The art and science of a lameness exam

Athletic trainers, orthopedic surgeons, and all the various other professionals involved in human sports medicine have it easy.  Waaaay easy.  When a person has pain when they are doing an activity (running, jumping, etc), they can go into the doctor or trainer and “Here’s where it hurts” and “It hurts whenever I do X activity”.  The doctor can get essential information from the patient in less than 10 minutes simply by asking the right questions and getting detailed, honest answers.

Screen Shot 2015-05-12 at 8.51.37 AMNow lets talk about the difference a veterinarian faces when performing a lameness exam on a horse.  The horse can not tell us which leg hurts, where on the leg it hurts, what activity makes it worse, how long it has been happening, etc, etc, etc.  A veterinarian relies on the owner or horse trainer to gather some of this information, but often the information is vague or conflicting depending on whom you are talking with.  Many times I get some variation of the following history:

“My horse has been ‘off’ for a couple of months now.  It feels like it is in the hind leg but my trainer said she is short striding in the front.  I gave the horse some ‘bute’ but I ran out so I stopped a couple of weeks ago.  My farrier put on shoes last week.”

This type of history is very vague and really does not tell the vet much except this is a chronic mild to moderate lameness.  Now it is up to the vet to figure out what is really going on and how to fix it.

Which leg or legs are lame?

This is the first question the vet attempts to answer when performing a lameness exam.  Sometimes it is very obvious, other times it can hard to tell.  In order to determine which leg or legs are lame, the vet will watch the horse perform different gaits, starting with a basic walk.  If not obvious at a walk the vet will move on to a trot in a straight line.  If it is still not obvious the vet may lunge the horse in different directions and on different surfaces.  Basically the idea is to visualize the lameness or gait abnormality that the owner or rider has noticed.

The vet will watch the horse move at different gaits on different surfaces to help determine which leg is lame. Source: thehorse.com
The vet will watch the horse move at different gaits on different surfaces to help determine which leg is lame.
Source: thehorse.com

Several things can come up that make finding the lame limb difficult or impossible:

1.  The horse is not lame the day of the examination.  This situation happens very often and is a major frustration for owners.  You can have a horse that has been consistently lame for three months but the day the vet examines it the horse will suddenly be sound.  An important piece of advice is to exercise your horse before the vet appointment and make sure his is actually still lame!

2.  Multiple legs are lame.  It is extremely hard to make an accurate diagnosis when a horse has multiple limbs that are making his gait abnormal.  One leg may be compensating for another or the legs may have two completely different issues.

Where in the limb or body is the lameness coming from?

Once the vet determines which limb is lame, the next step is to find where in that limb the lameness is coming from.  Again, sometimes this can be quite obvious.  For instance, if the right front leg is lame and the fetlock is swollen, hot, and painful your vet probably will be confident that the lameness is coming from the fetlock region.  If it is not obvious, your vet can perform certain tests to help localize the lameness.

Your vet may perform a flexion test in order to determine where in the limb the lameness is coming from. Source: vetmed.vt.edu
Your vet may perform a flexion test in order to determine where in the limb the lameness is coming from.
Source: vetmed.vt.edu

One simple test is called a “flexion test”.  Your vet will hold certain joints in flexion for various periods of time and then watch the horse trot.  If flexing a joint makes the lameness worse, it is highly likely that the lameness is coming from that joint.  Another way to help localize a lameness is to test the hoof for sensitivity to pressure.  A hoof tester is a device that puts pressure on certain regions of the foot.  A reaction or pulling  the foot away from the examiner tells the vet that the horse is sore at that particular location in the foot.

If after performing flexion tests, palpating the limb, and manipulating the limb, the location of the lameness is still not obvious your vet make begin “blocking” the limb/joints.  “Blocking” refers to numbing portions of the limb and watching the horse trot. If the lameness disappears after a nerve “block”, then the vet can be confident that the problem area is within the portion of the leg that was numb.  This test does not always pinpoint the exact location of the lameness, and sometimes the results can be questionable – for instance, the lameness might improve by only 50%.  If this is the case your vet may repeat the block on a different day or use a combination of tests to localize the lameness within the leg.

What pathology or abnormality is causing the lameness?

In some cases your horse may need an MRI for accurate diagnosis of the cause of his lameness. Source: purdue.edu
In some cases your horse may need an MRI for accurate diagnosis of the cause of his lameness.
Source: purdue.edu

After your vet is confident that they have pinpointed the lame leg and localized the lameness to a region of the leg, they can begin to look for an abnormality in that region that is responsible for the lameness.  The most common way to detect the abnormality is by using diagnostic imaging (x-rays, ultrasound, MRI, etc).  Depending on the case and the experience of the vet, they will usually start with either x-rays or ultrasound to image the leg.  X-rays are used to visualize bones and joints, whereas ultrasound is better for looking at tendons and ligaments.  Sometimes a defect or abnormality may be very small and impossible to see with x-rays or an ultrasound.  At that point your vet may refer your horse for an MRI or a nuclear scan.  Diagnostic imaging often is the most costly part of the lameness exam.

What can an owner do prepare for a lameness exam?

If a horse owner has never had the experience of dealing with lameness issues, there are several things that I think they should know before having a lameness exam done on their horse.

– Do not give your horse any pain medication (bute, Banamine, etc) at least 48 hours before a lameness exam.  The vet wants to see your horse when it is as lame as possible.  This make localizing the lameness much easier.

– Bring your tack with you and be prepared to ride.  Sometimes a gait abnormality is only visible under saddle.  The vet needs to see the lameness in order to make a diagnosis, so you will need to recreate the situation in which the lameness occurs.

A nerve block numbs portions of the limb.  If the lameness improves by 80% or more, it is likely the cause of the lameness is in that region.  If the lameness only improves slightly then different nerve blocks may need to be attempted. Source: research.vet.penn.edu
A nerve block numbs portions of the limb. If the lameness improves by 80% or more, it is likely the cause of the lameness is in that region. If the lameness only improves slightly then different nerve blocks may need to be attempted.
Source: research.vet.penn.edu

– The examination may take several hours, maybe even days.  The more difficult it is to determine where the lameness is coming from, the longer the exam will take.  If blocking the leg doesn’t show >80% improvement then it may need to be blocked a different way (for example a joint blocked instead of a region of the leg) to narrow down the source of the pain.  The numbing effect of a block can last hours and the vet needs to be sure that the first block has completely worn off before trying a second one in the same region.

