Table of Contents

[ezcol_1third] Introduction
Equine Ozone Therapy
Equine Hyperbaric Oxygen Therapy
[/ezcol_1third][ezcol_1third] Equine Stem Cells Therapy
Equine Platelets Rich Plasma (PRP) Therapy
IRAP Therapy – ProStride
[/ezcol_1third][ezcol_1third_end] Equine Amniotic Membrane Therapy (AMT)
Conclusion
References
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Introduction

Innovative equine regenerative therapies are the need of the hour to save horses from getting overloaded with pharmaceutical agents ie drugs. There are many reasons to adopt such therapies. It is actually the ethical responsibility of the clinicians to not just only treat the patients with strong dosages of drugs but to find innovative solutions which are less harmful and safer. Many times, due to a lack of availability of the latest therapies, patients couldn’t just stay alive. It is of great concern.

The good news is that there are many new equine regenerative therapies available now and more are in clinical trials which means they will also be available soon. The purpose to adapt these therapies is to help patients avoiding much pain and treating them in a safer way. Life is precious, we must strive hard to protect it.

You will find more information about some of the advanced equine regenerative therapies, which are being used these days, in this booklet. Some examples of this include ozone, prolozone, equine hyperbaric oxygen therapy, stem cell therapy, platelet rich plasma (PRP), autologous conditioned serum (IRAP), amniotic products.

Equine Ozone Therapy

Introduction

Ozone, as an immune stimulator, is being used as a bactericidal, antifungal, and antiviral which can be introduced in the body intranasally, topically, or Intravenous. The ozone molecule consisting of three oxygen atoms and is the allotropic and unstable form of oxygen. (Allotropic means the existence of a substance or element in a second form). Being a highly reactive molecule, it can inactivate the microorganisms, boost the immune response, and can induce the analgesic effect (Fitzpatrick, Holland, & Vanderlelie, 2018).

The use of ozone is beneficial in the health science within the therapeutic window but can be harmful if it exceeds the limit. It has the ability to oxygenate every cell of the body thus increasing the stability of those cells. The horse suffering from the pneumonia is carefully nebulised to kill the bacteria in the lungs using this therapy. An ozone machine resembling the mini hyperbaric chamber produces wonderful effects on the infected tissues. Note: When combined with hyperbaric oxygen chamber, ozone effects are multiplied.

In the past few decades, ozone therapy has shown encouraging results in treating a wide spectrum diseases and equine disorders encompassing bacterial and viral infections. It produces obvious benefits in equine-related anaemia, chlamydial abortions, lymphomas, and ehrlichiosis. It is now an established treatment choice for many equine infectious diseases in some parts of the world. Antioxidant enzymes like superoxide dismutase, catalase, glutathione peroxidase can be boosted by ozone therapy (Flores-Colin & Gayon-Amaro, 2019).

The delivery of oxygen and its availability, glucose, and ATP in the ischemic tissues is increased with the body tissues after ozone therapy. Bone marrow implantation can be enhanced at the lesion site increasing angiogenesis, neovascularisation, and tissue regeneration. The neurohumoral reaction can be activated so that it can improve the quality of life. The expression of antioxidant enzymes and heme-oxygenase can be upregulated producing the preconditioning benefits.

How It Works

A regular oxygen molecule, when treated with high energy, can be spliced into two single oxygen atoms. The single oxygen atom binds with a regular oxygen molecule to form ozone. The extra oxygen atom then becomes a scavenger, destroying viruses, bacteria, pollutants, and odors. The third oxygen atom has a half-life of 20 minutes and it is very powerful in contributing the destruction of viruses, fungi, and bacteria. There are several methods of administration of ozone to horses (Sciorsci, Lillo, Occhiogrosso, & Rizzo, 2020).

Auto-hemotherapy

The major autohemotherapy includes the collection of 250ml of blood from the animal in heparin or 3.13% sodium citrate anticoagulant and blood ozonation is done out of the body for 5-10 minutes. The ozonated blood is infused slowly back to the animal body through intravenous routes. This autohemotherapy approach was used in treating chronic laminitis and mechanical lumbar pain in a 10-year-old mare and riding horses respectively (Coelho et al., 2015).

