Check out our article in the March 2019 Hay & Forage Magazine!
Check out our article in the March 2019 Hay & Forage Magazine!
By Nancy S. Loving, DVM
Immunizations are the cornerstone of disease prevention if given appropriately and in a timely manner. One of the brightest spots of equine medical care for horses is the availability of many safe and effective vaccines to protect horses from infectious and noninfectious diseases. Sometimes it is confusing as to which ones your horse might need. Let’s look at the vaccine options, the necessity of each, and how to plan for boosters throughout the year. Always keep in mind that your veterinarian is the best person to advise you on the vaccinations needed for your particular horses and your area.
Mary Scollay, DVM, previous chair of the Infectious Disease Committee of the American Association of Equine Practitioners (AAEP), urges, “I would like to reinforce that the development of an effective vaccination program requires a partnership between the veterinarian and the horse owner. A horse owner has an obligation to provide input when a vaccination program is being developed. It is not a passive process. Examples of information that should be shared include how the horse is used, whether it travels, and what other animals is it likely to come in contact with.”
Vaccines are only one aspect of preventing disease; it is just as important to implement good horsekeeping and biosecurity strategies (see page 31 for more information) to minimize disease risk.
The AAEP developed a useful vaccination protocol that can be accessed at www.aaep.org/vaccination_guidelines.htm.Core Vaccines
Spring heralds more riding and transport, so schedule your horse’s annual spring veterinary checkup. (For more information see article #11398 at TheHorse.com.) Your veterinarian will administer “core vaccines,” which are those considered important for every horse to have annually, regardless of geographical location or athletic use.
Vaccine Timeline for the Adult Horse
DEC/JAN/FEB: During the winter months, not much needs to be considered in the way of vaccinations unless a horse will be traveling to an area with diseases for which he would be at high risk and has not yet been immunized.
MAR/APR/MAY: Administer spring immunizations during these months in order to have vaccines on board in advance of warming weather and an active mosquito season. Your horse should receive, at the very least, Eastern and Western equine encephalomyelitis (EEE and WEE), West Nile virus (WNV), tetanus, and rabies vaccines (first three are spread via mosquitoes). Other immunizations commonly given this time of year are influenza and herpesvirus vaccines. In high-risk areas or situations, your horse might also be immunized against strangles, Potomac horse fever (PHF), or botulism. In breeding situations where a horse is likely to be exposed to equine viral arteritis (EVA), this vaccine would also be included.
By the last month of gestation, the pregnant broodmare should be toward the end of her series of primary immunizations or boosters against all “core” diseases and those specific to your general area for which she’s at high risk.
JUNE/JULY/AUG: In the summer months you’ll want to make sure your horse is protected against all the necessary insect-related diseases for which there are vaccinations.
SEPT/OCT/NOV: In the autumn months preparations are under way for winter. This is the time of year your horse should be well-protected against respiratory viruses, specifically influenza and the respiratory form of herpesvirus (rhinopneumonitis). These are usually incorporated into the vaccine program at the time of the fall veterinary visit. Boosters can be given at this time for WNV, EEE, and WEE in areas with mosquito seasons that extend into winter months.
The AAEP and the American Veterinary Medical Association (AVMA) describe core vaccines as those “that protect from diseases that are endemic (prevalent with a high rate of occurrence) to a region, those with potential public health significance, required by law, virulent or highly infectious, and/or those posing a risk of severe disease.” These include: tetanus, West Nile virus (WNV), Eastern and Western encephalomyelitis (EEE and WEE), and rabies.
TETANUS Horses spend a lot of time around dirt/manure, so they are at particular risk for contamination of even the smallest wound with Clostridium tetani spores. An annual booster of tetanus toxoid in the spring is recommended.
Debra Sellon, DVM, PhD, Dipl. ACVIM, a professor of equine medicine at Washington State University, suggests, “The tetanus toxoid is inexpensive and safe, and the disease is highly fatal. Therefore, I always recommend a booster tetanus toxoid injection in horses with wounds or with plans to undergo surgery if it has been more than six months since that horse received its last booster injection.”
WEST NILE VIRUS This disease, which causes potentially fatal neurologic illness and is endemic in the lower 48 states, is carried by birds and transmitted by mosquitoes to horses. Luckily, there are three vaccines against WNV–all are safe and have demonstrated good efficacy. Horses should receive an annual booster following the initial vaccine series.
Keep in mind the timing of your annual boosters, making sure the horse is protected during mosquito season. In warmer climes where mosquitoes abound year-round, it might be necessary to administer boosters twice a year, depending on the vaccine product. Scollay says if your veterinarian recommends vaccinating twice yearly, “it might be prudent to consider vaccinating say, April 1 and Aug. 1, to enhance immunity during the period of high risk for exposure, instead of at a rigid six-month interval.”
EASTERN AND WESTERN EQUINE ENCEPHALOMYELITIS Encephalomyelitis (or encephalitis) virus, which causes neurologic disease, also is carried by birds and transmitted by mosquitoes. The vaccination strategy for EEE and WEE is comparable to WNV–once or twice annual boosters, depending on length of mosquito season, following an initial priming series. Horses living in states directly bordering Mexico might also receive an annual booster for Venezuelan equine encephalomyelitis (VEE).
