Tennessee Horseman Unifying Horse Owners Through Science-Based Information

Tennessee Horseman Unifying Horse Owners Through Science-Based Information Volume II Issue I; Fall 2017 West Nile Virus and Equine Infectious Anemia Cases in Tennessee Dr. Jennie Ivey, PhD, PAS UT Animal Science; Extension Equine Specialist Horses in Davidson and Knox county have tested positive for West Nile Virus (WNV) and another tested positive for Equine Infectious Anemia (EIA) in Bedford county over the past few days. Awareness of disease signs and symptoms, along with preventative strategies and farm management are important to protect your horses. West Nile Virus West Nile Virus is transmitted from bird reservoir hosts by mosquitoes to horses. Mosquitoes must first feed from an infected bird before it is able to transmit WNV to a horse or human. Since horses and humans are dead end hosts for WNV, the disease cannot be directly transmitted from horse to horse, or horse to human. Horses with WNV do not need to be isolated from other horses, as the WNV is not present in high amounts within their blood to allow for mosquitoes to pass the disease from horse to horse. Horses affected with WNV may display depression, muscle tremors, convulsions, and/or have a decreased appetite. Also, horses may be easily startled by noise or touch, while others may seem drowsy and less reactive than normal. Other indications of WNV include continuous walking without purpose, lack of coordination, or paralysis especially in the hind legs. The WNV vaccine is considered a core vaccination and is recommended for all horses, independent of location, travel and management practices. Additionally, most Veterinarians recommend horses in Tennessee receive Spring and Fall booster vaccinations after the initial two-dose series. Equine Infectious Anemia Equine Infectious Anemia, or Swamp Fever, is transmitted through blood-sucking insects, such has horse or deer flies. Residual blood from one horse is carried within the insect s mouthparts, and then can be passed to other horses. Also, transmission can occur from bloodcontamination when reusing needles, or other medical instruments, along with passage from mare to foal in-utero or through milk. EIA can be difficult to diagnose, as symptoms can vary from horse to horse, and many horses may not demonstrate obvious signs of illness. Symptoms of EIA include fever, weakness/fatigue, depression, pale or yellow mucous membranes, and decreased appetite. A complete blood count performed by a veterinarian may show decreased red blood cell count or anemia, along with low platelets, which are cells needed for blood clotting. Continued on page 7 1

Steps to Successfully Establish Pastures and Hayfields Dr. Gary Bates, PhD UT Plant Science; Extension Forage Specialist I have asked numerous times over the last several months why the weeds are so bad this year, or something similar. There could be many different reasons, but one of the primary reasons could be due to having a poor stand of tall fescue after the last couple of years of drought, coupled with overgrazing. One of the best ways to decrease weed pressure may be to thicken the stand of tall fescue. Have you ever thought about the fact that anytime you plant something, there is only one good thing that can happen? You get a thick, competitive stand of whatever grass or legume you planted. This one good thing often gets overshadowed by all the bad things that can happen. Too little rain, too much rain, ground too soft, ground too hard, too hot, too cold, and on the list goes. The following is a list of steps to improve your chances of getting a good stand established. 1. Fertilize and lime according to soil test results. Don t have a stand failure simply because the ph was too low, or adequate nutrients weren t available. Take a soil sample and have it tested well ahead of planting, in case lime is required. 2. Plant into a weed-free field. Prior to planting, make sure that everything in the field is killed, either through disking or by using herbicides. Planting seed If managed properly, pasture can provide an economical forage option for horses. Follow instructions in this article to improve your pasture quality. into a field with weeds present puts the new seedlings at a severe disadvantage and can result in establishment failure. 3. Plant into moist seedbed. Seed need to absorb water in order to germinate. Planting into a dry seedbed will mean that rainfall is needed before any germination begins. Hot, dry seedbeds can result in seed viability decreasing rapidly after planting. Be sure that moisture is adequate at planting. This keeps you from having to pray for rain, and reduces the risk for planting failure. 