Weeks 6-9 at Littleton Equine Medical Center

Hello again from Littleton!

I hope everyone is having as great of a summer as I am!  I have been learning so much here as always and have been getting to spend some time with family in Boulder doing fun outdoor activities.  There have been a lot of neat cases here lately, and I’m excited to share some of what I’ve been learning here with you.

Things have been going pretty much as usual around here lately with a lot of colic and lameness work.  There have been a few horses that have come in with septic joints or that have been suspected to have them, so I have been able to watch and help with several regional limb perfusions.  Regional limb perfusions are great because they utilize a tourniquet proximally and infusion of a concentration-dependent antibiotic such as amikacin distal to the tourniquet to achieve a high concentration of antibiotic in the area of concern.  This is also favorable because you can avoid some potential complications that could result from systemic use of antibiotics.

One interesting case that came in was a 4-month old foal that was referred in because it had had seizures over the few days prior.  The owner started noticing the seizures occurring after it ran into a fence and was treated for head lacerations.  Luckily for me, I was working in the ICU the day that the foal was admitted so I was able to follow its case and observe it very closely for a few days.  Initially, the foal was somewhat obtunded mentally and was suspected to be blind, but upon ophthalmic exam was seen to have pupillary light reflexes and a dazzle response.  Its menace responses were absent, but those are a learned behavior so they may not have been developed yet in this foal.  Radiographs of the head were unremarkable, and the owner declined to have an MRI performed.

The foal also had some concerning lacerations over two of its fetlock joints, so it was sedated and Dr. Hill distended the joints with sterile saline to see if the lacerations communicated with the joints.  One had a small communication and was flushed and infused with amikacin, but the other joint was intact.  The foal did not have any seizures over the next few days, but over the weekend started having them daily.  Dr. Mullen made a great point by suggesting that either the foal could have had seizures because of the head trauma from running into the fence, or could have run into the fence because it was having a seizure.  She was more inclined to believe that due to the fact that two weeks after the traumatic event that the foal was still having seizures, that it was more likely to have idiopathic juvenile epilepsy rather than being simply trauma-induced.  Initially, the foal was treated with an IV fluid cocktail that included DMSO to help with any potential edema in the brain and later was medicated with phenobarbital and gabapentin to control the seizures.  Once the dose was adjusted, the owner elected to take the foal home.

Speaking of neurologic cases, there was a horse that came in that the owners said appeared to have acutely developed neurologic signs when ambulating.  We had a slow afternoon in the ICU, so I was able to observe Dr. Hill and Dr. Kurkowski work up its case.  When the mare arrived, she was hypermetric in all of her limbs and really hesitated to set down her feet when moving forward.  When she was moved in circles, she didn’t appear to be particularly neurologic—she wasn’t circumducting her hind limbs (swinging them outward when moving) too much and didn’t seem to have any proprioceptive deficits (she appeared to know where her feet were).  On physical exam, the vets noted that she had increased digital pulses in all four limbs, and increased digital pulses indicate pain in those distal limbs that have the stronger pulses.  She also had a positive response to hoof testers in all four limbs, particularly over the toe region.  Due to the quick onset of her signs and the clear indications of foot pain, she was most likely laminitic.  To further assess whether her odd movement was due to pain instead of being neurologic in origin, the vets then did an abaxial sesamoid nerve block with carbocaine in both front feet to block any pain that might be originating from the foot, as would be expected with laminitis.  The difference in her movement was very dramatic, and she moved almost normally after the nerve blocks.  Radiographs were then taken and did show early indications of some rotation, so the mare was treated for laminitis with ice boots and anti-inflammatories.  She did well, and was sent home a few days ago.

