The FAEP Practitioner 2, 2022

Photo courtesy of Maven Photo & Film

The President's Line

Hello fellow practitioners,

Summer is over, and fall is on the horizon!

This means a break in the weather and holidays to spend with our special people. It also means that our premier, equine-exclusive conference Promoting Excellence Symposium (PES), Oct. 6-9, is around the corner! PES is an exciting opportunity for your whole team to earn RACE-approved CE while enjoying our luxurious new venue, the Sawgrass Marriott in Ponte Vedra Beach, Fla. We have an incredible meeting planned with world-class speakers on our roster. Our in-person conferences are a valuable way to network with peers and industry leaders. There are also multiple activities for us and our families in the area. You can find more information in the center of this publication – we can’t wait to see you there!

I want to remind everyone to stay involved with the profession – because we need you! I know we all stay busy, but participation should be a priority. The FVMA/FAEP offers multiple ways to engage. In particular, our 2023-24 Power of Ten (P10) leadership program is accepting applications until Oct. 1, 2022. Please encourage young veterinarians (0-10 years post-graduation) to apply. Learn more here: https://fvma.org/about-us/ fvma-power-of-ten/

Legislative Action Days (LAD) 2023 are also quickly approaching. Please keep an eye on your emails and stay engaged as we continue to protect veterinary medicine in Florida.

Armon

If anyone is struggling with mental wellness, please do not hesitate to reach out to colleagues, friends, or the FAEP (call 800.992.3862).

We are launching a brand new Membership Assistance Program (MAP), which is free for all members. MAP offers personal and professional consultation to help you be your best. For more information, email info@fvma.org

Opinions and statements expressed in The Practitioner reflect the views of the contributors and do not represent the official policy of the Florida Association of Equine Practitioners or the Florida Veterinary Medical Association, unless so stated. Placement of an advertisement does not represent the FAEP’s or FVMA’s endorsement of the product or service.

800.992.3862

407.240.3710

EMAIL: INFO@FVMA.ORG

WWW.FVMA.ORG

understanding your business, we can offer you the right resources and solutions to help your practice succeed. We are a full-service equine partner committed to helping you stay on top of industry advancements that impact the health of your practice and patients.

our continuing education, products, software, equipment and unrivaled service, we are here to help you keep your patients healthy and performing at their highest level.

Ralph Huber, FVMA Industry Relations

It is with considerable pleasure and gratitude that we welcome our 2022-2023 educational partners. The FAEP established the educational partnership in 2012 and has enjoyed industry membership and support ever since. Some of these partners have been with us from the beginning, and all are key contributors to our successful equine outreach in Florida and beyond.

The importance of our educational partners cannot be understated. Their support helps to finance the activities of the FAEP including the following key programs, events and activities:

• The FAEP’s two annual conferences, Ocala Equine Conference (OEC) and Promoting Excellence Symposium (PES); conference speaker programs; event activities and continued growth

• The FAEP’s The Practitioner equine journal

• Emergency response initiatives throughout the United States

• Legislative advocacy in Tallahassee to promote healthy veterinary-related lawmaking by supporting key lobbyists and legislators who support our mission

The commitment from our educational partners is key to the success of our association’s mission. Our mutual support contributes to our partners’ sustained engagement in our programs and events.

2022-2023

American Regent

Booth 49

Jeff Queen | 561.215.7089 jqueen@americanregent.com

BoehringerIngelheim

Booth 24

Stacie Sink | 484.467.1140 (North Florida) stacie.sink@boehringer-ingelheim.com

Heather Walston | 252.205.7372 (South Florida) heather.walsron@boehringer-ingelheim.com

Dechra Animal Health Booth 38

Shelly Derks | 913.302.0239 shelly.derks@dechra.com

Diedra de Bruin | 727.366.7462 diedre.debruin@dechra.com

BiMeda Booth 43

Ed Howard | 630.828.1006 ehoward@BiMeda.com

PARTNERS

"

Covetrus

Booth 28

Lynn Fedash | 954.614.2476 (South Florida)

lynn.fedash@covetrus.com

Kaylynne Brennan | 352.286.1567 (Central Florida)

kaylynne.brennan@covetrus.com

Kentucky Performance Products

Booth 33

Delia Nash | 859.361.2575 dnash@kppusa.com

The commitment from our educational partners is key to the success of our association’s mission. Our mutual support contributes to our partners’ sustained engagement in our programs and events.

Merck Animal Health

Booth 29

Steve Montemarano | 740.972.6554 steve.montemarano@merck.com

Patterson Veterinary (Equine)

Booth 48

Gretchen Hill | 352.843.8822 (North and Central Florida) Gretchen.hill@pattersonvet.com

Wedgewood Pharmacy

Booth 39

Mary Stumbo | 856.689.7445

Mstumbo@wedgewoodpharmacy.com

Jenn Hibbard | 856.832.2336 (Headquarters) jhibbard@wedgewoodpharmacy.com

Brian Conner | 315.335.0003 (South Florida) brian.conner@pattersonvet.com

Amber Moore | 386.689.9543 (North Florida, GA, AL) amber.moore@pattersonvet.com

Zoetis

Booth 19

Courtney VanDerbeck | 352.239.2039 (north Florida and south Georgia) courtney.vanderbeck@zoetis.com

Barbara Lanigan | 561.309.7473 (South Florida) barbara.lanigan@zoetis.com

OUR EDUCATIONAL PARTNERS WILL BE AT THE PROMOTING EXCELLENCE SYMPOSIUM (PES) THIS OCT. 6-9, 2022. THE BOOTH NUMBER FOR EACH IS INCLUDED IN THE LIST ABOVE. WE ENCOURAGE YOU TO STOP BY THEIR BOOTHS TO SAY HELLO AND THANK THEM FOR THEIR CONTINUED SUPPORT.

Excellence in Equine Practice in Challenging Times

Offering 40 Hours of Cutting-Edge CE

The FAEP invites you to the Promoting Excellence Symposium from Oct. 6–9, 2022, for its world-class program of cutting-edge lectures and hands-on instruction.

