Equine Health Studies Program

The Equine Health Studies Program (EHSP) is the premier equine biomedical center in Louisiana and the Southern region. The EHSP was developed by and for Louisiana's illustrious $2.4 billion equine industry, and is dedicated to the health, well-being and performance of horses.
 
The EHSP and the equine clinic at the LSU Veterinary Teaching Hospital supports the mission by providing state-of-the-art diagnostic and therapeutic solutions for critically ill and injured horses in Louisiana and the surrounding region. Known for its incredible variety and diversity, Louisiana boasts a rich multi-disciplined equine industry, which is embraced by the EHSP team. Horses with different backgrounds and levels of training are all welcomed by a Board Certified team of veterinarians, technicians and caretakers.

Tips for Horse Health

Equine Health Emergencies

If you own horses long enough, sooner or later you are likely to confront a medical emergency. From lacerations to colic to foaling difficulties, there are many emergencies that a horse owner may encounter. 

You must know how to recognize serious problems and respond promptly, taking appropriate action while awaiting the arrival of your veterinarian. 

Preparation is vital when confronted with a medical emergency. 

No matter the situation you may face, mentally rehearse the steps you will take to avoid letting panic take control. Follow these guidelines from the American Association of Equine Practitioners (AAEP) to help you prepare for an equine emergency:

  • Keep your veterinarian’s number by each phone, including how the practitioner can be reached after hours.
    Consult with your regular veterinarian regarding a back-up or referring veterinarian’s number in case you cannot reach your regular veterinarian quickly enough.
  • Know in advance the most direct route to an equine surgery center in case you need to transport the horse.
    Post the names and phone numbers of nearby friends and neighbors who can assist you in an emergency while you wait for the veterinarian.
  • Prepare a first aid kit and store it in a clean, dry, readily accessible place. Make sure that family members and other barn users know where the kit is. Also keep a first aid kit in your horse trailer or towing vehicle and a pared-down version to carry on the trail. First aid kits can be simple or elaborate. Here is a short list of essential items:
    • Cotton roll
    • Cling wrap
    • Gauze pads, in assorted sizes
    • Sharp scissors
    • Cup or container
    • Rectal thermometer with string and clip attached
    • Surgical scrub and antiseptic solution
    • Latex gloves
    • Saline solution
    • Stethoscope
    • Clippers

Many accidents can be prevented by taking the time to evaluate your horse’s environment and removing potential hazards. Mentally rehearse your emergency action plan. In an emergency, time is critical. Don’t be concerned with overreacting or annoying your veterinarian. By acting quickly and promptly, you can minimize the consequences of an injury or illness. For more information about emergency care, ask your equine veterinarian for the “Emergency Care” brochure, provided by the AAEP in partnership with Educational Partner Bayer Animal Health.

Reprinted with permission from the American Association of Equine Practitioners.

Preventing Colic

The number one killer of horses is colic. Colic is not a disease, but rather a combination of signs that alert us to abdominal pain in the horse.

Colic can range from mild to severe, but it should never be ignored. Many of the conditions that cause colic can become life threatening in a relatively short period of time. Only by quickly and accurately recognizing colic – and seeking qualified veterinary help – can the chance for recovery be maximized.

While horses seem predisposed to colic due to the anatomy and function of their digestive tracts, management can play a key role in prevention. Although not every case is avoidable, the following guidelines from the American Association of Equine Practitioners (AAEP) can maximize the horse’s health and reduce the risk of colic:

  1. Establish a daily routine – include feeding and exercise schedules – and stick to it.
  2. Feed a high quality diet comprised primarily of roughage.
  3. Avoid feeding excessive grain and energy-dense supplements. (At least half the horse’s energy should be supplied through hay or forage. A better guide is that twice as much energy should be supplied from a roughage source than from concentrates.)
  4. Divide daily concentrate rations into two or more smaller feedings rather than one large one to avoid overloading the horse’s digestive tract. Hay is best fed free-choice.
  5. Set up a regular parasite control program with the help of your equine practitioner.
  6. Provide exercise and/or turnout on a daily basis. Change the intensity and duration of an exercise regimen gradually.
  7. Provide fresh, clean water at all times. (The only exception is when the horse is excessively hot, and then it should be given small sips of lukewarm water until it has recovered.)
  8. Avoid putting feed on the ground, especially in sandy soils.
  9. Check hay, bedding, pasture, and environment for potentially toxic substances, such as blister beetles, noxious weeds, and other ingestible foreign matter.
  10. Reduce stress. Horses experiencing changes in environment or workloads are at high risk of intestinal dysfunction. Pay special attention to horses when transporting them or changing their surroundings, such as at shows.

Virtually any horse is susceptible to colic. Age, sex, and breed differences in susceptibility seem to be relatively minor. The type of colic seen appears to relate to geographic or regional differences, probably due to environmental factors such as sandy soil or climatic stress. Importantly, what this tells us is that, with conscientious care and management, we have the potential to reduce and control colic, the number one killer of horses.

For more information about colic prevention and treatment, ask your equine veterinarian for the “Colic” brochure, provided by the American Association of Equine Practitioners in partnership with Educational Partner Bayer Animal Health. 

Reprinted with permission from the American Association of Equine Practitioners.

Recognizing the Signs of Dental Problems

Horses with dental problems may show obvious signs, such as pain or irritation, or they may show no noticeable signs at all. This is because some horses simply adapt to their discomfort. For this reason, periodic dental examinations are essential to your horse’s health. It is important to catch dental problems early. If a horse starts behaving abnormally, dental problems should be considered as a potential cause. 

Waiting too long may increase the difficulty of remedying certain conditions or may even make remedy impossible. Look for the following indicators of dental problems from the American Association of Equine Practitioners (AAEP) to know when to seek veterinary attention for your horse:

  1. Loss of feed from mouth while eating, difficulty with chewing, or excessive salivation.
  2. Loss of body condition.
  3. Large or undigested feed particles (long stems or whole grain) in manure.
  4. Head tilting or tossing, bit chewing, tongue lolling, fighting the bit, or resisting bridling.
  5. Poor performance, such as lugging on the bridle, failing to turn or stop, even bucking.
  6. Foul odor from mouth or nostrils, or traces of blood from the mouth.
  7. Nasal discharge or swelling of the face, jaw or mouth tissues.

Oral exams should be an essential part of an annual physical examination by a veterinarian. Every dental exam provides the opportunity to perform routine preventative dental maintenance.

