Photographs courtesy DePaolo Equine

As serious competitors, barrel racers invest significant time and money in the health and conditioning of their horses. When a horse does not feel its best, there will be little chance for success regardless of talent or training.

Unfortunately, not all health issues are easy to pinpoint, and serious disease can lurk behind random or non-specific symptoms. Neurological disorders have become increasingly common and diseases like Equine Protozoal Myeloencephalitis (EPM) can be misdiagnosed early on. A range of ambiguous symptoms may lead to confusion and frustration during diagnosis, while delays in treatment could lead to permanent damage—or worse.

It’s important to learn how to perform a basic neurologic exam that may help limit the impact of neurologic distress. You will be able to involve your veterinarian much sooner, which will minimize the potential threat of physical impairment.

Severe Neurologic Symptoms

  • Ataxia (incoordination) typically in hind limbs
  • Stiff or spastic walk
  • Head Tilt
  • Drooping eyelid or lip
  • Trouble swallowing
  • Abnormal eye movements
  • Circling – unable to travel a direct path
  • Difficulty standing up
  • Seizures
  • Collapse

*Call your veterinarian immediately if you notice any of these symptoms


Most neurologic diseases exhibit very similar symptoms. Depending on which type of virus, bacteria or protozoa has infected the body, the clinical signs may develop gradually, which is common with EPM, or quite rapidly, as is typical with EHV-1, Rabies or West Nile.

While the obvious signs are called out in the boxed text above, it is just as important to recognize the more subtle symptoms that are present at the beginning of the disease process. Owners often note that their horse isn’t performing up to its usual standard. A common comment is, “My horse just isn’t right.

Many times there is an obscure lameness that may even change from one leg to another. Multiple joint injections, chiropractic sessions, or even time off does not solve the problem. If anti-inflammatory drugs are administered, they may help for a while, but the symptoms return.

A change in attitude may be an important sign that your horse is feeling out of sorts. Usually owners report that their horses become dull and lethargic, especially when working with them from the ground. Occasionally, those same horses are more fractious under saddle.

Something that sneaks up on owners that see their horses every day is muscle loss or atrophy. It comes on slowly, so it’s hard to notice. In particular, look for the back and hip muscles to lose substance near the spine, resulting in a loss of topline. There will be an overall look of loss of condition.

It may also be hard to keep weight on your horse. Many horses will have a lack of appetite and develop a ribby appearance. No matter how much sweet feed or hay you put in front of them, they will not fill out.

A very subtle sign to be aware of is the loss of sensation along the face, neck and/or body. Your horse may not respond to hand or leg pressure as he normally would. Tail swishing or skin twitching at flies will diminish, if not completely disappear.

Oscar’s Story

My wife’s Quarter Horse, Oscar, was moved from Oregon to Texas in December of 2012. He had been living in semi-retirement in the pasture for six years.

We knew it would take a couple of months for him to get in shape and lose the “brood-gelding” look, but there was no rush. While legging him up, she was surprised at how much more anxious Oscar was while under saddle. Even after lunging, he still acted “hot” and seemed to always be anticipating what he should be doing next.

By April, Oscar was much more fit, but didn’t seem to be settling in with his new work regime. My wife chalked it up to him holding out for pasture ornament status again, and kept him in training. While he was no longer chubby, his coat didn’t look good, even after shedding out by mid-May. A fecal test showed he needed to be dewormed, so he was given Strongid paste at the end of the month.

When I saw Oscar again a few weeks later, it was immediately apparent how much muscle loss he had along his spine. His appetite was weak and he appeared to be underweight. In addition, his trainer filmed an eye spasm on her phone that was of concern to us. All of these little issues aren’t generally alarming when seen separately, however, put together they were leading me to suspect a serious health issue.

I palpated his neurologic points, and it became apparent that we were dealing with a neurologic problem. I then performed a neurologic exam, which Oscar flunked rather resoundingly. He was given antiprotozoal medicine along with IV ozone treatments. At about the four-week mark, he took a turn for the worse. The medication was changed to a different antiprotozoal suspension, which brought about positive results within a week.

