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Friday, March 6, 2015

Conditioning part 1-How the Horse's body responds

Conditioning is vitally important to all horses in all disciplines from the elite three day eventer to the weekend trail rider.  Every horse needs to be properly conditioned for the task they perform to prevent injuries and other detrimental effects such as tying-up.  There are multiple reasons to condition your horse.  Conditioning helps the horse by increasing cardiovascular fitness, strengthening support structures, increasing neuromuscular coordination, and improving thermoregulation (the body’s ability to control temperature).  All of these things are very important to keep you and your horse safe and healthy throughout any activity. 

Cardiovascular fitness encompasses many things.  First, the heart is a muscle that through proper conditioning and over time, it’s strength and pumping capacity will increase.  As pumping capacity increases the amount of beats necessary to supply properly oxygenated blood to the body decreases (i.e. your heart rate decreases).  This is why heart rate is such a great way to monitor fitness.  You can do this with a heart rate monitor or by simply learning to take heart rate 5, 10, and 15 minutes after exercise.  Overtime as your horse reaches a better fitness state, the amount of time it takes for the heart rate to return to normal and the peak heart rate your horse experiences should decrease.  As your horse gains fitness it will be able to more efficiently oxygenate the system thereby increasing the length of time in aerobic metabolism. Aerobic metabolism, during exercise, is the most efficient way to supply energy for muscle contraction.  Aerobic metabolism requires oxygen though so once the body is pushed beyond its ability to oxygenate fully you enter into anaerobic metabolism. Those of you that hit the gym or in other ways exercise on a regular basis know well what lactic acid is.  Horses just like humans produce lactic acid when they push past their body’s limit to oxygenate entering into anaerobic metabolism. Increased cardiovascular fitness leads to decreased anaerobic metabolism and lactic acid production.  Lactic acid buildup leads to fatigue while exercising and muscle soreness.  Significant fatigue while exercising increases a horse’s chance of injury.  So you can see why cardiovascular fitness is so important.

Strengthening of support structures takes more time than cardiovascular fitness.  It is vitally important that a horse’s muscles, tendons, and ligaments are up to the task at hand.  If you put a completely unfit horse back into work it can take 4-6 months for all the support structures to completely strengthen depending on the intensity of the horse’s job.  This is why a horse is brought back very slowly following a serious tendon/ligament injury.  First the injured tendon needs to slowly strengthen back to full capacity to avoid being reinjured.  Secondly an injured horse has usually been on stall rest so all support structures have weakened and need time to adapt to exercise again.  When starting into a conditioning program it is important to carefully monitor your horse’s limbs on a regular basis so heat or swelling can be picked up on immediately and attended to properly.  When a horse is pushed to perform more than their support structures are ready for, they can end up compensating, leading to lameness, soreness, and possible significant injury. 

Increased thermoregulation is tied into cardiovascular fitness.  Within 1-2 weeks of starting a regular conditioning program the horse’s volume of plasma, red blood cells, and hemoglobin increases.  Plasma is the liquid (non-cellular) part of the blood.  Also over a period of months the amount of capillaries present in the muscle increases.  These increases help better oxygenate muscles and cool the body.  It is a common misconception that a fitter horse starts sweating later and sweats less.  In contrast the fitter horse has a more efficient thermoregulation leading them to sweat sooner and stay cooler.  A fit horse is able to do this due to increased blood volume and capillary system carrying blood to the skin where heat is evaporated off while also still efficiently supplying muscles.  Effective sweating starting earlier helps dissipate heat before the thermoregulatory system is overloaded i.e. overheating occurs.  Aerobic metabolism, while the best way to get energy for muscle contraction, is very inefficient and produces large amounts of heat.  This significant amount of heat production during exercise explains why efficient cooling is so important.

Now we understand the different systems and how they are enhanced by a conditioning program.  There are many ways to approach starting a conditioning program depending on your horse’s job.  The basics of this will be covered in our next blog post.  Please stay tuned for more information and tips on how to successfully and safely get your horse fit.  In the meantime Dr. Oehling would be happy to answer any questions you may have about conditioning and how it applies to your specific horse and situation.

Wednesday, January 28, 2015

Thinking of Breeding Your Mare in the Spring?

