Shockwave treatment for horses: More than just bowed tendons!

Shock-wave treatment has been used in veterinary medicine for over a decade.  Initially, the primary use was for inflamed tendons and ligaments; however, this modality of treatment is now commonly applied to chronic wounds (Figure 1 and 2), bone fractures (Figure 3), navicular disease, back pain, sacro-iliac (SI) pain, muscle pain/inflammation, osteoarthritis, and chronic foot pain. 

Shock-wave treatment consists of exposing a specific area of interest to acoustic waves of varying intensity. There are different size probes which correspond to the depth of tissue penetration. A more shallow probe is used for tendonitis of the superficial digital flexor tendon and the deepest probe is used for chronic pain within the epaxial musculature of the horse's top line. The number of shock waves and intensity is adjusted depending on the specific area being treated. For most conditions, the area is treated with 3 sessions that are separated by 10-14 days. For chronic wound healing, low energy is applied and the sessions are every 5-7 days. 

Generally speaking, shock-wave therapy has its greatest benefit by enhancing the development of new blood vessels and thus increasing the blood supply to a region of interest. This will increase the quality and quantity of "healing". In addition, shock-wave therapy will provide short term pain relief to the soft tissues that are inflamed. 

It is very important to remember that shock-wave therapy is only 1 part of managing the above mentioned conditions. It does not replace time nor the benefits of medical treatment and corrective shoeing. However, it does improve the "quality" of healing which is evident in the final product. 

Chronic wound over elbow which has stopped
shrinking in size 2 months after initial injury.

Chronic wound after 3 shockwave treatments.
The cross sectional area has decreased by nearly 30%

A chronic exostosis or splint bone fracture is treated with
shockwave treatment to stimulate healing

Horse with heaves....not so fast!

A middle-aged draft gelding presented for a complaint of difficulty breathing for several months duration. The increased respiratory rate began during the late summer months and was presumed to be likely Heaves/COPD. As the ambient temperature cooled during the fall and winter months, the gelding's respiratory efforts remained elevated. He was referred to PHD Veterinary services to confirm the diagnosis of Heaves/COPD. At presentation, the gelding displayed a significant abdominal component during inspiration and expiration. However his lung sounds were relatively normal. The typical crackles and wheezes that are common in horses with Heaves/COPD were not present. The gelding was slightly under weight and the rest of the physical exam was normal. A bronchio-alveolar lavage (BAL) was performed through a bronchoscope. Upon inspection of the larynx, it was noted that there was minimal if any movement of either arytenoid cartilage (Figure 1).     The image below was taken during inspiration when the airway should be at its maximum diameter. Due to the apparent bilateral paralysis, the gelding's airway consisted of a small slit which would be similar to trying to breath through a straw. The BAL procedure was performed and the cytology results were normal which completely ruled Heaves/COPD. 

The figure below is that of a normal larynx during inspiration with functioning arytenoid cartilages. Note the size of the airway compared to the above image. 

                        

The image below is that of a "roarer" in which the left arytenoid cartilage is completely paralyzed and not moving. This type of condition and varying degrees of paralysis are most common in horses. Bilateral paralysis is rare and carries a worse prognosis. The cause of the paralysis is unknown and management of horses with bilateral arytenoid paralysis is limited.  Permanent tracheostomy is a recommended procedure and will allow the horse to return to a normal respiratory rate and comfortable life in the pasture. 

There are many horses with increased respiratory effort during the warm summer months in the Southeastern USA that suffer from Heaves/COPD. A large percentage of these horses are treated empirically with medications and management practices.  However, this case highlights the importance of diagnostic imaging of the airway to help confirm the diagnosis, especially in those horses that are not responding as expected to medical treatment. 

The Benefits of Platelet Rich Plasma (PRP)

Platelet Rich Plasma (PRP) treatment has been used in modern medicine since the 1990s. It was originally used to facilitate wound healing in humans after oral surgery. Platelet-rich plasma is a blood product that has a high concentration of platelets, growth factors and cytokines that enhance healing of bone and soft tissue. 

In human medicine, PRP has been implemented in the treatment of nerve injuries, tendinitis, osteoarthritis, bone repairs, plastic surgery, and oral surgery. In horses, veterinarians are using PRP for the treatment of tendon/ligament injuries and osteoarthritis. 