As always with veterinary medicine, not all cases have a happy ending.  Fortunately, the vast majority of the colic cases (and all cases in general) that I have seen here have been successfully treated, but some horses that require surgery to correct their colic unfortunately do not have that option due to owner constraints.  Other times, horses are not able to arrive until it is too late and some part of their GI tract has ruptured, which is beyond repair.  Last night, two emergency colic cases arrived late in the evening.  One was a horse in its early 30’s that had been seen in the field and was suspected to have a strangulating lipoma but needed further evaluation to be sure.  This horse did not have a surgical option.  Ultrasonography revealed some even distention of the small intestine but good motility and passage of digesta rather than it “settling out”, or rather seeing the digesta sitting in the bottom on the intestine and not filling it and moving through.  An abdominocentesis was performed (in other words, a belly tap) and lactate was evaluated, which was not significantly elevated.  These were good findings for the horse, because a high lactate (should normally be below 2) indicates poor perfusion (lack of blood supply), and a very high lactate suggests that there is likely dead bowel somewhere in the abdomen.  So, what was expected to be a bad case ended up going pretty well, and the mare was instead treated with IV fluids and monitored closely because she did have a number of signs of dehydration.

Sadly, the other colic that came in was not expected to be as severe as it turned out to be, and the lactate on that horse’s abdominocentesis was 17.  Combined with the other findings on her workup, the owner elected to euthanize her.  I observed and helped take part in the necropsy, which helps the vets and the owner to know definitively what went wrong.  This is helpful, as sometimes a horse’s cause of death is preventable, otherwise can help assure an owner that they made the correct decision, and is a good learning tool for the veterinarians involved as well.  This horse did in fact have a strangulating lipoma (a growth of fat that can tighten down over a loop of intestine, block food from passing through it, and cut off its blood supply) and as a result had several feet of very dead ileum.  The owner definitely made the correct decision for the circumstances involved in this case.  Other cases have been highly rewarding, such as a horse that survived colic surgery that had a 720 degree torsion at the base of her cecum, and two year old that did not have a surgical option and survived medical management for a suspected right dorsal displacement.  Although such cases are highly rewarding and others are very sad, I am so appreciative that as veterinarians we are able to alleviate suffering in either situation.

I wish I could share all of the other neat things I’ve been seeing here lately but seriously, I’d be writing a novel.  I saw an OCD the size of a golf ball removed from a hock, a horse that was referred in to have a vaginal cyst removed but here was found on pre-surgical exam to be an intact hymen, a “sidewinder” horse (a neurologic horse that moves sideways everywhere it goes), and a mare that fractured her coffin bone while playing in the pasture.  This weekend they’re having an open house here, and I’m very excited for my family to see where I’ve been working.  Also, they’re having pony rides and face painting so my 2 and 5-year old nieces will be happy campers. J  Although I love vet school, I am truly not excited for my time to be dwindling down to my final two weeks here.  I’ll save the sappy goodbyes for next week, and I’ll give you all one more post after my final week.

-Calli

Equine Athlete: Week 12

Hello again!  After a day of rest once returning from Youth Nationals we hit the ground running on Wednesday to get back to our home-base patients.  We spent the remainder of the week around Michigan and Indiana doing prep for the upcoming Canadian Nationals.  Although technically considered a 'normal' week, we did see some very interesting cases around the area.

Image I. Nail found in horses heel.

This week Dr. Hill, Dr. Smith, and I had full days every day.  Our week started off with a bang at a small private farm in Michigan.  We were called out to do a few lameness exams and treatments, which all went well.  Then, as we were cleaning up they asked if we could take a quick look at a 2 year old colt that had suddenly been found lame.  We  lunged the horse and pinpointed the area of concern.  As soon as we picked up the foot to do a flexion test we found the problem.  A nail was protruding from the horses heel (Image I).  The location of the nail was concerning as its angle of entry, from our external perspective, suggested possible involvement of the deep digital flexor tendon or navicular bursa. We took radiographs of the foot to make sure that no key structures were involved.  Luckily, the nail was 'U' shaped and only involved the edge of the heel bulb.  So, we simply removed the nail at the proper angle, soaked the foot, cleaned and dressed the area, and were off to our next stop after a very interesting morning.