Thinking of Breeding Your Mare in the Spring?  What you can do now to prepare!

 by Dr. Tena Boyd

  • Consider putting her “under lights” now to help ensure that she is cycling well by March 1*
  •  Plan on ultrasound examination with uterine culture and cytology +/- uterine biopsy at least one month before your desired breeding date
  •  Pick your stallion now and make early contact with the stallion manager or owner. Occasionally there are “early booking” discounts on stud and/or breeding fees!
  •  Be sure that she is current on de-worming, vaccinations, and has a current negative Coggins’ test prior to breeding
  •  Are your registrations or incentive registry information up to date?

Putting a mare “under lights”

·A mare’s reproductive tract and hormonal surges associated with estrous or heat cycles and becoming pregnant are geared to occur during the season of the year with longer day lengths (spring & summer)

· To stimulate this response for March or even February breeding, we want to expose the mare to light for 60 days prior to our desired “date”. This is accomplished by adding light to the mare’s environment followed by several hours of darkness. Examples: Turning on a 100 watt or equivalent light in her 12’ x 12’ stall from 4:30 pm and turning that light off at 10 PM or housing the mare in a run in area with floodlights on during those hours.

· It is important that the light hours are followed by darkness to trigger natural season

· Left on her own, mares in our region typically do not cycle well until mid-March

Winter is here and how good is your hay?

Winter is Coming/Here and how good is your hay?  By Dr. Tena Boyd

With winter upon us, we need to examine our horse’s diet.  As we all know, the bulk of a horse’s diet should come from forage sources such as pasture (now dwindling!), hay, hay substitute pellets or cubes, and chopped hays.  Our horses need to consume 1 – 2% of their body-weight in hay daily or 12 – 24 lbs of hay/day for the average 1200 lb horse.

How do we assess hay quality?  The first assessment is always visual.  We are looking at color, indication of maturity (how “stemmy”?), “leafiness”, odor & condition, and the presence of foreign materials such as trash, plants/weeds, wire, etc.  In the most general of terms, your first impression of color (the greener the more nutritious and palatable/tasty) and odor are the most important.  If this hay makes you sneeze or your eyes water, it may not be the best for your horses (assuming you are not allergic to hay!) or you may need to soak or “rinse” dust off the hay before feeding.

Color and “leafiness” are indicators of what stage the plant was in when the plant was cut and cured and secondly, how well the hay was handled after cutting.  If the outside is yellow and the inside nicely green, the hay may have been sun-bleached versus the hay that is yellow throughout from being over-mature when cut.  If exposed to rain or heavy dews, the hay may be very brown in color and suffering mold growth and not safe to feed our horses.

For those who have horses that are “easy keepers” (overweight, insulin resistant, prone to founder, or have Cushings’), it may be most important to obtain a good nutrient analysis from a forage testing laboratory.  These horses are very susceptible to health concerns from consuming diets too high in simple sugars or Non-Structural Carbohydrates (NSC).  As well, if your horse is one of the over 100 Draft breeds or one of our stock horse breeds (Quarter Horse, Paint, Appaloosa) that suffer from EPSM or PSSM (Equine Polysaccharide Storage Myopathy), this is important as well.  With these horses, we need to know that our hay is less than 20% NSC in general and for the EPSM/PSSM horses, no more than 15% of their total calories can come from starch or sugar.  Timothy hay is typically 15% NSC while Alfalfa hay is 20% NSC.  Hay analysis can change in the same field depending on which cutting it is, how the hay was cut, amount of rainfall, and soil condition (pH, fertilized).

Forage testing is done by take samples from the center of a hay bale.  It is best to sample several bales from a load of hay to be most accurate.  These samples are then placed in a tight, clean, plastic bag and sent to the lab.  Our county extension offices can provide information for this service.  These offices can be found at www.offices.ext.vt.edu .  Typically, these offices are open Monday – Friday from 8 – 5.  The Fauquier office phone number is 540-341-7950 and Culpeper 540-727-3435.

Always remember to provide a good source of liquid water with these lower temperatures.  The colder it gets the more hay our horses want to eat but they also need to increase their water consumption.  Soaking some of their hay or finding the most desirable way each horse will consume water is worth the effort!  Some horses like warm water added to their buckets, some like loose salt added to their feed, some like Gatorade in their water.  Whatever accomplishes this goal and keeps them healthy!

