Chapter 16 Common management practices.
After completing this chapter, you should be able to:
* Recognize stress in horses
* Describe methods of marking and identifying horses
* Discuss procedures for the neonatal foal
* List methods of fly control
* Describe common fly problems and the habits of several species
* Explain the best management practices for pastures and forages
* Describe wound types and their proper management
* Discuss the management considerations when weaning a foal
* Explain the importance of records to the management of horses
RECOGNIZING STRESS IN HORSES
Stress is a demand for adaptation. Some stress is necessary, but each horse has its own tolerance level; when that level is exceeded, failure results. Knowing the signs of stress, monitoring the signs of stress, and reducing stress are all signs of good management.
Anyone working around horses needs to learn to recognize the signs of stress. A horse experiencing stress may appear frightened or nervous, it may be pacing or running, or it may develop a vice such as cribbing or stall weaving. Abnormal sweating may signal physical or psychological stress. Muscle tone can provide some clues. If the horse is tense, sweating, and the muscles are contracted, it may be tying up. If the muscles are flaccid and extremely relaxed and the horse is depressed, the central nervous system may be damaged. If any of these signs are observed, a closer inspection is needed. Intervention may be necessary.
To recognize changes in the horse's condition, normal values must be known. They will be different for each horse, so each horse needs its own permanent record. Horse owners must keep a file on every horse that includes the following information:
* Permanent identification, birth date, and registrations
* Reproductive history, breeding dates, and foaling dates
* Weight and condition scores
* Normal temperature (T), pulse (P), and respiration (R), or TPR
* Deworming dates and products used
* Vaccination dates, diseases, and products used
* Illness dates, diagnoses, and treatments
* Injury dates and treatments
* Surgery dates and outcomes
* Allergy causes
This record can be a handwritten form, or it can be computerized. Figure 16-1 illustrates a computerized form.
Stress can be grouped into four different categories for horses:
1. Behavioral or psychological
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Managing horses in a low-stress environment requires understanding how their senses perceive the world and a few principles of their behavior. For more information on behavior, refer to Chapter 19.
Sensory Perception. Horses do not see the world as humans do. Horses have both binocular and monocular vision. Monocular vision allows them to see 220 degrees around them when their head is down to graze. Binocular vision allows them to focus on objects in front of them.
Horses hear much better than people do, but olfaction is even more acute--smell is their strongest sense.
Horses are also very sensitive to touch. Their untrained natural response is to move into pressure.
Communication. Horses communicate with each other through visual signals. Recognizing these signals can help owners understand their horses. Anger is demonstrated by laying the ears back, pursing the lips, and swishing the tail. Interested horses cock their ears forward and have a relaxed body. A fearful horse may put its ears forward or to the side; its body is tense and its tail clamped or stiff. Relaxed horses have relaxed ears and one hind leg cocked. They may chew or lick their lips.
These behaviors can be easily recognized and may alert the owner to certain stereotypes of horse behavior. For example, some horses are sullen and difficult most of the time, while others are actually treacherous. Bad-tempered, resentful horses may bite, strike, or kick at any time.
Social Behavior. The social behavior of horses is controlled by the herd instinct. Horses seek out and enjoy the company of other horses (Figure 16-2). Social order is important, and there is an established dominance hierarchy in any herd of horses. Dominance is the ability to control access to resources. The dominance hierarchy requires that each horse recognize other horses and determine through some initial aggressive acts (biting or kicking) and submissive acts (running away) which horse is dominant and which is subordinate. After the initial conflicts establish the hierarchy, just the signs of anger from the dominant animal will be enough to warn subordinates. Pecking order can change if a horse is removed from a group for several weeks, or if a mare is in estrus or going to have a foal.
Initial contact across safe wooden fences can alleviate some social stress, and introducing horses gradually can help avoid injuries associated with fighting. Providing extra feeding stations and dividing the feed so horses all get adequate portions is another way to avoid conflict.
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Structural injury can be detected by lameness, local inflammation, swelling, heat, and/or pain. Checking for injuries should be part of the daily routine.
Nutrition and Metabolic Stress
The horse's digestive system is designed to handle frequent small meals. They are continuous grazers by nature and usually do best when kept at pasture. If this is not possible, good-quality hay fed in frequent meals is the next best thing.
Nutritional programs are designed by evaluating each horse's weight and condition. Horses must be fed individually in most cases. Energy requirements of "easy keepers" and "hard keepers" can differ by up to 30 percent. About 80 percent of a horse's feed goes to meet its energy requirement. The hay used should contain the most nutrients per dollar.
To reduce stress, horses require that a certain proportion of the diet be roughage. Vitamin and mineral requirements must also be met but not exceeded for the stage and condition of the horse. Nutritional requirements and feeding guidelines are given in Chapters 12 and 13.
Three metabolic problems in horses are closely associated with nutrition:
3. Tying up
Horse owners need to learn to recognize these conditions. They can be serious health problems for a horse.
Colic. Colic is an acute abdominal crisis or stomachache. In its most serious form it can cause death, and it often does. Abdominal pain can lead to shock, which causes dramatic changes in fluid balance. Signs of colic include pawing, looking at the belly, stretching out, rolling, not eating, violent movement, kicking and biting at the flank, and depression. Every sign is not seen in every case. If colic is suspected, the horse's temperature, pulse, and respiration should be taken and recorded and a veterinarian called. An elevated heart rate and/or respiration signals a potential emergency. The many causes of colic include sudden changes in diet, parasites, twisting of the intestines, gastric ulcers, lack of a quality water source, cribbing, compaction, and gas. Colic is discussed more completely in Chapter 14.
Laminitis. Laminitis is any condition that leads to separation of the sensitive and insensitive lamina of the hoof. Early signs include a rapid heart, pounding digital pulse, depression, elevated temperature, and circulatory impairment. As the condition progresses, the horse will become lame. The horse will extend its legs out in front and rock back over its hocks and will be reluctant to move or pick up its front feet. A veterinarian needs to be called at the earliest signs of laminitis. Laminitis is covered more completely in Chapter 14.
