Ask Your Veterinarian: What Are Hoof Growth Rings?

by | 01.10.2019 | 3:06pm

QUESTION: What are hoof growth rings and what does it mean when you see them on a horse at sale?

DR. SCOTT FLEMING: Growth rings are externally visible ridges in the hoof that indicate differences in the rate of growth or quality of a horse’s hoof wall. The appearance and number of rings can vary from several consecutive rings to a single or widely intermittent pattern. Growth rings can be indicative of a problem within the hoof capsule or may just be an external map of changes in activity, nutrition, or a systemic disturbance that altered hoof growth at one time.

The average hoof on a healthy adult horse will grow from the coronary band to the ground in approximately one year. Alterations in hoof growth or quality such as laminitis can greatly affect growth rates. For example, the hoof wall at the toe may grow slower than the heels in both laminitis and clubfooted hooves while exhibiting a similar dished appearance. Both conditions may take much longer for the toe to grow to the ground.

 

Visually, the growth rings will appear small and tightly spaced at the toe and become wider and more pronounced toward the heels where the growth rate is more rapid. We describe these growth rings as being divergent. They are wider in one part of the hoof than another region. They can be divergent in several planes, such as those described previously, or wider at the toe than heels or even wider on the outside of the hoof than the inside or vice versa. These patterns tell us something about the hoof and what forces, either internal or external, are causing growth differences in the hoof. Wider (faster growth) at the toe than heels can mean the heels are compressed or compromised in some manner. We often see this pattern with negative palmar/plantar angled coffin bones.

The hoof may also exhibit a rounded “bullnosed” appearance and the angle of the coronary band is higher than a normal hoof. Rings that are divergent from one side of the hoof compared to the other may result from differential loading due to conformation or can result from more significant insults such as medial sinking or failure of the internal suspension of the hoof. Divergent rings can often result from overloading or imbalance of one portion or structure in the hoof and can be improved through trimming and shoeing that reduces stress in the affected region.

Reading growth rings offers valuable information but is only part of the picture to overall hoof health. The rings that are visible, are a history of where that hoof has been recently, but internally, a hoof can be catastrophically failing without external signs having shown in the wall itself. Physical evaluation, a detailed history, and radiography remain the cornerstones for diagnosing hoof problems.

Scott Fleming, originally from Northeast Texas, grew up riding Western performance Quarter Horses and working with cattle. Upon graduating from high school, Fleming attended farrier school and maintained a quarter horse centric farrier business in Northeast and central Texas until moving to Lexington. He also served in the Marine Corps Infantry for four years.

Fleming graduated from veterinary school at Texas A&M University in 2013. He then completed an internship at Rood & Riddle in 2013-2014, continued at the hospital as a fellow, and is currently an associate veterinarian at Rood & Riddle.

Outside of Rood & Riddle, Fleming enjoys spending time on the farm with his wife, Tina and their two children, Callie and Case . A special interest for Dr. Fleming is participating in Equitarian Initiative trips to Central America to help working equids in the region.

Do you have a question for a veterinarian that you’d like to see in Ask Your Vet? Email natalie at paulickreport.com

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When The Storm Clears, Veterinary Challenges Remain For Horses Stuck In Flood Waters

by | 09.12.2017 |

 

Hurricanes Harvey and Irma flooded two of the largest horse populations in the United States. Texas has a million horses and Florida has a half-million. During the hurricanes, the major threat to these animals was flying debris, but in their aftermath, horses struggled through floodwater to survive.

Floodwater is particularly hazardous because of the level of pollutants it carries. Not only does it harbor bacteria from sewage and other sources, but it also contains harmful chemicals from flooded industrial facilities and breached storage areas on farms.

“I’ve been through a lot of floods,” said Dr. William Moyer, who in 2015 retired from Texas A&M University after a 22-year career as a professor and head of the Large Animal Clinical Sciences Department. He still helps out as a member of TAMU’s Veterinary Emergency Team, which he helped establish during Hurricane Rita in 2005. The unit is the largest and most sophisticated veterinary medical disaster-response team in the country.