RABIES Scollay says, “Rabies is a fatal neurologic disease of warm-blooded animals; that means horses and humans.” Wild animals such as bats, skunks, foxes, or raccoons can bite a horse and pass this virus without anyone being aware. Given that humans are constantly inserting their hands into horses’ mouths when placing a bit, checking age, floating teeth, or administering dewormers and paste medications, Scollay asks, “Why would you risk contracting a fatal disease from routine contact with a horse, especially when the disease can be effectively prevented?”
Rabies vaccine is labeled to be given once a year, but Scollay says if you have concerns about a specific horse’s immunity, it would be appropriate to consider a series of two vaccinations.Risk-Based Vaccines
Vaccines against certain diseases are given based on anticipated degree of risk.
INFLUENZA VIRUS Horses that travel or encounter horses that have been traveling are at an increased risk of exposure to equine influenza virus. The 2007 Australian epidemic, in which thousands of unvaccinated horses were exposed to flu, displayed how readily the disease could spread. There are many effective equine flu vaccines, and a horse should receive two or more boosters a year (depending on which product is used), usually in the spring and fall, following the initial series of three injections and/or intranasal (IN) administration of certain products.
HERPESVIRUS OR RHINOPNEUMONITIS Equine herpesvirus (EHV-1 and EHV-4) can cause respiratory problems (this disease expression is known as rhinopneumonitis). Rhino is spread through respiratory secretions–on shared objects or airborne. Cough, runny nose, or fever can be readily apparent, but EHV can be latent (hidden) in the horse, meaning it sits in the lymphatic tissue without producing any proteins and, therefore, the horse does not “respond” to it. Stressors such as transport, weaning, castration, mixing of horses, or foaling can reactivate the virus, which the asymptomatic horse sheds in respiratory secretions. EHV-4 causes mostly respiratory disease, whereas EHV-1 can cause respiratory disease, abortion, or neurologic disease.
Scollay says research has shown EHV vaccination programs help reduce clinical disease and the period of viral shedding in adult horses. “It is reasonable to assume that many of the horses that experience these benefits were initially infected as foals,” she notes. “This is an important ‘herd health’ concept–that by minimizing clinical disease and viral shedding in horses that respond well to vaccination, you are also providing increased protection to horses in the same population that did not, for whatever reason, develop a good immune response to a vaccination.”
Vaccination can prevent the return of disease, suppress virus so it remains latent, and stop shedding in nasal secretions, limiting transmission to naïve horses.
STRANGLES Available vaccines do not protect entirely against Streptococcus equi-caused disease, and there are controversies surrounding its use in some animals. Sellon weighs in: “Strangles IN vaccine is used in horses at risk of exposure to strangles. The exception to this is horses with very high previous, especially if recent, exposure to strangles. Most experts agree that vaccination of horses with either IM (intramuscular) or IN vaccines, if they have a pre-existing high titer to the bacterial organism, is associated with an increased risk of adverse effects. I recommend IM strangles vaccine for broodmares in the last 30 to 60 days of gestation if they or their foals are at risk of exposure.
All strangles vaccines have been associated with immune-mediated reactions, such as vasculitis (inflammation of blood vessels) and myositis (inflammation of muscles). The IN vaccine, which is (made with) modified-live bacteria, may cause abscesses, rarely. The IM vaccine often causes soreness, swelling, or potential abscesses at the vaccination site. Base your decision to vaccinate for strangles on assessment of the potential risks (farm history, lots of horse traffic on and off farm) and benefits.
EQUINE VIRAL ARTERITIS This disease is encountered most commonly in the semen of an infected carrier stallion, yet it can be passed from horse to horse in respiratory secretions. Most times this vaccine is used to protect breeding stallions, mares with planned breeding to a known infected stallion, and nonbreeding horses in the event of an outbreak. Pregnant mares should not receive the EVA vaccine. Before vaccinating, you can screen a horse for previous exposure to EVA with a blood test. Vaccinating for EVA might also preclude a horse’s entry into some countries, as it is difficult to determine natural versus vaccine titers. (For more information see article #10215 at TheHorse.com.)
POTOMAC HORSE FEVER (PHF) This is a diarrheal disease (and occasional cause of abortion) caused by the organism Neorickettsia risticii. Its effect on horses follows a seasonal pattern, usually between late spring and the fall during hot weather (vaccinate prior to insect hatching and warm weather). Horses are infected by ingesting infected insects derived from aquatic environments. Current vaccines do not have challenge information based on this natural route of infection, but, instead, are based on a transmission method that was suspected and now has been disproven (ticks, so tests to determine vaccine efficacy were done with blood challenge).
ANTHRAX This is a fatal disease caused by Bacillus anthracis, occurring in specific geographical locations where the spores remain in the soil for decades. This vaccine is usually only administered to pastured horses in high-risk areas. A primary series is followed by an annual booster.
BOTULISM This fatal neurotoxic disease disease is caused by Clostridium botulinum. A vaccine is available for C. botulinum type B, which is particularly useful to protect foals against shaker foal syndrome that have acquired botulism through ingestion of the spores.
Sellon comments, “Botulism should be included in broodmare vaccinations if the horses reside or will travel to areas where type B botulism is known to occur. This generally means Kentucky and the mid- Atlantic region of the eastern United States.”
Pregnant mares in high-risk areas should be receive a primary series at least four to six weeks prior to foaling to ensure transfer in colostral antibodies for the foal. Foals should also receive this vaccine series in high-risk areas. Vaccinate adult horses in these areas based on a veterinarian’s recommendation.