4. Plant the proper amount of seed. Don t just assume that the seeder you are using is putting out the proper amount of seed. Be sure to spend a few minutes prior to seeding to calibrate your seeder, particularly if it is a drill that you have rented. This will save you time and money by preventing all your seed being put on half of the field, or having to run over the field two or three times because it wasn t putting out enough seed. 5. Check planting depth. One of the biggest mistakes that can be made is placing seed too deep at planting. Putting a tall fescue seed at 1" deep will cut seedling establishment in half compared to planting at ½ inch. No-till drills are generally heavy to help cutting through the sod. They can place seed too deep, so check the depth of seed placement when preparing for seeding. 6. Control weeds after planting. Monitor the field after planting. If weed pressure is becoming too great so that establishment is in jeopardy, consider using a herbicide to eliminate the weeds. Contact your local Extension office for specific herbicide recommendations. 2

Equine Vaccination Schedules Dr. Lew Strickland, DVM, DACT UT Animal Science; Extension Veterinarian Vaccination schedules aid in determining when to administer core preventative vaccinations to your horse. Keep in mind that this is not a one size fits all, and to discuss with your veterinarian a vaccine protocol that best suits the needs of your horse. Equine Eastern/Western Encephalomyelitis (EEE/WEE) EEE/WEE are carried by biting insects with mosquitoes being the major vector. To provide the most protection from these vaccines, a protocol should be in place prior to and during the warmer seasons of the year. Adult horses, of unknown EEE/WEE vaccine history: Administer an initial dose followed by a booster within 4-6 weeks. Horses should then be vaccinated prior to mosquito season the following year. Since some areas have prolonged insect seasons, your veterinarian may elect to revaccinate later in the fall. Adult horses previously vaccinated: Vaccinations should be completed annually prior to mosquito season in the spring. Even though the label directions only recommend once a year boosters, your veterinarian may choose to booster EEE/WEE in areas where mosquitoes are active year-round to ensure uniform protection throughout the year. Safe locations to administer intramuscular (IM) vaccinations include a triangle-shaped area of the neck, outlined by the nuchal ligament, cervical vertebrae, and slope of the shoulder (scapula). Also, IM injections can be made into the pectoral muscle. Image courtesy of thehorse.com. Foals: In Tennessee, vaccination may be started at 2 to 3 months of age due to earlier mosquito season risk. Similar to other protocols, an initial dose is given and then followed by a booster 3-4 weeks later. A third dose is given 4 weeks later, with a final fourth dose 4 weeks after the third dose. This will place the foal at approximately 12 months of age when receiving the final dose. Then, the foal will be in the adult horse protocol. West Nile Virus (WNV) Similar to EEE/WEE, WNV is spread by biting mosquitoes, especially in areas of migratory birds. These vaccinations are necessary according to exposure risk, and more frequent vaccination may be indicated with any of these products depending on mosquito exposure and risk assessment. The age of your horse will dictate the need for additional protection. Younger (< 5 years) and older (> 15 years) are more susceptible to this disease, so more frequent vaccination may be necessary to provide protection of these horses. There are three vaccines with different West Nile components used for protection against the virus. Consult your veterinarian which vaccine will suit the needs of your horse. Adult horses, of unknown WNV vaccine history: Killed whole virus vaccine: An initial dose is given followed by a booster 4-6 weeks later. The label directions recommended revaccination annually, but depending on the mosquito risk, your veterinarian may require more frequent boosters. Recombinant live canarypox vector vaccine: An initial dose is given Continued on next page 3

Equine Vaccination Schedules; continued from previous page followed by a booster 4-6 weeks later. The label directions recommended revaccination annually, but depending on the mosquito risk, your veterinarian may require more frequent boosters. Killed flavivirus chimera vaccine: An initial dose is given followed by a booster 3-4 weeks later. The label directions recommended revaccination annually, but depending on the mosquito risk, your veterinarian may require more frequent boosters. Adult horses previously vaccinated: Annual vaccination in the spring prior to mosquito season. Foals: Inactivated whole virus vaccines: Administer an initial 3-dose series beginning at 3-4 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered when the foal is approximately 12 months of age prior to the next mosquito season. Recombinant canarypox vector