– Lameness examinations can be expensive.  A subtle lameness with a hard-to-visualize abnormality can be very difficult and time-consuming to correctly diagnose.  An owner needs to be prepared that in order to get definitive answers, they may be spending thousands of dollars.  On the other hand, an obvious lameness that is easy to diagnose (example: hoof abscess) will not be so costly.

To summarize….

In order for a veterinarian to be proficient in lameness diagnostics, they must be experienced in the observation of gaits, recognition of subtle abnormalities, interpretation of test results and diagnostic imaging.  The lameness exam is an exercise of both the art and science of veterinary medicine.

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Equine Corneal Ulcers – The Case of the Squinty, Watery Eye

Imagine that you are going out to feed your horses for the evening and you notice that one of them is holding her eye shut.  It looks pretty swollen and there is a bunch of watery discharge coming from the corner of the eye.  You put her in the cross ties and try to pry her eye open to have look at the eyeball, but those darn eyelids are so strong!  Finally you result to just standing there are staring at her, waiting for her to open the eye.  When she finally does, you notice the eye looks cloudy.  Time to call the vet……

Swollen, teary eyes that have a blue or cloudy tinge should be examined by your vet ASAP. Source: oceanstateequine.com
Swollen, teary eyes that have a blue or cloudy tinge should be examined by your vet ASAP.
Source: oceanstateequine.com

What could be going on with this eye?

The cornea is the clear tissue that covers the surface of the eye.  This is a diagram of a cross-section of the eye. Source:  thehorse.com
The cornea is the clear tissue that covers the surface of the eye. This is a diagram of a cross-section of the eye.
Source: thehorse.com

When a vet is presented with a horse that has a squinty and watery eye, we can assume that the eye is causing pain to the horse.  A cloudy eye usually indicates that there is “corneal edema”.  The cornea is the tissue on the surface of the eye that is normally clear/transparent.  When the cornea is damaged or irritated is becomes swollen, which creates a blue/cloudy tinge to the surface of the eye.  Corneal edema is not specific for any one disease or injury – it just means that the cornea is injured/irritated.  So the only information we have right now is that the eye is painful and the cornea is swollen.

What happens next?

Your vet will examine the eye.  This may take some sedation, depending on how the horse is behaving.  In some cases the vet may even “block” the eye, meaning they may use local anesthesia to numb the surface of the eye and eyelids as well as prevent the eyelids from squeezing shut.  You would be surprised how crazy strong those eyelids are – I am not kidding.

When doing an eye exam it is best to have the horse in a DARK quiet area.  It may seem counterintuitive, but it is much easier to examine the eye using an ophthalmoscope in the dark than in bright daylight.  Your vet will look through the ophthalmoscope to see the surface of the eye and possibly the back portion of the eye.

Your vet also will most likely stain the eye at this point.  A particular stain, fluorescein, is used to detect defects in the corneal tissue.  In the normal cornea the stain will not attach to the eye because of the surface of the cornea is covered by cells that don’t allow the stain to penetrate them.  If the cornea is damaged or ulcerated the underlying cells of the cornea (stromal cells) will be exposed and they will take up the stain.  The vet can now see where the cornea is ulcerated or damaged.

Fluorescein eye stain can show the location and size of a corneal ulcer. Source: ckequinehospital.com
Fluorescein eye stain can show the location and size of a corneal ulcer.
Source: ckequinehospital.com

If no stain taken up by the eye, the vet will then have to look for other possible reasons to explain why the cornea is swollen.  For the purpose of this article, however, let’s say that your horse had an area of stain uptake of about 2mm diameter.  Your vet now can be confident that a corneal ulcer is responsible for the clinical signs your horse is exhibiting.

How is a corneal ulcer treated?

Like many things in medicine, the answer is “It depends.”  In this case it depends on how deep the ulcer is, how long it has been going on, and how the ulcer responds to initial treatment.  In most cases of a simple ulcer that is caught early in its progression, treatment consists of topical antibiotic ointment, anti-inflammatory medication, and topical atropine.  In other, more complicated cases your vet may want to use additional medications like topical anti-fungals and serum.  In any case, do not use over-the-counter eye medication on your horse!  Do not use Neosporin in the eye!  The eye is VERY sensitive and needs ointment specifically designed to be applied to the eye.

Most of the time the topical medications are applied several times a day to the affected eye.  The constant manipulation of the eye can lead to a very cranky horse.  Sometimes owners will have such a difficult time with their horse that the medication never properly gets in the eye and the eye doesn’t heal.  In these cases there is a special medication delivery system that can be placed around the eye so that the medication can be applied without having to manhandle the horses eye.  The subpalpebral lavage system is definitely something to ask your vet about if you are having difficulty getting eye medications into your horse.

A subpalpebral lavage system allows medication to be administered through a syringe, where it travels down a tube and is deposited under the upper eyelid.   Source: veterinare-ophtalm-lengelle.be
A subpalpebral lavage system allows medication to be administered through a syringe, where it travels down a tube and is deposited under the upper eyelid.
Source: veterinare-ophtalm-lengelle.be

Finally, your horse will need to be kept out of daylight if she is receiving atropine topically to the affected eye.  Atropine forces the pupil to dilate, which is beneficial is terms of preventing pain and permanent damage to the eye.  However, the eye will not be able to adjust to light (by constricting the pupil), so your horse will need to either be in a dark stall or have a patch placed over the affected eye.  Once the atropine is out of the system, the horse can return to her normal turnout schedule.

How long does it take to heal?

Ulcers not treated properly can become infected with bacteria and/or fungi.  Infected ulcers take months to heal and can have major complications. Source: northfloridaequine.com
Ulcers not treated properly can become infected with bacteria and/or fungi. Infected ulcers take months to heal and can have major complications.
Source: northfloridaequine.com

A normal, uncomplicated ulcer should heal within a week or two.  Larger and deeper ulcers take longer to heal than small ones.  Ulcers that become infected with bacteria or fungi can take months to heal.  There are also “indolent” ulcers, which are ulcer that just seem very resistant to healing despite all therapies.  These are fairly rare.  The most important thing to remember is that early recognition and treatment can save you weeks of treatment and loads of money in the long run.  The “wait and see” approach is never a good idea when it comes to the equine eye.  There are several cases each year of clients who end up spending a lot of money treating an infected ulcer for months because they wasted three days treating the horse with an over-the-counter medication.