[EPSM/PSSM are heritable muscle disorders that can cause weakness and muscle wasting, poor performance, abnormal hind limb gaits, and “shivers”.  It can be seen as reluctance to move, muscle stiffness, sweating, shifting lameness, and tremors]

10 Tips for Preventing Colic from the AAEP

10 Tips for Preventing Colic

The number one killer of horses is colic.  Colic is not a disease, but rather a combination of signs that alert us to abdominal pain in the horse.  Colic can range from mild to severe, but it should never be ignored.  Many of the conditions that cause colic can become life threatening in a relatively short period of time.  Only by quickly and accurately recognizing colic – and seeking qualified veterinary help – can the chance for recovery be maximized.

            While horses seem predisposed to colic due to the anatomy and function of their digestive tracts, management can play a key role in prevention.  Although not every case is avoidable, the following guidelines from the American Association of Equine Practitioners (AAEP) can maximize the horse’s health and reduce the risk of colic:

  1. Establish a daily routine – include feeding and exercise schedules – and stick to it.
  2. Feed a high quality diet comprised primarily of roughage.
  3. Avoid feeding excessive grain and energy-dense supplements. (At least half the horse’s energy should be supplied through hay or forage.  A better guide is that twice as much energy should be supplied from a roughage source than from concentrates.)
  4. Divide daily concentrate rations into two or more smaller feedings rather than one large one to avoid overloading the horse’s digestive tract.  Hay is best fed free-choice.
  5. Set up a regular parasite control program with the help of your equine practitioner.
  6. Provide exercise and/or turnout on a daily basis.  Change the intensity and duration of an exercise regimen gradually.
  7. Provide fresh, clean water at all times.  (The only exception is when the horse is excessively hot, and then it should be given small sips of luke-warm water until it has recovered.)
  8. Avoid putting feed on the ground, especially in sandy soils.
  9. Check hay, bedding, pasture, and environment for potentially toxic substances, such as blister beetles, noxious weeds, and other ingestible foreign matter.
  10. Reduce stress.  Horses experiencing changes in environment or workloads are at high risk of intestinal dysfunction.  Pay special attention to horses when transporting them or changing their surroundings, such as at shows.

Virtually any horse is susceptible to colic.  Age, sex, and breed differences in susceptibility seem to be relatively minor.  The type of colic seen appears to relate to geographic or regional differences, probably due to environmental factors such as sandy soil or climatic stress.  Importantly, what this tells us is that, with conscientious care and management, we have the potential to reduce and control colic, the number one killer of horses.

For more information about colic prevention and treatment, ask your equine veterinarian for the “Colic” brochure, provided by the American Association of Equine Practitioners in partnership with Educational Partner Bayer Animal Health.  Additional colic information is available by visiting the AAEP’s horse health web site, www.myHorseMatters.com.

Reprinted with permission from the American Association of Equine Practitioners.

Preparing Your Horse for Travel

Preparing Your Horse for Travel by Dr. Tena Boyd


Travel or shipping of horses can be quite stressful on the horse physically as well as causing anxiety over new or unexpected events.  To help prepare for this a few tips “from the pros”.


1.    Health examination/certificate.  This is required for travel across state lines.  Establish normal body temperature, no clinical signs of disease, and to address any special physical needs for the trip (gastric ulcer preventatives, pain medication, electrolytes, diet changes).  It is also helpful to carry copies of your horse’s medical records to make special note of recent medications, on-going problems, or relevant medical histories (de-worming, vaccine, shoeing, dentistry histories for example).

2.    Have an emergency kit packed and accessible.  

3.    Pack hay and water from home whenever possible.  Water sources on the road may not be as potable or have a ‘funny’ taste that may discourage drinking well during the trip.  Soaking hay in your hay nets is a great way to keep wet fiber going through the horse keeping his gut happy!

4.    Pain medication to help ease stiffness at the end or mid-way through a long trip may be helpful.  Discuss this with your veterinarian during the health exam prior to leaving.

5.    Monitor temperature, water and feed consumption, and manure output for several days after arrival. Have a plan to slowly reintroduce grain or switch to a new feed if necessary.  During travel it is safer to feed hay only.

6.    Consider the prophylactic dose of omeprazole, Ulcergard©.  Several studies in horses that compete or travel even on short weekend trips demonstrate the widespread incidence of gastric ulcers.  Preventative doses of Ulcergard© have been shown to be very successful in alleviating symptoms associated with gastric ulcers in the horse.