Mature horses should get a thorough dental exam at least once a year, and horses 2 –5 years old should be examined twice yearly. For more information about proper dental care, ask your equine veterinarian for “Dental Care: The Importance of Maintaining the Health of Your Horse’s Mouth,” a brochure provided by the AAEP in conjunction with Educational Partner Bayer Animal Health.

Reprinted with permission from the American Association of Equine Practitioners.

Protecting Your Horse from Equine Infectious Anemia

Equine Infectious Anemia (EIA) is a potentially fatal disease that threatens the world’s horse, donkey and mule populations. The virus that causes EIA reproduces in the white blood cells that circulate throughout the body. The immune system, via antibodies, may attack and destroy red blood cells, leading to anemia. Infected horses may die from the direct effects of the virus or from secondary infections. Despite testing and measures to eradicate the equine infectious anemia virus, EIAV, more than 500 new cases are identified each year in the U.S. There is no cure for EIA. Although most horses show no symptoms, they remain contagious for life, endangering the health of other horses. For this reason, the United States Department of Agriculture and state animal health regulatory agencies require euthanasia or strict lifelong quarantine for horses testing positive for EIA.

Your horse’s only protection against EIA is prevention. Good management practices can reduce the potential of infection. The following guidelines from the American Association of Equine Practitioners (AAEP) will help:

  • Use disposable needles and syringes, one per horse, when administering vaccines and medications.
  • Sterilize dental tools and other instruments before using them on another horse.
  • Test all horses for EIA at least annually.
  • Test horses at the time of purchase examination.
  • Stable owners, horse show and event managers should require and verify current negative Coggins certificates for all horses entering the premises.
  • New horses should be quarantined for 45 days and observed for any signs of illness, including elevated temperatures, before introducing them to the herd. They should be retested if exposure to EIA is suspected at a 45-day interval.
  • All stable areas should be kept clean, dry and waste-free. Good pasture management techniques should also be practiced. Remove manure and provide adequate drainage to discourage breeding sites for pests.
  • Horses at greater risk, such as those in frequent contact with outside horses or who live or travel in geographic regions known for EIA outbreaks, should be tested more frequently, every 4–6 months.

For more information about EIA, ask your equine veterinarian for “Equine Infectious Anemia: The Only Protection if Prevention,” a brochure provided by the AAEP in conjunction with Educational Partner Bayer Animal Health.

Reprinted with permission from the American Association of Equine Practitioners.

Wage War on Equine Parasites

Internal parasites are silent killers. They can cause extensive internal damage, and you may not even realize your horses are heavily infected. At the very least, parasites can lower resistance, rob the horse of valuable nutrients, and cause gastrointestinal irritation and unthriftiness. At their worst, they can lead to colic, intestinal ruptures, and death.

Using deworming agents on a regular schedule in combination with good management procedures is critical to relieving your horse of most parasites. Since parasites are primarily transferred through manure, good management is key. In terms of management priorities, establishing a parasite control program is probably second only to supplying the horse with clean, plentiful water and high-quality feed.

To get rid of parasites before they attack your horse, follow these suggestions from the
American Association of Equine Practitioners (AAEP):

  1. Pick up and dispose of manure droppings in the pasture at least twice weekly.
  2. Mow and harrow pastures regularly to break up manure piles and expose parasite eggs and larvae to the elements.
  3. Rotate pastures by allowing other livestock, such as sheep or cattle, to graze them, thereby interrupting the life cycles of parasites.
  4. Group horses by age to reduce exposure to certain parasites and maximize the deworming program geared to that group.
  5. Keep the number of horses per acre to a minimum to prevent overgrazing and reduce the fecal contamination per acre.
  6. Use a feeder for hay and grain rather than feeding on the ground.
  7. Remove bot eggs quickly and regularly from the horse’s haircoat to prevent ingestion.
  8. Rotate deworming agents, not just brand names, to prevent chemical resistance.
  9. Consult your veterinarian to set up an effective and regular deworming schedule.

With the many safe, convenient products available today, establishing an effective deworming program is easy. Discuss a plan with your veterinarian and implement it without delay. A good parasite control program will go a long way toward maximizing your horse’s appearance, performance and comfort. The net result will be an animal that is as healthy on the inside as it appears on the outside.

For more information about waging war on equine parasites, ask your veterinarian for a copy of the “Parasite Control” client education brochure, provided by the AAEP in partnership with Educational Partner Bayer Animal Health. Information about equine parasites also can be found on the AAEP’s Horse Health website.

Reprinted with permission from the American Association of Equine Practitioners.

Recognize the Symptoms of Equine Protozoal Myeloencephalitis (EPM)

Equine Protozoal Myeloencephalitis (EPM) is a master of disguise. This serious disease, which attacks the horse’s central nervous system, can be difficult to diagnose because its signs often mimic other health problems in the horse and signs can range from mild to severe. More than 50 percent of all U.S. horses have been exposed to the parasite that causes EPM.

Horses can come into contact with the parasite while grazing or eating feed or drinking water contaminated by opossum feces. Fortunately, not all horses exposed to the parasite develop the disease. 

The clinical signs of EPM can be quite varied. Clinical signs are usually asymmetrical (not the same on both sides of the horse). Actual signs may depend on the severity and location of the lesions that develop in the brain, brain stem or spinal cord. If left undiagnosed and untreated, EPM can cause devastating and lasting neurological damage. Use this checklist of symptoms from the American Association of Equine Practitioners (AAEP) when assessing your horse’s condition for the possibility of EPM:

  • Ataxia (incoordination), spasticity (stiff, stilted movements), abnormal gait or lameness.
  • Incoordination and weakness which worsens when going up or down slopes or when head is elevated.
  • Muscle atrophy, most noticeable along the topline or in the large muscles of the hindquarters, but can sometimes involve the muscles of the face or front limbs.
  • Paralysis of muscles of the eyes, face or mouth, evident by drooping eyes, ears or lips.
  • Difficulty swallowing.
  • Seizures or collapse.
  • Abnormal sweating.
  • Loss of sensation along the face, neck or body.
  • Head tilt with poor balance; horse may assume a splay-footed stance or lean against stall walls for support.

Contact your veterinarian immediately if you suspect your horse has developed EPM. The sooner treatment begins, the better the horse’s chances for recovery.