Any prevention tips?

There is no possible way to 100% prevent the equine eye from getting injured – sorry.  But, keeping a vigilant eye out for areas that look like a good place to scratch or poke an eye can help.  Nail heads, chipped wood, or any piece of wire hanging around is an easy place for a horse to injure his eye.  Also, horses can get ulcers even if they have on a fly mask, so make sure to take off the mask every day and look at the horse :).

Foaling basics by the numbers

Equine reproduction and neonatal care are my favorite parts about veterinary medicine.  I absolutely love breeding and foaling season, despite the busy schedule and unpredictable hours.  A foal’s first whinny and the mare’s returning nicker are the some of the greatest sounds in the world, and there is nothing like watching a foal stand and try to figure out how to nurse for the first time!

Foaling is an amazing process!  The first look and nickers between the mare and foal are wonderful to observe.
Foaling is an amazing process! The first look and nickers between the mare and foal are wonderful to observe.

For the horse owners that have not had a mare and foal before, it can be quite intimidating to read about all of the aspects of foaling and caring for the new arrival.  Just like humans, each equine pregnancy is different and each foal is different.  What looks like no big deal to the average horse person may mean something different to a veterinarian. Furthermore, as you read this article, you will notice that foaling is a fast process where a lot can go drastically wrong in a short period of time.  Thus, one piece of very important advice is to develop a good relationship with your equine veterinarian before your mare is due.  Make sure they (or one of their colleagues) are available to answer your questions 24/7.  Ask them if they have a way to receive pictures on their phone.  Place their phone number up in the barn in big easy-to-read numbers.  This is to ensure you that when the big day comes you are prepared and can easily reach a trusted medical professional if needed.

Because foaling and neonatal care seems to revolve around some very important numbers, I would like to go over the basics of foaling by emphasizing these numbers and explaining what they mean.

320 days

This is the shortest gestation length for a mare.  Any less than 320 days from ovulation and the foal is considered premature.  The average length of gestation is 330-345 days, however some mares will go over 390 days.  We commonly get calls from worried owners because their mare is overdue by weeks, and they are concerned that the foal will be too big for her to deliver.  Many owners wonder if we can just induce the mare to deliver.  It is strongly discouraged in almost every case to induce a mare to foal.  First of all, the longer the gestation length, the smaller the foal tends to be when born – so the chance that the foal will be too big is very small.  Second, we need to remember that sometimes “nature knows best” and that it is the foal that tells the mare when it is ready to be born.  Hormones produced by the foal basically tell the mare that the foal is mature enough to be born and cause the onset of parturition (labor).  When inducing a mare, you run a high risk of having a dysmature foal, dystocia (difficult birth), poor quality colostrum, and a host of related issues.  It is better to let nature take its course and keep the “bun in the oven” longer.

4 to 6 weeks

It is ideal to vaccinate your mare approximately 4 to 6 weeks before her due date.  This ensures that she has the highest level of immunity to those diseases when she foals.  The colostrum (first milk) that she produces will have high levels of antibodies, which will pass to the foal when it nurses.  If the foal ingests the proper amount of colostrum from a vaccinated mare, then it will be protected from those diseases until about 4 to 6 months of age.

6 to 48 hours

Colostrum forms a waxy plug at the end of the teats 6 to 48 hours before foaling in 95% of mares. Source: extension.org
Colostrum forms a waxy plug at the end of the teats 6 to 48 hours before foaling in 95% of mares.
Source: extension.org

Approximately 95% of mares will develop “waxing” on their teats about 6 to 48 hours before the beginning of labor.  The waxy buildup is just colostrum that is starting to leak from the teats as the body prepares for foaling.  The mammary glad will develop and the udder begin to fill with colostrum several days before parturition.  Other signs that the mare may foal soon include relaxation of the vulva and relaxing of the ligaments on either side of the tailhead.

30 minutes

This is the maximum amount of time that a normal foaling should take after the mare’s “water breaks”.  Stage II of labor is the active delivery of the foal and begins once the chorioallantois (bag) ruptures and ends with foal being expelled from the birth canal.  During this stage the mare actively pushes and usually lays down to deliver the foal.  If progress is not being made, then it generally means something is wrong.  Because this stage of labor is so fast, it means that the foal will die very quickly if it is not expelled in the appropriate amount of time.  Improper position and/or presentation of the foal is the typical reason for a difficult birth in the horse.  The normal position and presentation is with both front feet coming out first, followed by the head and the rest of the body and hind limbs.  Any deviation from this positioning can cause a difficult delivery, which may need veterinary assistance.  Since equine labor is a fast and vigorous process, for delivery of a healthy foal by a healthy mare, it is important to have access to a vet nearby.  If you live far from your vet and your mare has a history of difficult deliveries or has any other health problems, it may be a good idea to see if you can have your mare foal at your veterinarian’s office.  Equine vets typically offer this service and may even have wi-fi cameras set up so you can watch the foaling from your home.

anterior_dorsosacral_deliverymerkvetmanual
Normal position and presentation during delivery. Any deviation from this form can cause difficulties for the mare and foal. Source: merckvetmanual.com

3 hours

The placenta or fetal membranes should be passed within 3 hours of delivering the foal. Source: horsejournals.com
The placenta or fetal membranes should be passed within 3 hours of delivering the foal.
Source: horsejournals.com

This is the maximum amount of time that it should take for the mare to deliver the placenta or fetal membranes.  Once 3 hours have passed, the mare is considered to have “retained fetal membranes” and begins to be at risk for infection and laminitis.  At that point it is important to call your veterinarian.  DO NOT try to pull the membranes out yourself!!!  You may end up leaving a piece of the membrane in the uterus, which can serve as a source of infection.  Your vet may give your horse oxytocin (to stimulate uterine contractions), manually remove the membranes, and/or flush out the uterus.  Additionally the mare will probably be given antibiotics and anti-inflammatories.