Tying Up. Tying up, or exercise-related muscle problems, are metabolic conditions related to nutrition and exercise. Signs include altered gait, rapid breathing, stiffness in the hindquarters, rigid back, trembling muscles, sweating, reluctance to move, collapse, muscle damage, brown urine, kidney failure, and laminitis. Some contributing factors include excess soluble carbohydrates in the diet, stress, metabolic and hormonal disturbances, electrolyte imbalances, and selenium and vitamin E deficiencies.
Tying up can occur shortly after exercise begins or after the horse has been worked hard, such as after an endurance ride. If the horse is exhausted and overheated, rest it immediately in the shade, cool its extremities by bathing them with cool water, and give the horse an electrolyte solution. Commercial electrolyte solutions are available through a veterinarian or feed store.
If the horse ties up shortly after the start of exercise, it should not be moved. Instead, dry off the horse and cover its hindquarters with a blanket; then call a veterinarian.
Once a horse has tied up, the condition will likely recur. Altering the horse's diet may help correct the problem.
Stress caused by disease and/or parasites can range from superficial discomfort to death. A good vaccination program is the best defense against infectious diseases. A veterinarian will help form a vaccination schedule based on disease prevalence, the use of the horse, the season, and the effectiveness of vaccines. Some of the vaccines available include protection against tetanus; influenza; rhinopneumonitis; Eastern, Western, and Venezuelan encephalomyelitis; strangles; Potomac horse fever; rabies; leptospirosis; and clostridium. Diseases and vaccination programs are discussed more completely in Chapter 14.
An effective deworming program must include good management practices as well as regular use of antiparasitic drugs. Parasite infections and control are discussed in Chapter 15. Some important guidelines include:
* Treat all horses at the same time
* Rotate clean horses to clean pastures
* Design feed and water facilities to prevent fecal contamination
* Remove manure frequently from stalls and paddocks
* Clip and harrow pastures regularly
* Consult with a veterinarian on selection and use of antiparasitic drugs
* Monitor the effectiveness of the parasite control program by checking egg counts in feces
MARKING OR IDENTIFYING HORSES
In today's competitive world of equine sports, proper identification is a high priority. Thorough and effective identification ensures that a horse being bought, sold, raced, or bred is indeed the horse claimed. Some circumstances in which positive identification is important include:
* Health and disease control
* Theft prevention, documentation, and recovery
* Recovery of animals lost or killed in natural disasters
* Fraud prevention
The Jockey Club was the first organization in the United States to set up an accurate identification system for horses. In the early 1900s, the Thoroughbred racing industry was having problems with "ringers" running under assumed names. A ringer is a falsely identified horse entered in a race below its class, giving it an almost certain chance to win.
Today there are many methods used to identify a horse, including body markings, tattooing, freeze branding, blood typing, microchip implantation, and DNA testing.
Obviously, coat colors such as bay, blue roan, dun, grullo, and palomino can be used to identify horses (Figure 16-3).
Distinctive markings or patterns such as a star or blaze on the head and stockings or distal spots on the legs provide more detail (Figure 16-4). The correct terms to use in identifying coat colors and facial and leg markings are listed and explained in Chapter 8.
Unique body markings used for identification include chestnuts, cowlicks, and dimples. Body markings are recorded as a picture or drawings.
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* Chestnuts or "night eyes" are horny, irregular growths on the inside of the horse's legs. On the front legs, they are just above the knee. On the rear legs, they are toward the back of the hock. Chestnuts are like human fingerprints because no two are alike, and they do not change in size or shape throughout the horse's adult life.
* Cowlicks are permanent hair whorls that cannot be brushed or clipped out. They are located mainly on the forehead and neck.
* Dimples are permanent indentations in the muscle under the skin. They are usually located at the point of the shoulder or in the neck muscles.
* Other markings can include white or black patches on the body and scars. Firing marks on the legs (where one leg strikes another) are also useful for identifying horses.
A tattoo consists of a letter corresponding to the year the horse was born and a number matching the registration number of the horse. The tattoo may be placed in several areas, but the upper lip is the most common site (Figure 16-5). The actual tattoo instrument consists of a chrome-plated brass block containing a pattern that uses a varying number of needles, depending on the particular number or letter. The needle pattern developed over several years until a specific pattern was obtained that could not easily be altered.
Before the tattoo is applied, the horse is carefully examined for color, markings, cowlicks, chestnuts, and other easily identifiable traits. Once the identity of the horse is ensured, the mucous membrane on the upper lip is exposed using a lip clamp. The area is cleaned with alcohol, and the proper digits are placed in the tattoo gun. The gun is then dipped in an antiseptic and applied to the lip. Finally, ink is rubbed into the perforations.
Lip tattooing was perfected by the Thoroughbred Racing Protective Bureau (TRPB). The Jockey Club uses this method of identification to guarantee the identity of every racing horse at a track that is a member of the Thoroughbred Racing Association (TRA).
A freeze brand uses an unalterable system of angular symbols developed by Dr. Keith Farrell, a veterinary medical officer with the U.S. Department of Agriculture. As with tattooing, the first symbol represents the year the horse was born, followed by the registration number. The brand is most commonly applied to an area approximately 2 inches by 7 inches midway on the neck, underneath the mane.
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The identity of the horse is double-checked before the brand is applied. Copper stamps or marking rods are cooled in liquid nitrogen or dry ice. An area under the mane is shaved and washed with 98 percent alcohol, which aids in conducting the intense cold. The copper stamp is applied to the animal's skin for 10 to 20 seconds. An indentation is left in the skin immediately after the brand is applied. Some swelling may occur in the first few days. However, after 2 months, a distinct and permanent mark remains. The intense cold kills the pigment-producing cells, called melanocytes, leaving an area of pigment-free skin. On dark-colored animals, the hair grows back white (Figure 16-6); on white animals, an area with no hair results.
Freeze branding has many advantages over fire branding. A freeze brand produces minimal changes in the hide, is more distinct and legible, does not produce an open wound, and is relatively painless.
