Sincerely,

Jessie Loberg BA, CVT, VTS-EVN

American Association of Equine Veterinary Technicians & Assistants

AAEVTS p r i n g 2 0 1 4 N e w s l e t t e r

Hello My Fellow AAEVT Members!

The Free Dictionary defines association as an organized body of people who have an interest, activity or purpose in common. What is the AAEVT’s purpose?

To promote the health and welfare of the horse through the education and professional enrichment of the equine veterinary technician and assistant.

I am so proud to be able to say that I am involved with, and am the current president, of this association who takes the welfare of the horse and it’s members to heart!

Thank you to everyone who has participated in our educational meetings over the past year, especially our annual convention in Nashville, TN. We offered 31 hours of continuing education credits for the participants and had wonderful speakers who covered areas such as anesthesia, biosecurity, imaging, ophthalmology, laboratory interpretation and communication techniques. Dr. Andy Clark and Dr. Betsy Charles opened our annual convention with an amazing keynote address titled “Leadership Begins With You”, which got our attendees excited and interactive. A new addition to our annual convention this year was an afternoon of case study presentations presented by our equine veterinary technician peers. Tennessee Equine Hospital graciously hosted a day of wet labs at their beautiful facilities where our attendees learned about the lameness locator, field anesthesia, bandaging, anatomy and an ophthalmology lab. Aside from the amazing educational opportunity from these meetings, I appreciate the opportunity to

network and communicate with like-minded individuals from around the world! Thank you all for your insight on how to make our association grow and how to continue to offer excellent educational opportunities!This year, the AAEVT plans to continue to offer relevant CE events, including a variety of one-day regional meeting around the country and an excellent annual AAEVT/AAEVT convention in Salt Lake City, UT in December. Your new president-elect, Jeannie Willems will be working on this project throughout the year, so if you have any speakers or topics in mind that you would like to see, please do not hesitate to contact her at jwillems@nutramaxlabs.com. The 2014 annual convention promises to be a wonderful experience!

In closing, I would like to thank our wonderfully supportive sponsors who have allowed our association to continue to grow! And, to all of the members, thank you so much for your support and ideas. Remember that this is your association! Try to utilize all the AAEVT has to offer and make it your goal to become more involved in 2014!!!

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Academy of Equine Veterinary Nursing Technicians Update By Jessie Loberg BA, CVT, VTS-EVN (AEVNT Immediate Past President)

(Pictured left to right) New academy members: Rebecca Johnston, Jaime Newbill, Christopher Rizzo and

Immediate Past President: Jessie Loberg

The Academy of Equine Veterinary Nursing Technicians just finished up with our annual convention with the AAEVT and AAEP in Nashville, Tennessee. We had a great annual convention this year with amazing speakers and attendees, along with a day of wet labs at Tennessee Equine Hospital.This year the AEVNT offered our annual examination to three applicants, and each of them met the application requirements and passed the exam! Congratulations to our new members of the AEVNT: Jaime Newbill, Christopher Rizzo and Rebecca Johnston! Our new members were inducted during our membership lunch meeting at the annual convention and were awarded placards that were graciously sponsored by Henry Schein.We also inducted our 2014-2015 executive board at our annual convention. Congratulations to the new board members!

President: Sharon KlinglerPresident-elect:

Heather HopkinsonSecretary:Sue Loly

Treasurer: Jamie DeFazio

Member at Large: Jessica Beamer

Immediate Past President: Jessie Loberg

2014 will bring another busy schedule for our academy members at veterinary conferences throughout the country. We will have members representing the academy at WVC, AVMA, IVECCS, ACVIM, AAEP and several smaller conferences this year!

If you have any questions regarding the AEVNT, please go to the Academy tab on the AAEVT website (www.aaevt.org) where you will find our information. Also, feel free to contact our new president, Sharon Klingler at sharon@premierequinevet.com