Insufflation

Ozone insufflation can be done in the body spaces like rectal, vaginal, and ear canal. However, rectal ozone insufflation is a commonly used method. Humidified ozonated gas is introduced in the rectal opening to treat diarrhoea and inflammatory bowel diseases caused by the infections i.e. Rotavirus and Ehrlichia. Patients with type II diabetes and diabetic feet can also be treated by rectal insufflation of medical ozone.

Ozone Bagging:

This method involves the use of ozone resistant bag pumped with the ozone oxygen mixture and then it is placed near the area to be treated. Superficial lesions treatments can be done because of ozone absorption into the skin. Cutaneous infections like chronic wounds and ulcers are being treated with this method.

Ozonated oil:

Oil can be used as a carrier of Ozone. Ozone bubbling is done in the oil like olive, sesame, or sunflower. Upon forming the gel consistency, it can be used for the treatment of infections like skin wounds, insect stings, ulcers, vulvovaginitis, and periodontitis.

Ozony Blanket:

The whole body of an animal is ozonated by using an ozonated silicone blanket being placed around the horse’s body. This system is an effective way of treating various equine diseases.

Clinical Application of Ozone Therapy in Equine

Clinical studies show that ozone therapy is useful to treat several equine complications including arthritis, muscular pain and spasms, viral and bacterial infections, immunosuppressive conditions, and neurologic syndromes associated with hypoxia and infectious agents (J. Bhatt et al., 2016).

A combinatorial therapy involving PRP, ozone, and rehabilitation was employed to treat equine lameness. It showed some exciting results (figure 3) that are very encouraging to continue using this approach.

Another combinatorial therapy involving PRP and ozone therapy was used to treat OCD in horses. It yields impressive outcomes (figure 4) that present evidence of the efficiency of this treatment.

Prolozone Therapy

It is an injection-based, non-surgical, treatment to treat several chronic and degenerative diseases by facilitating the body’s own natural ability to recover. The word prolozone is a combination of two words, ‘proliferation’ and ‘ozone’. The prolozone therapy is stimulated by ozone and other nutrients to trigger healing, regeneration, and regrowth within the weakened area of the body. This therapy involves an injection with various combination of procaine, anti-inflammatory medications, minerals and vitamins, and ozone to the affected area of the body.

Ligaments are the structures that hold together the joints, bones, and intervertebral discs. They can be affected as a result of injuries. The weakening of ligaments could cause pain and arthritis in the bones, joints, and discs.

This therapy works almost similar to the ozone therapy involving an injection of ozone into and around the area where ligaments and the bones are attached together. This ozone injection will boost the supply of blood, flow of minerals, and nutrients to the affected area and recruitment of fibroblasts. So, an increase in the flow of nutrients and the availability of fibroblasts makes it an ideal therapy for arthritis. Procaine acts to re-establish cellular membrane potentials. Anti-inflammatory agents decrease edema and swelling. Vitamins and minerals provide necessary substrates for oxygen utilization to overcome oxygen deficiency in damaged tissues. This oxygen utilization is stimulated, directly, by ozone (Shallenberger, 2011).

Clinical studies reported the use of prolozone therapy to treat several complications in equine including degenerative joint diseases, sports injuries, and osteoarthritis (do Prado Vendruscolo et al., 2018). In our practice we have performed a total of 2016 treatments as of may 2020. The chart below shows all the anatomical sites where we have used it.

Anatomical Part injected with Ozone

  • Back injections
  • Cervical Injections
  • Medial femoral Condyle Cyst
  • ​Mesotherapy treatment with ozone
  • ​Ozone Ultrasound Guided to masses
  • ​Cannon bone injection
  • ​Coffin Joint
  • ​Fetlock joint
  • ​Hock joints
  • ​Pastern Joint
  • ​Stifle Joits
  • ​Superficial Digital Flexor Tendon
  • ​Sacro Iliac Joint
  • ​Shoulder Joint
  • ​Suspensory Origin Injection LH prolozone
  • ​Suspensory Origin Injection RH prolozone
  • ​Uterine infusion

Equine Hyperbaric Oxygen Therapy

Introduction

The process in which we deliver a high amount of oxygen in a metallic chamber to treat diseased or affected part is called hyperbaric oxygen therapy (HBOT). In the 1960s it was revealed that by placing pigs in a chamber with high pressure of oxygen, their life can be maintained without red blood cells in their vascular system. In the 1990s the animal’s hyperbaric chambers were designed to treat them with hyperbaric oxygen (Weed, Bill, & Gampper, 2003).