SPEAKERS INCLUDE:

• Kent Allen DVM, Certified in Equine Locomotor Pathology (ISELP)

• Sally DeNotta

DVM, PhD, DACVIM

• David Freeman MVB, PhD, Dipl. ACVS

• Amanda House DVM, DACVIM (Large Animal)

• Gaynor Minshall BVSc, Cert ES (Orth), Dipl.ECVDI, MRCVS

• Pete Morresey BVSc, MVM, DipACT, DipACVIM

• Rose Nolen-Walston DVM, DACVIM

• Suzan Oakley DVM, DACVSMR, DABVP (Equine), ISELP

• Kyla Ortved DVM, PhD, DACVS, DACVSMR

• Angela Pelzel-McCluskey DVM, MS

• Ruth-Anne Richter BSc (Hon), DVM, MS

• Kurt Selberg MS, DVM, Dipl.ACVR

• Nathan Slovis DACVIM, CHT

• Ian Wright MA, VetMB, DEO, Dipl.ECVS, Hon FRCVS

This program is approved by:

- Sponsor of Continuing Education in New York State

- Florida Board of Veterinary Medicine, DBPR FVMA Provider #0001682

- AAVSB RACE, RACE provider #50-27127

- Course approval #20-927815

CREDITS

This program is approved by AAVSB RACE to offer a total of 48 CE credits for veterinarians and a total of 40 CE credits for veterinary technicians in jurisdictions that recognize RACE approval with a maximum 34 CE credits for veterinarians (if attending wet lab) and 28 CE credits for veterinary technicians.

• Station 1: Cervical Spine Sally DeNotta DVM, PhD, DACVIM

• Station 2: Carpal Canal/Sheath Gaynor Minshall BVSc, Cert ES (Orth) Dipl. ECVDI, MRCVS

• Station 3: Abdomen & Thorax Pete Morresey BVSc, MVM, DipACT,

Station 4: Hind

Ruth-Anne Richter BSC (HON), DVM,

Station 5: Stifle Suzan Oakley DVM,

(Equine),

THURSDAY, OCTOBER 6

TIME MASTERS E

8:00 a.m.4:00 p.m.

1:45 p.m.2:35 p.m.

C omprehensive Equine Ultrasound Wet Lab *off site location. Pre-registration required

Early Referral - Why It’s More Important Than Ever

Dr. Freeman

2:40 p.m.3:30 p.m.

What Practitioners Should Know About Colic Surgery and Its Complications

Dr. Freeman

3:30 p.m. - 4:00 p.m. | Afternoon Break in the Masters Foyer

4:00 p.m.4:50 p.m.

4:55 p.m.5:45 p.m.

5:45 p.m.7:00 p.m.

Emerging Disease Threats to U.S. Sport Horse

Dr. Pelzel-McCluskey

What Every Veterinarian Needs to Know About the Import Process

Dr. Pelzel-McCluskey

Welcome Reception in the Exhibit hall Free to all registered attendees!

AGENDA

Here’s an overview of (PROGRAM

FRIDAY, OCTOBER 7

TIME MASTERS A-D MASTERS E

7:00 a.m.7:50 a.m.

8:00 a.m.9:45 a.m.

Equine Regenerative Therapy –Autologous Blood Products Dr. Schmid

News Hour

Dr. Morresey & Dr. Ortved

9:45 a.m. - 10:30 a.m. | Morning Break in the Exhibit Hall

10:30 a.m.11:20 a.m.

Regenerative Medicine Dr. Ortved

11:25 a.m.12:15 p.m.

Treatment of Joint Diseases Dr. Ortved

Updates About Managing the Most Challenging Colic Cases

Dr. Freeman

Hyperbaric Medicine and the Sport Horse

Dr. Slovis

12:15 p.m. - 1:45 p.m. | Complimentary Lunch in the Exhibit Hall

The Clinical Application of

1:45 p.m.2:35 p.m.

Dr. Ortved

Neck Imaging

by:

2:40 p.m.3:30 p.m.

Dr. Selberg

3:30 p.m. -

4:00 p.m.4:50 p.m.

p.m.

Standing CT- What Can

by:

Dr. Selberg

Blocking

4:55 p.m.5:45 p.m.

by:

Dr. Selberg

5:45 p.m.7:00 p.m. Reception

and

Biosecurity

To Herpes

Dr. Slovis

Clinical Pathology: Interactive Case Discussion on How To Interpret Bloodwork and Cytology

Dr. Slovis

Being A Better VetWhy We Can Make Misdiagnoses and How Not To

Dr. Nolen-Walston

Being A Better Vet- Why We Feel Frustrated With Our Brains and How Not To

Dr. Nolen-Walston

in the Exhibit Hall

AT-A-GLANCE

what’s happening at the event!

SATURDAY, OCTOBER

7:00 a.m.7:50 a.m.

Dr. Hancock

Imaging

8:00 a.m.8:50 a.m.

8:55 a.m.9:45 a.m.

Dr. Minshall

Imaging

Sheath

Dr. Minshall

Dr. Nolen-Walston

SUNDAY, OCTOBER 9

TIME

7:00 a.m.7:50 a.m.

8:00 a.m.9:45 a.m.

10:30 a.m.11:20 a.m.

11:25 a.m.

12:15 p.m.

Dr.

E

EquiTrace – Unleash the Power of the Microchip

Dr. Corley

Case Study Panel Dr. Allen, Dr. Minshall and Dr. Wright

9:45 a.m. - 10:00 a.m. |

10:00 a.m.10:50 a.m.

Break in the Masters Foyer

Understanding The Pre-Purchase Exam in The Equine Athlete

Dr. Allen

Back Pain in The Equine Athlete Dr. Allen 11:50 a.m.12:40 p.m.

10:55 a.m.11:45 a.m.

Hind Limb Proximal Suspensory: Diagnosis and Treatment Dr. Allen

EXHIBIT HALL SCHEDULE OF EVENTS

Thursday, Oct. 6

Exhibitor Set Up: 12:00 p.m. - 5:00 p.m.

Welcome Reception: 5:45 p.m. - 7:00 p.m.

Friday, Oct. 7

Exhibit Hall Hours: 9:00 a.m. - 7:00 p.m.

Morning Break: 9:45 a.m. - 10:30 a.m.