vaccine: Administer an initial 3-dose series beginning at 3-4 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered when the foal is approximately 12 months of age prior to the next mosquito season. Inactivated flavivirus chimera vaccine: Administer an initial 3-dose series beginning at 3-4 months of age. A 4- to 6-week interval between the first and second doses is recommended. The third dose should be administered when the foal is approximately 12 months of age prior to the next mosquito season. Rabies Though horses are infected infrequently, Rabies is 100% fatal, and there is the potential for transmission from horses to humans. Adult horses previously vaccinated against rabies: Recommended to revaccinate annually. Adult horses unknown vaccine history: Administer an initial single dose and revaccinate annually. Foals: The first dose of vaccine should be administered at 3 to 4 months of age with annual revaccination. Tetanus Tetanus is not a contagious disease but is the result of Cl. tetani infection of puncture wounds, open lacerations, any exposed tissues and reproductive tract of the postpartum mare (retained placenta). Tetanus antitoxin is indicated to provide passive immunity in situations where the horse is at risk of tetanus infection because the horse has not been previously immunized for tetanus. Tetanus toxoid is utilized in the schedule detailed below unless otherwise specified. Adult horses, of unknown vaccine history: Administer an initial dose then booster 4- to 6-later. Vaccinate annually afterward. If a horse with an unknown history of tetanus is injured, it is recommended to give an initial dose of tetanus antitoxin along with a dose of tetanus toxoid given in a different area. Adult horses previously vaccinated against tetanus: Annual vaccination. Horses that sustain an injury/wound/surgery after their previous tetanus booster should be revaccinated with tetanus toxoid at that time of injury. Even small injuries can result in signs of tetanus, so booster regardless. Pregnant mares of unknown vaccine history: Administer an initial dose of toxoid then booster tetanus toxoid 4- to 6-weeks later. Booster 4 to 6 weeks before foaling. If a mare foals with an unknown vaccine history, follow the unknown adult horse protocol. Pregnant mares previously vaccinated against tetanus: Vaccinate 4 to 6 weeks before foaling, both to protect the mare should foaling-induced Continued on page 8 4

Equine Lacerations Dr. Megan J. McCracken, DVM, MS, DACVS-LA UT CVM Large Animal Emergency and Critical Care; Clinical Instructor You don t have to be around horses long to realize that they can be accident prone. Lacerations or wounds are one of the most common equine emergencies. While many lacerations will heal well with basic care, some can permanently threaten your horse s soundness or can even be life threatening. It is always a good idea to have a laceration or wound evaluated by a veterinarian. They can determine if a wound involves other important structures such as joints or tendons, can decide if sutures are needed, and can prescribe antibiotics if necessary. Your veterinarian is also an expert resource throughout the wound healing process. Some medications should only be used at certain stages of wound healing and your veterinarian is the best person to determine the ideal treatment for each stage of wound healing. Certain lacerations or wounds are especially concerning Wounds that are over a joint or tendon sheath, may have penetrated the joint capsule or entered the sheath that surrounds a tendon. It can be very difficult to treat infected joints or tendon sheaths and early and intensive veterinary treatment and often hospitalization or surgery are needed to save your horse s soundness and life. If left untreated these infections can cause permanent severe lameness and may even result in the necessity for euthanasia. Figure 1 shows the location of important joints and tendon sheaths in the lower limbs. Figure 2 shows a wound that entered the coffin joint. Wounds that involve tendons or ligaments may have completely or partially transected these important support structures. These wounds may require surgery, casts, or splints to provide support to the leg as the tendon or ligament heals. Figure 3 shows a wound that completely transected the extensor tendons on the hind limb and required a splint for healing. Wounds that expose bone can lead to infection of a portion of the bone and the development of a sequestrum, which is a dead piece of bone that the body walls off and attempts to extrude. Note the exposed bone in Figure 3. Wounds with excessive bleeding need prompt veterinary care to stop the bleeding. Excessive blood loss can be life-threatening. Large deep wounds over the chest or abdomen may penetrate the thorax or abdomen and can cause a life-threatening infection in these areas. Intensive veterinary care and hospitalization are needed for the treatment of these wounds. Wounds that are associated with lameness in the limb should always be evaluated as there could be additional damage to the limb. Figure 1: These photos highlight the location of a horse's joints and tendon sheaths. Lacerations that occur within the circled areas may have entered a joint or tendon sheath, and should always be evaluated by a veterinarian. Continued on the next page 5