For more than 20 years HBOT was only applied to humans for the treatment of injuries and inflammation. In a human, it was started with the treatment of scuba divers with decompression sickness. However, little research is being done for the clinical use of HBOT in animals. Currently, the extrapolation from early animals and humans is being applied to horses to check the physiological effects of HBOT because it seems similar in domestic mammals. In the USA many veterinarians have adopted HBOT for the treatment of infertility and chronic wounds in horses (Geiser, 2016).

The main purpose of HBOT is to increase tissue oxygen concentration to reduce or prevent tissue hypoxia. In many diseases and tissue damage, the oxygen concentration is decreased in the affected area. For this, arterial and capillary oxygen concentration is increased to enrich tissues with oxygen as the diffusion rate between pulmonary capillary blood and alveolus is increased by 4-fold for every 20-fold increased in oxygen pressure. This diffusion rate is increased by two pulmonary effects; high concentration of oxygen in inspired air and decreased alveolar volume by high oxygen concentration in the alveolus (Shah, 2010).

How It Works

During HBOT the metallic chamber is pressurized up to two or three times than normal atmospheric pressure and air is replaced with pure oxygen. The patient is kept placed in this chamber until the unit is depressurized. In horses, two to thirty treatment sessions can be done depending upon the severity of the disease. According to veterinarians’ recommendation, the pressure is increased from 1 to 2.5 ATA (atmosphere absolute) In the first 15 – 20 minutes for normal equine. The next session is of high pressure in the chamber for 45 minutes. After that operator brings back unit to 1 atm. Physicians and veterinarians explain that high levels of oxygen pressure force the oxygen to dissolve in the bloodstream and increase availability to injured tissues. This way the large wounds where oxygen supply has been compromised heal early. HBOT also induce free radical formation in inflammatory cells that kill microorganisms and increase antibodies. The total blood oxygen is increased to 15 times as compared to normal oxygen concentration. This significant increase in oxygen concentration also compensates to low blood flow for tissue oxygenation (Slovis, 2008).

Clinical Applications

HBOT is mainly used as adjunctive therapy but also considered as primary therapy because it provides therapeutic and physiological benefits. HBOT may provide positive outcomes when standard therapeutic measures do not work. Infected cells show a high survival rate in an oxygen-rich environment. The general beneficial effects of HBOT include an increase in tissue oxygen concentration, antioxidant production, fibroblast and collagen production, increased stem cell circulation. HBOT also decreases cerebral edema, cerebral blood flow, selective autoimmune response, and neutrophil-endothelial adherence. Furthermore, it also supports neutrophilic microbial killing, antibodies effectiveness, and aerobic metabolism. HBOT also has a rehabilitation effect on patients without any specificity i.e. it supports tissue regeneration and salvage, the release of stem cells from bone marrow, decrease lipid peroxidation, growth factor stimulation, and vascular neogenesis.

Severe wounds are treated with a combination of laser and hyperbaric oxygen therapy. The combinatorial therapy showed impressive results after 15 days of first treatment. The wound started healing to a great extent. This therapy proves to be useful to treat many complications including the joint diseases, severe chronic infections, laminitis, and lung bleeders etc. (Orsini, 2017)

HBOT has very minute side effects and considered a safe treatment. Patients’ suitability to experience high pressurized environment should be examined, proper screening of patient should be done, and assessments should be performed based on current therapies, diagnosis, pretreatments examination, and diagnosis. Furthermore, the total treatment of equine should be of 90 minutes including pressurizing and depressurizing intervals, the maximum pressure should not be more than 3 ATA and frequency of treatment varies from patient to patient and can reach from 3 to 50 treatments (Heyboer, Sharma, Santiago, & McCulloch, 2017).

