Update From The State Veterinarian: EHV-1

Horses at a boarding facility in central North Carolina have been confirmed to have the neurologic form of EHV-1. This facility has had little movement of horses on or off the farm. Our veterinarians are working closely with the practicing veterinarian and the farm owner. The premises has been quarantined and strict biosecurity measures have been in place since Dec. 23. All animals are having temperatures monitored twice a day, and no horses have had fevers or other clinical signs since Friday, Dec. 27, 2013, the first day there were confirmed lab results from the National Veterinary Services Laboratory. The quarantine will be held for 28 days after the last fever is recorded.

Additional investigation found that five horses were moved from the stable in the last four weeks and have been tracked to four locations in North Carolina where their health status is being monitored. All known exposed horses have been accounted for, are not showing clinical signs and have not been moved. No additional horses have been moved from any of the known sites.

At this point, we believe this is an isolated incident with low-risk to other horses. However, we do encourage horse owners to practice good biosecurity measures as a precaution. EHV-1 is not a reportable disease to the Office of the State Veterinarian under state law, however the office appreciates being made aware of suspicious cases and will offer help in controlling the disease. The last known case in North Carolina was in January 2012.

What is EHV-1?

EHV-1 (equine herpesvirus-1) is one of a large group of DNA viruses causing potentially serious disease in horses and other species. EHV-1 has two forms: one that causes abortion in mares and one that causes respiratory infection and neurological symptoms. The above cited outbreaks have involved the EHV-1 respiratory/neurological form of the virus causing a condition known as Equine Herpes Myeloencephalopathy (EHM).EHV-1 is contagious and is spread by direct horse-to-horse contact, by contaminated hands, equipment and tack, and, for a short time, through aerosolization of the virus within the environment of the stall and stable.

What are the Clinical Signs of EHV-1?

The initial clinical signs of the infection may be nonspecific and include fever of 102°F or greater. Fever may be the only abnormality observed. Other presenting signs may be combinations of fever and respiratory symptoms of nasal discharge and cough. Some horses have reddish mucous membranes. Horses with neurological disease caused by EHV-1 infection can soon become uncoordinated and weak and have trouble standing. Difficulty urinating and defecating may also occur. Often the rear limbs are more severely affected than the front. Signs of brain dysfunction may occur as well, including extreme lethargy and a coma-like state. The incubation period of EHV-1 infection is HIGHLY VARIABLE, depending on the host, on the virulence of the virus, and on environmental and other factors such as stress. The AVERAGE incubation period is 4 to 7 days, with the majority of cases being 3 to 8 days, but with some taking up to 14 days. When neurological disease occurs, it is typically 8 to 12 days after the primary infection involving fever. In most cases, horses exposed to EHV-1 will develop a fever and possibly nasal discharge and then go on to recover.

University of California, Davis, School of Veterinary Medicine

Submitted by Jared Harrell

Keeping Your Horse Comfortable During Cold Weather

The Christmas song, Baby it’s Cold Outside, made famous by Lee Ann Womack with Harry Connick, Jr., pretty well describes the 2013 winter to date. To make matters worse, 650 one day, followed by 360 the next, is hard on humans and horses alike. I have put on a jacket more times this winter than in the past 3 winters combined and more than once pulled out a heavy jacket for a 260 morning. So, what about the comfort of your horse?

As is the case with humans, some horses handle cold temperatures better than others. A normal Fall, when temperatures decline steadily over a 2 month period allows healthy horses to grow a full winter coat. The normal equine winter coat will protect most horses from cold temperatures and wind but, throw in rain on top of wind and chilling temperatures and even the best of coats may not provide adequate relief. This is the Rule of 2 out of Three. Simply put, a healthy horse can generally withstand a combination of two of the three extreme environmental conditions (wind, rain, cold temperatures) but may need assistance keeping warm when all three conditions exist in combination. Then, there are always those horses that do not grow sufficient coats to handle even two of the three factors comfortably.

Options for helping horses handle the winter weather include, stabling the horse during extreme weather, blanketing the horse as needed or providing windbreaks that provide needed protection. Just a quick word about stabling horses during the winter. Most barns are built more for human comfort than for that of the horse. Avoid heating barns if horses are going to be spending at least part of their time outdoors each day. Research indicates that horse health is enhanced if the inside temperature of the barn is no more than 100 warmer than the outside temperature. So, if the inside of your barn is more than 100 warmer than the outside, you may need to blanket your horses when turning them out.

So, when should you blanket your horse? Answer: when all three of the above mentioned weather conditions exist or when the temperature drops low enough to make your horse uncomfortable. Observe your horse multiple times each day to be sure it is not shivering. A horse that is really cold may shiver like you and I do. If your horse has a poor winter hair coat, you should anticipate this problem. If the weather report calls for cold temperatures, wind and precipitation and horses do not have shelter, make plans to blanket those horses that need it. Remember, just because your horse didn’t show signs of being cold during one weather event, does not mean it won’t the next time.