The following images are from 2 different cases in which treating with PRP made a significant difference in the quality of tendon repair. In the first case, a 6 year old Saddlebred mare presented for acute lameness at a show that was associated with soft tissue swelling over the flexor tendons. Ultrasound of the limb noted significant swelling of the superficial digital flexor tendon (SDF) and a core-like lesion (Figure 1) that appears as a black circular structure within the SDF tendon. This lesion extended 4-5cm in length. These findings were consistent with moderate to severe tendinitis of the SDF tendon.

Figure 1

The tendon was treated with approximately 10cc of PRP product by injecting the core lesion via ultrasound guidance. The area of interest was treated in multiple sites. In addition, the mare was treated with forced rest, daily ice therapy and extra-corporeal shockwave treatment (3X). The tendon was re-ultrasounded 6 weeks post PRP injection (Figure 2). The core-like lesion was filled in and the over-all cross sectional area (CSA) of the tendon was significantly reduced.

Figure 2

The second case was a 14 year old Fresian gelding that presented for a chronic (2-4 months) history of forelimb lameness. The lameness blocked out to the proximal metacarpal region which is just below the carpus (knee). The ultrasound exam of this area noted an enlarged SDF tendon with a CSA that was over 3X the normal size (Figure 3) . In addition, there was evidence of fiber disruption and edema present within the tendon. The area of interest was treated with approximately 10cc of PRP product that was injected at multiple sites. In addition, the gelding was treated with forced rest, ice therapy, and extra-corporeal shockwave treatment.

Figure 3

The SDF tendon was re-ultrasounded 4 weeks after PRP and the CSA of the tendon was greatly reduced (Figure 4). There appeared to be better fiber alignment and the gelding's lameness was greatly improved.

Figure 4

Both of these cases are good examples of the benefits of PRP treatment. However, it is important to note that forced rest and a controlled rehabilitation program are critical components to a successful outcome. Current PRP technology allows for on-site treatment and there are a variety of products available to the veterinarian for the production of PRP. The quality of product is directly correlated to the high concentration of platelets and the low concentration of white cells. More recently, practitioners are using PRP treatments in horses that have arthritis as a healthy alternative to cortisone treatment.

Recurrent Foot Abscess...Radiographs + Farrier = Success!

A 10 year old QH gelding presented to Dr. Porter with a history of recurrent foot abscesses in the left front foot. The gelding was lightly ridden and kept in pasture 24/7. At presentation, he was mildly lame in the left front at the walk and there was a draining track along the coronary band consistent with a recent abscess rupture or "gravel". Lateral  radiographs (figure above) were taken of the left front foot. A radiolucent pocket of gas/debris  (yellow line in above radiograph) was seen about 1cm deep to the sole and at the tip of the coffin bone. These findings were consistent with a current sub-solar abscess that was likely communicating with the gravel.

In addition to the lateral radiograph, a dorsal-palmar view was taken. Careful exam noted a gas/debris lucency that covered the entire sub-solar margin of the foot (Yellow arrows above). These findings suggested a much bigger problem.

Hence, a special radiographic view was taken of the coffin bone with the plate below the foot and the x-ray generator above the foot. The results indicated a severe sub-solar abscess that nearly consisted of the entire foot.

Following the radiographic exam, a modified hospital-plate shoe was fixed to the foot and the entire abscess (Red outlined area in figure above) was exposed by carefully removing the affected sole. There were pockets of gas along with pockets of purulent debris that appeared to communicate with the draining abscess along the coronary band.  This was not a simple sub-solar abscess but rather a very large, chronic abscess that required special radiographic imaging and a talented farrier. Special thanks to Billy Bishop for designing the hospital plate, setting it in place,  and helping with the abscess removal. The horses's foot was soaked in Epsom salt solution daily and then packed with sole pack. Within 24 hours, the gelding was sound at the walk and trot with plate in place. His recovery and treatment will be made easier with the hospital plate and we expect a full recovery! Disease states that may result in chronic foot abscesses include laminitis and keratomas. Conformational issues include thin soles and under-run heels. If you have a horse with recurrent foot abscesses, I strongly recommend a radiographic exam. 

Not all equine prepurchase exams are created equal!

When it comes to purchasing or acquiring a new horse, I have several "guidelines" that I strongly recommend to all prospective horse owners.

1) Have a prepurchase exam performed by a veterinarian that has no prior contact with the horse in question and does not work for the seller on a routine basis.

2) It is the veterinarian's responsibility to either PASS or FAIL the horse based on the exam.