Equine Stem Cells Therapy

Stem cells are the cells from which all of our body cells are generated. Under controlled conditions in the body or laboratory, they divide to form more cells, called daughter cells. These daughter cells have an ability to become new stem cells or specialized cells with a specific function such as heart muscle cells, bone cells or blood cells etc. Only stem cells possess this ability to produce new cell types (Łos, Skubis, & Ghavami, 2018).

Researchers and medical practitioners are taking great interest in stem cells with a hope to increase their understanding of the diseases and investigating the potential of stem cells in regenerative therapies. Stem cells are of different types i.e. adult stem cells (bone marrow or fat), embryonic stem cells (three to five days old embryo), and perinatal stem cells (amniotic fluid and umbilical cord).

Stem cell therapy is one of the latest regenerative therapies available for humans and horses. This therapy is aimed at treating a variety of diseases or injuries of humans as well as horses. It is popular among horse owners because it is mainly used for the treatment of tendons, ligaments, and joints diseases in horses. This therapy has immense potential in terms of medical treatment (Biehl & Russell, 2009).

Equine stem cells are known as adult multipotent stem cells that have the ability to become specialized cells. They are able to regenerate tissues e.g. bone, cartilage, tendon, and muscle. In horses, stem cell therapy is of two types;

  • Autologous (patient-derived) Stem Cell Therapy – Isolation of stem cells from your own horses
  • Allogeneic (donor-derived) Stem Cell Therapy – Isolation of stem cells from another horse

Stem cell therapy in horses typically involves the use of mesenchymal stem cells (MSCs) that would later form tendons, ligaments, muscles, bones, and fat. These MSCs are mainly isolated/collected from bone marrow, fat or the placenta of the horses. Under specialized conditions, stem cells can also be cultured and replicated in the laboratory (Wei et al., 2013).

How It Works (When Cultures)

Stem cell therapy is quite a straight forward procedure. Mesenchymal stem cells (MSCs) are collected from your horse’s bone marrow or placenta, weeks prior to the treatment. The collected stem cells are then cultured in large concentrations in a regenerative medicine laboratory. Some systems, also let you collect the stem cells and isolate them from fat the same day and inject the same day.

The doctor will perform an ultrasound or take radiographs of a horse’s leg before injecting stem cells. It would help him to evaluate and identify the exact location of the lesions for the efficient delivery of the stem cells to the affected area. The clinician can opt for performing a regional nerve block proximal to the affected area. In this way, horses can avoid discomfort while being injected stem cells for their treatment (Burk, Badylak, Kelly, & Brehm, 2013).

These stem cells will, then, be injected into the injured area in order to achieve proper healing, with minimum fibrosis and scarring of the originally affected tissue. Then, a protective bandage is applied to the site of injection. A physical rehabilitation plan is then followed until complete recovery (Richardson, Dudhia, Clegg, & Smith, 2007).

Clinical Applications of Stem Cells

The first case presented are the Ultrasonographic images of a superficial digital flexor tendon (SDFT) core lesion in an 4-year-old thoroughbred colt (Figure 9). The image on the left is the condition before treatment while the image on the right is after the treatment. This colt was treated with one injection of amniotic derived mesenchymal stem cells (MSCs) and PRP combined. After four months, it is evident from ultrasonographic images that the condition of SDFT core lesion has been resolved.

Stem cell therapy in combination with platelet rich plasma (PRP) therapy has produced impressive results in our patient population. Ultrasonographic images of a hypoechoic lesion on the check ligament are shown in figure 10. The image on the left shows the before treatment ultrasound image, the lesion on the center shows the needle going into the ligament and the image on the right shows the lesion 9 months after treatment.

Stem cells are used to treat equine musculoskeletal disorders including osteoarthritis, tendonitis, and laminitis. As the equine regenerative medicine continues to progress, it is essential for the clinicians to have current knowledge about the choice of stem cell type and recommendations regarding the clinical implications of stem cell therapies (Gugjoo, Amarpal, Makhdoomi, & Sharma, 2019).

Stem cell therapy is becoming very popular among masses because it has shown magnificent clinical results in humans as well as equines. There are several reasons that lead to the satisfaction and trust of people in this therapy. This therapy is safe, and it is a cost-effective treatment. The success rate of this therapy is tremendous, ranging from 85 – 90% in medical procedures. Stem cell therapy is an innovative approach that is changing the dynamics of medical treatment (Kornicka, Geburek, Röcken, & Marycz, 2019).