June 4-6 Nashville, TNACVIM

June 14 - Phoenix, AZAAEVT Patterson Veterinary Anesthesia Day

June 21 - Wauconda, ILAAEVT Regional EventMerritt Eq

July 26-29 Denver, COAVMA

July 31 - Aug 2 Rutherford, NJHambletonian

Sept. 10-14 Indianapolis, INIVECCS

Sept. 25-28 Norfolk, VANEAEP

Sept. 25-28 Fort Worth, TX SWVC

Sept. 28 - Irving, TXAAEVT Regional EventAnimal Imaging Center

Oct 9-12 St. Louis, MOPurina

Dec. 6-10 Salt Lake City, UTAAEP

2014 AAEVT Regions & Regional Contacts

Kindra Pierce Moreno, RVTPioneer Equine Hospital11901 Walnut AveOakdale, CA 95361Phone: (916) 769-0357kmoreno@pioneerequine.comkpierce0821@yahoo.com

Region 1:NorthwestWA, OR, ID, AK, MT, WY,

North CA

Kristine Cromwell CVT Running ‘S’ Equine Veterinary Services147 Kosciuszko Rd.Whitehouse Station, NJ 08889Home: (908) 268-5237Work: (908)832-5484x4kmatarazzo@hotmail.com

Region 7: NortheastNY, NJ, CT, MA, CT, RI, NH, ME

Genevieve BennettRAHT, RVT

2911 Lido Plage Rd.Cartier, Manitoba R4K 1A5

Phone: (431) 999-3782rvt007@rogers.com

Region 9Canada

Margeaux Day

3245 Chaparral Heights RoadJamul, CA 91935

Phone: (205) 561-8148margeauxday@yahoo.com

Region 2:PacificCA, NV, AZ, HI, UT

Region 3: MountainND, SD, CO, NM, NE, KS, MO

Meg Schenk,CVTColorado Equine Clinic

4077 Rainbow PlazaSedalia, CO 80135

Phone: (303) 668-2936rckymtnhigh@att.net

Region 5: MidwestMN, WI, MI, IA

Andrea DorschnerIowa State UniversityLloyd Veterinary Medical Center108 Park AveBoone, IA 50036Phone: (515) 294-1500adorsch@iastate.edu

Region 5: MidwestMN, WI, MI, IA

Sue Loly,LVT, VTS-EVNLeatherdale Equine CenterUniversity of Minnesota

1225 Ferndale St. N #12Maplewood, MN 55119Home: (651) 303-0220Lolyx001@umn.edu

Lori Dressel,RVT, BPS, VTS-AnesthesiaUniversity of Georgia VTH

1331 White Oak Dr.Athens, GA 30606Phone: (315) 569-1848sandue1@uga.edu

Region 8: SoutheastTN, AL, GA, FL, VA, NC, SC

Megan Belcher,LVTPfizer Animal Health

4107-A Townhouse RdRichmond, VA 23228Phone: (317) 445-0979Work: (804) 432-9361Fax: (866) 590-0527MegLeeLVT@yahoo.com

Region 8: SoutheastTN, AL, GA, FL, VA, NC, SC

Heather SupanikGreen Glen Equine Hospital429 Town Hill RoadYork Springs, PA 17372Phone:(717) 752-1785Work:(610)925-6145jamiedefaz@aol.com

Region 6: Mid-AtlanticOH, PA, DE, MD, IN, IL,

KY, WV

Executive DirectorDeborah B.ReederB.A., RVT, VTS-EVN539 Wild Horse LaneSan Marcos, CA 92078Cell: (214) 505-1548Fax: (760) 301-0349DBReeder@gmail.com

PresidentJessie LobergBA, CVT, VTS-EVN552 W. Jamison PlaceLittleton, CO 80120Work:(303)751-8700x 245Cell: (720) 810-3766 Lobergj@hotmail.com

President-ElectJeannie WillemsBA, LVT, RVT

5315 Stack RoadMonroe, NC 28112Cell: (443) 956-3646JWillemss@nutramaxlabs.com

Regional DirectorSue LolyLVT, VTS-EVN

1225 Ferndale St. N#12Maplewood, MN 55119Work:(651)303-0220lolyx001@umn.edu

Immediate Past PresidentKy CarterRVT

1422 Grimes RdMineral Wells, TX 76067Cell:(817) 996-1700kygcarter@yahoo.com

Vice PresidentNicole LaGrangeRVT

11145 Meadow Glen Way EEscondido, CA 92026Phone: (760) 672-9498nicolelagrange@gmail.com

SecretaryAli Fernandez

25125 N. Pearl Rd.Acampo, CA 95220Cell: (443) 956-3646Ali.Fernandez@yahoo.com

Financial & Membership DirectorKatie SoobrianRVT, BADVM Access Inc.419-2875 Osoyoos CrescentVancouver, BC V6T 2G3Cell: (604) 803-8787ksoobrian@yahoo.com