For more information on methods of prevention and the treatment options for EPM, ask your equine veterinarian for a copy of the “EPM: Understanding this Debilitating Disease” client education brochure, provided by the AAEP in partnership with Bayer Animal Health, an AAEP Educational Partner. 

The American Association of Equine Practitioners, headquartered in Lexington, Ky., was founded in 1954 as a non-profit organization dedicated to the health and welfare of the horse. Currently, the AAEP reaches more than 5 million horse owners through its over 9,000 members worldwide and is actively involved in ethics issues, practice management, research and continuing education in the equine veterinary profession and horse industry.

Permission for use is granted with attribution given to the AAEP and Bayer Animal Health.

Fung-infected Fescue

Tall fescue is a grass which grows on over 35 million acres of land in the United States. As many as 700,000 horses may graze fescue pastures or be fed fescue hay each year. Many of these pastures contain fescue that is infected with an endophytic fungus that is toxic to horses. 

When the horse ingests the grass, it is steadily poisoned by alkaloids produced by the fungus. 

What many owners may not realize is that there are some significant health risks associated with horses eating endophyte fungus-infected tall fescue. Some of these problems can be minimized with careful management of horses and pastures.

Follow these management tips from the American Association of Equine Practitioners (AAEP) to reduce the risks of health problems caused by EI tall fescue:

  1. Have your pasture tested to determine the level of infection.
  2. Mow fields prior to the development of seed heads, which contain the highest levels of toxins in the plant.
  3. Remove horses from EI fescue pastures in conditions of extreme heat and drought.
  4. Remove broodmares from EI fescue pastures 30 days prior to breeding and 60 – 90 days prior to foaling.
  5. Keep accurate records of breeding and anticipated foaling dates.
  6. Notify your veterinarian for initiation of drug therapy if your mare has been grazing EI fescue prior to foaling.
  7. Monitor the mare closely during late pregnancy.
  8. Contact your veterinarian if impending signs of birth, including udder development, relaxation of vulva, and muscles around the tailhead fail to develop within the expected timeframe.
  9. Attend the birth. If mare fails to show signs of normal birth progression, contact your veterinarian immediately.
  10. Keep mares and foals off EI fescue until after weaning to prevent poor milk production. If replanting a pasture, it is extremely important that all infected plants and seeds be destroyed prior to sowing. Discuss the best methods for eliminating stands of infected fescue with an agronomist, toxicologist or your county extension agent.

For more information about treating EI fescue problems in your horse, contact your equine veterinarian and request “Fescue: Minimizing the Risk to Your Horse’s Health,” a brochure provided by the AAEP in conjunction with Educational Partners Bayer Animal Health and Purina Mills. 

Reprinted with permission from the American Association of Equine Practitioners.

Choosing Hay for Your Horse

High-quality hay can be an important source of essential nutrients in your horse’s diet. 

A horse’s protein and energy requirements depend on age, stage of development, metabolism and workload.

A mature horse will eat 2 to 2.5% of its body weight a day, and for optimum health, nutritionists recommend that at least half of this should be roughage such as hay. For a 1000-pound horse, that means at least 10 pounds of roughage each day.

Hay generally falls into one of two categories – grasses or legumes. Legume hay is higher in protein, energy, calcium and vitamin A than grass hays. While hay alone may not meet the total dietary requirements of young, growing horses or those used for high levels of performance, high quality hay may supply ample nutrition for less active adult horses. Once you’ve determined the best category of hay for your horse, most people select hay based on how it looks, smells and feels. 

Use the following tips from the American Association of Equine Practitioners to select the best hay for your horse:

  • It’s what’s inside that counts. Ask that one or several bales are opened so you can evaluate the hay inside the bales. Do not worry about slight discoloration on the outside, especially in stacked hay.
  • Choose hay that is as fine-stemmed, green and leafy as possible, and is soft to the touch.
  • Avoid hay that is overcured, excessively sun-bleached, or smells moldy, musty, dusty or fermented.
  • Select hay that has been harvested when the plants are in early bloom for legume hay or before seed heads have formed in grasses. Examine the leaves, stems and flowers or seed pods to determine the level of maturity.
  • Avoid hay that contains significant amounts of weeds, dirt, trash or debris.
  • Examine hay for signs of insect infestation or disease. Be especially careful to check for blister beetles in alfalfa. Ask the grower about any potential problems in the region.
  • Reject bales that seem excessively heavy for their size of feel warm to the touch, as they could contain excess moisture that could cause mold, or worse, spontaneous combustion.
  • When possible, purchase and feed hay within a year of harvest to preserve its nutritional value.
  • Store hay in a dry, sheltered area out of the rain, snow and sun, or cover in the stack to protect it from the elements.
  • When buying in quantity, have the hay analyzed by a certified forage laboratory to determine its actual nutrient content.

Remember that horses at different ages and stages of growth, development and activity have different dietary requirements. Consult your veterinarian or a qualified equine nutritionist when formulating your horse’s ration. He or she can help you put together a balanced diet that is safe, nutritious and cost-effective.

For more information about choosing hay, ask your equine veterinarian for the “Hay Quality and Horse Nutrition” brochure, provided by the AAEP in partnership with Educational Partners Bayer Animal Health and Purina Mills, Inc. 

Reprinted with permission from the American Association of Equine Practitioners.

Understanding Your Horse Insurance Responsibilities

Whether a horse is purchased for personal or business reasons, ownership represents a significant investment of time, money and resources. 

While no one likes to think about the potential for tragedy, horses seem to be prone to illness, accidents and injury. Should some peril befall your horse, nothing may ease the emotional burden, but wise planning can help reduce the economic impact.

Insurance policies are legal contracts between the underwriter (the company) and the insured (horse owner). While individual policies vary so much from company to company and circumstance to circumstance, it is important to note is that each policy has its own terms, conditions and requirements, which may necessitate action from you, your veterinarian and your insurance company. 

To better safeguard yourself and your horse, follow these guidelines from the American Association of Equine Practitioners (AAEP):

  • Read the contract thoroughly before you apply for coverage.
  • Ask the insurance representative to explain any words, phrases or provisions you do not understand completely.
  • Know your responsibilities. What is required should your horse fall ill, become injured or die?
  • Understand any specific guidelines for emergency situations. A crisis is not the time to be trying to interpret your policy's fine print or to look for contact phone numbers.
  • If euthanasia is recommended, know what steps must be taken in order for a claim to be valid.
  • Make a list of questions to ask your insurance agent or company.
  • Define your needs.
  • Comparison shop. Besides cost, buyers should look at the longevity and reputation of both the agency and the insurance carrier.