ROTAVIRUS In the case of the diarrheal disease rotavirus, vaccinate the mare to protect the foal, especially if there have been previous problems with this disease on the farm or in the area. Sellon counsels, “All breeding operations, large and small, should have in place reasonable biosecurity plans to decrease the chance of accidental introduction of the disease on the premises. Vaccination for rotavirus should never be considered as a replacement for this type of husbandry.”
Administer a three-vaccine series to a pregnant mare by the last month prior to foaling. This way a foal receives colostral antibodies that provide resistance to rotavirus for the first 30 to 60 days. This vaccine is not necessary for other adult horses.Foal Vaccine Program
A foal’s first-year immunizations begin as a series of two to three injections (depending on the product), followed by boosters once or twice a year. Most foals are born in the spring and will not receive EEE, WEE, WNV, and tetanus immunizations until 4 or 5 months of age or later. Don’t start flu and rhino until 6 to 9 months of age, depending on the mare’s vaccination history.
Scollay explains that foal vaccination timing is based on maternal antibody interference. “While the antibodies in the mare’s colostrum provide a foal with early protection against infectious diseases,” she says, “those same antibodies can also inhibit the foal’s own immune system from ‘learning’ from a vaccine and developing its own immunity to disease. If the mare was vaccinated late in pregnancy, the foal’s vaccinations should begin later than if the mare was not vaccinated late in pregnancy. If you don’t know the mare’s vaccination status, you must assume she was both vaccinated and unvaccinated.”How Many Vaccines At Once?
Many horses can receive multiple vaccines at one time and have no adverse reactions, particularly if using separate injections rather than multivalent products, but not all horses fare well in this scenario.
Scollay gives the vaccinations in two sets, 10 to 14 days apart. She says, “I don’t know if this benefits in terms of developing better immunity, but I do think the horses are more comfortable with less localized muscle soreness and general ‘punkishness.’ ”
Determine how your horse fares with individual vaccine products, then try to minimize future adverse reactions.
Photo Source: Anne M. Eberhardt/The Horse
Horses have been around for many, many years. Some experts have determined from fossil evidence that horses have existed for over 55 million years. These early horses were probably browsers that ate soft, leafy vegetation and groundcover in the prehistoric woodlands. The horse evolved over time, and the current form and type of dentition in the horse is believed to have evolved about 15 to 20 million years ago. This evolution allowed adaptation that was better suited to grazing. The changes included a longer cheek teeth row and a deeper skull and jaw to better accommodate the hypsodont (high-crowned) tooth. The hypsodont tooth (a tooth that continues to erupt from the jaw over a very prolonged number of years) is better equipped to handle the increased wear that occurs when grinding the more abrasive grass (which may often have trace amounts of grit from the surrounding soil surface and plant roots).
The horse as we know it today has a hypsodont tooth and an anisognathic jaw conformation; the upper jaw, the maxilla, is wider than the lower jaw or the mandible. This arrangement allows horses to maximize their chewing efficiency, prolong the effective life of their chewing equipment (premolars and molars), and hopefully, remain adequately fed for a long, long period of time.
The hypsodont tooth erupts on average about three to four millimeters per year to compensate for the wear from the daily grinding action of the food processing. The average permanent (adult) premolar or molar (grinding or “cheek” teeth) have a reserve crown of approximately four inches (100 mm); under ideal conditions one could estimate that the happy, healthy horse should have teeth that should not wear out for 25 to 30 years.
In order for the horse to obtain food, it must first prehend or grasp the food. If they are grazing, as they lower their head to the ground surface the maxilla (upper jaw) slides slightly backward as the mandible (lower jaw) slides forward. As the head comes into position at the ground surface, the incisors (front) teeth should be aligned to cut or shear off the grass pasture. This allows the horse to graze or cut the pasture very close to the ground surface without disturbing a significant amount of surrounding grit, dirt and debris. Under normal circumstances, the horse will cut the grass off at ground level, rather than pulling the plant out by the roots.
The lips, tongue, cheeks and hard palate all serve a role in moving the food along the conveyor belt into the oral cavity for further processing. The lips act as a sorting/selection tool to find, test and pull food into the mouth. The tongue acts as an auger to work the food back in the mouth, where the bolus is pushed out onto the grinding surface of the cheek teeth (premolars and molars).
The chewing cycle is a repetition of a cyclical movement of the rhythmical contraction of the muscles that control the opening and closing of the jaw. There are three parts to the chewing cycle; the dropping or lowering of the mandible and it’s sliding sideways in relation to the maxilla, the closing of the mandible against the maxilla and the grinding of the mandible across the maxilla. The steps are called the opening, closing and power stroke phases of chewing. Some horses will consistently chew or process their food in one direction; others will process or chew their food in both directions. The important point to remember is that mastication (grinding) requires significant motion of the mandible and maxilla in relation to each other. Studies that have examined how the different types of feed affect how a horse chews its food have shown that a much larger range of motion is required to grind hay than a concentrated feed source (i.e. grain).