24 hours

This is the period of time that the gut of the foal can absorb antibodies from the mare’s colostrum.  It is imperative, therefore, that the foal nurses as early as possible and ingests an adequate amount of colostrum from the mare.  The only immune system that the foal has is that which he gains by ingesting his mother’s colostrum.  If the foal does not get enough antibodies from the colostrum, they are immunocompromised and extremely susceptible to any infection.  The normal foal should be standing by 1 hour after birth and nursing within 2 hours.  If you do not see this happen, you may need to hand milk the mare and bottle-feed the foal.  Over the first 24 hours of life the foal should ingest 1-2 pints of colostrum.  If the foal will not take the bottle, then you will have to call the veterinarian to come and place a tube down its nose and into the stomach.  The vet can then pour colostrum down the tube.  Again, this only works in the first 24 hours of life!  After that, any antibodies will have to be transferred to the foal in the form of intravenous plasma ($$$).

The foal in this picture hasn't figured out how to nurse yet but he should be nursing normally within 2 hours of birth.
The foal in this picture hasn’t figured out how to nurse yet ( :)) but he should be nursing normally within 2 hours of birth.

Additional numbers that are important to be familiar with are seen below in a graph borrowed from Foalcare.com.

foalingWatchChart

I highly recommend the Foalcare website for more detailed information on foaling and prenatal care for the mare.

Owning a mare and foal is a rewarding experience that can (at times) be stressful.  One way to ease some worries regarding the health of the mare and foal is to have a mare and foal check performed by your veterinarian 12-24 hours after the foal is born.  At that time the vet can:

– Check the placenta to look for any missing pieces or abnormalities indicating possible infections in utero.

– Make sure the mare has not torn her vulva and/or vagina during delivery.

– Look at the mares milk production to determine if it is adequate.

– Examine the foal for any congenital defects such as cleft palate, juvenile cataracts, hernias, and limb deformities.

– Determine if the foal has ingested enough colostrum to have an adequate immune response to pathogens by measuring the level of immunoglobulins in the plasma of the foal (IgG test).

– Make sure the umbilicus is dry and clean.  The umbilicus should be dipped in a chlorhexidine solution after it breaks off from the placenta.

– Give a tetanus vaccination to the foal.

Remember, timing is important and the earlier an abnormality can be recognized, the earlier treatment can begin.  For any issues regarding foaling and neonatal medicine, when it doubt – call the vet!

Good luck to all of you equine breeders out there and have a wonderful foaling season!

Continue reading Foaling basics by the numbers

Vaccinating Your Horses – What, When, and Why?

For an equine vet, springtime is extremely busy – foaling, breeding, vaccination, Coggins, etc.  Our clinic typically vaccinates over 100 horses per week from March until May.  That’s a lot of vaccinations!

Some vaccines are recommended for all horses, others just for "at risk" horses.  Each horse should have a tailored vaccination program designed by your veterinarian.   Source:  thehorse.com
Some vaccines are recommended for all horses, others just for “at risk” horses. Each horse should have a tailored vaccination program designed by your veterinarian.
Source: thehorse.com

I would like to write about this topic today because recently there have been outbreaks of diseases that could have been prevented or mitigated had the horses been vaccinated.  Additionally, because medical topics that affect humans (such as vaccination risks vs. benefits) often trickle over into vet medicine, I would like to address the risk vs. benefits of equine vaccines.

The recommendations for vaccinating in this post are taken from the American Association of Equine Practitioners Vaccination Guidelines.  As always, please discuss vaccinations for your horses with your personal vet for reasons you will learn about as you continue to read.

What Vaccinations Should My Horse Receive?

It depends…..

Several factors to consider include:

1.  The job of the horse

Some diseases that we vaccinate for are transmitted from horse to horse.  Others are transmitted to the horse from other animals.  Still others are contracted from the environment.  Horses that stay on the farm the majority of the time and rarely come into contact with other horses have a low risk of picking up diseases that are communicable.  In contrast, horses that are going to clinics and shows every weekend have a high risk of picking up these type of “bugs”.

2.  The location of the horse:

Different areas of the United States, and other countries for that matter, carry different risks for picking up particular pathogens.  For instance, Potomac Horse Fever is not prevalent everywhere in the US.  Some areas, such as the mid-Atlantic region, carry a very high risk for PHF yet other areas have relatively low risk.

3.  The health status, age, and medical history of the horse:

There is always a risk with vaccinating horses, as with anything you put into their body that is foreign (medication, food, etc).  Some horses are prone to vaccine reactions, which may include fever, lethargy, anorexia, and swelling of the vaccination site.  For these “sensitive” equids we try to only vaccinate with the bare essentials.  Additionally, different age groups of horses have higher risk of contracting specific diseases, so sometimes vets will recommend a vaccination for a young horse but not your geriatric horse.

4.  Recent disease outbreaks:

Disease outbreaks scare all of us and can lead to widespread panic amongst horse owners.  Couple that with the misinformation gained from social media and suddenly vets are receiving dozens of phone calls from frantic horse owners wanting their horse immediately vaccinated for X,Y, and Z.  This week there was a confirmed case of EHV-1 at Michigan State University in a barrel horse.  Two days later we are getting calls from people asking if they should not take their horse to any barrel races in the near future.  Cases like this can be scary, but it is very appropriate to discuss the risk of these diseases with your vet before vaccinating your horse.  Your vet will be the best source of information regarding any recent disease outbreaks in the area and if your horse should be vaccinated.

Map of EHV-1 Myeloencephalitis cases from March 2014 to March 2015.  Your vet can help you decide what vaccines are appropriate based on recent disease outbreaks.   Source: wormsandgermsmap.com
Map of EHV-1 Myeloencephalitis cases from March 2014 to March 2015. Your vet can help you decide what vaccines are appropriate based on recent disease outbreaks.
Source: wormsandgermsmap.com

Even though some vaccinations may not be necessary for your horse, there are a few vaccines that are considered “core” – meaning all horses in the US should receive these vaccines.  At a bare minimum the AAEP recommends all horses get vaccinated for:

– Tetanus

– Eastern and Western Equine Encephalomyelitis (EEE and WEE)

– Rabies

– West Nile Virus (WNV)

Risk-based vaccines are administered based on each horse’s particular risk for contracting the respective disease.  Some risk-based vaccines are:

– Potomac Horse Fever

– Strangles (Streptococcus equi)

– Equine Herpesvirus Type 1 and 4 (EHV-1, EHV-4) a.k.a Rhinopneumonitis

– Equine Influenza

– Botulism

For more details regarding each of these vaccinations and their recommendations, please visit the AAEP Vaccination Guidelines page.

