Environmental Effect on Hoof Wall Hydration Studied

Thehorse.com - Full Article

by: Casie Bazay, BS, NBCAAM
September 08 2012, Article # 20607

A recent two-part Australian study investigated hoof moisture levels in horses exposed to wet versus dry environments, as well as the the impact of soaking a hoof on moisture absorption.

Brian Hampson, PhD, member of the Australian Brumby Research Unit at the University of Queensland and lead author of the study, relayed, "The moisture content (of the hoof) is controlled by the internal circulation, which is fairly constant in the healthy horse."

Hampson and colleagues collected hoof wall samples from routine feral horse-culling operations in New Zealand and Australia. They measured the hoof wall moisture content in hooves from wet, semi-arid, and arid environments. Moisture content was nearly identical in hooves from all three environments, averaging 29.5%. .

For the second part of the study, the team aimed to evaluate the common practice of soaking a horse's hoof. Using six domestic horses, they placed each horse's right forefoot in a dry rubber boot and left forefoot in a rubber boot filled with water for two hours. Directly after, they trimmed the hoof walls of both forefeet with nippers and removed a small section of hoof wall horn and sole horn with a hoof knife and evaluated the moisture content of both...

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http://www.thehorse.com/ViewArticle.aspx?ID=20607

Starch Digestion in Horse Diets

Thehorse.com - Full Article

by: Kristen M. Janicki, MS, PAS
September 02 2012, Article # 20576

Starch is a highly digestible energy form and can provide energy needed for exercise, growth, metabolism, and other equine life functions. However, when fed improperly, this nonstructural carbohydrate can be detrimental to your horse's health.

Most of the energy contained in grains, such as corn and oats, and a percentage of the energy from forage is starch. During digestion, starch is broken down primarily in the horse's small intestine by an enzyme called amylase. This process efficiently produces glucose, a type of simple sugar essential for fueling some bodily functions.

The amount of starch consumed at one time also affects the amount of starch digested in the small intestine. If starch is not digested in the small intestine (which occurs when large amounts of starches are fed at once), it passes through the digestive tract and is fermented in the large intestine. This fermentation process, while less efficient than digestion in the small intestine, also produces energy to keep the horse's body functioning...

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http://www.thehorse.com/ViewArticle.aspx?ID=20576

Creepy Crawlies, Part 1: Mighty Mosquitoes

Thehorse.com - Full Article

by: Stacey Oke, DVM, MSc
June 01 2012, Article # 20322

They might be small, but these flying fiends can spread some deadly diseases
The original intent of this article was to relay how malicious and deadly some mosquitoes are, but according to Charles Calisher, PhD, professor of microbiology, immunology, and pathology at Colorado State University, mosquitoes are neither spiteful nor a menace to society. "Mosquitoes are not deadly," he explains. "It is the viruses and microbes they transmit that are deadly."

So although mosquitoes do not willfully harm horses (aside from getting a snack), it is still important for owners to minimize contact between mosquitoes' mouthparts and their horses.

"Mosquitoes transmit some of the deadliest and most debilitating diseases in the world, including malaria, dengue fever, and lymphatic filariasis," says Nicholas Ledesma, a DVM/PhD candidate in the field of Comparative Biomedical Sciences at Cornell University. "In addition to the human mortality and decreased quality of life they cause, mosquito-borne diseases (arboviruses) such as Eastern equine encephalitis afflict both domestic and wild animal populations."

In this article we will describe how mosquitoes transmit viral infections, identify the most important viral infections horses can acquire from these annoying arthropods, and describe methods for protecting horses from infection through vaccination and control ¬measures.

How Mosquitoes Spread Disease

Many consider mosquitoes to be one of the world’s most annoying creatures. They have six long, spindly legs, scaly wings and bodies, antennae, and the pièce de résistance: long, needlelike mouthparts able to pierce both human and animal skin...

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http://www.thehorse.com/ViewArticle.aspx?ID=20322

West Nile virus: Still a threat

Learn how you can help prevent it
 
West Nile virus (WNV) remains a threat to horses. However, with the right vaccine and preventive measures, it’s not too late for horse owners to help protect their horses against this life-threatening disease.
 
West Nile encephalomyelitis is an inflammation of the central nervous system that is caused by an infection with WNV.It is transmitted by mosquitoes — which feed on infected birds or other animals — to horses, humans and other mammals. So far in 2012, 31 states have reported 157 cases of WNV in horses, with Louisiana and Texas having the most confirmed cases — 26 and 16, respectively.
 
The number of reported WNV cases fell from 1,069 in 2006 to 146 in 2010, and the decline is said by health experts to reflect both vaccination and naturally acquired immunity.
 