As the food is ground, it is moved across the occlusal surface of the tooth, out into the buccal oral cavity; the cheek contains the feed and pushes it back onto the occlusal surface of the cheek teeth where it is crushed again. The palatine ridges on the roof of the mouth in the hard palate aid in the direction of the food bolus, passing it further back into the mouth where the tongue pushes it out onto the occlusal surface for additional grinding. This process is repeated multiple times until a thoroughly chewed bolus arrives in the back of the mouth at the glottis for swallowing. Any changes in this finely tuned, delicately balanced and “machined” process can greatly affect the horses ability to find, collect and process its food to nourish itself. Our domestication and current housing and management of the magnificent horse also can have a tremendous impact on the horses ability to maintain a balanced and healthy food processing machine (mouth).
Adult mammals have four types of teeth: incisors, canines, premolars and molars. Each tooth has several regions associated with it; the crown (visible, exposed portion), the reserve crown (portion that is hidden within the boney socket) and the root. Each tooth is made up of enamel, dentin, cementum and the pulp cavity.
Enamel is the hardest, most dense substance in the body. Although it is extremely hard, it is also very brittle. In most areas of the tooth it is covered by the cement; the exception is on the occlusal (chewing) surface of the tooth.
Dentin makes up the bulk of the tooth. One of the main purposes of the dentin is to act as “crack stoppers” should any micro fractures (tiny, microscopic fractures) occur in the adjacent, brittle enamel. Another equally important function of the dentin is that is allows a rough, irregular wear pattern to develop on the occlusal surface of the premolars and molars. This creates a more efficient grinding surface for the food to be processed on.
Cementum has several critical functions. It acts as a protective covering over most portions of the tooth, including the crown. The cementum also serves to attach the tooth to the boney socket as it continues to erupt throughout the life of the horse. Cementum helps protect the coronal enamel from cracking. It helps in forming the protruding enamel ridges on the occlusal surface and also makes up a significant portion or bulk of the clinical crown (i.e. exposed, visible portion of the tooth).
Pulp is a collection of soft tissues including blood vessels, nerves and connective tissues. The pulp fills the pulp cavity of the tooth; the size and shape of the pulp cavity changes throughout the life of the horse and the hypsodont tooth. The pulp cavity is much larger in the young horse that has the newly erupted, fully mature tooth than in the geriatric horse with minimal, remaining reserve crown.
Goat Facts (From various resources)
by Gary Pfalzbot
Origins of the Goat
Goats were one of the first animals to be tamed by humans and were being herded 9,000 years ago. They are a member of the cattle family and are believed to be descended from the wild goat, bezoar.
Breeds of Goats
There are over 210 breeds of goats with an estimated 450 million goats in the world (2001). Of the 450 million goats in the world, it is estimated that approximately 6 to 8 % of them are in North America (2001). The majority of the world goat population can be found in the Mideast and Asia.
Goats are ruminants or cud chewing animals that eat cracked or ground corn mixed with oats, hay and grass. Most breeders and producers prefer to limit the amount of corn in a goat's diet, preferring to feed specialized goat feed mixes with the majority of the diet being made up in a mixed, grassy alfalfa and other weeds, browse and shrubs known to be compatible with a goat's nutritional needs.
Goats also have specific mineral and vitamin requirements that determine their overall health and production. These requirements often vary between breeds of goats and coloration of the goat. Most people believe that goats will eat almost anything and this is simply not true. The goat has very sensitive lips and their natural curiosity gives them a habit of "mouthing" and "smelling" for food that is clean and tasty. Goats will not eat soiled food (unless they are pushed to the point of starvation - often preferring to starve).
Goats have a lower set of teeth which meet a hard pad in the upper jaw, and 24 molars on the top and bottom in the back of their mouths. Kids have 8 small, sharp teeth in their lower front jaw, and like children, when their baby teeth fall out they are replaced by permanent teeth. The age of a goat can often be closely determined by their teeth.
The overall health of a goat is largely determined by their environment, genetics and nutrition. There are a number of illnesses that can affect a goat both in chronic and curable form. Some of these illnesses can be passed to humans and other animals while some illnesses are specific to goats. Much research is being done to provide more drugs that are approved for use in goats.
Two illnesses that can bring sudden death to a goat are coccidiosis and pneumonia. Of most concern to breeders and producers are worms and parasites. A goat that is ridden with parasites and worms and left untreated will most likely suffer a rapid decline in health, production and often result in death.
Weight and Physical Characteristics
Depending on their breed, female goats weigh between 22 to 220 pounds, whereas male goats weigh between 27 to 275 pounds and are bigger and shaggier in appearance than females. Male goats are also endowed with beards that grow longer as they get older. Female goats are also capable of growing a beard. With the advent of the Boer or "meat goat" in the United States, these standards are becoming somewhat variable.
Cross-breeding and genetics have begun paving the future for new breeds of goats which will undoubtedly exceed current standards. Many a breeder and producer will share that their particular line of goats will often be bred for a specific characteristic or feature. It is important to understand that a "desirable" characteristic to one producer may be "undesirable" to another.
Widely accepted as a "standard", depending upon the breed, goats may be cream, white, black or brown in coloring. However, as more cross-breeding and genetic enhancement is achieved, the results are often dazzling sets of colors not previously seen. In my experiences, cross-breeding can often result in the offspring displaying both sets of colors from the original breeds. These cross-bred goats are often referred to as "Brush Goats".
The pupil in a goat's eye is rectangular in shape instead of being round like those of other animals. It is believed that goats have excellent night vision and will often browse at night. The actual color of the goat's eyes is varied with the most common color being yellow or brown. Blue coloration is a bit rarer and often a characteristic many breeders will try to achieve.