Lunch: 12:15 p.m. - 1:45 p.m.

Afternoon Break: 3:30 p.m. - 4:00 p.m.

Reception & Social Hour: 5:45 p.m. - 7:00 p.m.

Saturday, Oct. 8

Exhibit Hall Hours: 9:00 a.m. - 1:35 p.m.

Morning Break: 9:45 a.m. - 10:30 a.m.

Lunch: 12:15 p.m. - 1:35 p.m.

Cover-all Bingo Raffle: 1:20 p.m.

Exhibitor Load-out: 1:35 pm. - 4:00 p.m.

To learn more about Sawgrass Marriott and book your room, scan the QR Code.

Sawgrass Marriott Golf Resort & Spa 1000 TPC Blvd, Ponte Vedra Beach, Fla. 32082

The Next Generation of FLU Protection

The Science of Significant

Developed to help protect against influenza viruses threatening horses today, the Prestige line of flu vaccines offers the most encompassing and advanced level of protection against equine influenza.

Horses deserve the best protection we can give them. Contact Merck Animal Health or your veterinarian to learn more about the new Prestige line of vaccines.

www.merck-animal-health-equine.com

UPDATED INFLUENZA STRAINS INCLUDE:

Florida ‘13 Clade 1:

Based on a highly pathogenic isolate from the 2013 Ocala, Fla. influenza outbreak that impacted hundreds of horses. Florida ‘13 was exclusively identified and isolated through the Merck Animal Health Biosurveillance Program.

Richmond ‘07 Clade 2:

Meets World Organisation for Animal Health (OIE) and American Association of Equine Practitioners (AAEP) guidelines for Clade 2 influenza protection.

IN ADDITION TO:

Kentucky ‘02:

Influenza strain maintained from previous vaccine line.

to

3:35 PM

by or

of

the

of

We keep veterinary practices thriving.

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YOU ARE INVITED TO OCALA, FLORIDA, “The Horse Capital of the World”

The Ocala Equine Conference 2022 is presented by the Florida Association of Equine Practitioners (FAEP), the equineexclusive division of the Florida Veterinary Medical Association (FVMA).

Ocala is the proud home of the facility and personnel who were instrumental in the early training of American Pharoah, the first horse to win the “Grand Slam” of American horse racing, the Triple Crown and Breeders’ Cup Classic, in 2014.

This is an exciting opportunity for equine professionals to gather in Florida’s horse country for their CE and to network with colleagues as well as with representatives of the business sector who will showcase their products and services in the vibrant exhibit hall.

Photo courtesy of Maven Photo & Film

Photo courtesy of Maven Photo & Film

Aric Adams, DVMA, DACVS

Tiffany Hall, DVM, DACVIM,DACVECC

• Sara Lyle, DVM, PhD, Dip.ACT

• Martha Mallicote, DVM, DACVIM

• Brittany Martabano, DVM, MS

• Melissa Restifo, DVM, DACVIM

• Robin Bell, BVSc, MVSc, DipVetClinStud, DECVS, DACVSMR

Friday, January

8:15 a.m. – 4:00 p.m.

• Station 1: Metacarpal Aric Adams, DVM, DACVS

• Station 2: Eye Brittany Martabano, DVM, MS

• Station 3: Abdomen & Thorax

Tiffany Hall, DVM, DACVIM, DACVECC

• Station 4: Back & Pelvis

Suzan Oakley, DVM, DACVSMR, DABVP (Equine)

CONTINUING EDUCATION CREDITS

AAVSB RACE

This program #20-865863 (CE Broker #50-27127) is pending approval by AAVSB RACE to offer a total of 24 CE credits in jurisdictions that recognize RACE approval with a maximum 24 CE credits available to veterinarians and 17 CE credits available to veterinary technicians.

Image courtesy of Canva

Introduction

Whether you work with stallions, geldings, or both, you are likely to encounter male horses with reproductive tractrelated problems. Here, we will discuss some of the problems that are most likely to be encountered in ambulatory practice including cryptorchidism, acute and chronic paraphimosis, and evaluation of and treatment for an enlarged scrotum.

CRYPTORCHIDISM

Cryptorchidism is the condition in which one or both testes fail to descend into the scrotum. The condition is relatively common in horses and is believed to have a heritable component. However, the mechanism of inheritance in the horse is unknown.

Normal Testicular Descent

In colts, the testes normally descend into the scrotum between nine-11 months of gestation to 10 days after birth. Most breeders will not formally consider a colt to be cryptorchid unless the testes have not descended by one year of age.

Although normal spermatogenesis will not occur in a retained testis, testosterone production by the Leydig cells is only mildly affected. Therefore, a cryptorchid horse with no scrotal testis will almost always be sterile but will continue to exhibit stallionlike behavior.

The embryonic testis originates on the dorsal wall of the embryo medial to the mesonephros (the embryonic kidney). In the embryo, the gubernaculum extends from the caudal pole of the embryonic testis to the mesonephric duct (future tail of epididymis) and continues to the site of the future inguinal canal. Increased intra-abdominal pressure is believed to aid in formation of the vaginal process as a herniation of peritoneum through the inguinal ring of the abdominal wall. The distal end of the gubernaculum enlarges to allow for passage of the testicle.

As the testis descends, the ligaments are reduced in size until the testis reaches the normal scrotal position with the tail of the epididymis closely attached to the caudal pole of the testis.

The proximal part of the gubernaculum becomes the proper ligament of testis, connecting the caudal pole of the testis to the tail of the epididymis. The distal part of the gubernaculum becomes the ligament of the tail of the epididymis, connecting the tail of the epididymis to the parietal tunica vaginalis.

When a testis fails to descend, it can be located anywhere along the normal path of descent between the caudal pole of the ipsilateral kidney to the inguinal ring. However, the vast

majority of retained testes are located just inside the inguinal ring or within the inguinal canal.

Diagnosis

1. Physical examination of the scrotum and inguinal region: Visual examination and deep palpation of the inguinal region can be helpful in identifying the presence of a surgical scar (suggesting prior attempt at castration) or the presence of the testis itself. When a testis is not initially identified, moderate to heavy sedation of the animal is recommended to facilitate descent of the testis (if present) and to allow for deep palpation of the inguinal ring.