“It is a good sign that the number of cases has declined over the last decade, however there has been an increasing number of both human and equine cases, especially over the last couple months,” said Tom Lenz, DVM, MS, senior director, equine technical services, Pfizer Animal Health.
 
Vaccination remains the most effective way to help protect horses against West Nile and other encephalic or mosquito-borne diseases, such as Eastern equine encephalomyelitis and Western equine encephalomyelitis. A trusted vaccine is available to help offer demonstrated protection against WNV and, Eastern and Western equine encephalomyelitis and tetanus — WEST NILE-INNOVATOR® + EWT — all in a single vaccine. According to the American Association of Equine Practitioners guidelines, WNV is considered a core vaccination, along with Eastern equine encephalomyelitis, Western equine encephalomyelitis, tetanus and rabies.
 
In conjunction with vaccination, use good techniques for managing mosquitoes. This includes:
·       Destroying any mosquito breeding habitats by removing all potential sources of stagnant water.
·       Cleaning and emptying any water-holding container, such as water buckets, water troughs and plastic containers, on a weekly basis.
Remember that WNV does not always lead to signs of illness. Horses that do become clinically ill, the virus infects the central nervous system and may cause symptoms such as loss of appetite and depression. Other clinical signs may include fever, weakness or paralysis of hind limbs, impaired vision, ataxia, aimless wandering, walking in circles, hyper-excitability or coma.5 Horse owners should contact a veterinarian immediately if they notice signs or symptoms of WNV infection in their horses, especially if they are exhibiting neurological signs. The case fatality rate for horses exhibiting clinical signs of WNV infection is approximately 33%.
 
No matter the location, horses can be at risk. By providing proper vaccination and helping to manage mosquito populations, horse owners can do their part to help prevent WNV infections.  
 
For more information on the WEST NILE-INNOVATOR line of vaccines contact your Pfizer Animal Health representative, visit https://animalhealth.pfizer.com/sites/pahweb/us/en/products/Pages/West_Nile_Innovator.aspx or call 855-4AH-PFIZER(855-424-7349).
 
About Pfizer Animal Health
Pfizer Animal Health, a business unit of Pfizer Inc., is a global leader in the discovery, development and manufacture of animal vaccines, medicines, diagnostic products and genetic tests. We work to assure a safe, sustainable global food supply from healthy beef and dairy cattle, swine, poultry, sheep and fish while helping dogs, cats and horses live healthier longer lives.  We strive to be the animal health company that provides full healthcare solutions to veterinarians, livestock producers, and pet owners. To learn more, visit https://animalhealth.pfizer.com.

Oats: A Popular Ingredient in Horse Feeds

KER.equinews.com - Full Article

By Kentucky Equine Research Staff · July 10, 2012

Because the average oat grain is about 30% hull (fiber), and oats contain sufficient protein, calcium, and phosphorus to meet the requirements of mature horses, oats have traditionally been the predominant grain used by horsemen. Horses digest oats easily in comparison with heavier whole grains like wheat and corn.

Around the middle of the last century, more oats were grown in the U.S. than at present. The decline has been mainly due to poor yields. Genetic modification to improve yields has not been as successful in oats compared to gains in other crops. In spite of poor yields, the quality of oats cannot be denied.

Oat hulls are relatively low in energy and nutritive value. The majority of the protein is found in the groat...

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http://ker.equinews.com/article/oats-popular-ingredient-horse-feeds

Fighting White Line Disease

Thehorse.com - Full Article

by: Christy M. West
April 30 2007, Article # 9253

White line disease sneaks up on you without warning--one day your horse is fine, and the next day the farrier is digging a crater in your horse's foot, dumping what seems like handfuls of soft, crumbly hoof horn on the floor. You might ask, what the heck is white line disease? Why is it such a big deal? Your horse isn't even lame, although you fear he might be soon with that new crater in his foot.

This ugly mess called white line disease might not be a big deal initially, but left untreated it can undermine large amounts of your horse's foot (or feet), resulting in lameness and instability of the coffin bone within the horse's foot. Bill Baker, DVM, of Equine Associates in Hawkinsville, Ga., discussed the disease and its treatment at the recent Bluegrass Laminitis Symposium, held Jan. 25-28 in Louisville, Ky.

"White line disease doesn't seem to occur without some sort of mechanical stress (such as long toes or hoof damage from previous disease or injury)," he began. "The only known certainty (about its cause) is that a breach in the hoof wall has to occur for the disease to occur. (Opportunistic bacteria and/or fungi then invade the defect and begin destroying hoof wall from the inside, starting at the bottom and working their way up.) There is no breed, age, or sex predisposition to this disease. It occurs in anything from Minis to drafts, donkeys, and mules. It may invade one foot or all four feet...