Oscar stayed on this new regimen for two months. He never showed any severe symptoms like ataxia or nerve paralysis. During the treatment, the trainer either gave him pasture turn out or light riding as exercise. This can help regenerate nerves faster and keep the immune system from staying depressed.

Full training resumed at the end of September and the change in Oscar’s demeanor under saddle has been remarkable. He is much calmer and doesn’t want to charge around the arena at the slightest leg cue. While he doesn’t completely pass a neurologic exam, we are hopeful that he will continue to improve. His immune system is now much stronger to aid in fighting off the infection, while the nervous system is repairing the damage.

We were lucky to catch this neurologic dysfunction when we did, before it got worse. I think it’s essential to recognize that veterinarians don’t always know exactly what is wrong with your horse at the first exam, so you need to be diligent in noting all of the changes you see. Learning how to perform a basic neuro exam will allow you to help your veterinarian.

The Neurologic Exam

A basic neurologic exam consists of six different tests. Learning how to do each of these is simple.


First, palpate the low back and sacrum area with your hands. You want your horse to flinch or drop away from the pressure. Many horses will turn and look at you as well. If your horse acts like he doesn’t feel the pressure this may be a sign of neurologic impairment.








Neur_2Palpation of acupuncture meridians to look for painful responses can be helpful. Take a needle cap or pen and apply medium pressure running down along the lower part of the neck and then onto the chest. Next, brush the needle cap from the point of the hip up and back to the sacrum. Finally, run it down the middle of the hind leg down past the stifle. If you elicit painful twitching or your horse gives you a warning look upon palpation of the chest, hip or stifle, this may indicate immune and/or nervous system compromise.
















Neur_9Take a piece of hay and lightly touch the side of the barrel in multiple areas. You are trying to mimic a fly walking on your horse. Also do this along the hip and stifle. Look for the skin to twitch to rid itself of the “poking” from the piece of hay. Check both sides, as there may be asymmetrical dysfunction.







Neur_13Move to the back of your horse and grasp the tail about two hand widths down from the dock. Pull the tail up and poke the underside of the tail with your finger. Your horse should try to clamp its tail back down into a normal position. If it is easy to hold the tail up in the abnormal position, this is referred to as weak tail tone.







Neur_26BWhile standing next to a hind leg, facing the tail, pick up the near foot and place it away from you to cross in front of the off hind foot. If it takes longer than 5 seconds for your horse to bring its foot back into a correct square position, it flunks the placing test. Again, do this with both hind feet as sometimes the deficit is worse on one side than the other.










Neur_2030The final part of the exam is the sway test. While facing your horse, take the tail, and wrap it around your hand one time. Step to the side and draw the tail towards you, trying to pull your horse off balance. It is common that you will be able to do this the first time with little to no resistance. During the second attempt, your horse should resist you and lean against your pressure. If you find you can repeatedly pull your horse’s feet your direction, this demonstrates weakness in the hind end.

If your horse fails more than two of these tests, you need to have your veterinarian come out for a more thorough examination.






Diagnosis and Treatment

Once a more thorough neurologic examination has been conducted by the veterinarian, he or she may take one or more blood samples for testing. There is the possibility of false positives or false negatives, so your veterinarian may perform more than one test.

Upon reaching a diagnosis, the appropriate treatment protocol will be prescribed. The drug choice and length of duration will depend on the severity of symptoms.

With a more acute, hard-hitting disease like the neurologic strain of EHV-1 or West Nile, treatment revolves around supportive care, fluids and anti-inflammatory drugs. If the horse is recumbent (unable to stand), the prognosis is usually very poor.

For EPM cases, an antiprotozoal drug will be prescribed for a minimum of 30 days. Often, this is not a long enough duration to prevent a reoccurrence of the disease. A more cautious approach would be to treat for 30 days after you stop seeing improvement. This will help the immune system be able to fight the infection on its own.

Alternative therapies are available that may be used in conjunction with or instead of drug therapies. They include supplements that boost the immune system and help fight infection, acupuncture, hyperbaric chambers and IV Ozone.