2. Ultrasonographic evaluation: Since most cryptorchid testes are located within the inguinal canal or just inside of the inguinal ring, many can be readily identified by transcutaneous ultrasonographic evaluation of the inguinal region and the area just cranial to the inguinal rings (Pozor, 2016). A retained testis is typically smaller and slightly less echogenic than a normal, descended testis (Figure 1). Testicles located within the inguinal canal can be somewhat distorted in shape. Visualization of the central vein, the tunica albuginea, the epididymis, and/or the spermatic cord all can help to confirm that a structure is, in fact, a testis. If the testicle is not identified by transcutaneous inguinal ultrasonography, a transrectal approach can be used. The area around the internal inguinal ring can be scanned and then the ultrasound transducer can be used

Body Wall

Figure 1: Ultrasonographic image of an abdominal testis located just inside the body wall, adjacent to the inguinal ring. The image was obtained with a 7.5 MHz linear array transducer positioned transcutaneously, high in the inguinal region just over the external inguinal ring. The cursors (two white and one yellow cross) delineate three edges of the testis. Note that the testicular parenchyma is somewhat irregular in shape and slightly less echodense than is typically seen in a descended testis. The central vein of the testis can be used as a distinguishing ultrasonographic feature to differentiate an abdominal testis from other intraabdominal soft tissue structures.

Image courtesy of Dr. Regina M. Turner.

Testicular Parenchyma

Central Vein Intra abdominal

Extra abdominal fat and soft tissue

Figure 2: Treatment of traumatic paraphimosis in a stallion. (A) Starting appearance of penis on first examination. Ultrasonographic examination confirmed the presence of marked soft tissue swelling and edema. Two small hematomas were identified adjacent to the corpus cavernosum, but these were unlikely to be contributing significantly to the increased size of the penis. Attempts were therefore begun to reduce tissue swelling and edema to allow for replacement into the sheath. (B) Application of a vet wrap bandage, applied distally to proximally under pressure and left in place for 10-15 minutes per application. After the third application and removal, the penis remained too large for replacement into the sheath. (C) Application of a rubber compression (Esmarch) bandage applied distally to proximally under pressure and left in place for 10-15 minutes per application. After the third application and removal, the penis was sufficiently reduced in size to allow for replacement into the sheath (D). These pressure treatments were combined with nonsteroidal anti-inflammatory medication, antimicrobials, and cold hydrotherapy. The penis was successfully replaced in the sheath and held in place with a “Probang” as described and referenced in the text. The stallion recovered normal use of the penis and returned to breeding.

Image courtesy of Dr. Regina M. Turner.

to sweep the caudal abdomen, starting at the inguinal ring and advancing cranially towards the caudal pole of the ipsilateral kidney. If a testicle still is not identified, careful transcutaneous ultrasonographic evaluation of the caudal abdomen can be performed, focusing on the area caudal to the kidney.

3. Endocrine testing: Testosterone. Baseline testosterone can be highly variable and is dependent on the animal’s age, the season of the year, the presence of other stallions, and normal pulsatile changes throughout the day. Nonetheless, a single elevated testosterone level can be diagnostic of the presence of a testicle. Check with your laboratory to determine their “cutoff” values.

Human Chorionic Gonadotropin (hCG) stimulation test. Evaluation of testosterone before and after administration of hCG is a highly sensitive endocrinologic method for identification of a retained testis. A resting blood sample is drawn prior to administration of hCG and again between 1 and 72 hours post hCG administration. Recently, it has been suggested that the best times to sample testosterone are one, 12, 24, 48, 72, or 96 hours after hCG administration. The largest increases in testosterone were identified at 48, 72, and 96 hours (Esteller-Vico, 2021).

Anti-müllerian hormone (AMH). Unlike testosterone, AMH production is not under the control of the hypothalamic/pituitary axis. As a result, AMH levels are

less variable. It has been suggested that a single baseline AMH sample may be the most diagnostic and reliable single endocrine test for cryptorchidism (Conley, 2021).

Treatment

Although treatments to encourage descent of a retained testis have been described, this approach is not advisable because of the likely heritable component of cryptorchidism. The best treatment for cryptorchidism is bilateral castration.

Various medical treatments have been proposed as a means of increasing the likelihood that a retained testis will descend into the scrotum. Most of these treatments are based on administration of GnRH or an LH analogue like hCG (Brendemuehl, 2006). The ethics of these treatments are questionable, as is their efficacy since most studies suffer from a lack of controls.

ACUTE PARAPHIMOSIS

Paraphimosis is the inability to fully retract the penis into the preputial cavity (i.e., sheath). Under normal circumstances, the penis is held in the preputial cavity by the actions of the retractor penis muscles and smooth muscle within the cavernous spaces of the penis. Trauma or other factors that cause bleeding and/ or edema in the loose connective tissue between the penis and internal preputial lamina result in additional weight that creates

muscle fatigue and causes the penis and internal preputial lamina to protrude from the preputial cavity. This becomes a vicious cycle, because the dependent penis further impairs venous and lymphatic drainage, exacerbating the situation. The problem is compounded by the relatively inelastic preputial ring that acts as a constricting band impairing vascular and lymphatic drainage distally. Once the penile and preputial skin is exposed, it rapidly thickens, excoriates, and/or cracks, stimulating additional local inflammation. Prolonged protrusion contusion and stretching of the pudendal nerves across the ischial arch causes neuropathy, leading to penile paralysis.

The most common causes of acute paraphimosis are penile trauma and administration of phenothiazine-based tranquilizers. Less often, paraphimosis can be caused by large lesions of the glans penis that mechanically prevent retraction (e.g., squamous cell carcinoma), severe systemic disease, particularly those diseases that cause extensive subcutaneous edema (e.g., purpura hemorrhagica), diseases that affect penile innervation such as EHV-1 or rabies, severe debilitation, severe exhaustion, and severe edema/swelling post-castration.

Diagnosis

Visual examination is usually sufficient to make a diagnosis of paraphimosis. Gently clean the penis and prepuce to allow for complete inspection and physical examination and to determine the extent of any primary injury as well as the extent of any secondary penile damage, such as edema, skin ulceration, tissue necrosis, etc. Ultrasonographic evaluation can help to determine if penile enlargement is caused by swelling and edema, or if other factors are present such as a hematoma/ seroma or abscess.