Blankets come in all different sizes and colors and, like cars, come with many options. Do you want a closed front or buckled/Velcro front? How much insulation do you want? What denier should the outer shell be? Denier refers to the fineness of the yarn/thread that was used to make the product and thus, the ability of the material to keep wind and water out. A higher denier indicates a higher level of protection and durability. How much insulation do you want, 200 grams, 400 grams? Do you want a cut-back neck line or regular? The cut-back neck line works well for some horses and may actually help the blanket fit better. To provide the greatest comfort and to avoid slippage, a blanket should fit the horse properly. Measure the horse from the center of the chest to the point-of-the-buttock (as viewed from the side) to determine proper blanket size.  Blankets may be sold according to the length in inches or as Small (60”-66”), Medium (69”-72”) or Large (>74”). If you will turn horses out in a blanket during cold weather, it should be a heavy duty blanket with double stitching and reinforced stress points.

For extreme cases, you may also include a hood. Hoods give extra protection and are made having most of the same properties as blankets. Hoods should have large eye holes, so the horse can see effectively and usually attach to the blanket by means of one or more elastic straps so the horse may extend its head to the ground for feeding purposes. Also, for horses turned out in a blanket, be sure the blanket and hood are waterproof. During extended rain your horse will likely get at least partially wet anyway, but water proof materials will extend the protection and extend the life of the blanket. Higher quality blankets may include materials that actually wick-heat and moisture away from the horses skin if the horse gets too hot. This is particularly helpful for young horses that may run and play while blanketed and when temperatures vary throughout the day.

A couple of points to remember: 1. We blanket the horse to protect it from the elements. Some horses will actually sweat from being blanketed, especially if a hood is used in combination. If your horse sweats while wearing a blanket, cool the horse and re-evaluate the need for a blanket at that temperature. 2. When purchasing blankets for turnout, it is recommended that materials of greater than 1200 denier be used because of their strength and durability. 3. In cold weather, feeding additional hay to horses will actually help generate more body heat than feeding an equal amount of additional grain; a practical way to keep your horse comfortable during cold weather.

Submitted by Walter Earle, from an article by NCSU Horse Husbandry

Winterizing Your Horse For Breeding Season

As summer comes to a close, horse owners should be making management plans for the cooler seasons ahead. For the majority of horses, cold weather does not mean coming in from the cold, but being assisted to withstand the cold as comfortably and healthy as possible. From the owner’s standpoint, winter management gets very basic: routine health care, feed, water and shelter. Yet there are an amazing number of horses each winter that are abused as a result of one or more of these basic management principles being neglected.

A healthy horse in the fall will factor into a healthy horse going into the winter. If your horse is free of parasites, in good flesh and properly immunized going into the winter, the greater the chance of your horse being an “easy keeper” during the winter. Emotions and welfare obligations aside, economics dictates that the cost of anthelmintics, veterinarian checkups and immunizations will more than pay for themselves in reduced feed costs through the stressful winter months. Work with your vet to set up a health program for each of your horses and stick with it.

Winter conditions will increase the horse's energy requirements.

Know in advance what you are going to feed during the winter months. Waiting until after the first frost kills your summer pasture to decide on a winter feeding program is detrimental to your horse. Chances are the grass that he was feeding on was devoid in nutrient value and he was losing body condition anyway. With three weeks to acclimate your horse to new feed sources, plus a declining body condition, you have lost valuable time to prepare the horse for more extreme weather.

The first step in planning a winter menu for your horse is knowing the nutrient value of your hay. Your local county extension office can assist you in getting your hay tested. The test will take several weeks, so plan ahead. While you are waiting on your hay sample, find out the nutritional requirements of your horse. There are nutritional tables that determine equine nutritional requirements. These may be found in reference books, or in some cases, your feed store may have a copy. The nutritional requirements are based on age, size, reproductive stage for mares and amount of work performed.

When your hay sample results are returned, compare the nutrient value of your hay to the nutrient requirements of your horses. In some cases, such as that of a mature horse with low workload, a good quality hay may provide all the necessary nutrients. However, in most cases, a combination of hay and grain will be required to meet the nutritional needs of the horse. Savings may be realized without affecting the horse if you can utilize more of the cheaper hay and less of the more expensive grain. Make sure that vitamin and mineral requirements are met as well.