When Should My Horse Get Vaccinated?

Many diseases are transmitted by insects, which are seasonal depending on where you live.  Your vet will help you decide the optimum timing for your horse's vaccinations. Source: ocalapost.com
Many diseases are transmitted by insects, which are seasonal depending on where you live. Your vet will help you decide the optimum timing for your horse’s vaccinations.
Source: ocalapost.com

For most vaccines it takes two weeks to develop immunity or protection from disease.  That means your horse should be vaccinated a minimum of two weeks before he needs protection.  Many of the diseases we vaccinate for are transmitted by insects or mosquitoes (PHF, EEE, WEE, WNV), so we recommend vaccinating a short time before these insects are active, and repeat yearly.  additionally, for communicable diseases such as Equine Influenza, your vet may suggest a second vaccination in the autumn if your horse will continue to travel through the winter.  It is less than ideal to wait until July or August to vaccinate your horse because insects will have already been active and could transmit disease before then.

Why Should My Horse Get Vaccinated?

My guess is that your horse is more than just an animal to you.  He or she is probably your companion and you love them.  Because you love your horse, you would not want to see him sick.  Many of the diseases we can vaccinate for are not pretty to see.  I know many horse owners who feel guilty if there horse gets injured or sick, even though there is not way they could have prevented it.  Imagine how it would feel to know that a horse is sick but it could have easily been prevented.

Vaccines are rigorously tested and inspected before being allowed to be administered.  This is to ensure their safety and effectiveness in preventing disease.  Although the rare horse will have a reaction to a vaccine, by far the majority are mild and temporary.  So yes, there are risks with giving a vaccine, but the benefits (protection from deadly disease) are greater.

Screen Shot 2015-03-27 at 10.24.12 AM

Finally, the cost of treatment FAR surpasses the cost of a vaccine.  For instance, a vaccine may cost anywhere from $15-80 plus any additional services or fees.  An emergency call for an acute neurologic disorder may run you into the $1000’s in just one night.

Veterinarians are not doing the job for the money.  We are not pushing vaccines to try to please “big pharma” and get fancy rewards from drug companies.  I know conspiracies are interesting, but honestly, we make very little money in administering vaccines to horses.  It is not fun to spend the day jabbing horses with needles and giving injections.  We just want to keep your horse healthy and happy – like you!

Reasons a Prepurchase Exam is Like a Home Inspection

If you have purchased a home you know that it is vital to have a home inspection done before you sign all of the paperwork.  Similarly, when purchasing a horse you have the option to have it examined by a veterinarian before you make the final decision – a.k.a, a prepurchase exam.  Here are some reasons why a prepurchase exam is like a home inspection.

With any important purchase it is a good idea to have a professional inspection performed before buying. Source: hudpass.com
With any important purchase it is a good idea to have a professional inspection performed before buying.
Source: hudpass.com

1.  To save money you have to spend money. When buying a home you are buying all of the issues that go along with it.  A home inspection may detect some of these issues, such as water damage or foundation cracks.  If those problems are addressed with the seller, you may be able to negotiate a lower price or have the repairs done before you buy the home.  Either way you end up saving money – but you had to spend money to get to that point.  The same is true with a prepurchase exam when buying a horse.  If an issue, such as arthritis in the hocks, is detected you may be able to negotiate down the price of the horse or have the seller pay for hock injections.

2.  An impartial eye is able to see better than one clouded with emotion. Many home buyers will become emotionally involved with a house before buying it, which can make it easy to overlook problem signs.  Similarly, many people will become attached to a horse before purchasing and find themselves not looking critically at the animal.  Your veterinarian should be impartial to the horse, it’s seller, and the buyer.  During a prepurchase examination the veterinarian will inspect the horse for any abnormalities, interpret those findings, and relay them to the buyer.  Sometimes the buyer will not want to hear about the potential issues in their “perfect” horse, but nevertheless these facts will be documented by the veterinarian for the buyer to review when they are at home and emotionally collected.

You may fall in love with a horse before a prepurchase exam, which means you may overlook certain issues that may become a problem. Source: imgarcade.com
You may fall in love with a horse before a prepurchase exam, which means you may overlook certain issues that may become a problem.
Source: imgarcade.com

3.  A licensed and trained professional will pick up subtle clues to potential problems. Home inspectors are trained to look for signs of potential issues in homes that the majority of people would not notice.  The inspector also knows how to interpret these findings and explain them to potential buyers.  For instance, a home may have a fan ventilation system that opens up into the attic (bad) rather than to the outside of the home (good).  At the time of the purchase the attic may not have any mold or visible damage, so the buyer does not think there is a problem.  However, the home inspector is trained to look at ventilation systems and will explain to the buyers that the improper setup will likely lead to future problems.  Likewise, a veterinarian is trained to look for clinical signs indicating a problem that may not be so obvious to others.  For instance, the vet may notice the horse has worn down the front of his toes excessively.  Hoof wear pattern can be a subtle clue to look for lameness or neurological problems.  Your vet will know what tests to perform in order to rule out or diagnose major underlying issues that can cause these hard to detect abnormalities.

4.  There is no “pass” or “fail”.

A prepurchase exam does not "pass" or "fail" a horse - it just gives a snapshot image of the overall health of the horse at a particular time. Source: depositphotos.com
A prepurchase exam does not “pass” or “fail” a horse – it just gives a snapshot image of the overall health of the horse at a particular time.
Source: depositphotos.com

A home does not “fail” inspection.  Here is an excerpt from the American Society of Home Inspectors regarding passing or failing home inspections: “A professional home inspection is an examination of the current condition of a house. It is not an appraisal, which determines market value. It is not a municipal inspection, which verifies local code compliance. A home inspector, therefore, will not pass or fail a house, but rather describe its physical condition and indicate what components and systems may need major repair or replacement.” – http://www.ashi.org/customers/faq.asp.  A prepurchase exam is not a pass or fail exam, but an examination of the current condition of a horse.  The veterinarian states the findings of a physical examination and interprets those findings as current problems or as clues to potential future problems.  If someone says “Did the horse pass the prepurchase exam?”, I often reply with “Only you can decide whether the horse will pass your personal criteria as something you want to undertake.  I can only tell you what I found today and what that means or can mean for the future of this horse’s health.”  Some people don’t want to hear that, they want you to make the decision for them so they feel absolved of blame if something goes wrong with the horse’s health in the future.  However, purchasing a horse is always a gamble and the person spending the money needs to make the decision as to how much or if they want to ante up.