A healthy immune system is the first line of defense against infection. This is influenced by feed, supplements, immunostimulants, vaccinations and stress. Let’s walk through these one at a time.


Storing grain and supplements in covered containers can help prevent exposure of feed to dangerous contaminants.


There are a multitude of feeds on the market for horse owners to choose from. Those that are the healthiest will not contain molasses, corn, soy, bi-products or middlings. These can be hard for the horse to digest, usually contain high amounts of herbicides, and may induce an allergenic response from the immune system. It is difficult to handle an inflammatory diet and the invasion of viruses, bacteria and protozoa all at the same time.

In conjunction, 70 percent of the immune system is contained in the digestive tract. Therefore, it is important to make sure your horse does not have ulcers. A daily digestive conditioner can be very helpful, especially for performance horses that are hauling and competing.

Another beneficial supplement is L-Lysine. It is key to calcium absorption, building muscle protein, boosting the immune system and supporting the body’s production of hormones, enzymes and antibodies. This proactive approach will help your horse when exposed to infectious illnesses while under stress.

An immune stimulant activates a non-specific response to target any pathogen that may be recognized as a threat. Because of this rapid and general response, immunotherapy is a valuable addition to those horses that travel and compete on a regular basis. These stimulants are given IV and three doses are needed three days apart starting eight days before you leave.

It is prudent to make sure your horse has been adequately vaccinated in the past with the core vaccines. However, not all neurologic disorders can be prevented with vaccines. It is not recommended to vaccinate within the 21 days prior to major stress like hauling, competition, change of stabling environment and surgery (including castration). The immune system is busy trying to mount an antibody response to the vaccine(s), so it will be ill equipped to handle actual infection. It is also crucial to not over-vaccinate, as this can deplete the immune system as well.

It is hard to avoid stress with a competitive barrel horse. Your best option is to limit the amount of stress as much as possible. Provide stalled horses turnout every day. Avoid major medical and dental treatments immediately prior to competitions. Maintain a consistent feed source and monitor water consumption, especially during travel.

Finally, to help prevent EPM, it is important to make sure your feed is not exposed to fecal contamination from opossums and cats. It is known that EPM is caused by a horse ingesting protozoa from infected feces. Store grain and supplements in closed containers. Make sure your hay does not have dirt in it. If the baler was very low to the ground, there is a good chance it could pick up small animal feces.

Neurological diseases present significant challenges in diagnosis and prevention.  Early detection is key as the longer it takes to eliminate the infection, the more irreversible damage it can cause.  By taking note of the small changes in your horse and administering a basic neuro exam, you may be able to help pinpoint a problem before it gets too severe and the sooner you can get your horse on the road to recovery.


About Mark DePaolo, DVM

Mark DePaolo, DVM earned his veterinary degrees from Oregon State University and Washington State University in 1994. After working at two mixed practice clinics, Dr. DePaolo decided to specialize in holistic equine healthcare. He furthered his education by learning equine chiropractic and acupuncture in order to open his own practice, All Star Equine. He graduated from Colorado State University’s Acupuncture program in 2000.

Experience, innovation and a holistic approach to equine well-being have enabled Dr. DePaolo to become a leader in preventative and integrative veterinary medicine. A commitment to exceptional personalized care partnered with a genuine passion for providing a complete health care program drive his businesses.

In 2005, Dr. DePaolo’s passion in holistic equine health spurred him to create a new venture, DePaolo Equine Concepts, Inc. He recognized the need to combine both Western and Eastern approaches to medicine in order to create what he feels is the best medicine. Dr. DePaolo is constantly striving to create new methods to address the many problematic issues people experience with their horses.

Looking to broaden the awareness of holistic equine medicine, Dr. DePaolo moved to Horse Country U.S.A. in the summer of 2011. Using Pilot Point, Texas as his base of operations for both All Star Equine and DePaolo Equine Concepts, he strives to build long term relationships with clients based on integrity, willingness to help each client understand their horses’ specific concerns, and using “common sense” approaches to equine health.

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