Cold and wet weather can cause problems with hooves, colic, stable vices such as cribbing and increase the horse’s nutritional needs. As the weather gets cold, horses expend more energy staying warm. Horsemen should normally increase the feed by 1 or 2 pounds during cold weather to provide adequate energy to assist the horse in maintaining his body temperature. It is also critical to provide adequate roughage for the horse to avoid cribbing and other stable vices associated with a lack of roughage. This time of year grass is 80 to 90 percent water; therefore, grazing horses consume mostly water. Their desire to chew on something is not satisfied, and cribbing often begins during times of wet weather. Horsemen should provide hay free-choice to satisfy these needs and avoid potential cribbing problems.

Provide horses with access to clean, unfrozen water sources.

Impaction colic also becomes more prevalent during cold weather. This normally occurs because the horse does not consume an adequate amount of water during cold weather and does not have an adequate amount of water in his digestive tract for digestion. Ideally, water should be warmed so that the horse will consume adequate amounts. Water should be available at all times.

Hoof care may also become critical during winter months. Many times, horse’s feet become so wet that the outer covering of the foot deteriorates, which causes cracking and splitting. Mud and sand can work their way into the cracks, causing the hoof to spread even further. Every effort should be made to keep the hoof wall intact. This can be done by keeping the hoof as dry as possible and applying hoof dressing regularly. Hoof dressing is basically an oil or grease that keeps water from soaking into the foot. During wet weather, this is a very difficult task; however, it is important to maintain the hoof quality and integrity.

During the winter months, many horses are kept in closed barns and develop respiratory problems. When the barn is closed up because of rain or cold weather, ammonia, dust and stale air are trapped inside. Research indicates that most of the ammonia and dust are below the level of 2 to 3 feet. This makes air quality a big problem for young horses. Therefore, it is important to have good ventilation and air flow through the barn to maintain good air quality and minimize respiratory problems.

Proper ventilation is important in horse barns.

Several management practices can assist in improving the air quality in a barn. First, the barn should be designed so that the prevailing wind can move through it. Even though it may be cold outside, it is better to open the barn doors and let good air flow through to improve air quality and decrease the probability of respiratory problems. Second, the barn should be designed to allow good air to flow through vents on the sides and in the roof to maintain air flow when barn doors are closed. Third, cleaning stalls daily and removing manure and wet bedding greatly improves the quality of the air. A fourth suggestion is to design the bottom of the stall to allow good air flow at ground level. Slatted boards at the bottom of the stall up to 4 to 5 feet are recommended to allow air flow at ground level. Wire panels or metal bars are normally recommended for the upper half of the stall.

Horse care during the winter months is important in having a sound and healthy horse later in the year.

Written by Steven M. Jones, Extension Horse Specialist

The Science behind Barefoot Hoof Care

 

Like most horse people, I have too many!  That “too many” number isn’t the same number of horses for everyone – or even the same number all throughout the year -  and certainly doesn’t mean we have any type of personality disorder – it just means we love horses and can’t quite ever get enough!  With “too many horses”, I’m sure you have all noticed, like I have, the rising cost of hoof care.  I am in no way criticizing the farriers for charging what they do – it’s a tough job!  But I needed to start exploring options.  Having been searching and providing scientific, research-based answers for my Extension clients for the last 25 years, that’s what I wanted too – science and research.  I studied boots and natural trimming theories, quizzed my farrier and my farrier friends, tried several products designed to “toughen up” a horses hooves, fixed muddy places in the pastures and run-in sheds and still, had more questions than answers.  I have several clients, colleagues and friends who are firm believers in keeping their horses barefoot, so when our Extension Horse Advisory committee met this summer to help plan our Fall Field Day and requested a barefoot trimming demo,  it fueled my interest in finding the science behind the barefoot trim and the difference between that and “regular” hoof trimming.   

 Planning to use my own horses as guinea pigs for the demo, I took stock of the herd.  I have a few with those cast iron hooves that no matter what, go barefoot year round and their hooves stay perfectly shaped and handle the rockiest terrain without a misstep.  I have a couple who are tough enough to go with just front shoes and a couple who require shoes all around – or so I thought.  A very interesting situation caused me to take my “pet” and use him as the shod-to-barefoot guinea pig.  My favorite horse – the one who has packed my daughter around for 6 years and made her the good rider – and good kid – she is today, came up lame.  Really lame.  Having an excellent vet, we pulled out all the stops to find the cause.  We removed the left front shoe, took radiographs and found nothing - no navicular changes, no rotation of the coffin bone – nothing that would have resulted in such an extreme lameness.  And no apparent abscess.   As great a horse as he is mentally, he has a few challenges physically and one of those is his feet.  For his height and thickness, he has a foot I’ve always considered to be a little too small.  Not extreme, but the one major thing I’d change about him.  And he had a tendency to grow a disproportionate amount of toe which caused him, in his constant state of “energy conservation”, to tend to stumble especially when he was near the end of a shoeing cycle.  And his feet were tender – during a campout last summer, he lost a hind shoe and was so sore after a couple hours on relatively good terrain, I ended up leading him the last hour back to camp. I tell this story not to be “telling my story”, but because it’s everybody’s story – I hear similar accounts from so many people!