Goats generally live 10 to 12 years. There have been cases of goats living up to 15 years.
The behavior of a goat can vary widely based upon a number of factors such as breed, surroundings, and size of the herd. For the most part, goat behavior is often summed up as: goats are very sociable, lively, inquisitive and independent animals. They are also quite intelligent and can learn how to open latches on farm gates. Goats are also herd animals.
One particular behavior of goats that is intriguing is that while they are independent, they often prefer to surround themselves with goats of their same breed in a mixed herd. Another example of goat behavior is that the kids will prefer to remain nearby their mother, even if separated for years and reintroduced.
Goats can climb, run, crawl under fences and some breeds of goats are able to jump heights of over 5 feet. It should be noted as well that most goats will also stand on their back legs to reach tree branches and shrubs.
The main products associated with goats are milk, cheese, meat, mohair, and cashmere. Large dairy does produce 3,000 to 5,000 pounds of milk each year. (On a daily basis they produce 2 or 3 quarts of milk). With the emphasis on genetics, it should be noted that breeders and producers are beginning to surpass previous levels of milk and meat production with daily yields often exceeding one gallon of milk per day.
Goat Names and Terminology
You will often hear goats referred to by the following: "Buck or Billy" - a male goat. "Doe or Nanny" - a female goat. "Kid" - a young goat. "Wether" - a castrated male goat. "Hermaphrodite" - a goat showing both female and male characteristics, most likely unable to reproduce. "Herd" - a group of goats. "Wattles" - little round balls of fur on a goats' neck close to its chin. Not all goats have wattles.
Insulin resistance is a problem that has recently been documented in horses, ponies and donkeys. The causes and effects of insulin resistance, as well as its diagnosis and treatment, as well as some tips on feeding the insulin resistant horse will be provided.
The horse digests and ferments carbohydrates in feedstuffs to produce glucose, which is its primary source of energy for body functions. Insulin resistance (IR) occurs when body cells that use insulin to regulate the uptake and metabolism of blood glucose become less sensitive to insulin’s effects. This means that insulin is required in greater amounts to keep blood glucose concentrations within normal amounts, especially after a meal high in starch and/or sugar.
There are many contributing factors to IR including diets high in starch and sugar, obesity, breed, age and inactivity. In one research study, horses fed a high sugar and starch feed had increased IR compared to horses fed a high fat and fiber feed, even when they were not overweight, Horses that become obese may develop IR and have an increased risk of laminitis. Horses or ponies with a history of laminitis without an obvious cause such as grain overload, heat stress, recent intestinal surgery or road founder likely have IR. IR is the major symptom of Equine Metabolic Syndrome (EMS), which is the term used to describe horses that have IR as a result of genetics and/or obesity. Horse diagnosed with EMS are characterized by abnormal fatty deposits on the neck (cresty neck), rump and above the eyes, voracious appetite and reduced stamina. Weight loss in obese EMS horses may allow them to return to a normal metabolic status, but other horses may still be symptomatic as there is likely a genetic connection with certain equine breeds and EMS.
Ponies, donkeys and “easy keeper” horse breeds may have a “thrifty gene” which is a genetic adaptation to sparse vegetation in geographic areas where they originated. An altered metabolism that allows maintenance of body weight on a less feed, and the secretion of more insulin or an insulin resistant metabolism allowed these IR-type equids a greater chance of long-term survival. Insulin has the effect of directing blood glucose into body cells and storage of glucose as fat, which is the most efficient method of storing energy when food is not available. Modern equine management providing excessive calories from improved pasture and grain feeding has resulted in obesity and the many problems associated with EMS.
Equine Cushing’s Disease (ECD), which is also known in the horse as Pituitary Pars Intermedia Dysfunction or PPID. ECD is common in horses over 20 years of age, and can include symptoms such as hirsuitism (long curly hair that won’t shed in spring), excessive sweating, muscle wasting, excessive water consumption and urination, frequent infections and infertility. Horses can have EMS or be insulin resistant and also develop ECD in their later years, with both problems causing health issues.
Regular exercise reduces blood glucose and insulin levels, allowing an active horse to prevent IR even when fed high sugar and starch meals. However, lack of activity combined with overfeeding can result in obesity and onset EMS. Prolonged high levels of blood glucose and insulin due to insulin resistance can have harmful effects on the horse’s health, so diagnosis and treatment are important.
Your veterinarian can diagnose IR in your horse by measuring blood levels of glucose and insulin. A combined glucose-insulin test may be used but more likely a resting serum insulin concentration will be utilized to diagnose IR. Levothyroxine (also called Thyro-L) has reduced IR symptoms and laminitis and increased weight loss when used over a 4 month-long period in horses diagnosed with EMS. A weight management program should also be initiated with or without the use of Thryo-L for the obese horse, with the use of a supplement pellet such as Legends CarbCare Balancer Pellet, Triple Crown Lite Formula or 30% Ration Balancer, limited hay feeding at 1.5% to 1.25% of body weight daily, and limited or no pasture for horses diagnosed with Equine Cushing’s Disease (EMS) and an increased risk of laminitis.
Prevention is always more economical than treatment, so use the following tips on feeding your horse to help prevent and/or treat IR:
- Adjust your feeding program to maintain proper body condition of your horse, avoiding obesity. This may require limiting pasture grazing time or the use of a grazing muzzle, and limiting the amount of hay and grain fed, especially for pony breeds and horse breeds such as Peruvian Paso Fino, Paso Fino, Icelandic Horse and Morgan, and many Arabians.