5.  There are no guarantees, we do not have x-ray vision, and we are not fortune tellers

nogaurantees

Despite spending money on a home inspection, you could have a major unforeseen repair needed the minute after you purchase your home.  It is not fair but life is not fair.  For instance, mice could live in the walls of the home, and there may be no signs of infestation at the time of home inspection.  The inspector does not have x-ray vision so he can not tell you what is going on inside those walls.  He can only look for outward signs of mice (droppings, holes, etc).  Furthermore, he can not see the future and predict that you will have a major roof leak in 2 years. In the same way, a prepurchase examination is not a guarantee that the horse will not be lame or sick in the near or distant future.  We can spend money on all of the fancy tests available, but the horse could still stumble and break it’s leg on the first day home.  Again, spending money on a horse is a gamble and we have to learn to accept that risk.  Even despite taking x-rays or performing an MRI, there are still areas of the horse that are not able to be visualized and examined.  Tiny microfractures could be present in the cannon bone or a small tumor could be growing inside the abdomen – these things are undetectable.  And finally, even the small abnormalities that are detected are not always going to cause a problem.

For instance, a horse may not be lame but has some signs of arthritis in his hocks.  The buyer naturally wants to know if this is going to cause the horse to be lame in the future.  Sorry, but there is no way to tell that – we can’t predict the future.  My typical response to this conundrum is “This horse is sound today, but the x-rays show some signs of arthritis.  There is no way to determine if these abnormalities are going to result in the horse being lame.  However, you need to be aware that there is a greater chance of this happening than if he did not show arthritis signs on the x-rays.  You may be looking at regular joint injections in the future, which will cost money.  It is up to you to decide whether you are comfortable paying the current price of the horse and taking the risk of a higher probability of lameness issues in the future”.  Again, the buyer would probably be happier if I said “Oh, he looks great and those x-rays shouldn’t be a problem!”, but that is how lawsuits happen.

To sum it up, a prepurchase exam is a good investment for potential buyers and should be performed by a veterinarian.  It may help detect subtle issues that can impact a horse’s performance currently and in the future.  It helps alliviate some of the risk when spending the money on a horse.  However, there is no way to completely eliminate risk or predict the future soundness and performance abilities of a horse.

What is “Choke”?

When most people hear the word “choke” they think of a person choking on something, such as a piece of food or small toy (for those little kiddos who like to eat anything in sight).  In those instances they are referring to an object lodged in the trachea – the tube from the mouth to the lungs, which prevents breathing from taking place.

In the horse world “choke” refers to when your horse gets something stuck in his esophagus – the tube from the mouth to the stomach.  The trachea is free of obstruction, so the horse can breathe, and thus choke is not an immediate life-threatening emergency.  However, a horse with an esophageal obstruction (aka “choke”) can develop serious complications if the situation does not resolve in a timely manner.

Obstruction of the esophagus (not the trachea) is typically called "choke" in horses. Source: visual.merriam-webster.com
Obstruction of the esophagus (not the trachea) is typically called “choke” in horses.
Source: visual.merriam-webster.com

What Causes Choke?

Horses usually choke on feed, not foreign objects.  Feed can be grain, pellets, hay, or treats (apples, carrots, etc).  In a case of choke, most of the time the horse does not chew its food properly, which results in a bolus of food getting stuck as it goes down the esophagus on its way to the stomach.  Reasons for not chewing the food properly are:

Poor dentition:  If the horses teeth do not “occlude” (or touch one another) properly the food will not be ground up efficiently when being chewed.  Missing teeth, overgrown teeth, or worn down teeth are examples of issues that can cause improper chewing.  The feed being swallowed may be too large to move down to the stomach, or it may just travel slowly through the esophagus and build up to cause an obstruction.

Poor teeth alignment or "malocclusions" can cause problems chewing and lead to choking episodes. Source: straightfromthehorsesmouth.com
Poor teeth alignment or “malocclusions” can cause problems chewing and lead to choking episodes.
Source: straightfromthehorsesmouth.com

Eating too fast: Why would a horse eat too fast?  One reason is they are really hungry and just want to stuff their face.  Horses are designed to be grazers and should have constant access to forage (hay or grass).  If they are only fed twice a day you may find your horse voraciously eating at breakfast and dinner.  More common, however, the horse that gulps its food down is trying to eat before another horse comes and steals his food.  You would be surprised at the number of choke cases I see that are essentially due to poor herd management.  It is important to watch your horses eating, at least for a couple of minutes.  Ideally you would feed them and watch for a few minutes, clean a stall, watch again, clean another stall, watch again, etc.  You may find one horse eats a bit slower than the others, and when the others are finished they chase him away from his food.  Eventually he will figure out he has to eat fast in order to get his full ration.  Sooner or later he will end up with an esophageal obstruction.

Pain:  When it hurts to chew we humans tend to switch to softer foods to avoid the pain.  Horses don’t have this option (although I have seen them “dunk” their hay in water) so they may just decide to chew less or less efficiently.  This can cause a choke episode in the same way as poor dentition.

Aside from improper mastication (fancy term for chewing), there are other more rare causes for esophageal obstruction.  Trauma to nearby structures in the neck and chest can result in narrowing of the esophagus (esophageal stricture).  Sedation decreases the ability of the muscles that make up the esophagus to move food down into the stomach.  Anatomical abnormalities, such as an esophageal diverticulum (a small outpouching of the esophagus) can also result in a choke episode.  Often these more rare causes of choke (except sedation) tend to show up as recurrent choke despite making needed changes in the horse’s diet and management.

What does choke look like?

The classic signs of a horse with choke are as follows:

Nasal discharge with food particles is a classic sign of a choking horse. Source: equineink.com
Nasal discharge with food particles is a classic sign of a choking horse.
Source: equineink.com

– excessive drooling or saliva

– coughing

– nasal discharge with food particles present

– “retching” or stretching and arching the neck

– pawing or laying down

– head shaking

The horse may refuse to eat or drink.  They generally act distressed – with good reason.  I know people who have experienced an esophageal obstruction – they tell me it is horrible!

How is choke treated?

