Knowing Your Horse Inside and OUT: UTCVM Annual Horse Owners Conference

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By Nancy Brannon, Ph.D.

Nearly 100 people came to the Ag Campus at the University of Tennessee, Knoxville for the annual College of Veterinary Medicine Horse Owners Conference on March 5, 2016. Topics covered included Equine Nutrition Basics, PPID, Back Pain, Where to treat your horse’s illnesses and injuries, Toxic Plants, Natural Food Care, and Equine Dentistry. The information-packed day-long conference included breakfast donuts and coffee, lunch, and break snacks, as well as a delicious barbeque lunch. Participants received a notebook of information from each of the presenters to take home with them.

Equine Nutrition Basics
Dr. Jeannie Ivey led the day’s informational lectures with a presentation on how to evaluate your horse’s weight and body condition. In the notebook is a thorough explanation of the Henneke Body Condition Scoring System and chart showing characteristics of each of the 9 levels. All this is part of UT’s Equine Welfare Series for ensuring accuracy in determining a horse’s nutrient requirements.

PPID
Dr. Melissa Hines explained PPID – pituitary pars intermedia dysfunction, or Equine Cushing’s disease. The disease is fairly common in aged horses because aging causes loss of neurons in the Hypothalamus and dopamine is decreased. Without the inhibitory effects of dopamine, the pars intermedia gets larger in size and increases its hormone production. The most common clinical sign is long, curly hair coat that does not shed normally, but there are other signs of this disorder. After appropriate diagnostic testing, the treatment of choice of Pergolide, in addition to good management/husbandry. She also described Equine Metabolic Syndrome (EMS) and listed the features common to both EMS and PPID. These are not the same diseases, although some horses can have both conditions.

Parasitology Update
Next on the agenda was Dr. Carla Sommardahl with information on Parasitology. The types of internal parasites in horses are: small and large strongyles, tapeworms, ascarids, pinworms, bots, lungworms, and strongyloides. Control of these parasites includes use of anthelmintics and proper pasture management practices. She went over the Ten Commandments of horse parasite control, several of which debunk the “common knowledge” myths that people have practiced for years. Before using an anthelmintic (dewormer), it’s important to know its efficacy against its intended parasite population.

Fecal egg counts (FEC) are important in monitoring the effectiveness of one’s deworming program. However, the FEC mostly counts strongyle type eggs and is a crude estimate of one point in time of how many eggs the horse is shedding. FECs are measured as the number of eggs per gram of feces. Horses are classified as high, medium, and low shedders. Even if a horse has a zero eggs doesn’t necessarily mean the horse has no parasites. FECs are best done in September for horses in the southeast. Keep in mind that it’s the larval stages of the parasites that cause problems in horses.
Dr. Sommardahl discussed several deworming programs, based on the FEC, including horses on a daily deworming schedule. Bottom line recommendation is 1 to 2 yearly treatments in the spring and fall to target all parasites with ivermectin or moxidectin. Further treatments may be necessary based on the FEC and the type of parasites targeted.

Back Pain in Horses
Dr. José Castro was quite entertaining as he began his presentation with tales of his visits to the Kentucky Horse Park. Of particular interest is champion race horse Lexington, whose skeleton has been unearthed and is on display in the Museum. [read more at: http://www.examiner.com/article/lexington-s-skeleton-now-resides-at-the-kentucky-horse-museum] On one of his recent trips, he took a closer look at Lexington’s skeleton and discovered several problems with the horse’s spine – “kissing lesions” that would indicate the horse experienced back pain. “I can still diagnose back problems on my day off!” he joked.

He used the analogy of a suspension bridge to explain how the back of a horse is structured. “Two main ligaments, the supraspinous ligament and the interspinous ligaments, attach to this bridge,” he explained. He also showed the main back muscles that attach to the bridge. He explained how to feel these muscles on the horse’s back.

There are several causes of back pain, including conformation, fractures, muscle injuries, and others. “Some lamenesses are related to back pain,” he said. “This is a fascinating topic!”

Among all kinds of diagnostic procedures, the two he would choose over all others are the clinical signs and saddle fitting.

 “For lameness, time and rest are what’s best. For back problems, exercise helps best.”

He showed an interesting animated short video of a saddle on a moving horse. View it at: http://frt-system.com/videos/index.html. It’s also a great video for seeing how the horse’s skeleton moves during the walk. There’s another animation on this web page showing the muscles with the horse moving at a walk.