- Maintain good soil fertility of horse pastures. Research has shown that a well-fertilized pasture of cool-season grasses will have lower levels of sugars that have been implicated in causing laminitis.
- Provide as much exercise and turnout for your horse as possible. Consider a sacrifice area or paddock, where pasture grass is not available but horses can be turned out daily for activity.
- Avoid or severely limit access to pasture grazing for IR horses in the spring and fall. Cool season grasses are growing most rapidly during these times and contain the greatest amount of sugars, including fructan sugars, which have been implicated in causing laminitis. Horses with IR are more likely to have a laminitic outbreak when grazing on pasture during these times.
- Select hay with a low level of soluble carbohydrates for the IR horse. Small grain hays such as oat and ryegrass have much greater sugar content than other grass hays like timothy and orchard grass. Alfalfa hay and coastal Bermuda grass are usually the lowest in soluble carbohydrate (sugar and starch) content, but alfalfa contains more calories and feeding rate must be monitored closely. Clover hay should be avoided for the IR horse as the starch content can be high as well as the caloric density. Moderate quality grass hay is preferred due to its low soluble carbohydrate content and moderate caloric content. Soaking hay for 60 minutes in cool water or hot water for 30 minutes will significantly reduce its soluble carbohydrate content.
- Select a horse feed low in sugar and starch (20% or less) to normalize blood glucose and insulin levels for your horse with IR. Beet pulp and soy hulls contain very low levels of soluble carbohydrates, so select a feed that is based on one of these ingredients. Southern States has the soluble carbohydrate values of its horse feeds available for you to select an appropriate one for your horse, and many products with 20% or less sugar/starch content. There are four Legends CarbCare horse feeds. They are formulated with low levels of sugar and starch content and are recommended for IR horses. All of the Triple Crown Horse Feeds are formulated with low levels of sugar and starch and are recommended for insulin resistant horses.
- Proper hoof care is essential for the IR horse due to increased incidence of laminitis. Select a well-fortified horse feed and make sure you are feeding an adequate amount of feed to meet requirements for protein, lysine, calcium, phosphorus, zinc, copper and iodine, these nutrients are especially important for good hoof growth. Also consider selection of a horse feed with added biotin or the use of a hoof supplement containing biotin if hoof quality is poor.
- Magnesium is involved in insulin secretion and supplementation of magnesium has been recommended for horses with IR. Chromium has been used to reduce blood glucose levels in horses and has also been recommended for supplementing the IR horse. Select a horse feed with a higher guaranteed level of magnesium or consider using magnesium and chromium supplementation for a horse with IR. Dietary guidelines would be 2 grams of magnesium per 100 pounds of body weight and 1 gram of chromium per 100 pounds of body weight.
- Many horses with IR are fed small amounts of horse feed to decrease calories but may not be provided with optimal amounts of required nutrients. Consider the use of a balancer pellet, such as Legends CarbCare Balancer Pellet or Triple Crown 30% Ration Balancer or a concentrated feed such as Triple Crown Lite Formula. Triple Crown Lite Formula is specially formulated for miniature horses, ponies, overweight and “easy keeper” horses with a low feeding rate, concentrated nutrient profile, and low starch and calorie content to be fed with an all forage (hay or pasture) diet.
- A convenient option for miniature horses or ponies is Triple Crown Safe Starch Forage. This is a chopped hay product that is fortified with minerals and vitamins and has a sugar and starch content of less than 10%. Triple Crown Safe Starch forage can be fed as the sole feed source for the horse. The recommended feeding rate is 1.0% to 1.5% of body weight per day.
- Source: https://www.southernstates.com/articles/feed-insulin-resistant.aspx
Hay as Primary Feed
Most horses’ diet needs can be met primarily with pasture or hay. Mature horses in light work may not need grain; they can usually get all the nutrients they need from good hay, salt and water. This assumes that your pasture is producing high-quality forage or that you can grow or purchase good-quality, nutritious hay.
Don’t mistake the greenery or dried plants (in winter or drought) of your pasture for feed. Walk around in the field and look to see what percentage of these plants is edible. Weeds grow more easily than desirable plants, particularly when the weather is not ideal. Some weeds are toxic, and while horses generally won’t eat these if there is something better to eat, you don’t want him hungry enough to try them. You may need to feed hay other than during the winter.
Hay alternatives like chopped hay products and hay cubes may be more nutritious than the hay you can purchase. They can be expensive. Even if you choose to feed them, your horse still needs the roughage equivalent of some long-stemmed hay each day.Providing roughage twice a day is considered by many to be the minimum. We want the horse to have something to chew on for as much of the day as our schedules allow.
The horse’s digestive tract is designed to process relatively low-energy and low-protein forage around the clock. Wild horses spend a great deal of time eating, and they choose their forage carefully from what is available. When we take over the responsibility of feeding, we must provide roughage that will keep the horse’s digestive tract working. Without adequate roughage, digestive disturbances like colic can develop, plus your horse will be more likely to chew on other items—like the wooden fence or the barn.
Providing roughage twice a day is considered by many to be the minimum. We want the horse to have something to chew on for as much of the day as our schedules allow. If you care for your horse at home, throw him a flake of hay when you check on him last thing at night. If you share duties, arrange to have one person feed hay in the morning and the other in the evening. If the only hay available is low in nutrients, it is still important. We can make up nutrient requirements with other feeds.