Common types of coverage available for horses include but are not limited to:

  • Mortality: Paid if the horse dies.
  • Loss of Use: Paid on a percentage basis if horse is permanently incapacitated for its intended use or purpose.
  • Major Medical: Like health insurance, offsets costs of veterinary care for catastrophic conditions.
  • Surgical: Policies that cover only specific procedures such as colic surgery.
  • Breeding Infertility: Covers stallions or mares for reproductive failure.
  • Specified Perils: Includes any number of things such as lightning, fire or transportation.

For more information about equine insurance, ask your equine veterinarian for “Understanding Horse Insurance Responsibilities: Guidelines to Consider,” a brochure provided by the AAEP in conjunction with Bayer Animal Health, an AAEP Educational Partner.

The American Association of Equine Practitioners, headquartered in Lexington, Ky., was founded in 1954 as a non-profit organization dedicated to the health and welfare of the horse.

Currently, the AAEP reaches more than 5 million horse owners through its over 9,000 members worldwide and is actively involved in ethics issues, practice management, research and continuing education in the equine veterinary profession and horse industry.

Permission for use is granted with attribution given to the AAEP and Bayer Animal Health.

Recognizing the Signs of Laminitis

Every day veterinarians across the country see hundreds of cases of laminitis, a painful disease that affects the feet of horses. Laminitis results from the disruption of blood flow to the sensitive and insensitive laminae within the foot, which secure the coffin bone to the hoof wall. 

While the exact mechanisms by which the feet are damaged remain a mystery, certain precipitating events can produce laminitis. Although laminitis occurs in the feet, the underlying cause is often a disturbance elsewhere in the horse’s body. As a horse owner, it is important to recognize the signs of laminitis and seek veterinary help immediately. 

Signs of acute laminitis include the following:

  • Lameness, especially when a horse is turning in circles; shifting lameness when standing
  • Heat in the feet
  • Increased digital pulse in the feet
  • Pain in the toe region when pressure is applied with hoof testers
  • Reluctant or hesitant gait, as if “walking on eggshells”
  • A “sawhorse stance,” with the front feet stretched out in front to alleviate pressure on the toes and the hind feet “camped out” or positioned farther back than normal to bear more weight.

Signs of chronic laminitis may include the following:

  • Rings in hoof wall that become wider as they are followed from toe to heel
  • Bruised soles or “stone bruises”
  • Widened white line, commonly called “seedy toe,” with occurrence of blood pockets and/or abscesses
  • Dropped soles or flat feet
  • Thick, “cresty” neck
  • Dished hooves, which are the result of unequal rates of hoof growth

If you suspect laminitis, consider it a medical emergency and notify your veterinarian immediately. The sooner treatment begins, the better the chance for recovery. For information about laminitis, ask your equine veterinarian for the “Laminitis: Prevention and Treatment” brochure provided by the American Association of Equine Practitioners (AAEP) in association with Bayer Animal Health, an AAEP Educational Partner.  

Reprinted with permission from the American Association of Equine Practitioners.
 

Nutrition and Foal Growth

A healthy foal will grow rapidly, gaining in height, weight and strength almost before your eyes. From birth to age two, a young horse can achieve 90 percent or more of its full adult size, sometimes putting on as many as three pounds per day.

Feeding young horses is a balancing act, as the nutritional start a foal gets can have a profound affect on its health and soundness for the rest of its life. At eight to ten weeks of age, mare’s milk alone may not adequately meet the foal’s nutritional needs, depending on the desired growth rate and owner wants for a foal. As the foal’s dietary requirements shift from milk to feed and forage, your role in providing the proper nutrition gains in importance. 

The following are guidelines from the American Association of Equine Practitioners (AAEP) to help you meet the young horse’s nutritional needs: 

  1. Provide high quality roughage (hay and pasture) free choice.
  2. Supplement with a high quality, properly balanced grain concentrate at weaning, or earlier if more rapid rates of gain are desired.
  3. Start by feeding one percent on a foal’s body weight per day (i.e. one pound of feed for each 100 pounds of body weight), or one pound of feed per month of age.
  4. Weigh and adjust the feed ration based on growth and fitness. A weight tape can help you approximate a foal’s size.
  5. Foals have small stomachs so divide the daily ration into two to three feedings.
  6. Make sure feeds contain the proper balance of vitamins, minerals, energy and protein.
  7. Use a creep feeder or feed the foal separate from the mare so it can eat its own ration. Try to avoid group creep feeding situations.
  8. Remove uneaten portions between feedings.
  9. Do not overfeed. Overweight foals are more prone to developmental orthopedic disease (DOD).
  10. Provide unlimited fresh, clean water.
  11. Provide opportunity for abundant exercise.

The reward for providing excellent nutrition and conscientious care will be a healthy foal that grows into a sound and useful horse.

For more information about providing proper nutrition for your foal, talk with your equine veterinarian and ask for the “Foal Growth” education brochure provided by the AAEP in conjunction with Education Partners Bayer Animal Health and Purina Mills. 

Reprinted with permission from the American Association of Equine Practitioners.

Caring for the Older Horse

Because of advances in nutrition, management and health care, horses are living longer, more useful lives. It’s not uncommon to find horses and ponies living well into their 20s and 30s. 

While genetics play a role in determining life span, you too, can have an impact. 

You may think that turning your old-timer out to pasture is the kindest form of retirement. But horses are individuals. Some enjoy being idle; others prefer to be a part of the action. 

Whatever you do, don’t ignore the horse. Proper nutrition, care and exercise will help the animal thrive. Follow these guidelines to develop a total management plan for your older horse:

  1. Observe your horse on a regular basis. Watch for changes in body condition, behavior and attitude. Address problems, even seemingly minor ones, right away.
  2. Feed a high quality diet. Avoid dusty and moldy feeds.
  3. Feed your older horse away from younger, more aggressive ones so it won’t have to compete for feed.
  4. Feed at more frequent intervals so as not to upset the digestive system. Two-three times daily is best.
  5. Provide plenty of fresh, clean, tepid water. Excessively cold water reduces consumption which can lead to colic and other problems.
  6. Adjust and balance rations to maintain proper body conditions. A good rule of thumb is to be able to feel the ribs but not see them.
  7. Provide adequate, appropriate exercise to maintain muscle tone, flexibility and mobility.
  8. Groom your horse frequently to promote circulation and skin health.
  9. Be aware that older horses are prone to tumors. Look for any unusual lumps or growths from head to tail as well as beneath the tail (especially on gray horses).
  10. Schedule routine checkups with your equine veterinarian. Call immediately if you suspect a problem.