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http://www.thehorse.com/ViewArticle.aspx?ID=9253

Be Alert for Early Signs of Fatigue in Endurance Horses

Equinews.com - Full Article

By Kentucky Equine Research Staff · August 29, 2012

A study of fatigue in long-distance endurance horses might offer some helpful insights for trail riders who ride for shorter distances.

In a study conducted by the University of California-Davis, researchers analyzed almost 3,500 records of horses competing in endurance rides. These rides were sanctioned by the American Endurance Ride Conference and all horses were required to have veterinary checks every 10 to 20 miles throughout each race, which ranged in distance from 25 to 100 miles. Horses were eliminated from the competition if they were found to be lame or showed signs of significant fatigue.

For the horses whose records were examined, 19% were eliminated for some reason before completing the race. About 47% of eliminations were because of lameness. The next most common reason for elimination was a metabolic cause such as delayed capillary refill or slow cardiac recovery at a vet check...

Read more here:
http://www.equinews.com/article/be-alert-early-signs-fatigue-endurance-horses

The Best Time to Feed Before Competition

By Joe Pagan, Ph.D.
 
One of the most common questions asked about feeding the performance horse is when to feed before a competition. Theoretically, feeding should be timed so that all of the nutrients from a meal have been digested, absorbed, and stored before starting exercise, but not so long before exercise that the horse begins to mobilize fuels just to maintain its resting body functions.
 
It is probably better to exercise horses eight hours after feeding rather than fasting them overnight, since an overnight fast may disrupt digestive function and may lead to gastric ulceration.
 
To test this hypothesis, Kentucky Equine Research (KER) conducted an exercise experiment. Six trained Thoroughbreds performed a standardized exercise test (SET) at three different times after eating a grain-based meal. The exercise was performed eight hours after eating, three hours after eating, or after an overnight fast. This SET, carried out on the high-speed treadmill, consisted of a two-minute warm-up walk, one-half-mile trot, one-half-mile slow gallop, one-mile fast gallop (25 miles per hour), and a warm-down trot and walk. Heart rate was monitored throughout exercise and blood samples were taken before feeding, hourly until the beginning of the SET, throughout exercise, and 15 and 30 minutes post exercise. Blood was analyzed for glucose, insulin, and lactate.
 
Heart rate was higher at the slow gallop and during the warm-down trot when the horses were exercised three hours after feeding. Insulin was significantly higher in the three-hour-fed horses at the beginning and throughout exercise. Blood glucose was also higher after the three-hour feeding at the beginning of exercise. During exercise, however, blood glucose dropped in the horses exercised three hours after eating while it increased in the horses fasted overnight or fed eight hours before work. Lactate increased with exercise, but was unaffected by time of feeding.
 
The large drop in blood glucose experienced by the horses worked three hours after feeding is not desirable. Basically, the horse has three sources of energy to fuel muscle contraction during exercise. It can use fat, either from the diet or from body stores; it can use muscle glycogen; or it can use blood glucose. Fat stores are plentiful and are good sources of energy during slow work. As exercise intensity increases, faster fuel is needed and glucose is oxidized. If this glucose originates from muscle glycogen, stores are fairly plentiful and depletion is unlikely at distances shorter than endurance rides.
 
Blood glucose is the most limited fuel available to the horse. Blood glucose is maintained primarily from mobilization of liver glycogen and these stores are small compared to the amount of glycogen stored in the muscle. If blood glucose is used extensively by the muscle, then blood glucose will fall and this may lead to central nervous system fatigue since glucose is the primary fuel used by the nervous system.
 
The horses exercised three hours after feeding experienced a large drop in blood glucose because insulin was elevated at the onset of exercise. This caused an increased uptake of glucose by the working muscle. The horses exercised after an overnight fast or eight hours post feeding began work with resting levels of both glucose and insulin. During exercise, blood glucose actually increased, indicating that the horses were mobilizing liver glycogen at a faster rate than the glucose was being cleared from the blood.
 
Time of feeding had no effect on lactic acid accumulation during exercise, suggesting that time of feeding only affected how fuels were used for aerobic exercise. Anaerobic energy generation was unaffected. This means that during extremely intense exercise of short duration such as a Thoroughbred race, time of feeding is not nearly as important as when the horse is performing strenuous exercise of longer duration such as the cross-country phase of a three-day event. All of the parameters measured responded nearly the same whether the horses were fed eight hours before work or fasted overnight. It is probably better to exercise horses eight hours after feeding rather than fasting them overnight, since an overnight fast may disrupt digestive function and there is evidence that fasting horses may lead to gastric ulcers.
 
Kentucky Equine Research is an international equine nutrition, research, and consultation company serving both the horse owner and the feed industry. For more information, visit ker.com or visit our online library of nutrition and health articles at Equinews.com.