7.    For airline shipping across the country or overseas, more diligence and planning are needed to prepare horses.  Britta Johnston, internationally known dressage trainer, has successfully shipped many horses from the USA to her native Germany.  She recommends for these long flights that horses be supplemented with electrolytes and ‘probiotics’ for 5 days prior to shipping.  She gives her horses wet hay, apples, and further electrolyte supplements during the trip all in effort to maintain hydration, prevent muscle soreness, and protect against other complications. She stresses that these horses are kept in containers for hours before and after the flight, placed in quarantine, and then shipped to the destination.  An 8- 9 hour flight might mean 45 – 50 hours of confinement for the horse.


            To reemphasize, it is very important to monitor the horse’s temperature; manure production; feed, water and hay intake; and to watch for coughing or nasal discharge after arrival at the new destination. 


Just a note, your friendly, neighborhood veterinarian may be enticed to be a veterinary flight attendant in order to broaden her (or his) international travel experience!

Tick-Borne Diseases by Dr. Scott Wilson

Tick-Borne Diseases by Dr. Scott Wilson

            Horses are afflicted by a variety of parasites that can carry diseases, including ticks.  These small spider-like blood-suckers can be found on horses almost any time of year, causing a variety of clinical signs.  A commonly observed behavior that might be seen is intense scratching (sometimes until the skin is raw).  Other signs often seen include a swollen area of skin where the tick has attached, and this area may drain yellow or white discharge.  Ticks usually inhabit areas of tall grass or brush piles, and wait for animals to walk nearby to crawl onto.  Once on the animal, ticks will crawl to an area where they are covered by hair or where it is very warm, and begin to feed.  Ticks will usually feed for several days before releasing and falling off of an animal. 
                During this feeding time on a horse, there is a potential for regurgitation of blood from the tick’s stomach into the horse.  This transfusion takes place approximately 1-2 days after the tick first attaches.  In certain ticks, namely Ixodes species, this regurgitation of blood can cause the horse to be inoculated with any bacteria that the tick may be carrying.  Commonly encountered bacteria within Ixodes ticks include Borrelia burgdorferi and Anaplasma phagocytophlium.  These are the agents that cause Lyme disease and equine anaplasmosis, respectively. 
                Lyme disease is a commonly misunderstood disease of horses.  It has been documented to be the causative agent in only a few cases, including horses with neurologic disease, skin lesions, or uveitis.  It has also been found in the lining of inflamed joints and has been suspected to have caused laminitis.  A diagnosis of Lyme disease has classically become associated with a horse that has lethargy, shifting-leg lameness, and hyperesthesia (overly dramatic response to being touched).  Numerous research projects involving B. burgdorferi have attempted to elicit clinical signs in horses that were experimentally infected, but these studies have not been able to produce consistent clinical disease in these test subjects.  That being said, we do know that ticks commonly carry B. burgdorferi and can transmit this bacteria to horses while the tick is feeding.   The most recently developed  diagnostic test comes from Cornell University and can differentiate vaccination from acute exposure and from chronic infection.  There is no licensed vaccine for horses, but numerous veterinarians elect to administer a vaccine that was developed for use in dogs.  There are numerous anecdotal reports of horses testing positive for Lyme disease and having a favorable response to antibiotic treatment; that makes this disease a difficult one to argue against.  Lyme disease has been shown to regularly affect people, dogs, cats, and other common species, but it still remains a bit of a mystery in horses.  Some more common differential diagnoses for horses suspected of Lyme disease include arthritis, muscle disorders, neurologic diseases (such as Equine Protozoal Myeloencephalitis), or gastric ulceration.
                Equine anaplasmosis, caused by Anaplasma phagocytophilum, is an emerging disease that has gained a lot of attention in the past half-decade.  This disease is also caused by a bacteria transmitted by ticks, and its prevalence is increasing rapidly.  The first case in Virginia was reported by the Virginia Tech Equine Field Services team in 2009, and the number of cases per year is on the rise.  Horses afflicted with anaplasmosis consistently have a high fever, lethargy, and have a very poor appetite.  They may have yellow-tinged mucous membranes, and also may have limb swelling or even mild neurologic signs.  Diagnosis can be confirmed by sampling the blood and observing a particular life-stage of the bacteria within some white blood cells under a microscope.  Other available tests include PCR (Polymerase chain reaction) that detects the bacteria’s DNA within the blood, and checking the horse’s antibody titer against the bacteria.    
            Treatment for both of these diseases is similar: daily administration of a tetracycline antibiotic.  A horse infected with B. burgdorferi needs to be treated for at least 3-4 weeks, as this bacteria can be difficult to clear from the horse’s system.  Clinically signs usually improve relatively quickly, but it is important to finish the antibiotic regimen so that persistent infection does not ensue.  A recheck  test can be performed a few weeks to months after initiation of treatment to assess the effectiveness of the antibiotic therapy.  A horse infected with A. phagocytophlium should be treated with a non-steroidal anti-inflammatory drug (NSAID), such as Banamine, in addition to a tetracycline, for a few days to help stimulate appetite and to decrease fevers.  Antibiotic therapy to treat anaplasmosis is much shorter than that for Lyme disease, with regimens lasting approximately 10 days.  Clinical signs associated with anaplasmosis typically abate within 1-2 days with appropriate treatment
There are three choices for a tetracycline antibiotic in the horse: Oxytetracycline, minocycline, and doxycycline.  Oxytetracycline is an injectable drug that has been shown to reach therapeutic levels in the blood when given once daily by intravenous injection.  Minocycline is an oral antibiotic that has recently been discovered to have excellent efficacy against B. burgdorferi, and is thus preferred over doxycyline, which is poorly absorbed as an oral tablet.  Minocycline and doxycycline must be given twice daily by mouth.  Oxytetracycline, if given too quickly intravascularly, can cause some horses to faint, as it binds the calcium in the horse’s blood.  Minocycline and doxycycline, as with any oral antibiotic, have the potential to cause a serious colitis.  The recommended treatment for a horse with Lyme disease is 2 weeks of intravenous oxytetracycline, followed by 2 weeks of oral administration of minocycline.
                There is evidence that some Ixodes ticks in this region of the nation carry both B. burgdorferi and A. phagocytophilum, and thus can infect horses with both of these bacteria in a single feeding.  Not all ticks carry one or both of these diseases, so simply finding a tick on your horse does not mean they will get sick.  Some simple management strategies for decreasing ticks on your farm include keeping grass length short, removing brush or leaf piles, and checking your horse daily for ticks.  There are some products available for killing ticks once they are attached to the horse, like Frontline (Fipronil) spray.  This product can be sprayed in the usual places that ticks like to attach, such as the mane, between the front legs, between the hind legs, and around and underneath the tail.  If your horse presents with any of the signs listed above, please contact Old Waterloo Equine Clinic and schedule a visit.