The Arabian Registry uses freeze branding to identify purebred Arabians. An "A" is placed in the first position of the system of marks to indicate "Arabian."
Although markings, tattooing, and freeze branding are effective in differentiating individual horses, blood typing has been developed over recent years and is an equally effective alternative. Serologists test for the 16 most common blood antigens and serum proteins. The combinations seem limitless--as there are some 125 billion possible blood types in horses. Blood typing is used by the Jockey Club, the American Quarter Horse Association, the Arabian Horse Registry, and others.
Radio frequency identification microchip (RFID) technology consists of a sterile microchip, about the size of a grain of rice, implanted under the skin (Figure 16-7). The microchip contains identifying information about the horse, such as a registration number, thus allowing any horse to be quickly identified by a reading device. RFID technology is becoming commonplace. It is used on other animals including pets. Outside the animal industry, businesses use RFID to monitor and track product inventory. RFID technology has benefited hundreds of stolen horses. Slaughterhouses are required by law to check a horse for an RFID chip implanted under its skin. The RFID process is quick and painless.
The veterinarian uses a specially designed needle and syringe to implant the microchip. A local anesthetic is administered about midway down the horse's neck, just below the crest. The chip is then inserted into the ligament in the neck, using the custom syringe. The chip is actually lodged about an inch underneath the skin's surface. It is equipped with a nonmigratory tip to ensure that it stays in place.
The microchip identification cannot be altered. The chip is read by using a handheld scanner, similar to those used in grocery stores. Many slaughterhouses and brand inspectors have scanners for identification in several states.
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The newest technology in identifying horses is DNA testing. DNA is fixed at the moment of fertilization and can be determined from an analysis of blood or tissue samples. The DNA test for horses assigns an individual horse's genetic variation at 10 to 15 different genes of a general type known as microsatellites. Microsatellites are composed of simple repeats of DNA subunits, primarily in chromosomal regions not used as templates for protein synthesis. These genes are chosen as effective for identifying individuals and verifying parentage, not for their value in making horse-breeding decisions.
Each gene has about 5 to 12 recognizable variants, which differ from each other in the length of the repeated sequence. The variants are assigned letter designations using an internationally accepted nomenclature. Taken together for all the genes tested, the marker types define a genetic profile and provide a powerful tool for individual-specific identification and evidence for parentage exclusion.
The first important neonatal task is treatment of the foal's navel with a tincture of iodine solution. The umbilical cord should be allowed to sever naturally, rather than being cut or tied off. The navel stump should be saturated with tincture of iodine immediately after tearing. Treating the navel stump will prevent joint infection or navel ill. This is a bacterial infection usually resulting from poor navel treatment--umbilical infection is its source. It develops in foals less than 30 days of age and is considered a medical emergency. Aggressive therapy is needed to prevent permanent cartilage or bone damage. Symptoms of navel ill include sudden lameness with or without systemic illness, swollen and painful joints, and stiffness. More than one joint may be involved, such as stiffness through the back or neck pain.
The naval stump is an ideal growth environment and entrance for potentially life-threatening bacteria into the newborn's system. Simple iodine treatment quickly and easily minimizes the risks of navel ill and other infections. The treatment should be repeated daily until the navel stump is completely dry. If the navel does not close properly or begins to leak urine, additional treatment and veterinary attention may be needed.
The second task to be attended to is a foal enema to prevent impacted meconium and to stimulate intestinal peristalsis. The meconium is a soft, dark greenish-brown substance consisting of digested amniotic fluid, glandular secretions, mucus, bile, and epithelial cells that accumulates in the digestive tract during development. Natural elimination of the meconium should occur within 3 hours after birth, but retention and constipation may occur anywhere from 6 to 24 hours after birth and after prior fecal passages. The meconium needs to be passed for normal intestinal activity to begin. Foals often have trouble expelling the meconium and have a tendency toward painful constipation if it is not passed soon after birth.
There are two types of meconium retention: in the large colon (high), and in the rectum (low). The signs of meconium retention and constipation are similar: restlessness, tail switching, attempts to defecate, elevated tail, straining, colic pain, rolling, getting up and down often, and lying upside down with knees and forelegs extended toward the head.
An enema is used to treat and prevent meconium retention. The foal's rectum and anus are easily damaged. The enema should be administered with 1 pint of warm, soapy water through a soft, narrow, pliable rubber tube inserted no more than 4 to 5 inches into the rectum. Mixtures of warm water and mineral oil or commercially obtained human enemas can also be used.
Exercise often helps foals pass their meconium. Weather permitting, a foal with signs of impaction should be turned out.
The timing for a mare and foal to be first turned out depends on the climate, time of year of foaling, and weather conditions. Turnout on the first day after birth is fine if the temperature is mild and the ground is not icy or muddy. The pair should not be allowed to become fatigued or overly stressed by temperature extremes or by overheating as a result of exercise or excitement. This can be minimized by frequent turnout of the mare before she foals. Often, only the mare is led to the turnout area and the foal is simply guided behind her. If the foal is led to the turnout area, a rump rope and halter should be used properly, without jerking or pulling, so as not to hurt the foal.
The mare should be released first into the turnout area since she will usually want to run and kick for a moment or two. This prevents the potential disaster of the foal being accidentally in her way. The pair should be turned out alone for the first week or so, and then allowed to join any other mares and foals. Observation is required for the following 10 days, as problems could still occur (Figure 16-8). The mare's udder should be closely watched and the foal's temperature monitored daily. A subnormal, out-of-range temperature indicates an infection and requires immediate attention.
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WEANING AND CASTRATION
After being separated from the mare, the foal usually experiences more contact with human handlers who require certain standards of behavior. Therefore, the foal should be taught to accept basic handling and discipline before weaning. Haltering, brushing, and leading the foal while it is still at the side of the mare will make training easier.
Because weaning can be very stressful, the foal should be in good health before being separated from its dam. The only exception would include weaning to facilitate medical treatment of the foal or mare, as recommended by a veterinarian.