guarantee your horse will never cut themselves, you can manage their environment to minimize the risk. Figure 2: This wound entered the coffin joint and resulted in an infection. The horse was promptly treated by a veterinarian receiving multiple joint flushes and antibiotics both systemically and directly within the joint. She made a full recovery. What to do when your horse has a serious wound or laceration Call your veterinarian. Describe the wound and listen to their instructions. Almost any wound can safely be cleaned with saline. You can buy spray cans of sterile saline in the contact lens section of your local drug store. Heavily contaminated wounds can often be cleaned with cold hosing, but make certain to check with your veterinarian first. Don t hose for too long as it can cause tissue swelling. Do not put any topical creams or other treatments on the wound until it is evaluated by your veterinarian. Some popular wound treatments are actually caustic to wound tissue and other products should only be used during specific stages of wound healing. Your veterinarian can recommend the appropriate topical medication to put on the wound. If there is severe bleeding, apply a firm bandage over the leg. If an upper body wound is bleeding excessively apply firm direct pressure till your veterinarian arrives. Prevention The best way to treat a laceration, is to never have your horse get one in the first place. Although there is nothing you can do to Eliminate or minimize the use of barbed wire fences and make certain any smooth wire fences are highly visible and properly maintained. Barbed wire can easily cut and saw through your horses limb especially if they become entangled in the fence. Keep your pastures free of debris, old boards, trash, farm equipment, and vehicles. These are all things that could easily cause a laceration. If T-posts are used in fencing, they should be capped. Uncapped t-posts can cause devastating penetrating wounds to the abdomen and thorax. Regularly inspect your barn, pasture, fencing, arena, and horse trailer for protruding nails, broken boards, sharp pieces of protruding wood or metal, or anything else that could cause injury to your horse. Ways to help ensure the health and soundness of your horse so they can enjoy many years as your active companion includes working with your veterinarian to ensure proper treatment of wounds and lacerations. Also, learn and practice first-aid techniques often. Manage your property to minimize the chance of wounds and lacerations. Figure 3: This wound completely severed both of the extensor tendons and exposed a large section of cannon bone, as a result of the horse becoming caught in a wire fence. Treatment included antibiotics, extensive wound care, splinting, and a short period in a cast. The horse made a good recovery. 6

horses congregate will help to decrease breeding areas for many fly species. Move waste holding areas as far as possible away from where horses are housed. Composting is an ideal solution for horse owners, can be easily achieved through a bin system, and produces a usable product that eliminates internal and external parasite reproduction, along with weed seeds if done correctly. The Tennessee Master Horse Program is a science-based educational program designed to deliver applicable, unbiased information to equine owners and business operators. Programs are being planned throughout Tennessee for early 2018! Contact your local County Extension office or visit UTHorse.com for information on courses near you! West Nile Virus and Equine Infectious Anemia in TN; Continued from cover There is no vaccination available for EIA, but annual screening through a Coggins Test should be performed on all horses. Testing horses for EIA aids in eradicating the disease, as there is no treatment. Unfortunately, options for horses that test positive are minimal. The American Association of Equine Practitioners supports euthanasia of EIApositive horses and other equids as the best option. An alternate option is lifelong quarantine in a screened stall, and sequestration from other horses to prevent transmission of the disease. Preventative Management Using good management practices in combination with preventative health measures can greatly reduce the risk of both WNV and EIA. Reducing the ability for flies and mosquitoes to breed by managing waste and standing