The Latest News on Lyme Disease and Vaccination

The Latest News on Lyme Disease and Vaccination by Dr. Alisha Oehling

In December 2013, Dr. Oehling attended a discussion on Lyme Disease at the national AAEP conference in Nashville.  While much of the talk created more questions than answers, what did come out was a clearer consensus on vaccination.  As most of you know there is not an equine vaccine.  At this time we use a canine vaccine that has proven to be efficacious in most of our equine population without confusing future test results.

The testing we perform looks at three different proteins OspA, OspC, and OspF.  In equine Lyme infections we rarely see elevation in OspA.  OspC indicates an early stage infection and OspF tends to show chronic infections.  So, in order to not confuse testing, most equine veterinarians are using vaccines that only raise OspA.  That way if your horse does acquire an infection even after vaccination, it's easy to recognize.  At this time we recommend testing before vaccination to determine the levels of all three proteins in your horse.  This allows us to see if the horse is actively infected and also gives us a baseline for OspA.  If the test results shows no active infection we recommend starting the vaccine series.

The first time the horse is vaccinated for Lyme Disease, the vaccine needs to be given in a three dose series.  Give dose #1, three weeks later we give dose #2, then dose #3 is given 3 months after dose #2.  Lastly, one month after the final dose we do a second test.  This second test evaluates how much your OspA protein has changed.  Ideally we would like it to climb quite a bit indicating your horse's body has responded to the vaccine.  If your horse responded well, we recommend vaccination every 6 months after completion of the series.  This will ensure your horse has the best protection possible against this dangerous disease.

If you have previously vaccinated your horse for Lyme disease, give us a call and we can help you figure out how to alter your program based on the new recommendation.  Our staff would be happy to discuss all of this with you to make it a little clearer.