A quick response to ailments, injuries or a decline in fitness can keep your older horse from having a serious or prolonged setback. That means less worry for you and a better quality of life for your old friend. 

For more information about caring for the older horse, ask your equine veterinarian for the “Older Horse” brochure, provided by the American Association of Equine Practitioners in partnership with Educational Partners Bayer Animal Health and Purina Mills, Inc. 

Reprinted with permission from the American Association of Equine Practitioners.

Help Your Mare Have a Safe Delivery

If your mare has made it through 11 months of pregnancy, you’re almost home free. Labor and delivery, while momentous, are generally uneventful. In most cases, you will simply need to be a quiet observer – if, that is, you are lucky enough to witness the birth. Mares seem to prefer to foal at night in privacy, and apparently have some control over their delivery. Because most mares foal without difficulty, it is usually best to allow the mare to foal undisturbed and unassisted.

What you can do, however, is prepare your mare for a safe and successful delivery. Follow these suggestions from the American Association of Equine Practitioners (AAEP) to help the new mother and baby get off to a great start:

  • Write down your veterinarian’s phone number well in advance of the birth and keep it by all phones.
  • Keep a watch or clock on hand so you can time each stage of labor. When you’re worried or anxious, your perception of time becomes distorted. The watch will help you keep accurate track of the mare’s progress during labor.
  • Wrap the mare’s tail with a clean wrap when you observe the first stage of labor. Be sure that the wrap is not applied too tightly or left on too long, as it can cut off circulation and permanently damage the tail.
  • Wash the mare’s vulva and hindquarters with a mild soap and rinse thoroughly.
  • Clean and disinfect the stall area as thoroughly as possible and provide adequate bedding.
  • Consider using test strips that measure calcium in mammary secretions to help predict when the mare will foal. Sudden increases in calcium are associated with imminent foaling. If a mare is taking longer than 30 minutes to deliver the foal, call your veterinarian immediately.

For more information on labor and delivery and postpartum care for the mare and foal, ask your equine veterinarian for a copy of the “Foaling Mare and Newborn” client education brochure, provided by the AAEP in partnership with Educational Partner Bayer Animal Health. 

Reprinted with permission from the American Association of Equine Practitioners.

Pre-purchase Exams

Owning a horse can be a big investment in time, money and emotion. Unfortunately, horses seldom come with a money-back guarantee. That’s why it is so important to investigate the horse’s overall health and condition through a purchase exam conducted by an equine veterinarian. 

Whether you want a horse as a family pet, a pleasure mount, a breeding animal, or a high performance athlete, you stand the best chance of getting one that meets your needs by investing in a purchase exam. Purchase examinations may vary, depending on the intended use of the horse and the veterinarian who is doing the examination. Deciding exactly what should be included in the purchase examination requires good communication between you and your veterinarian. 

The following guidelines from the American Association of Equine Practitioners (AAEP) will help ensure a custom-tailored exam:

  • Choose a veterinarian who is familiar with the breed, sport or use for which the horse is being purchased.
    Explain to your veterinarian your expectations and primary uses for the horse, including short- and long-term goals (e.g., showing, then breeding).
  • Ask your veterinarian to outline the procedures that he or she feels should be included in the exam and why.
  • Establish the costs for these procedures.
  • Be present during the purchase exam. The seller or agent should also be present.
  • Discuss with your veterinarian his or her findings in private.
  • Don’t be afraid to ask questions or request further information about your veterinarian’s findings in private.

The veterinarian’s job is neither to pass or fail an animal. Rather, it is to provide you with information regarding any existing medical problems and to discuss those problems with you so that you can make an informed purchase decision. Your veterinarian can advise you about the horse’s current physical condition, but he or she cannot predict the future. The decision to buy is yours alone to make. But your equine veterinarian can be a valuable partner in the process of providing you with objective, health-related information.

For more information about purchase exams, ask your equine veterinarian for “Purchase Exams: A Sound Economic Investment,” a brochure provided by the AAEP in conjunction with Education Partner Bayer Animal Health. 

Reprinted with permission from the American Association of Equine Practitioners.

Colonic ULcers: A Pain in the Hindgut!

Ulcers in the equine colon (intestine) are common in performance horses and lead to decreased performance, vague clinical signs (partial loss of appetite, rough dull hair coat, intermittent mild colic, and diarrhea), changes in blood work (low protein and high white blood count, and inflammation) and may go undiagnosed for months  because horses are usually normal between acute episodes.  All ages and breeds of horses are susceptible to ulcers of the colon and current treatment focuses on reducing bulk in the diet, use of gut coating agent and condition agents, mild laxatives, and oils to promote healing.1

Ulcers of the colon are usually referred to as Right Dorsal Colitis (RDC) as most of the ulcers are located in this part of the large intestine, which is in contact with the right body wall.  This condition occurs less frequently than gastric ulcers, but might lead to fluid under the skin (edema) and diarrhea. In one study of 545 horses, nearly half (44%) of non-performance had colonic ulcers, whereas 65% of performance horses had  colonic ulcers.2  Colonic ulcers are probably associated with stress induced release of the body's natural steroids or the administration of non-steroidal anti-inflammatory agents, like Bute or Banamine.  Early in the condition, horses present with non-specific signs of mild intermittent or recurring colic episodes, lethargy and loss of appetite. However, as the condition worsens clinical signs may include complete loss of appetite, fever, colic and diarrhea.  Progression of RDC may lead to dehydration, ventral edema, and weight loss.  Other conditions that could look like RDC include gastric ulcers, other causes of colic (large colon displacement and/or impaction), infectious causes of diarrhea (Salmonellosis, Potomac Horse Fever, Clostridium), granulomatous and eosinophilic enteritis (inflammatory bowel disease), and intestinal neoplasia (cancer).