Moyer said skin problems are common in horses standing in floodwater. Water leaches natural oils and other protective factors from the skin, making it easier for pollutants to invade. Usually these horses don’t suffer from a specific skin disease with a name, he said, but from exposure to a variety of irritants, chemicals, and bacteria that can have a deleterious effect, depending on the concentration.

“If you look at some of these refineries, there are cattle or horses grazing on the other side of the fence,” he said. “But with the exception of one chemical plant incident during Harvey, I don’t think there have been any toxic spills.”

Moyer said the most important thing is to get the horse somewhere it can dry off and examine it closely to find and treat any open wounds, even small ones. He said to pay particular attention to the pasterns and the backside of the fetlocks, where the feather might hide a wound.

“You might see a little cut that you normally wouldn’t even treat,” he said. “But then two days later the leg is blown up all the way up to the horse’s chest because the contamination is such that just a nick potentially becomes a significant problem.

“Clean it up with soap and water or some kind of effective disinfectant,” he said.

Clean water in disaster areas usually is scarce, but if a safe water supply via a hose is available, Moyer said to bathe the horse in mild detergent, such as Dawn dish soap, to wash off contamination from the floodwater.

If possible, horsemen should try to find out the status of the tetanus vaccination of any horse pulled from floodwater and boost it, if needed.

Hoof wounds

Dick Fanguy is a former president of the American Farrier’s Association who lives near Baton Rouge, La. Though his area was spared from flooding this time around, he took care of many horses during Hurricanes Katrina and Rita, triaging their foot wounds and passing them on to veterinary students for further care.

“These horses are going to come out of that water and their feet are going to be extremely soft,” he said.

Soft hooves are more easily penetrated when they step on foreign objects. The hazards depend on the area where a horse is found. In urban areas, debris from damaged buildings is under the water, whereas horses in rural areas will be exposed to fewer hazards.

“I pulled so many foreign objects out of soles that it was ridiculous,” Fanguy said. “We rescued two horses from New Orleans, and I pulled roofing nails and glass out of their feet. But horses that were in a rural setting just came in with wet, soaked feet. It was just a matter of putting them in a dry stall and letting nature do what nature does.”

Puncture wounds were the priority because of the danger from pollution in the floodwater. For these, Fanguy immediately disinfected the wound with a surgical scrub, debrided it, packed it with a mixture of Epsom salt and povidone iodine (Betadine), and wrapped the foot.

“My experience is that a hoof is a very resilient thing and will come out all right,” he said.

One of the tragedies in the wake of disasters is that many horses (and other animals) are never reunited with their owners because they bear no identification. Moyer, a strong proponent of microchipping, hopes these hurricanes will be a wake-up call for owners to have their animals microchipped.

Louisiana requires all horses to be microchipped. In the aftermath of Katrina and Rita, all but one of 364 recovered horses were able to be reunited with their owners using microchip identification.

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Nail-Free Shoe Options For Thoroughbreds: Glue-Ons Prevail

by | 06.29.2017 | 9:49am

 

 

If you follow any fellow horse lovers on social media (and even if you don’t), chances are you’ve seen a photo of these nail-free, iron-free, colorful clip-on horseshoes sometime in the past several months. Photos of the Megasus Horserunners, as the shoes are called, have gotten a lot of attention on Facebook due to their bright colors and claims of a gentler, more supportive shoeing option for horses.

The Horserunners, expected to be available for sale later this year, are clip-on shoes with bottoms designed similar to human running shoes. The shoes are meant to be shock-absorbing and easily removed for riders who want to work their horses in shoes but turn them out barefoot. According to the company’s website, Horserunners are applied by placing two strips of Mega Lock tape onto the foot’s outside wall and adhering the shoe’s clips onto the tape strips.

So, will we soon see Thoroughbreds with equine running shoes color coordinated to their silks?