Elective surgery to correct conditions such as umbilical hernias and angular limb deformities should be performed well ahead of weaning. Not only will early treatment aid in more complete correction of some conditions, the stressful period surrounding the weaning process can be avoided.
Time of Weaning
The best age for weaning foals depends on the health of the mare and foal, the temperament and vices of the mare, the environment in which the foal will be weaned, the maturity of the foal at a given age, and the management level on a given farm. If necessary, foals can be weaned as early as a few days after birth, but the usual age for weaning is between 4 and 6 months. A newborn foal relies on the mare for nutrition, protection, and security. A foal weaned at an extremely young age requires intense nutritional and behavioral management. By 4 months of age, the foal should be eating feed and less dependent on its dam for protection and emotional support. Weaning before this age may increase weaning stress, especially if environmental conditions are harsh, the foal is not eating grain, or the foal is heavily dependent on the mare.
Little nutritional or social support is gained by waiting until 6 months of age to wean. In fact, later weaning may promote some unwanted behavior in foals. A breeder may want to separate a mare that has an adverse disposition or vices from her foal as early as possible. Some behavior patterns can be learned from the mare and, with early separation, the dam's behavior will have less influence on the foal's behavior.
The management level of the breeding farm, the condition and temperament of the mare and foal, the facilities available, and the number of foals to be weaned during a given period all affect the method with which foals are weaned. Foals weaned together and those consuming creep feed prior to weaning experience less weaning stress.
Weaning methods range from an abrupt separation in which the foal and mare are separated immediately from all contact, to gradual separation in which the foal and mare are allowed visual, auditory (sound), and olfactory (smell) contact before complete removal. Complete abrupt separation usually involves moving the mare to another turnout area, or moving the foal into a confinement completely separated from any contact with the mare. Advocates of abrupt weaning suggest that mare and foal injury is lessened when contact is completely prohibited.
However, some research indicates that foals weaned by complete, abrupt separation exhibit more behavioral problems associated with weaning stress than foals weaned by a more gradual separation. Gradual methods usually involve placing the mare and foal next to one another in enclosures that allow for visual contact for a period of several days to weeks. Fences or stall partitions used in gradual systems must restrict suckling (Figure 16-9). Again, weaning in pairs and preconditioning the foal to solid feed before weaning will reduce weaning stress.
One of the best ways to lessen weaning stress is to maintain familiar surroundings. This can be done by leaving foals of like size and age together. When other foals are not available, an older, nonlactating, well-dispositioned mare or gelding may be used for companionship. Some farms have successfully used goats for the same purpose. Use of other livestock species or mature horses as weaning companions may be especially beneficial when it is necessary to wean single foals that are very young or unusually nervous. The foal appears to experience far less stress when other elements of the environment are the same and when companionship is available. This limits weight loss, decreases the incidence of disease, and makes the transition to self-sufficiency less traumatic.
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Regardless of the method used, facility construction and design must emphasize safety. Any protrusions such as feed troughs can cause injury to nervous foals. Also, any area that is wider than a foal's hoof has the potential for trapping the foal's leg if it should strike or rear next to a stall wall.
Mare Care during Weaning
A mare usually calms down more quickly than a foal, although the time required for her to resume normal behavior may vary from a few hours to a few days. Just as foals should be weaned in pairs or small groups, newly separated dams may need to be maintained in pairs or small groups. Unless aggressive behavior between mares is evident, such grouping may aid in more rapid calming following separation from their foals.
If the mare still has significant milk production, grain intake should be decreased and exercise increased. If the udder becomes very tight, a small amount of milk may periodically be extracted by hand, but this practice is discouraged unless necessary. If the udder is still tight 4 days after weaning and the mare's temperature rises significantly or if other indications warrant it, the milk should be checked for the presence of mastitis (infection) and appropriate therapy started. A veterinarian's assistance is recommended.
A castrated horse is called a gelding. Geldings are easier to care for and not as prone to injury as stallions, they are easier to haul, and several geldings can be kept safely in a paddock.
Horses can be castrated at any age, but most horses are castrated between birth and 2 years of age. Colts with poor conformation or poor pedigrees are usually castrated as soon as the testicles descend into the scrotum. Testicles usually descend at birth or certainly by the 10th month after birth. If a horse has good conformation and a good pedigree he is generally kept intact until he fails to meet certain performance criteria.
Timing of castration depends on weather conditions and development of the individual animal. Spring, before fly season and hot weather, is the best time for castration. Most often castration is performed by an experienced veterinarian.
When one or both testes fail to descend into the scrotum, the animal is referred to as a cryptorchid or ridgeling. In horses, colts are considered cryptorchid if the testes are not descended by 15 months. These animals are difficult to castrate and since some tissue may continue to produce testosterone, they may retain their stallion attitude.
One of the more fundamental and less glamorous aspects of horse ownership is stall maintenance. A significant part of this is the choice of bedding. Good bedding protects the horse's feet from thrush. It encourages the horse to lie down to rest and cushions its feet and legs from the hard stall floor. The horse needs to have some material under it that will also soak up or drain off the urine and the moisture from the manure. Ordinary stall floors are unable to do these things.
The best bedding material should be absorbent, dust-free, readily available, easily disposed of, unpalatable, and affordable. One of the first things to look for in a bedding is its absorbency. The more absorbent the material, the less of it required, and the less frequently it must be replaced.
Cost is often the major consideration in choosing a bedding. Since many crop wastes can be made into bedding, owners should look around to see what is plentiful in the area. A specific bedding material may not be the most dust-free or the most absorbent, but if it is plentiful and cheap that may be enough to justify overlooking the disadvantages since it may be the most practical choice.
Of the common kinds of bedding, the most popular is straw. Straw makes an attractive bed, and many people are willing to put up with its disadvantages just because they like to see their horses knee-deep in a nice, shiny yellow bed. Straw is the bedding of choice for foaling stalls on many breeding farms, since there is the potential for finer bedding materials, such as shavings, to readily stick to the newborn's body and airways. However, straw is bad for horses that like to eat their bedding. It is also highly combustible.