Treatment

Treatment is directed at the inciting cause and also requires managing edema/inflammation and maintaining the health of the penile and preputial skin while they are exposed. Most importantly, in cases of acute paraphimosis, the penis should be returned to the prepuce and retained there to break the cycle of dependent edema/further protrusion, restore normal venous and lymphatic drainage, minimize pudendal nerve damage and maintain the health of the penile/preputial skin. The horse should be sedated to facilitate manipulation of the penis and placement of a retention device. Gentle massage combined with cold hydrotherapy can be used to reduce edema. If the penis still cannot be manually replaced within the sheath, an elastic compression (Esmarch) bandage can be used to reduce penile swelling/edema and facilitate replacement of the penis within the sheath. A tight bandage is placed beginning distally at the glans penis and moving proximally along the penis/prepuce. Remove the bandage after 10 to 15 minutes and attempt to

reduce the penis/prepuce into the preputial cavity. The Esmarch wrap can be applied repeatedly in an effort to reduce the penis size for replacement into the prepuce (Figure 2). In extreme cases, if large fluid pockets are seen ultrasonographically, aseptic drainage may be indicated before the penis can be reduced into the sheath. Prior to reduction, the tissues should be cleansed and lubricated with an emollient such as silver sulfadiazine cream or a compounded product consisting of 80 mg dexamethasone and 3.88 g oxytetracycline per one pound lanolin base or even a simple emollient udder cream (i.e., bag balm).

Once the penis and prepuce are reduced, a retention device should be applied to maintain the penis within the sheath. This can be accomplished in several ways. In more mild cases, a simple stretch lace support device may be all that is required (McDonnell, 2003; McDonnell, 2005). The fabric is cut to measure 0.5 x 3 meters for most stallions. The stretch fabric is applied circumferentially around the abdomen and tied in a bow off to the side of the dorsal midline to hold the penis against the ventral abdomen or, better, hold the penis within the sheath. The soft, non-lace side of the material should be adjacent to the skin to prevent ulceration. This fabric provides good support and allows the stallion to urinate.

Alternatively, an umbilical tape purse string suture can be placed at the preputial ring or preputial orifice to prevent recurrent prolapse, leaving enough of an opening for urination (Aurich, 2006). The suture should be untied every two to three days for examination of the penis. In our experience, this type of retention device results in excessive edema and swelling of the prepuce and is no longer our method of choice.

A third option is to use a homemade ‘Probang’ retention device (Koch, 2009). This is constructed using a 15 – 25-inch length of PVC tubing to which roll cotton is applied around one end to create a large cotton swab. The cotton is then contained by covering it with a latex exam glove and the cotton and glove are taped in place. Nitrofurazone is applied to the padded end of the probang, the penis is replaced in the sheath, and the proband is introduced into the preputial orifice. The device is held in position by taping the protruding end of the PVC pipe against the ventral abdomen with elastic bandage tape wrapped circumferentially around the abdomen. This device is well tolerated and allows for urination.

Ancillary treatments include nonsteroidal anti-inflammatory drugs, cold hydrotherapy, and, if infection or cellulitis is present, broad-spectrum systemic antimicrobial treatment. The duration of treatment varies but may take seven to 10 days before the penis is spontaneously retained within the prepuce.

With prompt and proper treatment, the prognosis is good

for full recovery in cases of traumatic acute paraphimosis. Phenothiazine-associated paraphimosis has a guarded to fair prognosis that is related to the duration of the paraphimosis. The prognosis for recovery of penile function is more guarded when penile innervation is affected (e.g., with ehv-1) and is poor when paraphimosis is associated with severe debilitation. Chronic paraphimosis/paralysis can develop from acute paraphimosis if the condition is not treated promptly and appropriately. The risk of permanent damage to the retractor penis muscle and nervous control of the penis is increased with increasing chronicity. Horses with protracted cases of penile paralysis are not likely to regain the ability to retract the penis.

SCROTAL ENLARGEMENT

There are many possible causes for scrotal enlargement, many of which are extratesticular. Causes include:

• Scrotal fluid: hydrocele, hematocele, and pyocele

• Inguinal and scrotal hernias

• Spermatic cord torsion

• Orchitis

• Epididymitis

• Sperm granuloma

• Testicular abscess

• Testicular hematoma

• Testicular neoplasia

Identification of an enlarged scrotum is a nonspecific sign of any of the above conditions. A detailed history, usually combined with additional diagnostics, is often required to determine the underlying cause. Because scrotal enlargement can result from such a wide variety of underlying causes, careful physical examination combined with ultrasonographic examination are helpful in arriving at a diagnosis. It is recommended that an examination of the internal inguinal rings per rectum be included in the workup to rule out the possibility of an inguinal hernia. Bloodwork (CBC, chemistry screen) is indicated when systemic disease is suspected. Sedation and analgesics are recommended in cases where the stallion is showing signs of pain associated with the enlarged scrotum.

SCROTAL FLUID - HYDROCELE, HEMATOCELE, AND PYOCELE

The vaginal cavity is continuous with the peritoneal cavity, and increased amounts of anechoic fluid (hydrocele) in the vaginal cavity can result from systemic disease causing increased production of peritoneal fluid or decreased drainage of peritoneal fluid from the vaginal space. Trauma, spermatic cord torsion, neoplasia, or systemic disease with dependent edema and/or pyrexia also can cause a hydrocele. Congenital hydrocele has been reported in shire horses.

Hematocele is most often the result of trauma. Pyocele is rare and is often associated with systemic illness. It can develop following a penetrating wound, secondarily to rupture of an abscess, or as a result of peritonitis. Ultrasonography can typically differentiate among the three conditions.

Treatment

Manage the inciting cause, if possible. Cold water hydrotherapy may help to reduce swelling and edema. Non-steroidal antiinflammatory drugs are often indicated. Prophylactic, broadspectrum antimicrobial therapy is recommended for cases of hematocele to prevent secondary infection and is required for treatment of pyocele. In severe cases of hematocele or pyocele resulting in permanent injury to the testicle, or unresponsive to treatment, unilateral orchiectomy can be considered.