He revealed that many a horse’s back problems stem from “lack of use of a mounting block” by the rider. “The horse develops pain on the left side because the saddle tilts a little to the left when the rider gets on.” Although riders try to re-straighten the saddle after mounting, “the saddle doesn’t go back to the correct place,” Castro explained. “Just a little variation causes a lot of stress.” In addition to proper saddle fitting, “Proper riding is important. It’s not just the tree or the saddle; the saddle must fit the rider properly, too.”

Another structural analogy he used is Roman columns, compared to knees. “Motion creates instability! Instability causes bone deposits, which leads to arthritis. There’s no cure, but the treatment is exercise,” he explained.

Muscles keep the column stable, but when a horse has muscle loss or atrophy, that makes the column unstable. An underwater treadmill works great on muscles for the six ways the back moves: up and down, front to back, and side to side.

He emphasized the importance of proper warm-ups and cool downs when riding. “The warm-up is very important!” He recommended longe lining at the canter not the trot. “Twenty minutes hand walking on a loose rein so the horse’s head can bob up and down, and the horse can stretch his back. Cooling down is even more important! The legs are bone and ligaments, and the ligaments are made of collagen (protein). If not properly cooled down, the metabolic heat melts the collagen, causing chronic damage.

For his finale, he showed the carrot stretch exercises. “Horses enjoy it! Just as they like grooming, too.”

Home or Hospital: Where to Treat What
When your horse has a sudden illness, like colic, or an injury, you’re probably going to call your veterinarian. Question is: where should your horse be treated? Home or Hospital? Drs. Meggan Graves and Rebecca Pierce were slated for a joint presentation, but Dr. Graves was called out on an emergency situation. Dr. Pierce more than adequately explained the various emergency situations that call for a veterinarian’s attention, either at the barn or in the veterinary hospital.

For colic and wounds/lacerations, the sooner the veterinarian sees the horse the better. “Gas colic is the most common type of colic seen by vets and horse owners,” Dr. Pierce explained.

“For wounds, it they are suturable, if they involve the eye – see your veterinarian!” she emphasized. “If there is synovial involvement, go to the UT clinic. If you get bacteria in a joint, you get damage and infection. This can be very serious! If tendons and ligaments are involved, the horse needs veterinary care. And get a tetanus booster.”

The take-away: when is hospitalization indicated? If your horse doesn’t improve with treatments performed at home. When tests such as bloodwork, ultrasound, and endoscopy are needed to evaluate colic symptoms. And, of course, as a last resort, if colic surgery is needed. The booklet given at the conference has an excellent Emergency Flow Chart for Wounds and Colic, showing the symptoms and directing what procedures to follow.

Toxic Plants
Dr. Lew Strickland was next on the agenda, talking about toxic plants. His “down home,” self-effacing humor offered a lighter side to the often very serious issues of equine disease and injury. Generally speaking, “Horses are smarter than we are,” he said, explaining that in most pastures horses will not eat toxic plants that might be there. “But if there’s not much to eat, horses can eat toxic plants,” which can also persist in hay, he said.

He clearly showed how to distinguish the red Maple, which has three lobes on its leaves and is toxic to horses, from the sugar maple, which has five lobes on the leaf.

“Check your pastures after storms,” he recommended, looking for downed trees. It’s the wilted leaves that have an unknown compound, making the horse’s blood no longer able to carry oxygen. “If your horse is urinating ‘rusty radiator’ water,” then that’s a likely symptom the horse has eaten toxic leaves.

“DVM stands for dumb veterinary man,” Dr. Strickland quipped, but he was quite astute in his expertise of plants that can cause horses harm. Some are showy crotalaria, which has yellow flowers, and ragwort – both often seen in pastures and hay fields. [see: http://www.lsuagcenter.com/topics/livestock/animal_health/horses/horses-poisoned-by-showy-crotalaria]
“Yew, with red fruit, an evergreen shrub – all parts of the plant are toxic and even small amounts ingested can be fatal.
“Spotted water hemlock, seen in low, swampy areas in the spring time, is very poisonous, even to humans.” [see: http://www.wildflower.org/plants/result.php?id_plant=CIMA2]

“Hemlock and black cherry, choke cherry are toxic. When wilted, the plant leaves have hydrocyanic acid,” he said. [see: http://www.wildflower.org/plants/result.php?id_plant=PRVI]

He described several other toxic plants and under what conditions they are most toxic. He recommend a good website for toxic plant identification: Cornell University Poisonous Plants list [http://poisonousplants.ansci.cornell.edu/], and Alabama Cooperative Extension system Poisonous Plants of the Southeastern United States [http://www.aces.edu/pubs/docs/A/ANR-0975/ANR-0975.pdf].