AAEVT Executive Board 2014

Adivsory Board:DeeAnn Wilfong, Sheri Miller, Kelly Fleming, Paul Vrotsos, Sandra Nunn, Jane Tyrie, Kristy Ely

Dominique Le BaronAustin Equine Hospital20640 Hwy 150Driftwood, TX 78619Phone: (512) 581-1943dominique@austinequine.com

Region 4: MidsouthTX, OK, LA, AR, MS

Nina SmithPeterson and Smith Equine Hospital

14681 SE 25th AveSummerfield, FL 34491Phone: (352) 615-1132ninasmith@embargmail.com

Region 8: SoutheastTN, AL, GA, FL, VA, NC, SC

Associate DirectorWiss Costanza

41 Achorn Hill Rd.Lancaster, NH 03584

Cell: (720) 810-3766 WCostanza@luitpold.com

We have all heard how effective Adequan® i.m. (polysulfated glycosaminoglycan) is, however, most of us don’t really know why and how this therapy works. It is not as complicated as it might appear and I hope this short article will shed some light on the subject. Let me start with why….

Adequan® i.m. is a therapy to be used for equine non-infectious degenerative joint disease, (DJD), often called osteoarthritis. Equine non-infectious DJD commonly affects the knees, hocks, ankles, stifles and coffin joints. Early recognition and treatment can limit the damage and restore the normal “wear and repair balance” in the joints before permanent cartilage or bone damage occurs.

What is a “balanced” joint? Balanced joints are made up of a healthy synovial membrane, joint fluid and articular cartilage that work together to minimize damage of normal forces. A healthy equine joint is in a constant state of “wear and repair”. As normal forces are exerted on the joint, cells actively regenerate and repair the cartilage. The lubricating synovial fluid in the joint also is replaced continually. This constant cycle of renewal, repair and replacement assures that no cartilage loss occurs and a functionally balanced, healthy joint environment is maintained. When DJD occurs this balance is affected.

Adequan® i.m. stimulates cartilage repair and reverses traumatic joint dysfunction. Extensive studies of Adequan® i.m. have proven it readily passes through the synovial membrane and is taken up into cartilage by diffusion. This results in the concentration and progressive accumulation of Adequan® i.m. at the site of injury. Proven to treat equine osteoarthritis and associated lameness, Adequan® i.m. breaks the destructive disease cycle, inhibits cartilage damage and stimulates the cartilage repair process.

Please feel free to check out our website: www.adequan.com to see an animated wear and repair cycle explanation.

Wister Costanza Associate Director, AAEVT Executive BoardTerritory Manager, Luitpold Animal Health

BRIEF SUMMARY:For the intramuscular treatment of non-infectious degenerative and/or traumatic joint dysfunction and associated lameness of the carpal and hock joints in horses. There are no known contraindications to the use of intramuscular Adequan® i.m. brand Polysulfated Glycosaminoglycan in horses. Studies have not been conducted to establish safety in breeding horses. Each 5 mL contains 500 mg Polysulfated Glycosaminoglycan. WARNING: Do not use in horses intended for human consumption. Not for use in humans. Keep this and all medications out of the reach of children. Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian.