The prognosis for stallions with scrotal fluid depends largely on the underlying cause. Any type of scrotal fluid can be expected to cause transient insulating effects on the testicle and a resultant transient reduction in semen quality and sperm numbers.

INGUINAL HERNIA

An inguinal hernia occurs when a loop of bowel passes into the inguinal canal and potentially progresses until the bowel enters the scrotum. Inguinal or scrotal hernias may be congenital or acquired and can be uncomplicated or complicated.

In cases of congenital hernias in foals, the problem typically resolves spontaneously within the first twelve months of age. Congenital hernias typically involve the small intestine, the herniated piece is usually viable, and the only recommended treatment is regular manual reduction of the hernia into the abdomen.

Acquired inguinal hernias occur most often in stallions (but can occur rarely in geldings). Standardbreds are reported to be at increased risk. In many cases, acquired inguinal hernias are associated with exercise or trauma and involve small intestine that is either strangulated or non-strangulated (Schneider, 1982).

Clinical Signs

Most horses present for evaluation of an enlarged scrotum and/ or colic. However, some horses with non-strangulating inguinal hernias do not exhibit signs of discomfort. Moderate to severe hydrocele is often present in association with inguinal hernias.

Diagnostics

Examine the scrotum and its contents by palpation. Scrotal edema and hydrocele often make palpation of the scrotal contents difficult. Sedation and analgesics are often required. Ultrasonography should be used to examine the scrotum and the region around the external inguinal ring to determine if bowel is visible in the vaginal space and, if present, whether the bowel is viable. Viable bowel will have peristaltic waves and normal wall thickness. Nonviable bowel will have reduced or absent peristaltic waves and a thickened, edematous bowel wall.

The type of bowel present in the hernia can also be determined using ultrasonography. Small intestine (most common) can be identified by its small diameter and long mesentery. Examine the internal inguinal rings by transrectal palpation. If a hernia is present, loops of bowel can be palpated passing through the affected inguinal ring into the inguinal canal.

Treatment

Treatment is not generally required for congenital inguinal hernias. The prognosis is very good and most resolve spontaneously with time. In protracted cases, surgical correction may be needed.

In cases of acquired inguinal hernias, treatment is required. In rare cases of uncomplicated acquired inguinal hernia, the hernia may be corrected manually by gentle transrectal traction on the herniated bowel. However, bowel viability should be confirmed ultrasonographically before attempting to perform rectal taxis. This approach is not recommended due to the risk of rectal perforation and because recurrence of the hernia is common. Most often, surgical correction of the hernia is performed. Any case involving strangulated bowel requires surgery for resection of the compromised tissue and reduction of the hernia. Even when bowel is viable, surgical correction is the treatment of choice. Generally, the testicle on the side of the hernia is removed at the time of surgery to allow for closure of the inguinal ring and prevent recurrence of the hernia. In some cases, it may be possible to salvage the testicle, but the owner should be aware of the possibility of recurrence of the hernia. Sedatives, analgesics, and NSAIDs are recommended during transport to the surgical facility.

In cases of acquired hernia, the most important prognostic indicator is the duration of the hernia. Regardless of whether or not the bowel is strangulated, prognosis is very good for cases in which the hernia is diagnosed and corrected early (< 24 hours). Cases in which the hernia is left untreated for a long period of time are associated with a poorer prognosis. In stallions, the prognosis for future fertility is good in most

cases. Even if a unilateral orchiectomy is performed as part of the surgical correction of the hernia, the remaining testicle typically returns to normal function once scrotal inflammation has resolved (Turner, 2014).

TESTICULAR ENLARGEMENT

Enlargement of the testicle is an uncommon cause of scrotal enlargement. Testicular enlargement can be caused by orchitis, vascular or lymphatic stasis within the testicle, or a testicular abscess, hematoma, or neoplasia. Clinical signs vary, depending on the cause of testicular enlargement.

Figure 3: Transcutaneous ultrasonography is arguably the most useful diagnostic tool when evaluating scrotal enlargement in the stallion. This imaging technique can greatly assist differentiation among many of the most common causes of scrotal enlargement including hematocele, hydrocele, pyocele, inguinal/scrotal hernias, spermatic cord torsion, and lesions within the testis itself. This figure illustrates a case of scrotal enlargement secondary to unilateral spermatic cord torsion in a stallion. Images were obtained using a 7.5 MHz linear array transducer. By comparing the normal (A) and affected (B) testes, one can readily appreciate the marked heterogeneity of the parenchyma on the affected side caused by edema and blood and lymphatic stasis. When comparing the normal (C) and affected spermatic cords (D), it is readily apparent that the affected cord is enlarged and the normal architecture of the pampiniform plexus (illustrated in panel (C) and delineated by the cursors) is lost in panel (D). The addition of Doppler ultrasonography, when available, can confirm the absence of blood flow on the affected side. Image courtesy of Dr. Regina M. Turner.

B

Normal

Cords

Orchitis or inflammation of the testicular parenchyma is uncommon and can arise secondary to trauma, infection, parasites, or autoimmune disease. The affected testicle is typically enlarged, hot, and painful and systemic signs such as fever, leukocytosis, and hyperfibrinogenemia may be present. If semen is collected and evaluated, large numbers of white blood cells are typically found and semen quality is often poor.

Vascular or lymphatic stasis is most often associated with torsion of the spermatic cord. If testicular enlargement is caused by spermatic cord torsion, abnormalities of the spermatic cord should be evident on palpation and ultrasonographic examination (Figure 3). The stallion is typically painful with pronounced scrotal edema and often hydrocele.

Testicular abscesses are uncommon but can arise as a result of a penetrating wound through the scrotum and testicle, secondary to testicular biopsy, as a progression of orchitis, or from a descending infection from the bloodstream or peritonitis. Stallions typically are febrile with a unilaterally enlarged, warm, painful testicle. Evidence of a previous wound or trauma to the scrotum may be found.