3) Be wary of horses with no recent show or performance record, especially those that have been turned out for greater than 6 months for no good reason!

4) Consider a 2-4 week trial period prior to purchasing the horse

5) Pursue digital radiographs that can be shared via internet or CD

6) If the horse is lame at the time of the exam DO NOT PURCHASE THE HORSE


7) In case you forgot #1, have a prepurchase exam performed!! Especially if the horse is for free!!

There are a several specifics that you, as the buyer, should expect from a prepurchase exam. These include:

1: Complete physical exam to include: oral exam (via speculum and light), eye exam (cornea and lens), cardiac exam (heart rate, sound, and rhythm), lung exam (re-breathing exam),  external genitalia exam, and general conformation evaluation (hoof-pastern angles, fetlock angles, stifle-hock angles, etc).

Corneal exam revealed a slight band
of edema across the cornea suggestive
of glaucoma

2: Complete lameness exam to include: Palpation and manipulation of the horse's entire musculoskeletal system, gate evaluation at the walk-trot-canter (straight-away and circles), flexion exam of all 4 limbs (upper and lower limb flexion), and hoof tester exam of all 4 feet.

3: Radiographic evaluation to include: Front feet  (minimum), hocks, fetlocks, stifles, +/- carpi. Note: if the horse is lame during at the time of the exam, I do not recommend continuing the exam hence radiographs would not be necessary.

Chronic founder was noted on radiographs which was not
disclosed by seller and the horse was sound at the time of the exam.

4: Drug screen to include: anti-inflammatory drugs, sedatives, and corticosteroids. At a minimum, have the veterinarian collect a blood sample to be stored for 30 days in case there is a problem after purchase.

5: Complete history to include: Vaccination history, deworming history, recent travel history, dental history, recent farrier history, previous health issues (including lameness issues).

Additional diagnostics that may be warranted:

1: Upper airway endoscopy (non-sedated horse): Strongly recommended for all performance horses
2: CBC and Chemistry analysis
3: Tendon/ligament ultrasound
4: Cervical spine radiographs
5: Trans-rectal palpation of female reproductive track (brood mares)
6: Semen collection and evaluation (stallions)

The above mentioned exam, with foot radiographs, should cost no more than $500. That should be a minimum for all horses that are changing owners.  Even if the horse is for "free", discovering serious lameness issues will save you much more in the long run!

And remember....

"Unless its your own mother that is giving/selling you the horse (assuming you get along with her), it should be mandatory to have the horse examined by a veterinarian prior to completion of the transaction."

Not just another bloody nose!

The above image is an endoscopic view into the left nasal passage of a warmblood gelding with a recent history of a intermittent, bloody discharge (epistaxis) from the left nostril. At presentation, there was a moderate decrease in airflow through the left nostril and a small trickle of blood was noted exiting the left nostril. Endoscopy revealed a soft tissue mass that was centered within the region of the ethmoid turbinate. The mass was golden in color and was exuding small amounts of blood. These findings are consistent with an ethmoid hematoma which is a locally destructive mass of the nasal passages and paranasal sinuses. Ethmoid hematomas resemble tumors in appearance and development but are not neoplastic. Treatment options include surgical resection and/or intramural injections with formalin.

The ethmoid hematoma was treated with approximately 20cc of formalin that was injected via an endoscopic guided technique using a guarded endoscopic needle (above image).  This procedure is easily performed in a standing horse with moderate sedation. The treatment may need to be repeated depending on the response to therapy.

The above image was taken 2 months after the initial formalin injection. The ethmoid hematoma is 60-75% smaller yet required a follow-up injection of formalin. Clinical signs resolved within 30 days after the initial formalin injection. Common causes of epistaxis in a horse include ethmoid hematomas, fungal infections of the guttural pouch, fungal infections of the nasal passages and/or pharynx, skull fractures, EIPH and sinus infections. These types of medical issues can be serious problems and require endoscopy plus skull radiographs to diagnose.

Digital Radiography sometimes is not enough!

The radiograph posted below corresponds to a 20yo thoroughbred gelding that presented for chronic lameness in the left hind limb. Physical exam revealed moderate effusion (swelling) within the left stifle (specifically, the medial femorotibial and femoro-patellar joint spaces). The gelding was a grade 4/5 lame at the trot and resented flexion of the left stifle/hock. Radiographic exam (3 standard views ) of the left stifle revealed mild to moderate arthritis of the medial femorotibial joint space, however, these findings did not explain the severity of the lameness and the degree of swelling associated with the stifle joint.