Pat Broadus, owner of Broadus Brothers Horseshoeing in Central Kentucky, has his doubts. A galloping Thoroughbred exerts roughly 30,000 pounds of pressure per square inch in his feet. Broadus isn’t convinced, from what he has seen of the Horserunners, the velcro-like tape combined with the shoe base would provide the right combination of adherence, traction, and slide needed to the hoof in that high-pressure situation.

 

“I’ve never seen a pair put on,” said Broadus, who had concerns about the tape used to adhere the clips. “It’s like Velcro. You know with Velcro, as soon as it gets dirty, it won’t stick anymore.”

 

Indeed, the target audience for Horserunners seems to be trail and casual riders, although initial tests suggests the clip-ons can withstand the force of jumping.

While the act of using nails to affix shoes is painless to the horse when done correctly, nails can pose problems. Horses with thin hoof walls can have shoes loosen, and nails can predispose the wall to cracks, chips or tears if the horse is stomping flies or steps on the edge of a loose shoe and pulls it the wrong way. Some horses, especially Thoroughbreds with thin walls, struggle to keep nailed-on shoes affixed.

If not clip-ons, what are the best options for racehorses needing a break from nails?

Broadus said glue-on shoes remain the standard for Thoroughbreds with special shoeing needs. They were initially found primarily in hospital settings but have become much more mainstream in the past few years.

“It used to be you’d go in a barn and it was taboo for them to have glue-ons, and now you’ll have three out of 20 with glue-ons on,” he said.

Broadus, who co-owns glue-on shoe company Hanton Horseshoes, says people have gained a better understanding of how to glue shoes to horses’ feet.

“When glue-ons first came around, everybody thought you needed a half a bucket of glue to glue a horse on,” he said. “I think we were way overkilling it and putting glue in places that didn’t need glue, and I put myself in that group. It’s the human mindset of, ‘More is better.’ It only sticks to so much. The more you put on, the more chance you have of part of it failing.”

Hanton’s shoes are a modified type of Victory Racing Plates with clips that rest against the outside of the hoof wall, and it is these that are glued on. More traditional glue-ons require a small amount of glue at the edge of the foot and are easy to remove as the hoof grows out, since the portion with the glue is often the part that would be trimmed off anyway.

Despite his involvement in the glue-on shoe business, Broadus said he only has about four horses actively wearing glue-ons across a practice with five farriers.

“I glue to get horses out of glue-ons, I do not put them on planning to leave them on for their entire life. That being said, I have done it when I’ve had a bad situation on certain horses,” he said. “A lot of times, I get a call to come put glue-ons on a horse and you’re not putting nails in so the feet grow out and they look beautiful, then they’re scared to go back to [nails].”

Broadus has one client whose top-level driving prospect had to be retired when he pulled a shoe, stepped on the nail, and developed an infection that spread to his ankle. She keeps her current driving horse in glue-ons for peace of mind, even though she acknowledges it’s unlikely such an accident would happen again.

The downside of glue-ons is they’re more expensive; some can run $75 to $80 a pair, a cost that gets passed onto the client. A pair of glue-ons cannot be reset after one use, which contributes to the bill, too.

Another option Broadus sees for Thoroughbreds needing a break from traditional shoes: hoof boots. Broadus has had good luck rehabilitating a horse on his farm with hoof boots for about seven months. Hoof boots have become better-fitted to horses’ feet in the past several years and have been a popular option among endurance riders negotiating significant mileage at a slow speed over tough terrain. He hasn’t had a request to try hoof boots from one of his racing clients yet, but he wouldn’t be surprised if it comes soon.

“I’m not so sure that that type of boot wouldn’t have its place at the racetrack at some point,” he said. “I don’t know that a horse would run in them because of the traction on the bottom. But I could see a horse come up with a bruised foot or something, and you put that on for a few days while you treat it. I could see where it would be a lot of protection. They’ve improved them so much.”

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