Make any diet change—for example, between hay types—as gradual as possible. This allows the gut bacteria to adjust and minimizes digestive upset. When possible, plan ahead so you still have some of the old hay left when you purchase the new. If you have to shop around and use different sources (whose hay is different), or if you run out between loads because of availability, start with smaller amounts for the first few feedings to let your horse get used to it gradually.
The two main types of hay fed to horses are grass and legume. Examples of common grasses are timothy and Bermuda; common legumes are alfalfa and clover. Grass hay is generally lower in protein and other nutrients than legume hay. Horses don’t necessarily need legume hay, but the legumes in a grass-legume mix can provide valuable protein. If you usually feed a legume like alfalfa but can’t get it, a grass-legume mix (like timothy with some clover) can be fed along with a protein supplement. Even plain grass hay can be supplemented to total the protein your horse used to get from alfalfa.
Cereal grain hay is also occasionally available. This is the grain (like wheat) when it’s still on the stalk. Mostly, however, the grains are harvested for human use and the remaining roughage is sold as straw.
While straw is usually considered horse bedding rather than feed, many horses will eat it. In times of serious drought, when suitable hay is not available, straw can provide roughage as long as it fits the other good hay criteria (no dust, mold, weeds, etc.).
Hay color can show hay nutrient content, though it’s not an absolute indicator. The loss of nutrients is somewhat linked to the loss of the desirable green color. Bright green is best; green is desirable over yellow or brown. If you are feeding hay for its roughage content, and recognize the horse’s need for additional nutrients, feeding brown hay is acceptable.
Choose soft, pliable stems and leaves over coarse and brittle ones.
Good hay has a fresh, sweet, pleasant scent recognized by horsemen everywhere. Avoid musty-smelling hay.
Leaves and Stems
The more leaves the better, relative to stems, because the leaves hold the majority of the nutrients in the plant. If you are feeding hay for its roughage value, stemmy hay is OK as long as your horse will eat it. Fine stems are preferable to coarse ones because they are generally more palatable and nutritious, but there is nothing harmful in coarse stems if that is what is available.
Whatever you choose, your horse has to eat it. If he wastes 90 percent of it by trampling it around his paddock, you’re not getting your money’s worth. If you have a choosy horse, he may refuse to eat the new, less tasty, hay. As long as you’ve chosen healthy hay (some horses won’t touch dusty or moldy hay, either), persist in offering him small quantities of the new hay until he eats it.
Whenever your best choice is less palatable hay, feed more than your horse will clean up. Your horse will pick through the hay; while this appears wasteful, it allows him to avoid the occasional weed or a patch that doesn’t smell as fresh. Consider this as insurance against his eating something he shouldn’t.
Stage of Maturity
The average stage of maturity of the plants at harvest is perhaps the most important factor in the nutrition available to the horse. Ideally, hay is cut just as grass heads begin to show and just prior to legumes blooming. This maximizes nutritional content. While preferable, this is not always possible. Dry weather influences the maturation process. There is nothing wrong with hay cut at earlier or later stages, as long as we recognize that it is less nutritious. It is still valuable as roughage and contributes to the total nutrition.
Harvest Weather and Handling
Rain falling on cut-but-not-yet-baled hay leaches out nutrients. Heavy dew causes haymakers to turn the hay additional times before it is dry enough to bale. Drought gives us dry, possibly immature, plants. When leaves are broken and lost during harvest, so is nutrition.
Hay put up too wet will probably mold—usually early in storage. Moisture content that allows the stems to bend crisply, but not crack and break, is ideal (this is 10—15 percent moisture content).
If your only choice is hay harvested a little too wet, store it with as much air circulation as possible around the bales, feed it as soon as possible, and check carefully for mold every time you feed.
Horsemen and hay dealers often generalize that hay from the “first cutting”—the first harvest of the summer—is better than second (or third) cutting hay. Some parts of the country don’t get more than one cutting. In times of drought, the number of harvests decreases. (This is the main reason that the price increases.)
It is best to look at the hay itself, rather than rely on the knowledge of which cutting it was. While the first cutting of the year is often more nutritious, it may have more weeds, or may have gotten rained on during harvest; both decrease its value.
If hay is stored well—dry and out of the weather, and where access by rodents is restricted—it will likely lose color and nutrients with age but is still healthy feed. If the hay gets wet during storage, moldy areas will appear—so sort through each bale as you feed. Last year’s hay can still be a good source of roughage if it was stored well.
Avoid Dust, Mold, Weeds and Trash
Do not accept dusty hay. Dust causes respiratory irritation, which can be followed by a bacterial infection, and it may promote allergy development. White dust is usually fungal spores from mold.
When water is available, slightly dusty (from leaf breakdown during handling, not from mold) hay can be used after soaking each portion for a few hours in a clean muck bucket or plastic trash can until thoroughly damp. The soaking container must be dumped and cleaned between uses or any remaining hay will mold. Spraying the hay with a hose is not effective in penetrating down to the dust.
Absolutely do not feed moldy hay. Exposure to hay molds can cause lifetime respiratory disease like chronic obstructive pulmonary disease (COPD, also called heaves). Hay molds may also contain toxins. Identify mold by its pungent odor and the tendency of hay to pack together rather than separate easily into flakes. White mold and dusty spores may or may not be visible. Try to trade moldy hay to a cattle rancher or dairy herder, since cattle can eat hay which horses cannot.