AHD024, Iss 3/2014

Checking for Equine Stomach Ulcers What Horse Owners Need to Know

April Knudson, DVM, is an equine specialist with Merial Veterinary Services. She has a special interest in equine gastrointestinal health, infectious disease and lameness. She holds a doctor of veterinary medicine from the University of California-Davis. Below, she answers a question about what to expect if your horse needs to undergo gastroscopy. Q. My veterinarian has suggested I bring my horse in for a gastroscopic examination. What is it, what can I expect to happen and how should I prepare my horse? A. If your veterinarian has recommended a gastroscopy, sometimes called a “stomach scoping,” he or she probably thinks your horse has equine stomach ulcers, which aren’t uncommon in horses. In fact, 62 percent of horses have them to some degree.1 The good news is they can be treated – and prevented in the future. While stomach ulcers can be presumptively diagnosed (by ruling out other possible problems and watching a horse’s response to treatment) without performing a gastroscopy, if your veterinarian has recommended this procedure, he or she has reason to want to make a definitive diagnosis in order to proceed with treatment. Gastroscopy is the ONLY surefire way to know what the inside of your horse’s stomach looks like. Here’s how to be sure you get the most accurate results and what to expect during the examination. For the best results, I recommend gastroscopy be conducted as early in the morning as possible because the horse cannot eat ANYTHING for 12 hours prior to the exam and should not drink water for four to six hours prior. What seems to work for most horse owners is to feed a light evening meal, and make sure all the scraps are cleaned up 12 hours before appointment time. If the appointment time is 10 a.m. the next day, the hay/feed needs to be COMPLETELY gone by 10 p.m. the night before and the water needs to be removed or turned off at 6 a.m. the day of the exam. DO NOT remove hay/feed and water at the same time. Your horse should have access to water for several hours after removing hay/feed, to help the already eaten hay move out of the stomach. Your horse should not have access to grazing pasture for 12 hours before the exam. Also, make sure your horse isn’t grazing on anything

FDA-Approved Products Provide Peace of Mind April Knudson, DVM, is an Equine Specialist with Merial Veterinary Services. She has a special interest in sport horse lameness and internal medicine. She holds a doctor of veterinary medicine from the University of California- Davis. Below, she answers a question about compounded equine drugs. Question: I’ve heard I should only use drugs that have been approved by the FDA. Why is that important?

Answer: That’s a great question, because with all the drugs and products available to horse owners, sorting through them can be a challenge. Should you choose based on price, your trainer’s suggestion or maybe what worked for a friend’s horse?

While these might be used as secondary considerations, none of them should drive your decision when selecting a drug to give to your horse. Instead, that decision should be made based upon your veterinarian’s recommendation and whether or not the product has been approved by the FDA. Here’s why:

Drugs approved by the FDA provide horse owners with the peace of mind that they have been thoroughly tested for both safety and effectiveness.1 So what does that mean to the health of your horse?

During a new drug’s development phase, the company bringing it to market conducts tests to demonstrate the safety of the proposed product in the target animal.2 Tests are also conducted to confirm the efficacy of a product.2 When the labeling and subsequent advertising are developed, the FDA regulates what claims can and can’t be included.3 The FDA’s stringent labeling guidelines help ensure product claims are fair and accurate and that horse owners will be aware of any possible risks associated with the product.3

After a drug is approved by the FDA and available on the market, the agency continues to monitor it, including any adverse events that may occur.1 This helps identify any problems that may arise and enables companies to address them quickly.

Unfortunately, some drugs are produced and marketed to horse owners that are not FDA-approved, and therefore have not undergone safety and efficacy testing. In many instances, these products make claims that have not been proven.4-6 Examples of products being falsely marketed are any that advertise themselves to be the equivalent of ULCERGARD® (omeprazole) or GASTROGARD® (omeprazole),4-6 which are the only FDA-approved products for the prevention7 and treatment8 of equine stomach ulcers.

Other products all horse owners should be wary of are those claiming to be the equivalent of ADEQUAN® (polysulfated glycosaminoglycan), BANAMINE® (flunixin), Phenylbutazone, PROTAZIL® (diclazuril), and REGU-MATE® (altrenogest). Non FDA-approved counterfeit versions of these drugs are also widely available. Taking chances with any product that has not been FDA-approved and therefore does not meet safety and efficacy standards, means your horse may continue to suffer and you may be wasting money.

So, how can you tell if a product has FDA approval and adheres to its stringent guidelines? Look for the six-digit New Animal Drug Application (NADA) number, or in the case of generics, the Abbreviated New Animal Drug Application (ANADA)number, on the label. Or, look up the drug in the searchable database at AnimalDrugs@FDA (http://www.accessdata.fda.gov/scripts/animaldrugsatfda/).

Remember, if you have any doubts, consult your veterinarian.

MPORTANT SAFETY INFORMATION: CAUTION: Safety of GASTROGARD in pregnant or lactating mares has not been determined. ULCERGARD can be used in horses that weigh at least 600 pounds. Safety in pregnant mares has not been determined.

For more information about ULCERGARD and GASTROGARD, visit www.ulcergard.com and www.gastrogard.com.