Diagnosis

A presumptive diagnosis of RDC can be made on history (recurrent colic episodes, intermittent diarrhea, loss of performance, weight loss), clinical signs as mentioned above, changes in blood work (mild anemia, toxic changes in white blood cells, and a high number of white blood cells, low blood proteins and high inflammatory proteins, and low calcium).  Peritoneal (belly) fluid analysis might show a mild increase in WBC count and increase in total protein concentration (> 2.5 g/dl).  The presence of blood in the manure can be helpful as an ancillary diagnostic test in horses with RDC.2 Recently, a new test (Succeed Fecal Blood Test, Freedom Health, LLC, Aurora, OH) (Figure 1) was commercially developed to measure blood in the manure and this test was shown to be very good at predicting RDC.  The positive test might help your veterinarian determine if the horse has RDC, but will be used as a part of a total diagnostic approach.

Figure 1. Succeed® Equine Fecal Blood Test™ showing positive result (TST) for albumin (A) and hemoglobin (H), denoting hemorrhage from the hindgut (colon) in a horse with colonic edema (on ultrasonographic examination) and right dorsal colitis.

Your veterinarian may  put an endoscope (gastroscope) in the stomach, to see if the horse has gastric ulcers, because the clinical signs of gastric ulcers are similar to those of RDC.  If gastric ulcers are present then your veterinarian may want to start antiulcer treatment to see if the horse gets better.  However, sometimes gastric and colonic ulcers can occur in the same horse, especially if there is concurrent changes in the blood work.  Treatment with antiulcer medications will have no affect on colonic ulcers.

Another diagnostic your veterinarian may perform is abdominal ultrasound of the right dorsal colon.  This technique may show thickening (normal < 0.4 cm) of the colon wall, which lies against the right body wall in the abdominal cavity.3 Your veterinarian will scan the right dorsal colon by placing the probe between the ribs over the colon in the right side of the horse.  Examination of the colon might reveal thickening of the colon wall as see in the photos below (Figure 2a and 2b).

If the horse has diarrhea, your veterinarian will make every effort to rule-out infectious causes such as, Salmonellosis and Clostridium, by using fecal cultures.  However, these conditions will have similar clinical signs might occur in the same horse.

Treatment

The principle goals of treatment for RDC includes discontinuing or avoiding the use of NSAIDs (especially Bute and Banamine), decreasing gut fill and bulk in the diet (mechanical load on the colon) to allow the colon to rest, frequent feedings, reducing inflammation, coating and restoring the normal colon absorptive function and implementing methods to decrease stress.1 To reduce gut fill your veterinarian might recommend replacing the dry hay in the diet with an alfalfa-based complete pelleted feed like Equine Senior (Purina Senior, Purina Mills, St. Louis, MO). This reduces gut fill and decreases the mechanical load on the colon. The horse can be allowed to graze small amounts of fresh grass (10 to 15 minute intervals four to six times daily) to help decrease the stress of stall or dry paddock confinement and maintain body weight. The switch to a complete feed diet should be made over several days to a week to allow the gastrointestinal tract time to acclimatize to the feed change. This dietary change is only temporary and may last up to 3 to 4 months or at which time the blood work returns to normal.  Your veterinarian may recommend weekly blood work once the horses diet is switched to the pellets.

Figure 2a. Edema (1.37 cm; yellow box) in the wall of the Right Dorsal Colon in a pony before diet and pharmacologic treatment.

Figure 2b. Right Dorsal Colon in the same pony after 4 weeks of dietary change and treatment with medications.  Note that the wall of the Right Dorsal Colon is 0.45 cm (yellow box).

Your veterinarian may recommend psyllium mucilloid (Equisyl Advantage, Animal Heath Care Products) or psyllium hydrophilic mucilloid (Metamucil, Proctor & Gamble, Cincinnati, OH) added to the diet to lubricate and shorten transit time for feed material and increase water content in the intestines.  Also, psyllium increased the concentration of fatty acid in the colon and reduces inflammation.

Furthermore, your veterinarian may suggest the addition of corn or safflower oil (1 cup, added to feed, q12h) added to the complete feed to increase Omega-3 fatty acids. Omega-3 fatty acids effectively block the chemicals released in the body due to stress, which decreases inflammation in the colon due to the ulcers.

The use of medication routinely used for gastric ulcers (antacids, omeprazole, or ranitidine) would not be expected to be effective in treatment of RDC. However, your veterinarian might recommend the use of sucralfate, a sucrose octasulfate and polyaluminum hydroxide complex, that binds to the ulcer bed and forms a bandage over the ulcer.  Also, sucralfate, once it has adhered to the ulcer crater, stimulates local protective chemicals called prostaglandins, which has a “cytoprotective” effect on the colon mucosa.

Minimizing physiologic and environmental stresses can also be helpful in controlling RDC. Stall rest, reduction of strenuous exercise or training, and reduction in travel are ways to decrease stress. Horses should always have adequate amounts of clean fresh water and should be provided a mineral/salt mix to ensure adequate water intake.  Flavored water can be given to horses at home so that water intake can remain the same on the road and at shows.

Length of Treatment and Prognosis

Generally it takes between 1 to 2 weeks to see improvement in clinical signs, once the diet has been changed.  Weekly monitoring of blood work is important indicators of response to treatment and prognosis.  Improvement in blood work might take several weeks.  In addition to blood work, your veterinarian will recommend serial ultrasonographic examinations of the Right Dorsal Colon to help in monitoring response to treatment.  Typically weekly to every two week ultrasonographic examinations can help your veterinarian gauge therapy.  The swelling in the wall of the Right Dorsal Colon should decrease within 4 to 6 week after initiation of dietary changes and treatment (Figure 2b), but may take longer in some horses.

The response to treatment is good, especially if the horses' clinical signs, blood work, and ultrasound signs improve rapidly.  Be sure you contact your veterinarian as soon as you recognize these signs as the longer it continues the more difficult it is to treat successfully.

References

Cohen et al. JVIM 1995;9:272-276.

Pellegrini FL. JEVS 2005;25 113-117.

Jones et al. JAVMA 2003;222:1248-1251.

Reduce Your Horse's Gastric Ulcer Risk 

Ulcers are a man-made disease, affecting up to 90 percent of racehorses and 60 percent of show horses. Stall confinement alone can lead to the development of ulcers. 

A horse’s feeding schedule also can be a factor. When horses are fed just twice a day, the stomach is subjected to a prolonged period without feed to neutralize its naturally produced acid. In addition, high-grain diets produce volatile fatty acids that can also contribute to the development of ulcers.