I suspect that the majority of cases of choke go undetected and are resolved naturally by the horse.  However, more severe cases or cases where the owner happens to observe the horse eating are the ones where the vet is called.  If your horse is showing the signs listed above, remove his food immediately.  Attempt to massage the throat from the throat latch to the chest.  You may be able to feel the bolus and help break it up.  Then call the vet.  They may ask you to give the horse some time to work it out naturally or they may come right out – it depends on the case.

A nasogastric tube goes from the nose to the stomach to help siphon out chunks of obstructing material.   Source: oakequine.co.uk
A nasogastric tube goes from the nose to the stomach to help siphon out chunks of obstructing material.
Source: oakequine.co.uk

If your vet does come to see the horse be prepared to have a bucket of warm water ready.  Your vet will probably start with a general exam and may then give the horse a muscle relaxer or sedation.  This relaxes the esophagus and sometimes results in the bolus moving down to the stomach.  The most important aspect of treatment is “tubing” the horse.  A tube is inserted into one of the nostrils and passed into the nose, which leads to the back of the throat and the entrance to the esophagus and trachea.  The vet will check and make sure the tube goes into the esophagus and not the trachea (it is easy to go into either structure).  One they are sure the tube is in the esophagus they will try to gently push the tube down the esophagus until it reaches the obstruction.  Sometimes the obstruction will be pushed down into the stomach by this simple procedure.  Other times the tube will not advance past the obstruction so warm water will be pumped through the tube and used to break up the obstruction and siphon it back outwards.  There may be copious amounts of food that comes back up through the tube – that’s ok.  Eventually the water and siphoning should break up the obstruction and the tube will be advanced to the stomach, letting the vet know that the esophageal passage is clear.

In complicated cases there are other options for removing the obstruction.  Your vet may use an endoscope to visualize the obstruction in the esophagus.  This may allow for removal using specialized instruments.  In severe (very rare) cases the esophagus may be surgically entered and the bolus removed manually.

How Can Choke be Prevented?

Because poor dentition can result in problems chewing food, regular oral examinations are important to preventing your horse from choking.  The most qualified person to examine your horse is your veterinarian.  It is important to note that only a veterinarian can perform and correctly interpret a comprehensive physical exam when looking at a horse’s mouth.  There may be other issues (besides the teeth) that could make your horse prone to choke that only a veterinarian will recognize.  Personally I would prefer a licensed professional (veterinarian) that could examine my entire horse rather than a person who just “floats” teeth.  Ok – off my soapbox for now ;).

A veterinarian can properly examine your horses' mouth and float the teeth to prevent "choke". Source: alpinehospital.com
A veterinarian can properly examine your horses’ mouth and float the teeth to prevent “choke”.
Source: alpinehospital.com

If there are issues with dentition, a veterinarian can “float” or “file” the teeth to help correct abnormalities.  Once the grinding surface of the teeth has been improved or corrected, the risk for choking decreases.  Other preventative measures against choke include proper herd management, attention to eating habits, and individualized feeding programs.  If a horse is getting bullied around for their food they must be fed separately in a place where they feel safe and can take their time chewing.  In the case that a stall or private pasture is not available it is a good idea to spread the feed pans and hay piles around the pasture.  Spreading out means that a horse can not walk over to his buddy and steal his food without taking 20-30 steps or more.

By paying attention to the eating habits of your horse you can determine if intervention is needed to help him slow down when eating.  Hay nets and boxes help to slow hay eating down, but grain can be another story.  One simple way to make a horse take time when eating grain is to place large rocks in his feed pan.  The horse has to work around the rocks to get the feed, which forces them to slow down.  Finally, each horse should be fed an individualized diet designed for their work, age, metabolism, and nutritional needs.  In the case of geriatric horses with multiple missing teeth, you may have to begin soaking their feed in order for them to avoid choking.  Sometimes they may even have to eat soaked hay cubes instead of hay because they cannot chew the hay properly.  When you have several horses it is always important to keep in mind, especially if they differ in breed, size, and age, that you may end up feeding them different feeds as well as hay, at different times in the day and in different locations.

I hope you, the reader, has been enjoying these posts as much as I do writing them!  If there are any topics you would like to know about or questions that you have, please let me know!

Hoof Abscesses

On a nice sunny cold winter morning you march out to the barn, determined to have a nice ride in the snow.  You put your horse’s halter and lead rope on and lead him out into the aisle to start grooming and tacking up.  Suddenly you notice your horse is not putting any weight on his right front foot.  He just holds it up and it is seems to be dangling there.  OMG – something is horribly wrong!!!  You call your vet in a panic, sure that your favorite horse has broken his leg.  The vet tells you to chill and put the horse back in the stall until they can get there.

Your vet arrives in about an hour and takes a look at your horse.  She palpates the leg and places her hand over the backside of the fetlock (ankle).  She feels the hoof and asks the horse to pick his foot up.  The hoof is picked out and she carefully looks over the sole surface.  Next, she gets this metal vise-like object out (hoof testers) and starts to squeeze the hoof in different places.  When she squeezes in one spot your horse winces and wrenches his foot out of her hands. The vet picks up her hoof knife and begins paring (carving out) the hoof in the place that was sensitive when she squeezed it.  Your horse is clearly really getting agitated the more the vet digs at the foot.  Suddenly the vet yells “There it is!” and you go over to see what she has found.  At the bottom of the hoof, on the sole, is a small hole with black liquid running out of it.  The vet smiles and tells you to touch the liquid and smell it.  She laughs when you practically barf all over the barn aisle because it stinks so bad (us vets have to get our kicks in somehow ;)).

The paragraphs above describe the typical presentation of a hoof abscess – severe lameness with a sudden onset.  But what exactly is a hoof abscess?  How does a horse develop one of these things?  This article will answer these questions and help explain how to prevent abscesses and bruises.

Explaining Hoof Abscesses 

An abscess, by definition, is an accumulation of pus anywhere in the body that causes swelling and inflammation around it.  Pus is basically a buildup of fluid, white blood cells, dead tissue, foreign bodies, and bacteria.  When discussing the hoof specifically, the pus forms between the germinal and keratinized layers of the hoof.  The “germinal” layers of the hoof are those that form new cells – these layers are “alive”.  The keratinized layers of the hoof are “dead” and hardened – this is basically the hard outer part of the hoof.