1 Animal Health Institute, American Veterinary Medical Association, American Veterinary Distributors Association. Veterinary Compounding. Available at: http://www.aaep.org/siteadmin/modules/page_editor/images/files/AHI%20Compounding.pdf. Accessed April 4, 2012.2 Medical Portal. Animal Drug Approval Process. Available at: http://www.dawnbreaker.com/portals/medicalportal/veterinary/drugapproval.Php. Accessed April 4, 2012.3 U.S. Department of Health & Human Services. FDA’s role in animal health. Available at: http://www.fda.gov/AnimalVeterinary/NewsEvents/FDAVeterinarianNewsletter/ucm235765.htm. Accessed April 5, 2012.4 Canada Generic Website. http://www.canadageneric.com/index/cfm.fuseaction/product.display/pn/ulcergard/product.display/pn/ulcergard/product.id/9697.htm. Accessed February 9, 2012.5 Omeprazole Direct Website. http://equine.omeprazoledirect.com/. Accessed February 9, 2012.6 OTCVetMeds Website. http://www.otcvetmeds.com/equine-stomach-ulcers/gastrogard.html. Accessed February 9, 2012.7 ULCERGARD product label.8 GASTROGARD product label.

Member of the Year Highlight: Amanda ComptonNicole LaGrange, RVT, BS, AAEVT Vice-President

When I first got the idea to write an article highlighting AAEVT’s member of the year I wasn’t sure what to focus on. However, after talking with Amanda Compton for over an hour on the phone and still feeling like we could talk for two more, I realized that I am not just writing an article about a member of the year, but more so about a dedicated, focused and most importantly, friendly person. Amanda was voted AAEVT’s member of the year because she represents not only an passionate, educated technician, but also for her ability to mentor and educate veterinary students, veterinary technician students, and 4-H groups to name a few. She currently runs her own business based from her website www.eqdent.com.

Amanda grew up with horses in West Virginia; she currently resides in Virginia with her husband and four horses. Although her primary passion is equine dentistry, she also enjoys nursing and critical care. She not only maintains her own business performing equine dentistry within Virginia and surrounding states, but also works part-time at the Marion DuPont Equine Medical Center, part of the Virginia-Maryland Regional Veterinary teaching hospital. Their website can be found at http://www.vetmed.vt.edu/emc/. In her free time she enjoys driving her Arabian horses competitively and had significant success this past year at the Arabian Sport Horse Nationals with her homebred ‘Finale AA” winning National and Reserve National Championships and four Top Tens in Carriage Driving.

After obtaining her Bachelor’s degree in veterinary sciences from WVU, Amanda returned to college to pursue a degree in veterinary technology. In 2013, Amanda became the first person to hold both licenses from the Virginia Board of Veterinary Medicine as an Equine Dental Technician (EDT) and Veterinary Technician (LVT). In addition, she has also become licensed in West Virginia as RVT. Her continued education sets her apart from other “lay dentists.” She told me that the reason she went back to get her LVT, is she wanted to have more education and credentials for her dentistry practice. Amanda also completed the AAEVT’s Online ACT Certificate Program in 2010.

Amanda works closely with many different veterinarians and their practices in order to legally tend to her equine dentistry patients. Frequently, she is contacted directly by potential clients and she sets up the appointment with the client’s veterinarian. Many veterinarians recommend her services to their clients, based on her professional working experience with them. That way, the veterinarian is legally present for sedation or supervision of the dental work being done. Tending to patients’ dentistry needs in this way provides a higher standard of care. This keeps all parties involved in patient care to assure nothing is missed.

Looking forward, Amanda hopes to see the day when all states offer credentialing with the boards of veterinary medicine to be licensed as equine dental technicians. In addition, she hopes to assist in working on creating an equine dental technician specialty, within the AAEVT specialty program.

Photo by Sara Hazard

The one-day regional AAEVT CE wet lab held at Running S Equine Veterinary Services in Califon, NJ was a fun-filled, educational day. Attendees came from as far as 4 hours away to participate. Technicians spent the day learning about ECGs, telemedicine, arterial blood gas; and performing blood typing, cross-matching and transfusions. Dr. Greg Staller has a beautiful facility and an awesome staff including Drs. Poulin Braim, Dr. Jochec, Dr. Durando, and regional rep for AAEVT, Kristy Cromwell, CVT. Several attendees were evaluated for the AAEVT ACT on-line wet lab participation, and all passed with flying colors! Unfortunately, Wiss Costanza was unable to make the event due to a skiing accident -- we wish her a speedy recovery! Thank you to all who made this great day of learning fun! We also want to extend a special thank you to both Dr. Greg Staller for allowing us to use his facility, Kristy Cromwell for her excellent organization of this event, and our main sponsors for this event -- Zoetis and Nutramax.