Stress, both environmental and physical, can increase the likelihood of ulcers, as can hauling, training and mixing groups of horses. Strenuous exercise can decrease the emptying of the stomach and the blood flow to the stomach, thus contributing to the problem. The treatment and prevention of gastric ulcers is directed at removing these predisposing factors, thus decreasing acid production within the horse’s stomach. 

Follow these tips from the American Association of Equine Practitioners (AAEP) to properly treat your horse’s ulcers:

  1. Allow free-choice access to grass or hay. Horses are designed to be grazers with a regular intake of roughage.
  2. If the horse must be stalled, arrange for the horse to see the horses he socializes with. Consider offering a ball or other object that the horse can enjoy in his stall.
  3. Feed the horse more frequently to help buffer the acid in the stomach.
    Decrease grains that form volatile fatty acids.
  4. Medications that decrease acid production are available, but are only necessary in horses showing signs of clinical disease or when the predisposing factors, such as stress, cannot be removed.

The prevention of ulcers is the key. Limiting stressful situations along with frequent feeding or free-choice access to grass or hay is imperative. Neutralizing the production of stomach acid is nature’s best antacid.

For more information about gastric ulcers, ask your equine veterinarian for the “Equine Gastric Ulcers” brochure provided by the American Association of Equine Practitioners (AAEP) in association with Nutrena, an AAEP Educational Partner.

The American Association of Equine Practitioners, headquartered in Lexington, Ky., was founded in 1954 as a non-profit organization dedicated to the health and welfare of the horse. Currently, the AAEP reaches more than 5 million horse owners through its over 9,000 members worldwide and is actively involved in ethics issues, practice management, research and continuing education in the equine veterinary profession and horse industry.

Permission for reprint is granted with attribution given to the AAEP and Nutrena.

Weight Reduction in Horses

As a horse owner, you play an important role in controlling your equine companion’s weight. Sound nutrition management, a regular exercise program and veterinary care are key to keeping your horse fit and healthy.

Maintaining the ideal weight is not always easy, however. When implementing a weight loss program for the overweight horse, it’s important to do it gradually and under the supervision of an equine veterinarian. 

Follow these guidelines from the American Association of Equine Practitioners (AAEP) to get you started:

  1. Be patient. Weight reduction should be a slow, steady process so not to stress the horse or create metabolic upsets.
  2. Make changes in both the type and amount of feed gradually. Reduce rations by no more than 10% over a 7- to 10-day period.
  3. Track your horse’s progress by using a weight tape. When the horse’s weight plateaus, gradually cut back its ration again.
  4. Step up the horse’s exercise regimen. Gradually build time and intensity as the horse’s fitness improves.
  5. Provide plenty of clean, fresh water so the horse’s digestive and other systems function as efficiently as possible and rid the body of metabolic and other wastes.
  6. Select feeds that provide plenty of high quality fiber but are low in total energy. Measure feeds by weight rather than by volume to determine appropriate rations.
  7. Select feeds that are lower in fat since fat is an energy-dense nutrient source.
  8. Switch or reduce the amount of alfalfa hay feed. Replace with a mature grass or oat hay to reduce caloric intake.
  9. Feed separate from other horses so the overweight horse doesn’t have a chance to eat his portion and his neighbor’s too. In extreme cases of obesity, caloric intake may also need to be controlled by limiting pasture intake.
  10. Balance the horse’s diet based on age and activity level.

Make sure the horse’s vitamin, mineral and protein requirements continue to be met. Once your horse has reached its ideal body condition, maintaining the proper weight is a gentle balancing act. You will probably need to readjust your horse’s ration to stabilize its weight.

Exercise will continue to be a key component in keeping the horse fit. Because obesity can affect a horse’s health, communicate regularly with your veterinarian. Schedule regular check-ups, especially during the weight reduction process. 

For more information about caring for the obese horse, ask your equine veterinarian for the “Overweight Horse” brochure provided by the American Association of Equine Practitioners in partnership with Educational Partners Bayer Animal Health and Purina Mills, Inc.

Reprinted with permission from the American Association of Equine Practitioners.

Reducing Risk of West Nile Virus Infection

Since first being recognized in the United States in 1999, West Nile virus (WNV) has posed a serious threat to horses and humans alike. In the equine population, the virus is transmitted when a mosquito takes a blood meal from a bird infected with WNV, then feeds on a horse. While many horses exposed to WNV experience no signs of illness, the virus can cause inflammation of the brain and spinal cord. In some cases, especially in older horses, WNV can be fatal.

As a horse owner, prevention is the key to reducing your horse’s risk of contracting WNV. Follow these guidelines from the American Association of Equine Practitioners (AAEP) to protect
your horse against WNV:

  1. Consider vaccinating your horse against the disease. In February 2003, a vaccine was licensed by the United States Department of Agriculture’s Center for Veterinary Biologics for use in healthy horses as an aid in the prevention of the disease. Talk with your veterinarian about the most appropriate vaccination schedule for your horse.
  2. Eliminate potential mosquito breeding sites. Dispose of old receptacles, tires and containers and eliminate areas of standing water.
  3. Thoroughly clean livestock watering troughs at least monthly.
  4. Use larvicides to control mosquito populations when it is not possible to eliminate particular breeding sites. Such action should only be taken, however, in consultation with your local mosquito control authority.
    Keep your horse indoors during the peak mosquito activity periods of dusk to dawn.
  5. Screen stalls if possible or at least install fans over your horse to help deter mosquitoes.
  6. Avoid turning on lights inside the stable during the evening or overnight.
  7. Using insect repellants on your horse that are designed to repel mosquitoes can help reduce the chance of being bitten.
  8. Remove any birds, including chickens, located in or close to a stable.
  9. Don’t forget to protect yourself as well. When outdoors in the evening, wear clothing that covers your skin and apply plenty of mosquito repellent.

For more information about the virus, ask your equine veterinarian for the “West Nile Virus” brochure, produced by the AAEP in conjunction with Bayer Animal Health, an AAEP Educational Partner. 

Reprinted with permission from the American Association of Equine Practitioners.

Guidelines for West Nile Virus Vaccination

Developed by the American Association of Equine Practitioners

This information is intended as a supplement to the AAEP's Guidelines for Vaccination of Horses (January 2001). 

Practitioners are directed to consult this publication as the following discussion is to be read in conjunction with those general guidelines for vaccination. 