How an Abscess Forms

Screen Shot 2015-01-22 at 9.28.07 AM

When micro cracks form in the hoof, bacteria and dirt can gain entry.  The body then sends white blood cells and inflammatory mediators to clean up the mess – this is how pus forms.  The inflammation, while helping to get rid of the bacteria and debris, causes the tissues to swell and become painful.  The swollen tissues inside the foot plus the pus accumulating mean that pressure inside the hoof starts to build.  Eventually the pressure will become so great that when the horse tries to stand on that hoof it causes lots of pain.  At that point we see a horse that won’t bear weight on his foot.

How an Abscess is Diagnosed

Any time a horse is 3-legged lame and there are no obvious swellings or injuries to the leg, your vet will probably start looking at the foot to be the cause of the lameness.  To assess the foot, it is cleaned off and inspected for cracks, wounds, foreign bodies (nails), etc.  Next, in order to determine the point of soreness your vet will probably use hoof testers to squeeze the foot in different areas.  Once they find a consistent “ouchy” spot they can begin to pare out that area of the foot.

Hoof testers are used to find a sore spot on the foot by putting extra pressure on specific areas. Source:  Stablemade.com
Hoof testers are used to find a sore spot on the foot by putting extra pressure on specific areas.
Source: Stablemade.com

“Paring the hoof” refers to carving at the outermost layers of the sole and white line.  Paring removes outer layers of dirt and allows the vet to look for a small tract (entry point of bacteria and debris). If a tract is found and followed by paring it, they may hit the jackpot – meaning they finally reached the abscess location and can open the abscess.  The pus will begin to drain, which will release the pressure that has built up inside the foot.  Often the horse will begin placing more weight on the foot immediately after the pressure is released.  Here is a great video of a farrier opening a hoof abscess.

Sometimes things are not so simple as explained above and seen in the video.  The horse may not show sensitivity to the hoof testers in a particular spot, or they may show sensitivity to multiple spots.  This situation may lead the vet to explore other possibilities for the cause of the lameness only to find the culprit was an abscess all along.  Sometimes a tract can not be found or will go very deep into the hoof.  If the tract is too deep your vet may decline to continue digging and opt for placing a poultice on the hoof.  Finally, your vet may see after cleaning up the hoof that a bruise is present on the sole of the foot.  It may be best to not dig a bruise but instead apply a poultice to help draw out fluid and keep the foot clean.  If your vet is on the fence about whether the horse has an abscess or not they may decide to x-ray the foot, which can show an abscess or possible other issues causing the horse to be lame.

This x-ray of the foot shows a dark circular lesion on the right side, which is consistent with an abscess.   Source:  equinepodiatry.com
This x-ray of the foot shows a dark circular lesion on the right side, which is consistent with an abscess.
Source: equinepodiatry.com

Treating the Hoof Abscess

There are myriads of opinions on how best to treat a hoof abscess.  Every vet/farrier/horse trainer has their favorite method, and the majority of these methods are based on several simple principles of treating any abscess.

1.  Establish drainage

An abscess can easily be drained when it is close to the solar surface of the hoof and easy to locate.  For the deeper, more difficult ones sometimes it is better to try to “draw” the fluid out and soften the hoof before trying to dig.  Sometimes the hoof is too dry and hard to even pare out effectively, so I like to place a poultice on the foot that will cause it to be “softer” and easier to work with.  If the abscess is really deep your vet may recommend using an “osmotic agent” to draw fluid out of the hoof instead of using a hoof knife to establish drainage.  An “osmotic agent” causes water and moisture to move towards itself.  Examples of this are Epsom salts and Animalintex poultice pads.  One thing to remember is that when fluid is moving it will always take the path of least resistance.  Sometimes, especially if the hoof is dry and hard, that path is upwards and out at the coronary band.  Don’t worry – it is still draining even though it is not in the exact location you would like.

A wrap has been placed on this horse's foot.  A final layer of duct tape is used to create a waterproof barrier. Source: kentuckyhorse.org
A wrap has been placed on this horse’s foot. A final layer of duct tape is used to create a waterproof barrier.
Source: kentuckyhorse.org

2.  Keep clean

Once the abscess is open and draining the hoof still is susceptible to infection.  Dirt, debris, and bacteria can still migrate into the open space and cause further infection.  It is important to keep the area of drainage and hoof in general clean until it has sealed.  I like to keep the foot wrapped with a poultice until I am sure the drainage has stopped and the area is sealed.  Some like to soak the foot a couple of times a day in Epsom salts.  The important thing is to not turn the horse back out into a muddy pasture right after the abscess opens.

3.  Control inflammation

Inflammation and pressure are responsible for the pain your horse is feeling when it has an abscess.  Once the pressure is relieved (abscess drains) it is still advisable to attempt to control the inflammation.  This can be done by giving the horse an anti-inflammatory drug, such as phenylbutazone.  Furthermore, the tissues above the hoof may have started to become inflamed and there may be some swelling at the pastern and fetlock area.  Placing a polo wrap around the swollen area will help move the fluid and decrease swelling.

Preventing Hoof Abscesses

An abscess can not be 100% prevented, but there are things you can do to decrease the likelihood of them forming in your horse. The importance of regular hoof trims in preventing abscesses can not be overstated.  Overgrown hooves tend to form cracks, which makes it very easy for bacteria to gain access to the inside.  Of special importance is the junction where the wall of the hoof and the sole of the hoof meet – the white line.

The "white line" is the junction where the hoof wall meets the sole.  Keeping this area healthy is important for preventing abscesses. Source: equinepodiatry.com
The “white line” is the junction where the hoof wall meets the sole. Keeping this area healthy is important for preventing abscesses.
Source: equinepodiatry.com

The white line is an easy place for bacteria and debris to enter into the hoof.  When the toe is too long the white line is easily “fractured”, which can result in a hoof crack extending up the foot.  Any time pieces of the hoof break off there is potential for an abscess.

Additionally it is important to pay attention the environment in which the horse is living.  Conditions that are excessively wet can make the compromise the integrity of the white line, but conditions that are too dry can lead to hoof cracks.  A nice balance is a good way to ensure you are doing your utmost to prevent abscesses.

Disclaimer:  This blog is not attempting to diagnose or treat your horse.  Your veterinarian is the only person who can do that.  This blog is not a substitute for your vet!