“Prevention!” Dr. Strickland emphasized several times. “Keep your horse well fed and your horse will avoid toxic plants.” If you see that your horse has eaten a plant and you’re not sure if the plant is toxic, Dr. Strickland’s humorous answer was: “Did the horse die? If not dead, the horse must be OK.”

Natural Foot Care
Dr. Neal Valk is one of the newest faculty members at UTCVM; he is a certified equine veterinary surgeon and is also an accredited barefoot trimmer; his topic was “Introduction to Barefoot for Horse Owners.” Dr. Valk said he was introduced to natural hoof care as an alternative to shoeing about 15 years ago. Looking at their evolutionary history, horses have been around 55 million years, compared to the domesticated horse (about 6,000 – 7,000 years ago). “We’ve been riding the horse about 5,000 years and shoeing the horse for about 1,000 years. If you look at Mustangs, feral horses go barefoot over rocky, varied terrain and they regularly live into their 30s. They walk 16-18 hours a day, covering up to 30 miles seeking food and water. Their soles are twice as thick as domestic horses, and their feet tend to be shorter than domestic horses.

“Why shoe horses? Tradition” is one reason, he said. “We say for protection, but if you look at where a rim shoe is placed, it only covers the hoof wall, which is insensitive in the horse.

“Another reason is for support, but the soft tissue structures can atrophy if there is too much support.

“When wear exceeds growth. The hoof is a very dynamic, adapting part of the horse. Hoof growth speeds up and slows down in response to several factors.”

He acquiesced that some horses are shod for gait enhancement, such as Tennessee Walking horses, and some are shod for traction, like event horses and pulling horses. Given the few exceptions, his overall belief is that “no horse needs metal shoes nailed to his feet.

“Most horses are never given the opportunity to acclimate to the terrain. Think about the terrain our horses are on the majority of time: soft grass, in a stall with bedding and mats, working in a sand arena or arena with soft footing. He quoted Professor Robert Bowker, VMD, PhD of Michigan State University: “Bed your horse in the terrain in which you wish to ride.” [see: Equine Foot Laboratory http://cvm.msu.edu/research/faculty-research/equine-foot-laboratory]
Dr. Valk explained in-depth the hoof mechanism and how it works, and compared that to the shod hoof and how shoes impair the natural function of the hoof mechanism. He explained changes in the hoof after nine months of barefoot trimming: “the frogs, soles, and hoof wall all get wider and thicker; the hoof gets bigger generally.”

He referred to Jaime Jackson, the “father” of natural hoof care [see http://www.jaimejackson.com/] and explained the “mustang trim” with the beveled edge and arch in the sole. He showed how he does the barefoot trim: “anything that can’t be scraped out with a hoof pick stays there.” He brushes the sole with a wire brush and trims the bars to the level of the sole. “I let the live sole tell how much heel to take off.” He finished with the “Mustang roll.”

Dentistry
Last on the agenda was Dr. Eric Martin, speaking on Dental Care in the Geriatric Horse. Horse owners are generally aware of the need for periodic “floating” of their horses’ teeth to remove the sharp edges of the teeth that form during the chewing cycle. “Horse owners are becoming aware that their horses need dental care that extends well beyond floating.”
Geriatric horses, ages 18-20 years, often have more complex conditions that require more in-depth evaluation and treatment. In addition to dental disease, geriatric horses often have concurrent disease processes of conditions that create additional challenges to their health care.

Dr. Martin explained generally the characteristics of a horse’s dentition, along with age-related changes to this dentition and the conditions commonly encountered as horses age. These conditions include diastemata (an abnormal space between teeth that is a major cause of oral discomfort, quidding and weight loss), periodontal disease, and EOTRH. Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) is a syndrome in horses that results in resorptive lesions of the incisors and sometimes canine teeth. It is usually gradual in onset, though often isn’t diagnosed until quite extensive lesions are present. Most commonly it is a condition of older horses (15+), although it has been seen it in horses as young as 13.

For more equine-related resources and up to date information, visit UTHorse.com at: https://ag.tennessee.edu/AnimalScience/UTHorse/Pages/default.aspx And visit Tennessee Horse Programs on facebook: https://www.facebook.com/TennesseeHorseProgram/?fref=nf

UT Institute of Agriculture has also published the first edition of its science-based newsletter, Tennessee Horseman. If you don’t have a paper copy, you can read it online at: https://ag.tennessee.edu/AnimalScience/UTHorse/Newsletter/TN.Horseman.VolI.Issue.I.pdf

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