Heatstroke Heatstroke is not as common today as it was when horses were used to power machines, but it still occurs in horses during the summer months. It can be caused by overexertion on a hot, humid day; by confinement to a poorly ventilated stall on such a day; and by transportation in hot vans. Horses exercised without shade from the sun are also susceptible to heatstroke. Horses that have been idle and are not conditioned to the work or the climate are the most susceptible. A lack of adequate drinking water can predispose a horse to heatstroke. Signs of heatstroke include collapse, a staring expression, vomiting, and diarrhea. The inside of the horse's mouth may be bright red, and the rectal temperature may reach as high as 109.5[degrees]F. Veterinary assistance is required immediately in cases of heatstroke and emergency first aid measures must be started. First aid consists of placing ice packs on the horse's head between the ears and cold cloth packs along its spinal column. If ice packs are not available, cloth sacks saturated with cold water should be directed over the head and down the spinal column. The veterinarian will provide other cooling methods and supportive treatment.
Straw is very absorbent and has a high comfort rating. Straw can be relatively dust-free, if carefully selected. However, other drawbacks include the high labor requirement in cleaning stables, the large volume of resulting material, and the difficulty in disposal.
The best time to buy straw is at harvest time, but facilities are necessary for storage. Straw is best if it is stored indoors.
Two other highly absorbent materials for bedding are wood shavings and sawdust. Horses will seldom eat these materials, and they burn much more slowly than straw. Shavings and sawdust also help keep down odors and require less-frequent cleaning than many other materials.
Black walnut, however, should never be used. Severe laminitis (founder) has resulted in horses where black walnut shavings were used for bedding. Black walnut (Juglans nigra) wood contains a number of aromatic chemical agents, some of which are quite toxic to horses. Eating just a few of the fresh shavings will cause severe gastrointestinal irritation and severe founder.
Softwood shavings such as pine are generally a safe and practical material to use. Pine shavings produce considerably less disposable material than straw and are generally disposed of more easily. Although shavings may be more expensive to use than straw, the additional cost can usually be justified in labor saved. Purchasing a large volume rather than buying it by the bale or bag saves money but a considerable storage area may be necessary. The shavings must be as dust-free as possible. Often, shavings are mixed with sawdust; however, too much sawdust can cause respiratory problems in some horses. The wood-shaving particles should be relatively large.
Sawdust and shavings should be stored indoors. If they are wet, their value as bedding is worthless and they will take a long time to dry.
A good, cheap bedding can be made from cornstalks or ground corncobs if they are readily available. After the corn has been picked, stalks can be chopped into bedding with a flail chopper. The cornstalks should be dry. At times, horses will eat chopped cornstalks. Ground corncobs can also make an absorbent bedding.
Another comparatively new bedding product is recycled newsprint. This product is pollenfree and has less dust than straw and shavings. As a result, horse owners with allergies or contact lenses and horses with respiratory conditions may benefit from its use.
Newsprint weighs less than that of an equal volume of other bedding products. Weekly stripping of stalls with newsprint bedding may not be necessary if the stalls are thoroughly picked daily and existing bedding is fluffed to keep it dry longer. Newsprint is very absorbent, softer, and more comfortable than either shavings or straw.
While good ventilation is obviously a part of stable management, proper ventilation can also lower the humidity, keeping most bedding drier and extending its effectiveness. Basically, the choice of bedding material should be determined by:
* Availability and price
* Absorptive capacity
* Ease of handling
* Ease of cleanup and disposal
* Nonirritability from dust or components causing allergies
* Texture and size
* Fertility value of the resulting manure
Table 16-1 compares the absorbency of various bedding materials.
A sound sanitation program is of paramount importance to fly control. All other types of control are doomed to failure without this important first step. Control of stable flies in barnyards, stables, or corral areas usually involves several methods, which also apply for the housefly (Figure 16-10). Chemical control directed at larval and adult stages of both insects is usually required periodically during the fly season.
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Sanitation around Stable or Corral
The basic aim of a sanitation program is to reduce or eliminate fly larval development sites. Several areas require attention because the larvae of these flies can develop in varied habitats. Manure management is essential. Timely spreading of manure promotes drying and prevents larvae from developing. In small areas manure provides an ideal breeding site for large numbers of both stable flies and houseflies. Wet areas where manure, mud, and plant debris accumulate also form ideal breeding habitats. Modifications to the drainage around corrals to reduce excess moisture can eliminate fly production sites and make chemical control efforts much more successful.
Various chemical control techniques are available to the horse owner. Generally, control of adult flies using insecticides on surfaces and as sprays to kill existing adult flies are the most effective techniques. In most barnyards a combination of surface treatment and aerosol sprays is used, often on an alternating schedule. Treatments applied directly to horses are not as effective for control of stable flies or houseflies as are residual surface treatments. In practice, both techniques usually are needed.
Applications of residual insecticides to premises are frequently used to control houseflies and stable flies. Longer-lasting residual insecticides provide control for an extended period when sprayed onto sites where adult flies congregate. Flies contact the insecticide when they land on the treated surfaces. Sides of buildings, inside and outside surfaces of stalls, and fences may be potential day or night resting sites for these flies. Observation of the barnyard situation will quickly indicate the favored resting sites for flies.
Knockdown sprays are effective for killing adult flies present at the time of application. The chemicals used for these applications are usually short-residual insecticides that have a quick knockdown and high-contact toxicity. Several types of spray or fogging apparatus may be used. Wind velocities should be low at the time of application, and the droplet or particle size should be small (50 to 75 microns) to ensure drift through the corral area. This method requires less application time, but the disadvantage is that it kills only those flies present at the time of application and thus provides only short-term relief.
Direct applications of sprays and dusts to animals may be used in some situations to protect them. Materials used for direct animal application usually have short-residual activity, and this type of application is labor intensive.
Other methods of fly control, such as baits, electric grids, and traps, have some limited use for housefly control but are ineffective for the blood-feeding stable fly. Baits may be used effectively for housefly control in enclosed areas. Fly papers, cords, and strips may also help alleviate fly problems in these areas. Such methods are usually ineffective in open areas.