West Nile virus (WNV) infection was first diagnosed in horses in the United States in 1999 and is now an important consideration in the differential diagnosis of horses presenting with signs of neurologic disease in all areas of North America. West Nile virus, a flavivirus, was first identified as a cause of infection and fatal encephalomyelitis (inflammation of the spinal cord and brain) in horses and people in Egypt, Uganda and France in the early 1960’s. 

Further epizootics of disease in horses have occurred in Morocco in 1996, Italy in 1998, France in 2000, and the United States from 1999 to the present. West Nile virus is now considered to be endemic in all areas of North America. The flaviviruses, like the other encephalomyelitis viruses, are transmitted by mosquitoes, and infrequently by other bloodsucking insects, to horses, human beings, and a number of other mammals from avian hosts, which serve as natural reservoirs for these viruses in nature. 

Horses and humans are considered to be dead-end hosts of the West Nile virus and, therefore, do not contribute to the transmission cycle. The virus is not directly contagious from horse to horse or horse to human. Similarly, indirect transmission via mosquitoes from infected horses is highly unlikely because horses do not experience a significant viremia (i.e. they have negligible amounts of virus circulating in their blood). 

The incubation period for West Nile virus in horses appears to be 3 to15 days. Clinical signs of WNV infection in horses may include fever, ataxia (stumbling or incoordination), depression or apprehension, stupor, behavioral changes, weakness of limbs, partial paralysis, droopy lip, teeth grinding, muscle twitching, fasciculation and tremors, difficulty rising, recumbency (inability to rise), convulsions, blindness, colic, and intermittent lameness, or death. 

The mortality rate for horses exhibiting clinical signs of West Nile virus infection is approximately 33%. Data has supported that 40 % of horses that survive the acute illness caused by WNV still exhibit residual effects, such as gait and behavioral abnormalities that were attributed to the illness by owners, 6 months post diagnosis. The variable clinical signs associated with WNV infection necessitate inclusion of many neurological disorders in the differential diagnoses. 

These include: rabies; equine protozoal myeloencephalitis (EPM); equine herpesvirus-1; botulism; eastern, western and Venezuelan encephalomyelitis (EEE,WEE,VEE); heat stress; trauma; bacterial meningitis; cervical vertebral myelopathy (wobbler syndrome); myeloencephalopathy; and equine degenerative myelopathy. Serologic tests used to diagnose WNV include plaque reduction neutralization (PRNT), virus neutralization, hemagglutination inhibition, complement fixation, ELISA and antigen (IgM and IgG) capture ELISA. Virus can also be identified in central nervous system tissue using techniques such as virus isolation, PCR and immunohistochemistry. The IgM-capture ELISA is currently the most reliable test for confirmation of recent exposure to West Nile Virus in a horse exhibiting clinical signs. 

Horses exposed to WNV typically develop a sharp rise in West Nile virus-specific IgM antibody that persists for 4-6 weeks after infection. Little IgM is demonstrated in horses that are recently vaccinated. The antibody measured by the PRNT is stimulated both by vaccination and recent exposure, making this test difficult to interpret in the suspect horse. Risk of exposure and geographic distribution of West Nile virus vary from year to year with changes in distribution of insect vectors and reservoirs of the virus. Because of the unpredictable nature of those factors and the effects of the disease, it is recommended that all horses in North America be immunized against West Nile virus. Preventive management practices may minimize the risk of the spread and transmission of West Nile virus from infected mosquitoes. Reduction of mosquito numbers and exposure can be achieved by reducing or eliminating any stagnant or standing water in your area, removing old tires, keeping horses in the barns from dusk to dawn (prime mosquito feeding times), setting out mosquito traps, keeping air moving with fans, and removing organic debris (muck) promptly. Chemical controls include the use of topical anti-mosquito repellent agents approved for the horse and use of mosquito dunks in areas of standing water.

Vaccination is the primary method of reducing the risk of infection from West Nile virus to the horse but clinical disease is not fully prevented. It recommended vaccination with one of the commercially available licensed vaccines for all horses residing in those areas of North America where the disease occurs. Of the licensed vaccines currently available, one is monovalent or multivalent inactivated and the other is a live canarypox vector vaccine. These available vaccines have been tested with a challenge model and have been proven to be effective as an aid in the prevention of viremia in experimentally infected vaccinated horses compared to nonvaccinated control horses for as long as 12 months after primary vaccination with two doses of vaccine. 

Following the label instructions, primary vaccination of previously non-vaccinated horses involves administration of 2 doses of vaccine 3 to 6 weeks apart. In endemic areas, boosters are required or warranted according to local conditions conducive to disease risk. Vaccinate semi-annually or more frequently (every 4 months), depending on risk. Annual revaccination is best completed in the spring, prior to the onset of peak insect vector season. While neither of the licensed vaccines is labeled for administration to pregnant mares at this time, it is recommended that mares be ideally vaccinated before breeding when possible.

However, practitioners have vaccinated thousands of pregnant mares due to the risk associated with pregnant mares getting the disease from infected mosquitoes. It has been accepted practice by many veterinarians to administer vaccines to pregnant mares on the assumption that the risk of adverse consequences of WNV infection outweighs any reported adverse effects of use of vaccines in pregnant mares. Booster vaccination of pregnant mares 4 to 6 weeks before foaling provides augmented passive colostral protection to their foals, lasting for 3-4 months. Primary vaccination of foals from vaccinated mares should be started at 3-4 months of age in order to avoid interference from colostral antibodies. 

Foals from non-vaccinated mares may be vaccinated earlier than three months of age as they may not have colostral interference issues; however, data on which to base more specific recommendations for foals from non-vaccinated mares is not sufficient at this time. Foals should be revaccinated at 1 year of age (in the Spring of the year following their birth) to ensure adequate protection. Because of the high mortality associated with West Nile virus, it is recommended that foals born in areas where there is a high risk of exposure to West Nile virus should receive an initial series of three (3) doses of vaccine against West Nile beginning at 3 months of age and at 4- to 6- week intervals. The third dose may go at an interval of 8-10 weeks if desired, followed by a fourth dose at 1 year of age. 

Many veterinarians, in Southern states where mosquitoes are active year-round, prefer to vaccinate horses semiannually or more frequently to help ensure uniform protection throughout the year, although this practice is not specifically recommended by manufacturers of vaccines. Horses that have been naturally infected with the disease should be vaccinated one year after the acute illness. Although the ability of horses to become re-infected with WNV is unknown at this time, horses that have been naturally infected with WNV may be included in a routine vaccination program as previously described.