Due to the lack of findings in the radiographic exam, the left stifle joint was examined via ultrasound. Several significant findings were noted (below image). These included significant fluid within the stifle joint (medial femorotibial joint), bulging medial meniscus, and a smoothly-defined bone fragmment/protuberance of unknown origin. The "bulging" meniscus  was consistent with significant inflammation of the meniscus which could explain the accumulation of fluid within the joint and the degree of lameness recorded during the exam.

The bone fragment/protuberance that was first visualized with the ultrasound required additional radiographic views that are not typically taken of the stifle joint. An osteochondroma was diagnosed based on the ultrasound and the additional radiographic views. Also called osteocartilaginous exostoses, osteochondromas are overgrowths of cartilage and bone near the end of the bone and near the growth plate. The stifle was treated with a cortisone derivative and sodium hyaluronate. Two weeks post-injections, the effusion was significantly diminished and the gelding's lameness was reduced from a grade 4 to a 1 out of 5. This case is a good example of the benefit of digital radiography and ultrasound when evaluating a complex anatomical structure such as the equine stifle.

Stem Cell Therapy: See it to believe it!

The above image corresponds to the pastern area of a middle aged quarterhorse that presented to PHD Veterinary services for recent forelimb lameness. The gelding was very sensitive to palpation over the back of the pastern area and there was some swelling noted in this area. An ultrasound exam revealed a significant disruption (black area) of the straight sesamoidian ligament. The lesion extended nearly the length of the ligament and was approximately 20% of the cross-sectional area. The client elected for stem cell therapy followed by rest and shockwave treatment.

Six months later the lesion has nearly completely resolved (above image). The gelding was treated with fat-derived stem cells  that were harvested, processed, and injected at the barn. Stem Logix (http://stemlogix.com/equine-stem-cell-horses.htm) provided the technology for stem cell harvesting and processing all within 2-4 hours of harvesting the fat sample. Dr. Porter injected the stem cells via an ultrasound guided technique. This case provides an example of the regenerative capabilities of stem cell therapy in horses. In addition to soft tissue injuries, stem cell therapy is being used in horses with chronic arthritis that is no longer responding to traditional treatment with cortisone and other anti-inflammatory products. Contact Dr. Porter with questions regarding stem cell treatment.

"To cut or not to cut?"

The above radiograph belongs to an aged stallion that presented to PHD Veterinary services with non-weight bearing lameness of 3 week duration in the left front limb. Historically, there was evidence of "white line disease" that had resulted in a partial hoof-wall resection however the stallion's condition was worsening on a daily basis. Radiographic exam (top radiograph) revealed greater than 20 degrees of coffin bone rotation and zero sole depth. The tip of the coffin bone was essentially about to come through the bottom of the foot. The decision was made to surgically transect the deep digital flexor tendon (DDF) in an attempt to reduce the "pull" of the tendon on the coffin bone. This procedure can be very effective in saving the life of a laminitic horse and eventually returning the horse to pasture soundness. The procedure is easily performed in the standing horse with sedation and a local block. Follow-up care is critical and requires collaboration with a farrier that is well-versed in shoeing laminitic horses (especially after transecting the DDF tendon). If the horse is not shod appropriately, the benefit of the surgery will be zero. Special thanks to Adam Whitehead for working with us on this case and all the other successful DDF transections that he has collaborated with. 

Two months after surgery, the coffin bone was properly aligned with the pastern bone and there is a significant amount of foot growth (sole depth). Note the specialized shoe-type and placement which is critical for this procedure to be a success! The stallion has not only returned to pasture soundness but was active as a breeding stallion within 3-4 months after the surgery. I strongly recommend having radiographs taken of your laminitic horse to determine what is the best approach to managing the case. Making the decision to cut or not to cut the DDF tendon should be considered sooner than later!

"Chronic Cough Surprise"

These images are from a quarter horse gelding in north-central Florida that presented for a chronic cough. Endoscopy revealed multiple fungal granulomas (bottom image) and the horse was treated with anti-fungals plus a pythium vaccine. Thirty days later (top image), the cough was resolved and the throat was much improved. The horse will continue treatment for another 30 days in hopes of shrinking the remaining granulomas. Pharyngeal or throat inflammation is a common cause of coughing in horses and should be evaluated with an endoscopy exam. Fortunately, fungal granulomas within the pharynx are relatively uncommon!