SuccessfulFirst AAEVT Wetlab of 2014 at Running S Equine Jeannie Willems, LVT, RVT, BS, Veterinary Product Technical and Training Specialist

Osseous Lesion of Third Tarsal Bone: A Diagnostic Imaging Case StudyJenna Farley, B.S., Artaurus Veterinary Clinic

Introduction: Fractures and cysts of the third tarsal bone are difficult to image by radiographs and digital ultrasound. Proper diagnosis often requires CT or MRI imaging. Return to athletic performance often requires surgical intervention.1

Signalment: Magnum, 18 year old Quarter Horse gelding used as a Mounted Police Horse

History: Magnum was tied in the barn when he spooked, pulled back on his tie, and fell on the concrete barn aisle. Magnum was brought to Artaurus Veterinary Clinic within a few hours of injury.

PE findings: On initial exam, Magnum was found to have superficial lacerations on all four distal limbs and was minimally weight-bearing on his left hind leg. Magnum was very sensitive to palpation of the medial aspect of his left tarsus. He was also acutely sore to palpation of his left ear and the wings of his atlas. Magnum was hospitalized for 3 days post injury for treatment and observation. During that time, Magnum’s pain level improved and he was able to walk more comfortably. Upon discharge, Magnum was walking comfortably, and mild lameness was only shown at the trot (2/5 AAEP lameness scale).On d7, Magnum was found to be 4/5 lame after an accidental turn out. On examination, Magnum was very sore and reactive to palpation of the medial aspect of the left tibiotarsal joint. At this point, Magnum was put on a very strict rest plan, to include stall rest with access into an outside 12’ x 12’ stall and the only exercise was to walk from his indoor stall to his outdoor stall. On d24, Magnum was found to still be distinctly more lame than when he was discharged on d2, despite strict rest and NSAID therapy. Based on ultrasound findings, handwalking for 3-5 minutes twice per day was added to Magnum’s rest plan.On d52, Magnum was rechecked after a possible fall. Upon examination, Magnum was non-weight bearing on his left hind leg, but would bear weight more evenly as he was walked out. The tibiotarsal joint was significantly distended, which was a substantial increase from previously that same day. Any forced flexion of the joint caused Magnum to react and hyperflex his left hock, becoming acutely sore afterwards.

Magnum continued to improve after his post-injury fall. By d124, Magnum was comfortable at the walk and 3/5 lame at the trot. However, the diagnostic imaging results did not match the level of lameness and lack of progression of healing that was observed, and Magnum was referred to the UC Davis School of Veterinary Medicine Teaching Hospital for a CT scan of the left tarsus.

Diagnostics: On the day the initial injury occured, digital radiographs were taken of Magnum’s left tarsus and atlas, and a digital ultrasound was performed on the left tarsus. The radiographs showed no evidence of fracture or avulsions of the tarsal joint or of the cervical vertebrae. The ultrasound showed desmitis of the long medial superficial collateral ligament of the left tibiotarsal joint. Magnum had recheck radiographs and an ultrasound performed on d24. The radiographs showed no bony changes from the radiographs taken on d0. The ultrasound showed a distinctly hypoechoic pocket with a hyperechoic avulsion seen near an insertion of the superficial medial collateral ligament. On d52, recheck radiographs were taken after a possible re-injury event. Radiographs continued to show no changes from radiographs taken on d0. Recheck ultrasound was performed on d111 from initial injury. At that time, there was no change to suggest new injury since d24. The joint capsule and tissues of medial tarsal joint all appeared to be slightly thickened. On d124, digital radiographs were taking of the left tarsus, and no change was noted.

Due to apparent poor healing and continued lameness, Magnum had a CT exam with contrast performed at UC Davis Veterinary Medicine Teaching Hospital on d175. An osseous cyst-like lesion was discovered in the third tarsal

bone that was nearly half the height of the bone with surrounding sclerosis. The cyst-like lesion was closely located to the articulation of the second and third tarsal bones which showed sclerosis of the articulate surfaces.