Later in the week we were examining a Warmblood gelding that we have seen multiple times throughout the summer.  He was originally being rehabilitated from a suspensory injury and has been deemed sound in that leg.  Unfortunately, he has been having trouble moving forward and bending.  We watched him move and noticed that he wasn't tracking forward as well with his left front leg.  After an examination and blocking of the leg up to the level of the shoulder, we knew it had to be something higher up.  Dr. Hill went through a chiropractic exam and noticed that he was reluctant to bend his neck.  That tipped us off and so we radiographed the region of the that was most sore.  Immediately the problem was evident, arthritis of his 5th and 6th cervical vertebrae (Image II-IV).  Once the vertebrae become arthritic you can only manage the condition, but cannot cure it.  So we opted to take an aggressive approach and attempt to slow down the bone growth using OsPhos (bisphosphnate), and alleviate the pain by injecting the cervical facets.  The horses case will be followed over time to assess the level of arthritis in that region.

        

Image II. Normal vertebrae

Image III. Arthritic vertebrae

Image IV. Oblique view of the arthritic vertebrae

Image V. Clubbed foot on a 4 month old filly

Continuing on our adventurous week we were called to examine a four month old filly with a clubbed foot.  I have seen quite a few clubbed feet but have yet to see one this sever, and in this young of a horse.  The client wanted to radiograph the foot in order to determine whether or not she would be a candidate for corrective surgery (Image V).  Clubbed feet can have a variety of causes including genetic predisposition, improper farrier care, or an injury causing excessive flexion (to name a few).  In foals of this age the major problem is often excessive flexion of the deep digital flexor tendon (DDFT).  Tightening of the DDFT causes the toe to rotate downwards and, without correction, clubbing of the foot.  The heel will grow too long and the front of the foot will become steep and dished.  If caught early there are many options for correction.  Corrective bandaging, farrier work to lower the heal and lengthen the toe, and surgery are the most common.  In this severe of a case surgery was deemed the best option. Surgery for a clubbed foot involves severing the inferior check ligament in order to release tension along the back of the leg.  The procedure is officially termed an inferior check ligament (ICL) desmotomy.  By ligating the ICL you essentially 'release' the DDFT and allow it to relax.  This should lower the heel and improve the clubbed foot.  The client elected to send the filly to surgery.  I am awaiting news on whether or not it was a success.

This week was filled with a lot of interesting cases. Too many to share in this "quick" blog post.  I am grateful for all that I have learned this summer thus far.  By this point I am well able to follow the cases and understand what is happening.  I am excited to head up to Canada next week and see what is in store!

Equine Athlete: Weeks 10-11

What more can I say then 'wow'?  The two weeks we spent at Arabian Youth Nationals were exciting, exhausting, and educational.  I have never experienced that scale of horse show environment.  Youth Nationals represents the culmination of a year of hard work put in by trainers, youth riders, and their mounts.  Unlike the other shows I have been to this summer, Youth had a much more exciting, even electric, feeling surrounding it.  Partially due to the fact that it is a strictly youth exhibition, and partially due to the sheer scale of the event.  Everywhere you looked there were more horses, more decorations, more excited youth riders charged with enthusiasm.  It was captivating.

What struck me the most was the amount of pride that this industry has for its breed.  The Arabian horse is rooted in history, and the Arabian Horse Association (AHA) doesn't fail to recognize that.  Costume classes pay homage to the breeds heritage in the Middle East.  While memorial classes recognize those persons who have made an impact on the industry itself.  It is encouraging, in the turbulent environment we live in, to see so many young people sharing an enthusiasm for the breed.  The Arabian industry took a hit when the economy turned but, with so much interest from a younger generation, numbers are coming back up and hopefully will stay that way for years to come.