Testicular hematomas usually result from trauma. Small hematomas are often seen following testicular biopsy. Hematomas can form within the testicular parenchyma or on the surface of the testicle. Small intratesticular hematomas may not cause a noticeable scrotal enlargement and the stallion may be asymptomatic except for localized pain on palpation of the affected testicle. In the acute stages of a hematoma, the scrotum is enlarged, warm, painful to the touch, and may be associated with scrotal edema and hydrocele.

Testicular neoplasia is uncommon in the stallion. Most testicular tumors are generally small, and the testicle is not grossly enlarged. In many cases of testicular neoplasia, testicular degeneration is also present, and the affected testicle is actually reduced in size. Because there is often no gross increase in testicular size, most tumors are identified incidentally during routine testicular examinations of breeding stallions. Most, but not all, testicular tumors in the stallion are benign. Histopathology is required for a definitive diagnosis.

Diagnostics

Palpation of the testicles should be attempted; in cases of traumatic injury, the scrotal contents may be painful, edematous, and a hydrocele may preclude a complete examination. Ultrasonographic examination is also recommended. The ultrasonographic appearance of an enlarged testicle will vary depending on the underlying cause:

• Orchitis: The testicle takes on a heterogeneous appearance with hypo- or hyperechoic foci scattered throughout the affected parenchyma.

• Abscess: A well-defined pocket of purulent fluid is generally visible within the testicular parenchyma. Fibrin tags and adhesions may be seen around the testicle and hydrocele may be present; if the abscess ruptures, pyocele may result. The ultrasonographic character of the surrounding testicular parenchyma may be altered because of pressure and inflammation associated with the abscess.

• Hematoma: Generally appears mottled grayish black within the surrounding parenchyma (similar to a corpus hemorrhagicum on a mare’s ovary). If bleeding is still occurring, large pockets of relatively hypoechoic unclotted blood may also be visualized. As the hematoma organizes, its ultrasonographic appearance becomes more echogenic, eventually appearing hyperechoic relative to the surrounding testicle. Fibrin tags and adhesions may also form in the affected area.

• Neoplasia: Results in a localized heterogeneous appearance to the normally very homogeneous testicular parenchyma. The exact appearance is highly variable and most appear as localized, soft tissue densities within the surrounding parenchyma. Color Doppler ultrasonography can help confirm the presence of a soft tissue structure within the testis.

Treatment

ORCHITIS

Treatment should be initiated as soon as possible. Broadspectrum, systemic antimicrobial drugs can be used prophylactically in cases of traumatic orchitis and for treatment of infectious orchitis. The choice of antimicrobials for testicular infection should ideally be based on culture and sensitivity testing of the ejaculate. NSAIDs and cold hydrotherapy are indicated. If the opposite testicle is normal, a unilateral orchiectomy can be considered.

ABSCESS

If an attempt is made to salvage the testicle, nonsteroidal anti-inflammatory drugs and systemic antimicrobials based on culture and sensitivity results from ejaculated semen are indicated.

Unilateral orchiectomy before rupture of the abscess can be considered. If the abscess ruptures, based on the ultrasonographic appearance of the scrotal contents, the stallion should be treated as for infectious orchitis. Surgery may be indicated to remove the testicle and drain the scrotal contents to prevent an

ascending peritonitis. Following surgical removal, the stallion should be placed on nonsteroidal anti-inflammatory drugs and systemic antimicrobials based on culture and sensitivity results.

HEMATOMA

If the hematoma is localized, anti-inflammatory drugs, cold hydrotherapy, and stall rest may be the only treatments needed. Prophylactic antimicrobials should be considered for large, diffuse hematomas. In cases of extremely large hematomas where bleeding is not controlled, unilateral orchiectomy can be considered.

NEOPLASIA

Most testicular tumors are benign and it may be best to refrain from treatment while continuing to monitor the lesion ultrasonographically for changes in tumor size and changes in the surrounding parenchyma. The unaffected parts of the testicle continue to function and contribute sperm to the ejaculate and sparing the testicle is usually justified.

If the tumor is unusually large, growing rapidly, or malignant, unilateral orchiectomy of the affected testicle is performed. Ultrasonographically-guided testicular biopsy guides the decision to remove the affected testicle. Testis-sparing surgery for removal of testicular tumors has not been reported in the horse.

Prognosis

ORCHITIS

Orchitis has a guarded prognosis for future fertility. In severe cases where both testicles are affected, inflammation and increases in local temperature results in fibrosis and degeneration of the testicular parenchyma. If only one testicle is affected, return to normal fertility is greatly improved.

ABSCESS

The prognosis for future fertility with a testicle abscess depends on the size, extent of resulting fibrous tissue formation, and pressure necrosis of the surrounding testicular parenchyma. Larger abscesses with extensive fibrous tissue decrease the likelihood that the testicle will return to normal function. If the opposite testicle is normal, the stallion may be fertile following successful treatment or removal of the abscess.

HEMATOMA

The prognosis for future fertility of the affected testicle depends on the size of the hematoma and the degree of fibrous tissue formation. Small hematomas –< 20 mm in diameter– would be expected to cause few, if any, problems. Large hematomas cause more severe effects on fertility, particularly if they are associated

with pressure necrosis of the surrounding parenchyma or adhesions/fibrosis.

NEOPLASIA

In the case of small, localized testicular tumors, it is likely that the unaffected parts of the testicle continue to function and contribute sperm to the ejaculate; fertility may not be noticeably affected. If the tumor grows or its presence results in degeneration to the surrounding parenchyma, a decline in semen quality is expected. If the contralateral testis is unaffected, the stallion should remain fertile. Multicentric or rapidly growing tumors are uncommon but would increase the chances that the tumor is malignant. In these rare cases, examination of regional lymph nodes and possibly a whole-body ‘metastasis hunt’ may be indicated.

SPERMATIC CORD TORSION

Torsions of < 180º usually do not alter blood flow and cause no clinical signs. Sometimes these torsions are intermittent. No treatment is required if the testis appears to be unaffected, the stallion is showing no clinical signs, and blood flow in the spermatic cord is normal. As long as blood flow is not compromised, these asymptomatic torsions can be present for years with no apparent adverse effects on fertility.

Torsions of > 180º typically compromise blood flow to the testicle and/or cause lymphatic and venous stasis; clinical signs are usually apparent. Affected stallions present with signs of colic associated with an enlarged, painful testicle, enlarged scrotum, hydrocele, scrotal edema, and enlargements of the spermatic cord.