Treatment: Magnum was initially treated with NSAIDs (banamine, phenylbutazone), muscle relaxants (methocarbamol), and rest. During the course of Magnum’s convalescence, Magnum received phenylbutazone and banamine to manage inflammation and soreness attributed to flares and re-injury. Magnum received an intravenous shot of hyaluronic acid (Legend®) on d2 and d65. On d24 and d111, the left tibiotarsal joint was sterilely drained and was injected with hyaluronic acid, triamcinolone and amikacin. On d111, when injecting the joint, the joint fluid appeared blood-tinged, as if resolving a hemoarthrosis. Outcome: Given Magnum’s poor healing and poor prognosis for a return to soundness in order to begin pasture retirement without a surgical intervention, Magnum was humanely euthanized after his CT scan at UC Davis Veterinary Medicine Teaching Hospital.

1. Fürst, A., 2013, Fractures of the Third Tarsal Bone, AO Foundation Surgical Reference, https://www2.aofoundation.org/wps/portal/!ut/p/c1/04SB8K8xLLM9MSSzPy8xBz9CP0os3hng7BARydDRwN3Q1dDA08XN59Qz8AAQwMDA6B8JJK8haGFgYFnqKezn7GTH1DahIBuP4_83FT9gtyIcgBttnJy/dl2/d1/L2dJQSEvUUt3QS9ZQnB3LzZfQzBWUUFCMUEwR0dSNTAySkowOFVIRzIwVDQ!/?segment=Tarsus&bone=HorseFoot&soloState=lyteframe&contentUrl=srg/h80/01-Diagnosis/H80_Diag_third_tarsal.jsp (July 15, 2013)

Case Study: Dentigerous Cyst.Tammy Treitline, LVT, VTS-EVN

On April 17, 2013, a six year old gelding presented at our veterinary hospital for a second opinion. The gelding presented with purulent material draining from below the right ear. The gelding had the draining material present for two years. A previous veterinarian had examined the gelding and surgically removed a hard piece of tissue from below the right ear. A short period of time after the surgery, the draining material returned.

The veterinary team started with physical examination of the paint gelding. The physical examination was normal, but there was evidence of a small hole filled with granulation tissue, and dried material in the hair below the right ear. The gelding did seem sensitive to touch and had asymmetry of the temporal region. The veterinary team proceeded with radiographs of the skull. An oblique radiograph revealed a dental remnant present by the ear (dentigerous cyst) (Figure #1). Dentigerous cysts are a congential defect that occur when there is a failure of the first branchial cleft to close.1,2,3 The veterinary team continued to explain to the owner that a dentigerous cyst commonly produces a draining tract that never completely resolves, due to the cystic material produced by the stratified squamous cells and expelled by the body. The best option for resolving the draining tract is to surgically remove the cystic tissue and dental remnant. The surgery does contain risk of loss of ear movement, due to the aurical muscles, nerves, and aurical artery that are present in that region. The owner consented and surgery was scheduled for the following day. Blood was collected for a complete blood count. The complete blood count results were normal. The packed cell volume was 33.9% ( normal 32-53% ), white blood cell count was 7.18 K/µL ( normal 5.40 - 14.30 K/µL) , and the platelet count was 172 K/µL ( normal 90 - 350 K/µL).

Figure 1. Oblique radiograph of skull in the standing horse. Arrow revealing dental material.