water is critical in preventing WNV and EIA transmission. Regularly removing manure and other waste from stalls, pastures, and other areas where Reducing standing water within your farm is important for preventing mosquitoes. Any object that can hold water can become a mosquito breeding ground. Check for buckets, wheelbarrows, plant pots, or other items around farms that can store water and eliminate these sources. Additionally, look for areas where water collects in pasture, and take measures to increase drainage and/or increase grass stands. Bring horses inside during peak insect feeding times (early morning and dusk) to reduce exposure, and use a topical insect repellent can to aid in decreasing mosquito and fly feeding. WNV or EIA can be devastating for your horse; however, prevention and management will decrease the risk at your facility. For more information on waste management, drainage, and equine health, contact your local county extension office, veterinarian, Dr. Lew Strickland at lstrick5@utk.edu or Dr. Jennie Ivey at jzivey@utk.edu. Also, for online information on equine diseases, management, and health, visit UTHorse.com. Know a horse enthusiast in grades 4-12 that is looking for an equine-centered activity? The Tennessee 4-H Horse Program offers Tennessee youth valuable educational opportunities through raising, exhibiting, and learning about horses! Participants do not need to own a horse in order to participate in events such as horse bowl, hippology, and horse judging! Learn how to become involved as a youth participant or adult volunteer through your local County Extension office. To make the best BETTER! 7

Fall is for Forage Testing Dr. Jennie Ivey, PhD, PAS UT Animal Science; Extension Equine Specialist As many horse owners look to secure enough hay for the Winter months, Fall is an excellent time to submit a forage test. Forage testing utilizes laboratory analysis to determine the nutrient content of hay or pasture samples. Information gathered from a test provides insight as to the nutrients provided to the horse, and is a critical component of evaluating the equine diet. Sampling Technique Submitting a sample is a simple process, and can be done independently, or with assistance from your local County Extension Office. Samples from at least 10-15 bales of hay should be collected, either from a forage sampling probe (bale corer) or grabbed samples. If grabbing samples from a variety of bales, be sure to select hay from different parts of the bale to represent the inside, outside, either end and the middle of the bale. Submit a sample that fills a gallon sized zip-lock bag. Sample Submission Visit the UT Soil Plant and Pest Center website (http://www.ag.tennessee.edu/spp) to fill out a Forage Analysis Information Sheet to be submitted with the forage sample. Be sure to indicate which test is to be performed; a Horse Basic Package provides moisture, dry matter, relative forage quality, crude protein, digestible energy, acid detergent fiber, neutral detergent fiber, lignin, ash, calcium, phosphorous, magnesium and potassium content. For owners looking for simple sugars (ethanol-soluble carbohydrates), water-soluble carbohydrates, non-structural carbohydrates, fructan, and starch content, along with copper, zinc, manganese, and sulfur values, the Horse Professional Package adds this information to the Horse Basic report. Report Analysis Once the analysis is complete, a local County Extension agent, equine nutritionist, or veterinarian can aid in interpreting the results. So, what are you waiting for? Sample your forage today and find out exactly what your horse is eating! Equine Vaccination Schedules; continued from page 3 trauma or retained placenta occur and to provide protective immunoglobulins for the foal. Foals of unvaccinated mares or mares of unknown vaccine history: Tetanus antitoxin should be given providing passive immunity in situations where a foal is born to a non-vaccinated mare and is at risk of tetanus infection. Then an initial 3-dose series of toxoid beginning at 3-4 months of age. Allow a 4- to 6-week interval between the first and second dose. The third dose should be administered at approximately 12 months of age. Foals of mares vaccinated against tetanus in the prepartum period: Administer an initial 3-dose series of toxoid beginning at 3-4 months of age. Allow a 4- to 6- week interval between the first and second dose. The third dose should be administered at approximately 12 months of age. Working closely with your veterinarian or Extension agent to decide which type of protocol best suits the needs of your farm. If you have any questions please do not hesitate to contact me at 865-974-3538, or lstrick5@utk.edu. Follow us on Facebook to stay up to date with the latest programs, notifications, and updates for all your equine needs! @TennesseeHorseProgram 8