Control of immature flies (larvae) is sometimes possible. Usually, the best approach is to remove the potential source of fly production with sanitation practices. When this is not possible, a larvicide can kill the developing flies. A larvicidal insecticide may be applied directly to places where eggs are laid and larvae develop.
Biological control has potential for controlling barnyard fly problems. A number of parasites and predators of both houseflies and stable flies exist that help to reduce fly numbers. Some of these natural parasites are available commercially; but to date, research has not demonstrated their cost-effectiveness.
Management efforts are needed to control horseflies and deerflies, blackflies, gnats, horn flies, and general nuisance flies like houseflies. The following information briefly describes these flies, their life cycles, habits, and control.
Horseflies and Deerflies
Horseflies and deerflies are large, biting flies that can inflict painful bites on horses and humans. Several species may become abundant enough to constitute a problem for grazing horses, particularly animals pastured near streams or low, wet areas. Both types of flies have been incriminated in the transmission of equine infectious anemia. Further, because the bite is painful, horses may become restless and unmanageable when trying to ward off attacks by these flies. Immature larval horse flies are aquatic or semiaquatic, and the last-stage larva overwinters. Life cycles are long. Most species have only one generation per year, and some species may have a 2-year life cycle. Only female flies feed on blood. Control is difficult. Treating individual animals with repellents or insecticidal sprays may reduce fly bites.
Blackflies or buffalo gnats are small (1/2 to 1/15 inch long), humpbacked, biting flies that may reach high populations in the spring and early summer, particularly in pasture areas along streams. The immature stages are found in flowing water. Pupation occurs under water, and the adults float to the surface--ready for flight, feeding, and mating. Adult flies feeding on horses and other animals can pose serious animal health problems, and the irritation caused by blackfly bites can make horses unmanageable. Anemia, as a consequence of blackfly population, is high. Bites may also cause severe reactions such as toxemia and anaphylactic shock, which can result in death. Control is difficult. Species that feed in the ears of horses can be controlled by applying insecticides or petroleum jelly inside the horses' ears. When possible, horses can be stabled during the day and pastured at night. Blackflies feed only during daylight hours and usually do not enter stable areas. Area sprays or general topical applications of insecticides are not very effective.
"No-see-ums," "punkies," or biting midges are a serious pest of horses. Blood loss and irritation associated with the feeding of these very small (usually less than 0.04 inch), blood-feeding flies can be significant. The immature stages of these flies complete development in water in a variety of locations, from tree holes or manufactured containers to lakes and streams. Adults often are unnoticed because of their size and because they are active at night, late evening, or early morning. Direct treatment of horses with wipes or sprays containing insecticides or repellents can provide them relief.
The horn fly is normally a pest of grazing cattle. However, when cattle and horses are pastured together, this fly will feed on horses. Horn flies are about half the size of stable flies and, like stable flies, are biting flies. The horn fly usually remains on the host animal almost continually, both day and night. Females lay eggs on fresh cattle droppings. Sprays or wipes can be used successfully on horses.
Several types of nuisance flies may be associated with horses or their premises. These include the housefly, bottle flies, false stable flies, and other species of barnyard flies. Face flies, usually a pest of cattle, may also affect horses, particularly when cattle are nearby.
Two major pest species that bother horses are the stable fly and the housefly, a nonbiting species. A distinguishing feature, visible to the naked eye, separating the two species is the distinct stiletto-like proboscis of the stable fly that extends forward beyond the head. This sharply pointed beak is used to pierce the skin and draw blood. The housefly cannot bite because it has sponging mouthparts.
Housefly. Both male and female houseflies are grayish-brown with a black- and greystriped thorax. The housefly is a medium-sized fly ranging from about 1/4 to 1/3 inch long with sponging mouthparts. Houseflies do not bite but feed on a variety of plant and animal wastes and garbage, as well as other sources of carbohydrates and proteins (Figure 16-11).
[FIGURE 16-11 OMITTED]
Housefly eggs are about 0.04 inch long, whitish, and slightly curved. The females generally deposit eggs in batches of about 100 eggs at a time. Each female may deposit four to six batches of eggs during an average lifetime of 2 to 4 weeks during the summer.
The three larval stages are similar in appearance to stable fly larvae. The third stage reaches approximately 1/2 to 2/3 inch in length. Differentiation of the two species is based on the size and shape of the posterior spiracles (or respiratory tract openings).
Housefly pupae are barrel-shaped. They are of the same approximate size and coloration as stable fly pupae.
Housefly females lay their eggs in clusters, preferably in moist, decaying organic material. Eggs hatch within 8 to 40 hours, depending on temperature. Larvae feed on yeast, bacteria, and decomposition products in their development site. Larval development through three stages takes from 3 to 8 days. Larvae crawl to drier areas to pupate when feeding is completed. The pupal stage lasts from 3 to 10 days, depending primarily on temperature. Adults emerge from the puparia and begin feeding within 24 hours. Males are ready to mate shortly after emergence, and females begin mating by the 2nd or 3rd day. Most females mate once and deposit eggs in batches every 2 to 4 days.
The flies feed on carbohydrates and proteins. Females require protein to produce viable eggs. Solid foods are first liquified with saliva and are then ingested using the sponging mouthparts.
The entire life cycle from egg to adult can be completed in as little as 10 to 14 days during warm weather. Like the stable fly, houseflies overwinter in sites, such as silage or manure piles, where microbial fermentation heats the larval habitat. Houseflies may develop throughout the year in heated livestock facilities. They are active near sources of food during daylight hours and generally rest at night on stationary objects both indoors and out. The flies prefer shaded areas during much of the day and commonly move inside structures where livestock are held.
Housefly management, like stable fly management, is based on a strong farm sanitation program. The methods for reducing houseflies are the same as those discussed for the stable fly.