On April 18, 2013, the paint gelding was prepared for surgery. The right jugular vein was prepared in standard sterile fashion, and a fourteen gauge , five and one fourth inch extended use over the needle catheter was placed. The gelding was administered 10,000,000 IU of Procaine Penicillin G intramuscularly, 3,000 mg of Gentamicin Sulfate intravenously, and 500 mg of Flunixin Meglumine intravenously thirty minutes prior to surgery. The veterinary team administered 500 mg xylazine intravenously for sedation prior to induction of anesthesia. Then 25 mg of diazepam combined with 1000 mg ketamine was administered intravenously to induce anesthesia. A 24 mm endotracheal tube was placed, and the gelding was maintained on a ventilator with continuous flow of isoflurane. The patient was maintained on isoflurane at a rate 1.75%. His heart rate maintained between 28 to 32 beats per minute, the end tidal carbon dioxide maintained between 33mgH and 36mgH, and respirations were set at 7 breaths per minute. His saturated oxygen maintained at 98% until 2 ½ hours into the procedure, then significantly decreased to 88%. The patient’s arterial blood pressure decreased at the same time, and at this point in time he was administered dopamine to support the cardiovascular system. The anesthesia team increased the patient’s lactated ringers fluid rate to a bolus of 1500 mls which increased cardiovascular volume, increasing the arterial blood pressure. The surgical site around the right ear was clipped and prepared in standard surgical fashion. A sterile opened ended tom cat catheter was inserted into the draining tract to aid with identification of the cyst. Radiographs were also performed during surgery as needed to aid with identification of the position of dentigerous cyst (Figure 2, 3, and 4). A T-shaped incision was made ventral to the right ear then extended up toward the poll on the medial aspect to achieve access to the cystic material. Blunt and sharp dissection was used to remove the cystic structure that was filled with purulent material. Extreme precision was used during the dissection to avoid the auricular artery and nerve. The cyst structure did not directly communicate with the dental tissue palpated, instead it was attached ventrally to the bone. The point of attachment was removed with a rongeurs.

Figure 2. Oblique radiograph of skull intra-operatively. Arrow revealing dental material.

Figure 3. Oblique radiograph of skull intra-operatively; there is a needle placed next to the dentigerous cyst for identification of location.

Figure 4. Oblique radiograph of skull intra-operatively after the dentigerous cyst has been removed.

The dental material was present at the axial aspect of the right ear, tightly attached to the cranium, with a superficial layer of bone covering. The layer of bone was removed to access the dental material. A periosteal elevator and a chisel were used to extract a large tooth. After all of the dental cystic material had been removed, a rongeurs was used to smooth the rough bone. An impression of dental material was still present on the bone, where it had formed around the tooth. Physiological saline, infused with gentamicin, was used to lavage the incision before closure. Monocryl 2-0 suture was used to close the deep muscle, superficial muscle and soft tissue. Skin staples were used in closure of the skin. A stent, consisting of two 4 x 4 gauze sponges was sutured in place over the incision with vicryl 2-0. The entire procedure was 3 ¾ hours, and the recovery phase was good and uneventful. The patient was standing in 1 ½ hours post operative. Dentigerous cysts are also known as an ectopic tooth, ear tooth, aural fistula, or heterotopic polydontia.1 Presentation of a dentigerous cyst will consist of swelling over the temperal bone and a draining tract from the rostal/proximal pinna. A dentigerous cyst is described as an embryological abnormality that originates from the first branchial cleft failing to close. The ectomesenchymal cells do not migrate to proper position either in the midbrain or hindbrain to form teeth. Instead the ectomesenchymal cells become fixed and the first branchial cleft does not close completely, causing a fistula to form. The tooth forms, lined with stratified squamous cells, which is displaced toward the ear as the embryo further develops. 1, 2, 3 The cyst lining is composed of stratified squamous epithelial cells. The stratified squamous epithelial cells act as a semi permeable membrane allowing water, and crystalloids to enter, increasing its size. The fluid is a seromucous fluid with non- inflammatory cells. Dentigerous cysts need to be differentiated from other disease processes like abscess formation from foreign material, a hematoma from trauma, or a tumor. Obtaining fluid from the draining site for microscopic examination, performing radiographs, computed tomography (CT), or magnetic resonance imaging (MRI), are useful in diagnosing dentigerous cysts.1 Once diagnosis of a dentigerous cyst is confirmed, the treatment option recommended is surgical extraction of the entire cystic lining and dental tissue.3 If the dentigerous cyst is not removed, the result is continuous expulsion of seromucous fluid through the fistula from the cystic lining. Surgical correction does include risks due to the close proximity of the auricular artery, nerve and muscles, which can be damaged during the procedure.

References:1. JT Easley, R.P. Franklin, and A. Adams. Surgical excision of a dentigerous cyst containing two dental structures. Equine Veterinary Education, Education vet. Educ.(2010); 22 (6):275-278.2. Jack Easley, DVM, MS, Diplomate ABVP (Equine). A review of Equine Dentistry: First year of life. http://www.ivis.org Proceeding of AAEP Focus Meeting 2008. 162-163.3. Auer & Stick. Equine Surgery Third Edition. Saunders Elsevier Copyright 1992, 1999, 2006. page 317, 317F.

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