Diagnostics

When blood flow is compromised, the stallion is usually in pain. Sedation and analgesics are often needed before examination. The spermatic cord and scrotal contents should be examined by palpation, but edema and hydrocele may preclude a complete physical examination. During palpation, attempt to identify the location of the tail of the epididymis:

• In a normally oriented testis, the epididymal tail will be located caudally.

• In cases of 180º spermatic cord torsions, the tail will be located cranially.

• In cases of 360º torsion, the tail may again be located caudally but is often displaced dorsally. Changes in the spermatic cord are usually present.

Ultrasonographic examination of the scrotal contents reveals

abnormalities, including changes in the luminae of the vessels of the spermatic cord, changes in the ultrasonographic appearance of the testicular parenchyma associated with vascular and lymphatic stasis, and the presence of hydrocele. Evaluation of the testicular artery, arcuate arteries, central vein, and pampiniform plexus may allow the ultrasonographer to determine the presence or absence of blood flow to and from the testicle (Figure 3). The application of color Doppler ultrasonography can be very informative (Turner, 2014).

Treatment

The usual treatment for spermatic cord torsion with vascular compromise is emergency castration of the affected testicle. This surgery is generally performed at a referral hospital.

In rare cases of spermatic cord torsion where the stallion is exhibiting signs of discomfort but the testicle is viable, surgical correction of the torsion and orchiopexy may be possible to salvage the testicle. Prior to referral, the stallion should be sedated and analgesia provided. Non-steroidal anti-inflammatory drugs (NSAIDs) should be administered. Prophylactic broadspectrum antimicrobial therapy is recommended because of the possible presence of necrotic tissue.

Prognosis

The prognosis for stallions with unilateral testicular torsion and compromised blood flow is very good with prompt and appropriate treatment. If the contralateral testicle is normal before the torsion, the stallion should be fertile once normal thermoregulation is restored and following a complete spermatogenic cycle. Untreated, this condition can lead to tissue necrosis, endotoxemia, and death.

References

Aurich J., Aurich, C. 2006. Treatment of penile prolapse in horses using a modified Buhner suture technique. Veterinary Record, doi: 10.1136/vr.159.15.491

Brendemuehl, J., 2006. Effects of repeated hCG administration on serum testosterone and testicular descent in prepubertal Thoroughbred colts with cryptorchid testicles. Proceedings of the 52nd Annual Convention of the American Association of Equine Practitioners, 381 – 383.

Brinsko, S., Blanchard, T.L., Varner, D.D., 2007. How to treat paraphimosis, 53rd Annual Convention of the American Association of Equine Practitioners, Orlando, 580 - 582.

Conley, A. 2021. Reproductive endocrinology for equine practitioners. West Coast Equine Reproduction Symposium.

De Browuer E., Ribera T., Climent F., Prades, M. 2016. Alternative method to facilitate resolution of paraphimmosis after penile trauma in the horse. Equine Veterinary Education 29 (12); 6655-6658.

Esteller-Vico A., Ball, B., Bridges, J., Hughes, S., Squires E., Troedsson, M. 2021. Changes in circulating concentrations of testosterone and estrone sulfate after human chorionic gonadotropin administration and subsequent to castration of 2-year-old stallions. Animal Reproduction Science 225; doi. org/10.1016/j.anireprosci.2020.106670

Regina M. Turner, VMD, PhD Diplomate

Dr. Regina Turner graduated from the University of Pennsylvania’s School of Veterinary Medicine in 1989. She completed a residency program in Large Animal Reproduction at New Bolton Center and became board certified in theriogenology in 1994. Between 1995 and 1999, Dr. Turner completed a PhD in Cell and Molecular Biology at the University of Pennsylvania’s School of Medicine. She was then hired as a faculty member in the Section of Large Animal Reproduction and Behavior in Penn’s Veterinary School where she currently serves as a Professor of Large Animal Reproduction. Dr. Turner has broad clinical experience working with both mares and stallions that are presented for routine, referral, and emergent reproductive issues. Her research interests have focused on age-related stallion infertility and the molecular and cellular regulation of sperm motility. She is also a low-level amateur event rider.

Koch C., O’Brien T., Livesey M. 2009. How to construct and apply a penile repulsion device (Probang) to manage paraphimosis. Proceedings of the 55th Annual Convention of the American Association of Equine Practitioners, 338 – 341.

McCue, P., 2021. Diagnostic tests for cryptorchidism, In: Dascanio J., McCue P. (Eds.), Equine Reproductive Procedures, Wiley-Blackwell Oxford, doi. org/10.1002/9781119556015.ch179

McDonnell, S.M., 2005. Managing the paralysed penis, priapism or paraphimosis in the horse. Equine Veterinary Education 17, 310 - 311.

McDonnell, S.M., Turner, R.M., Love, C.C., LeBlanc, M.M., 2003. How to manage the stallion with a paralyzed penis for return to natural service or artificial insemination, 49th Annual Convention of the American Association of Equine Practitioners, New Orleans, 291 - 292.

Pozor, M. 2016. Application of various techniques in localizing retained testes in horses before cryptorchidectomy. Journal of Equine Veterinary Science 43, Suppl.; S45-S48.

Schneider, R.K., Milne, D.W., Kohn, C.W., 1982. Acquired inguinal hernia in the horse: a review of 27 cases. J Am Vet Med Assoc 180, 317-320.

Schumacher, J., Varner, D.D., 2011. Abnormalities of the Penis and Prepuce, In: McKinnon, A.O., Squires, E., Vaala, W.E., Varner, D.D. (Eds.), Equine Reproduction, WileyBlackwell, Oxford, pp. 1130 - 1144.

Turner R., Dobbie T., Vanderwall, D. Stallion Reproductive Emergencies, In: Orsini, J., Divers, T. (Eds), Equine Emergencies: Treatment and Procedures. Elsevier/Saunders, St. Louis MO.

Varner, D., Schumacher, J., Blanchard, T., Johnson, L., 1991. Diseases and Management of Breeding Stallions. American Veterinary Publications, Goleta, CA.

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