Face Fly. The face fly is usually a pest of grazing cattle. However, when horses are pastured with or close to cattle or when face flies are numerous, these flies will feed on secretions around the eyes of horses. Adult face flies look much like houseflies. The face fly does not bite, but the persistent feeding behavior of the fly makes it a nuisance pest. In addition, the face fly can mechanically transmit parasites or pathogens to the horse. Control of face flies is difficult. Relief can be obtained by stabling horses during the daytime when the face fly feeds. Also, since the face fly feeds predominantly on cattle, pasturing horses separately from cattle will lessen the incidence of these flies on horses. Topical insecticide applications are usually not effective, because face flies spend little time on the vertebrate host.
MANAGEMENT OF PASTURES
Horses do best when they are allowed to graze, so maintaining good pastures is an important management priority. Sound management is essential to keep the desired grass species persistent and productive. Pastures can be improved by using lime and fertilizer or by reseeding. The following are management tips for pastures.
Avoid over- or undergrazing. Horses are notorious spot grazers. They will seriously damage desired species in some areas unless they are moved into new pastures frequently. Some form of rotational grazing is desirable. The correct acreage per horse changes with the season as well as with other factors. However, a good rule is to provide at least one acre of good-quality pasture per horse. Five or six paddocks should be set up and horses permitted to graze first in one area for about a week and then changed to another. This system helps to keep the legumes and grasses growing better and increases the feed available per acre. Rotating horses from pasture to pasture also breaks the life cycle of some parasites (Figure 16-12).
Clip pastures regularly during the growing season. Clipping to a height of 2 to 3 inches after horses are moved to a new paddock helps to control weeds, prevent grasses from heading, and in general keeps the pasture in a more desirable condition.
Drag pastures with a chain-link harrow at least once per year. Dragging helps to spread manure droppings, which reduces parasite populations by exposing them to air and sunlight. Dragging also helps to smooth over areas dug up by horses' hoofs on wet soil.
[FIGURE 16-12 OMITTED]
Apply fertilizer as needed. Improved horse pastures must be fertilized annually if legumes and grasses are to survive and remain productive. The fertilizer to use depends on the grass species present. A complete soil test every 2 or 3 years is the best guide.
Pastures with good stands of desirable grass and legume species need proper soil fertility combined with good management to assure continuing good horse pasture. Most permanent bluegrass pastures produce less than 2,000 pounds of dry matter per acre per year, which is far below their potential. Yields on many pastures can be doubled simply by applying lime and fertilizer. Liming and top-dressing Kentucky bluegrass pastures with phosphate, potash, and nitrogen costs much less and is less work than complete pasture renovation.
However, sometimes lime and fertilizer are not enough to restore a pasture, and complete renovation is necessary. When renovating an old pasture, the following points should be considered:
1. Perform a soil test to determine lime and fertilizer requirements. This is the only sure way of knowing how much lime and fertilizer are needed.
2. Apply required lime several months before doing the actual seeding. Disking or plowing will help to mix the lime evenly throughout the soil.
3. Select a seed mixture that complements the pasture drainage characteristics.
4. Destroy or suppress the old pasture by plowing or using herbicides.
5. Use the appropriate method of seeding based on extent of tillage.
6. Protect the seeded area until the new plants are well established. Where recommended mixtures are seeded without a companion crop and weeds are controlled, new seedings can become established in a single year.
In heavy-traffic areas, along fences and around gates and water troughs, tall fescue may be used. Fescue is generally considered less palatable than bluegrass, but tall fescue produces one of the toughest heavy-traffic sods of any adapted grass. Older stands of fescue often are infested with an endophyte (within the plant) fungus. Toxins associated with this fungus can cause lowered reproductive rates, abortion, agalactia (lack of milk), and prolonged gestation with mares. Thus, whenever establishing new fescue stands for horses, endophyte-free tall fescue seed should be used. Broodmares should be removed from pastures containing endophyteinfested tall fescue at least 90 days prior to foaling.
Managing Health Concerns of Forages
Horses are extremely susceptible to molds, fungi, and other sources of toxic substances in forage. Mold problems generally occur in hay that has been baled at too high a moisture level (20 percent or more) without the use of a preservative. This is especially a problem with firstcutting hay because it is harvested during a period of time when it rains frequently and the weather conditions are less than ideal for hay drying.
Horses should always be fed clean, unmoldy forages. In addition to molds and fungi, some forage species contain chemical compounds that can have negative health effects on horses.
Sudangrass and sorghum-sudangrass hybrids contain compounds that can cause muscle weakness, urinary problems, and death in severe cases. Do not feed these grasses to horses!
Older varieties of tall fescue contain an endophyte fungus that could cause severe health problems if horses have only tall fescue to eat during the summer months. Newer tall fescue varieties that are free of the endophyte fungus are now available.
Another health problem occurs when horses are fed hay that contains blister beetles. When consumed, the beetle causes irritation to the lining of the digestive tract that usually results in death. The danger of blister beetles is discussed in Chapter 14. Alfalfa hay produced in southern areas of the United States is most generally associated with blister beetle contamination. Do not feed any hay containing blister beetles to horses.
Poisonous plants in pastures or hay can also be fatal to horses. Ornamental shrubs and nightshade are common poisonous plants. Any plant poisonous to other animals is probably poisonous to horses. Some are highly palatable and should be identified and removed from pastures, but many poisonous plants are not palatable and horses will not eat them unless the forage is inadequate to meet their needs. A list of common poisonous plants is found in Table 14-4 in Chapter 14.
A wound is a disruption in the integrity of living tissue caused by physical means. Managing wounds requires recognizing the types and characteristics of wounds and the associated symptoms in the horse. Characteristics of a wound include:
1. The horse's temperature is usually normal, but will be elevated when infection is present and below normal if the horse is going into shock.
2. Pulse is often normal even with severe wounds, but may be increased if blood loss is excessive.
3. Mucous membrane color will range from normal to pale in cases of excessive blood loss.
4. Capillary refill time will be normal except in the case of blood loss and shock, when it may be over 2 seconds.
Wounds can be classified as clean wounds, contaminated wounds, and infected wounds; or they can be characterized as open or closed wounds.