Some weeds are a nuisance; others are toxic. Good hay contains a minimum of weeds. The more roughage you provide (within reason), the more picky your horse can be; he should avoid most weeds.
Foreign material like trash is to be avoided. If you know the grower and the hay fields, you may be able to predict that trash won’t be included. Regardless, trash sometimes gets baled with hay, so it’s a good idea to keep an eye out for it while feeding.
Roughage is vital. Hay is the best way to provide roughage if you can obtain and afford it. Low-nutrient roughages can be used. Choose carefully to keep your horse healthy.
This article originally appeared in Eclectic Horseman Issue No.9
There are a wide variety of different hay types – each with its own benefits (a few even have drawbacks) for your animals. Always consult your vet or an equine nutritionist before you decide which hays to feed your horse, as their results can vary widely from breed to breed.
A palitable hay that horses like the taste of, this is the hay often used to make cubes & pellets. Alfalfa is easy to digest & high in protein, energy, vitamins & minerals. It is also produced & sold in every state of the US.
Has been thought to cause impaction in horses when low in quality, so buyer should be very aware of the product they are purchasing. This is a good flavored hay & generally animals like the taste of it.
When dried, clover hay doesn’t preserve the green color & becomes dry looking. This is normal. Clover is often mixed with grass hay & comes in red, white, crimson, alsike & landino. *Be aware when you feed clover hay that if it becomes damp, the mold can make horses very sick.
Oat hay has thicker, tougher stalks than the other options available (which some horses won’t eat). It is a hardy hay & seems to take a while for them to eat. Can be higher in sugar – not a good option for insulin resisting animals.
Orchard grass hay is not as sensitive to time of cutting with regards to end-stage nutrient content. While it is not as nutrient rich as alfalfa hay, it has good flavor & is high in fiber.
Fescue – both in pasture & hay form – can be damaging to pregnancy in mares. This is a long, soft hay which also yellows as it dries.
Timothy hay is easier on the digestive system than some of the others, it is high in fiber & low in calcium content. Timothy has a tendency to be more expensive, but high in nutrients for aged animals, lactating mares & growing young.Source: http://www.theequinest.com/care/food/hay/
Out of nearly 1,000 randomly chosen horses, 85% had at least one hoof disorder visible during a regular farrier visit.
By Christa Leste-Lasserre, MA Photo: Erica Larson
If your horse suffers from a foot disorder, he’s far from being alone. A recent epidemiological study from the Netherlands has revealed an unexpectedly high rate of mild foot disorders in a representative average horse population.
Out of nearly 1,000 randomly chosen horses, 85% had at least one hoof disorder visible during a regular farrier visit, said Menno Holzhauer, PhD, of GD Animal Health in Deventer.
Farriers and researchers identified multiple hoof issues, including:
- Thrush (45.0%);
- Superficial hoof wall cracks (30.4%);
- Growth rings (26.3%);
- Sole bruises (24.7%);
- White line disease (17.8%);
- Perforating hoof wall cracks (16.4%)
- White line widening (11.8%);
- Horizontal hoof cracks (5.2%);
- Chronic laminitis (3.6%);
- Quarter cracks (2.7%);
- Keratoma (1.8%); and
- Frog canker (1.0%).
“This was really higher than expected, and it’s important to diagnose and treat these disorders at an early stage because they interfere with animal welfare and cause lost days of performance in these horses,” Holzhauer said. “Individual farms should compare the prevalence of hoof disorders in their farms with the general prevalence. And, they should learn about risk factors so as to reduce them, thereby striving for maximal soundness and comfort of these horses in relationship to the hoof disorders found.”
In their study, Holzhauer and his fellow researchers asked 21 farriers across the Netherlands to record their impressions of the feet of the horses they saw. The farriers randomly chose one horse from each farm to examine during their regularly scheduled visits. The horses they treated were riding and driving horses, representing a variety of disciplines and levels. They averaged 11 years old.
Although 85% of the horses had at least one foot disorder, most of the disorders were mild, Holzhauer said, and the horses appeared healthy with no obvious lameness. About a quarter of the horses had two disorders.
Most scientific studies on hoof disorders focus on a single horse or a single disorder, he added. So having a study that looks at multiple disorders from a global, population-wide perspective is helpful in understanding how challenging these conditions are, Holzhauer said.
Many hoof disease risk factors appeared to be related to different external farm conditions, he added. For example, horses that spent more time indoors were more likely to have thrush. Horses whose hooves were picked out only once a week had more hoof cracks. And the bedding material increased some risks and reduced others. Other factors include soil type, discipline, age, hoof color, and trimming intervals, but, overall, each condition seemed to have multiple factors, he said.
“Both farriers and veterinarians should advise owners based on the presence and their knowledge of proven risk factors on the farm and give a follow-up after adaptations made by the farmer/owner during the next farm visit,” Holzhauer said.
“Some problems can’t be solved in one trim,” he added. “They can take a lot of time. But we noticed that some farriers don’t make a big issue of mild problems when they see the horses often, for example, with thrush. But reducing the risk through management changes could prevent these problems in a lot of cases.”
The study, “Cross-sectional study of the prevalence of and risk factors for hoof disorders in horses in The Netherlands,” was published in Preventive Veterinary Medicine.