From our position as show vet, we got a unique perspective of the show.  We arrived on Tuesday with the show set to start that Friday and run to the following Saturday.  Only a fraction of the horses had arrived yet, but we were already hitting the ground running.  Equine Athlete brought quite an impressive team with them.   Five veterinarians, two from the Texas branch and three from the Central Michigan group.  Including our newest edition, Dr. Bailey Smith.  To assist, there were five technicians/vet student assistants, two from Texas and three from Central Michigan.  All in all we had a team of ten taking on Youth Nationals.

Once we arrived the work seemed to never stop.  The first battle we had to face was respiratory distress induced by the long travel and high temperatures in Oklahoma; commonly referred to as shipping fever.  A lot of our clients had traveled more than 15 hours in order to reach Oklahoma.  Long rides like that put a lot of stress on horses, not to mention the huge temperature change from the Midwest.  High heat and humidity, combined with the position horses are in when in trailers creates a perfect storm for respiratory pathogens.  Naturally, horses eat with their heads down.  This allows dust and debris that might be in the hay to be cleared from the horses airway by gravity.  When trailering, horses stand for long periods with their heads tied up, preventing the clearing of microorganisms and debris.  After a stressful trip or the excitement of being in a new place, many horses presented with respiratory symptoms.  Luckily, these horses get the best care possible.  As soon as they come off the trailer farms take their temperature and look them over for any scrapes or soreness.  If anything is out of sorts, we are immediately called over to assess and treat.

Image 1. Infected region of lung

Shipping fever presents in a relatively recognizable fashion.  Horses will have an elevated temperature, increased respiration rate (often coupled with a labored breathing pattern), 'harshness' upon auscultation of the lung fields, and lethargy (head droop, reluctance to move, refusal of feed).  Our exam includes a complete physical, paying close attention to auscultation of the the lungs and gastrointestinal tract (in case the stress has induced colic).  Next we will ultrasound the lungs and look for evidence of consolidation/infection (Image 1).  Some major pathologies that we will see are "comet" like streaks indicating infected regions of lung, or darker, fluid filled regions indicating a possible abscess.  We also ran a stable side test for SAA or serum amyloid A.  SAA is an indicator of the severity of the respiratory disease process.  SAA is a bio-marker for the inflammatory process, which takes place when the lungs become infected.  More traditionally, fibrinogen levels are the standard for measurement of the inflammatory response, yet they take longer to elevate and are not as convenient in these acute cases.  Levels of SAA are measured for many pathologies resulting in inflammation; including laminitis, cellulitis, joint swelling, etc.  We monitor these levels every few days and use them to help paint a picture of the horses recovery.  Levels below 50 ug/mL (according to StableLab guidelines) are considered normal, although it takes a while for the levels to drop completely.  As long as they trend downwards consistently the doctors consider that an indicator of healing. If the horses are dehydrated we will place a catheter and run them fluids to help get them on the road to recovery.  We then place them on a round of antibiotics if the case warrants them.  Depending on the presentation and severity horses were mostly placed on a combination of Gentimicin and Sulfamethoxazole (SMZ), or Naxcel (ceftiofur sodium).  We rechecked the horses twice a day and continued the antibiotics for at least three-five days until they showed significant improvement.  Thankfully all of our respiratory cases resolved before the actual start of the show.

The rest of Youth went by in a whirlwind of treatments, a few colics, a handful of lacerations, and not much sleep.  It was thrilling to see the event proceed and the teams at each stable working together to make their riders dreams come true.  I enjoyed watching horses that I now recognized from the different farms go in and show at their best thanks, in small part, to our hard work.  The common consensus was that this turned out to be one of the most competitive years to date; between the quality of horses in the ring, and skill presented by the youth riders.  This industry is so very different from anything I have seen before.  The quality of animals, kindness and enthusiasm of the people, and sheer passion show by all involved.  I won't soon forget the feeling of being at Youth, or my fortune in being part of a team of practitioners that helped make it happen.  We now set our sights on Canadian Nationals but will be riding the high of Youth for some time.

The final class at Youth Nationals!