vision. The most common eye abnormalities include cataracts, vitreous degeneration and senile retinopathy.
If your horse has battled recurrent bouts of uveitis (moon blindness) throughout his life, he may also have some of these changes. Luckily, active inflammatory conditions can often be controlled with a variety of topical and systemic therapies.
As horses age, they become more prone to heaves, or recurrent airway obstruction (RAO). In fact, RAO is the most commonly diagnosed respiratory condition in older horses. This is because repeated bouts of airway inflammation throughout the years can lead to long-term physical changes within the airway. Inflammation may be a result of infection or, more commonly, environmental allergens and irritants.
You may notice a cough, nasal discharge, exercise intolerance and wheezing during exertion. If so, try making changes in management and diet, such as wetting down hay to reduce dust and better ventilating your barn. More severely affected horses may require bronchodilators and/or steroid therapy. Talk to your veterinarian if your horse’s condition is worsening.
Older horses can experience a variety of dental problems, including sharp points on their molars, missing teeth, and a misaligned bite or wave mouth. All of these can lead to increased difficulty chewing and masticating long-stemmed feed, which can increase the risk of choke.
During an episode of choke, a bolus of food becomes lodged in the esophagus, resulting in gagging, profuse salivation and possibly nasal discharge. Luckily, choke is not normally life threatening, but prompt attention from your veterinarian is a must.
Dental issues may also increase the risk of impaction colic, so make sure your senior horse’s teeth are attended to at least once per year, preferably twice.
Older horses are also more susceptible to colic caused by strangulating lipomas – fatty tumors with long stalks of attachment that wrap around sections of the intestines. The complete obstruction of the intestine results in colic that usually requires surgery to resolve. Some seniors also experience colic and weight loss associated with other forms of cancer, including lymphosarcoma.
Your veterinarian may be able to detect some forms of cancer with rectal palpation to search for enlarged internal lymph nodes and other internal masses. Gray horses are at increased risk for melanomas that might become larger and more invasive with advancing age.
Melanomas are malignant tumors that can be locally invasive as well as metastatic (spread internally to distant sites). These tumors are often progressive and can have an unpredictable pattern of growth. More common in gray horses, melanomas frequently occur on the surface of the body, such as under the tail and in the area surrounding the anus and external genitalia. They can vary in appearance from flat to wart-like to attached by a stalk. Melanomas, even small ones, should not be ignored.
If you are in Orange County, CA and you have an older horse and either want to schedule a well visit check or you are concerend of some of the conditions just mentioned do not hesitate to call. She frequents the areas of San Juan Capistrano, Huntington Beach, Laguna Hills, Coto de Caza and every where in between.