I’m happy to report that after 10 days of supportive care, he recovered.  But a most interesting thing happened when we removed that one shoe - almost instantly, his foot changed shape.  What used to have been a somewhat narrow and elongated foot, suddenly became very much round again.  I have a really good farrier – even the barefoot trimmer who did our field day demo remarked what a good shoe job he still had as she removed the three remaining shoes.   But when we took off that first shoe and his foot became more balanced and normal looking than I had seen in 6 years, I was motivated to take the chance and see how he’d fare barefoot.  After removing the remaining three shoes and receiving a very well-done barefoot trim, I’m happy to report no tenderness issues, better hoof shape, better movement - happy and healthy hooves and horses!  Stay tuned for progress reports…

I admit, money was the initial motivator.  But while seeking the science to support a more economical hoof care option, I have found a lot of information (see the links below) to support the philosophy behind returning our horses to care standards more closely resembling those they would experience on their own in nature (can ya tell I dislike the word “natural”?!?)  From nutrition to housing to handling, we have made great strides in the last few decades to try our best to recreate for our horses what makes the most sense to them and for them.  Without many exceptions, the problems our horses present to us are most likely caused by us and the way we ask our horses to adjust to live by our standards of care rather than us taking the effort to provide care that most suits their physiology and psychology.  Not saying any of us would intentionally do something to harm our horses, but we should always strive to know better so we can do better. 

 

http://www.equinesciencesacademy.com/index.htm

http://hoofcare.blogspot.com/2011/07/research-clayton-and-bowkers-effects-of.html

http://www.healthyhoof.com/articles/BarefootList/BowkerPhysiologicalTrim.html

http://www.bloodhorse.com/horse-racing/articles/75324/study-barefoot-trimming-shows-positive-effects

Garlic and Horses

Many horse owners have recently been asking about giving their animals herbs or natural supplements, specifically garlic.  They have heard that it can help with fly and worm control, pain relief, treatment of infection, and many more issues.  The problem with feeding garlic to horses is that horses will willingly consume toxic amounts.  Research shows that a toxic amount is more than 0.2 mg/kg of their body weight.  This is only .003 ounces in a 1000 lb horse.  These amounts have caused Heinz body anemia during times of consumption.  Heinz-body anemia is a complicated process.  The toxic element in garlic and onions is a chemical called N-propyl disulfide.  By altering an enzyme present within the red blood cell, it depletes the cell of a chemical known as phosphate dehydrogenase (PD), whose job is to protect the cell from natural oxidative damage.

When the PD level gets low enough, the hemoglobin in the cell oxidizes and forms a bubble called a Heinz body on the outside of the cell.  This Heinz body is distinctive and able to be seen under the microscope. The spleen quickly removes the deformed red cell from the bloodstream. As more and more red cells are prematurely damaged and removed, as happens from consistent poisoning with N-propyl disulfide, horses gradually becomes anemic.

Toxic effects are more gradual but still very dangerous when a lower dose is consumed on a regular basis, resulting in a mild anemia without obvious symptoms.  Some cases of Heinz-body anemia occur every year in horses that graze on wild onions or garlic growing in their pastures.  Depending on the dose, and the frequency and duration of dosing, there could be low-grade damaging effects, due to red-blood-cell damage that's not enough to cause an emergency situation, but just enough to cause a mild anemia that might not be outwardly evident.  It might affect your horse's stamina, energy level, or resistance to disease.

Recovery from anemia may not occur until after 5 weeks following termination of dietary supplementation with garlic.  Research further suggests that the only real benefit of feeding garlic to horses is that it may increase concentrate consumption.  Since most horses readily consume plenty of concentrate anyway, there is little reason to add garlic to an animal’s diet. 

The potential for garlic toxicosis also exists when horses are chronically fed garlic.  Animals are not able to digest garlic like people can, which is why a buildup occurs.  Symptoms of garlic toxicity include trouble breathing, lethargy, diarrhea, vomiting, an elevated heart rate, an increased respiratory rate, weakness, and collapse.

Most herbs have not been scientifically tested for use in animals.  It is therefore unknown if they are safe or even effective.  They are also not regulated with the same scrutiny as conventional drugs.  Some commonly found supplements fed to horses other than garlic include:  Echinace, ginger, ginseng, peppermint leaf, and yucca.  Some herbs have drug-like actions that interact with dietary components.  Drug-herb interactions are common and caution needs to be taken when implementing natural product usage.

Anytime you are thinking about introducing new supplements or a home remedy treatment for your animals, always consult your veterinarian first.  If you need help finding a balanced ration for your horses, please call your local Livestock Agent.