1. A clean wound is a sterile or noncontaminated wound less than 6 hours old. After this time, the wound may or may not become infected.
2. A contaminated wound is less than 6 to 8 hours old and, despite the presence of bacteria, the wound is not infected.
3. An infected wound is usually more than 6 to 8 hours old, during which time bacterial activity has infected the wound. The result is pus and dead tissue, and there may be septicemia (the presence of bacteria or their toxins in the blood).
Open wounds include incisions, lacerations, abrasions, punctures, perforations, and penetrating.
Closed wounds include contusions, hematomas, seromas, abscesses, or traumatic hernias. Veterinarians need to examine, or at least discuss, a wound on an emergency basis during the first 6 to 8 hours after an injury occurs. Suture repair has the best chance for healing if performed within this time period. Once this time has elapsed, wounds that are sutured invariably break down and, for that reason, older wounds are often left to heal by granulation after they have been cleaned, rather than sutured.
Tetanus toxoid booster should be given if the horse has not had one within 6 months. If the vaccination status of the horse is unknown or uncertain, both tetanus toxoid and tetanus antitoxin should be administered.
A well-equipped first aid kit (see page 292) can be useful in coping with wounds.
Good management is knowledge in action. Good managers learn to recognize horses under stress and, where possible, take action to alleviate stress. Stress can be caused by mechanical injury, poor nutrition, and disease. Horses indicate stress through behavioral changes.
Positive identification of horses is practiced by a good manager. Horses can be identified by body markings, tattoos, freeze brands, blood typing, and microchips. Positive identification prevents theft, fraud, and is necessary for insurance.
Two of the most critical times in the life of a horse are the neonatal and weaning periods. Good management practices here ensure a healthy foal for training and a healthy mare for future foals.
Proper selection of bedding is necessary for stall maintenance. Selection of bedding depends primarily on availability, price, and absorptive capacity.
All good managers will have a sound sanitation program for fly control. This program can also include various chemical methods. An understanding of the types of flies, their life cycles, and their habitats is a necessary part of control.
When possible, horses should be pastured. Sound management keeps pastures productive and improves poor pastures through renovation.
Horses sometimes receive a wound. Wound management requires that the owner recognize the characteristics of the various types of wounds.
Success in any career requires knowledge. Test your knowledge of this chapter by answering these questions or solving these problems.
True or False
1. The Jockey Club was the first organization to set up an accurate identification system for horses.
2. A clean wound is one that has been cleaned properly.
3. A foal's navel cord should be allowed to sever naturally.
4. A foal should be taught to accept basic discipline and handling at weaning time.
5. Horses have only binocular vision.
6. Social order is important in a herd of horses.
7. List the four categories of stress for a horse.
8. List the 10 types of information every horse owner should keep on file for each horse.
9. What are the three metabolic problems closely associated with nutrition in a horse?
10. Identify four characteristics of a wound.
11. List the five factors that determine the best time for weaning a foal.
12. Name the two substances that could be added to a pasture to double its yield.
13. What is the most popular type of bedding material?
14. What are the reasons for marking or identifying a horse?
15. Why is bedding for a horse important, and what are the factors that determine the type of bedding used?
16. Discuss three management practices for pastures.
17. Discuss a fly control program.
18. Why would an enema be used on a foal?
19. Indicate the differences among a relaxed horse, an angry horse, and an interested horse.
20. What is the best method for permanently identifying a horse?
1. Using Table 16-1, collect some bedding materials and develop a demonstration to show the water-absorbing ability of each material.
2. Draw a diagram that explains monocular and binocular vision. What type of vision do humans have?
3. Observe behavior of horses within a herd. Record your observations in a written log and with a video camera.
4. Research the tying-up syndrome. Use the Internet or other resources to develop a report or presentation that gives the recent physiological explanations for the condition.
5. Draw diagrams of the different types of wounds.
6. Visit several horse pastures and describe their conditions. Identify management practices that are being practiced or those that are missing. Collect, press, mount, and label plant samples from the pastures.
7. Make a set of flash cards to teach someone how to identify the common body markings of horses.
8. Make an insect collection of the flies found around horses. Using an insect key, label the flies with their common and scientific names.
American Youth Horse Council. (2004). Horse industry handbook: A guide to equine care and management. Lexington, KY: Author.
Bishop, R. (2005). The horse nutrition bible: The comprehensive guide to the correct feeding of your horse. Newton Abbot, Devon, England: David and Charles Publishers.
Davidson, B., & Foster, C. (1994). The complete book of the horse. New York: Barnes & Noble Books.
Evans, J. W. (1989). Horses: A guide to selection, care, and enjoyment (2nd ed.). New York: Freeman.
Hill, C. (2005 2nd ed.). Horsekeeping on a small acreage. Pownal, VT: Storey Publications LLC.
University of Missouri-Columbia Extension Division. (n.d.) Missouri horse care and guide book. Columbia: Cooperative Extension Service, University of Missouri and Lincoln University.
Internet sites represent a vast resource of information, but remember that the URLs (uniform resource locator) for World Wide Web sites can change without notice. Using one of the search engines on the Internet such as Yahoo!, Google, or About.com, find more information by searching for these words or phrases:
castration of horses
fly control for horses
horse blood typing
horse body markings
horse freeze branding
nutrition in horses
stress in horses
weaning of foals
Table A-18 in the appendix also provides a listing of some useful Internet sites that can serve as a starting point for further exploration.
TABLE 16-1 Bedding Materials and Amounts Needed Pounds of Water/ Material 100 Pounds Dry Matter Wood Products Hardwood chips 150 Hardwood sawdust 150 Hardwood shavings 150 Pinewood chips 300 Pinewood sawdust 250 Pinewood shavings 200 Processed wood pellets 400 Straw Barley 210 Oat, long 280 Oat, chopped 375 Wheat, long 220 Wheat, chopped 295 Other Cornstalks, dried 250 Corncobs 210 Hay, chopped 200 Peat moss 1,000 Shredded newspaper 400
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|Publication:||Equine Science, 3rd ed.|
|Date:||Jan 1, 2008|
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