Equine Platelets Rich Plasma (PRP) Therapy

Introduction

The liquid portion of our blood is called the plasma. It mainly consists of water and proteins. It, basically, gives a medium, to red blood cells, white blood cells, and platelets, of circulation through the body. Platelets or thrombocytes have a specific role in causing blood clots in our bodies. They also provide essential growth factors for several healing conditions. Therefore, their activation contributes a key role in the natural healing process in the body (Urrea-Chávez, 2012).

Platelet rich plasma (PRP) is a volume of plasma that has platelet count more than that of whole blood. The platelet count and concentration is extremely variable among different products. It can be obtained from patients by gravity filtration or centrifugation of their blood because of their small size and less density than red blood cells (RBCs) and white blood cells (WBCs). The degranulation of platelet α-granules causes a release of a large number of growth factors including platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), transforming growth factor-beta (TGF-β), epidermal growth factor (EGF) etc. that promote the healing response in damaged tissues (Brossi, Moreira, Machado, & Baccarin, 2015).

PRP therapy is used to stimulate the healing and tissue regeneration of soft tissues, bones, and skin. In horses, it is employed to treat arthritic joints, tendons and ligament injuries, skin wounds, and eye ulcers and more, specifically at the areas with limited blood flow. It is advantageous in a way that it is readily available and autologous which means that PRP is taken from patients and it will not get rejected by the immune system of the patient (Torricelli et al., 2011).

Recent research suggests that PRP promotes the healing process by stimulating angiogenesis (new blood vessel formation), improving matrix synthesis, increasing cell migration to damage tissue, proliferation, and differentiation. Several equine clinical studies provide evidence of the significance of PRP therapy that has played a key role in the treatment of tendon and ligament lesions. PRP therapy improves the elasticity and strength of tendons and ligaments while reduces the reinjury rates (Bazzano et al., 2013).

How It Works

Equine platelets rich plasma (PRP) therapy is routinely performed, these days, by clinicians. The procedure consists of several steps starting from the diagnosis of the problem via radiographs or ultrasound examination of the horse. This is followed by taking blood from the jugular vein in a specialized syringe place it in a specific container. Later, this blood is centrifuged for some time to separate the plasma from the blood. The platelet-rich plasma which contains essential growth factors is separated from the platelet-poor plasma. The injured portion of the horse is anaesthetized to eliminate the pain, followed by the injection of PRP on the site of injury with ultrasonographic guidance. A 2nd injection of PRP or even a third treatment can be performed in case of incomplete healing of the injured area. This therapy is considered an extremely safe treatment because platelets are isolated from the blood taken from the same patient (Garbin & Olver, 2020).

Clinical Applications of PRP Therapy

PRP therapy can be used to treat several equine conditions involving an area where platelets could be injected. These conditions include tendon and ligament injuries, suspensory desmitis, coffin joint collateral ligament injuries, osteoarthritis, bone and joint injuries, and superficial or deep digital flexor tendon (SDFT) lesions, some osteochondral defects and more.

Clinical evidence suggests that the procedure is extremely safe. In a study, the echographic characteristics of the treated tendons were comparable with healthy tendons. The transverse and longitudinal aspects of equine superficial and deep digital flexor tendons (SDFT) showed impressive clinical improvement after PRP therapy as no lesions were seen in the post treated examinations. The subjected horses responded similarly well to the standardized rehabilitation program (Bazzano et al., 2013).

PRP therapy is, undoubtedly, one of the emerging fields of equine regenerative medicine and it holds great potential to change the equine therapeutic dynamics.

IRAP Therapy – ProStride

Introduction

Before we dive into the topic of Prostride. It is important to understand what Autologous Conditioned Serum (ACS) is. The ACS is derived from the horse’s own blood and injected back into the affected part to treat inflammation and several other complications such as degenerative joint diseases.

Interleukin-1 (IL-1) is a cytokine (a substance released by the cells to affect other cells) that is a key mediator of joint diseases. It also plays a significant role in equine musculoskeletal diseases e.g. osteoarthritis. Inhibitors of this cytokine (IL-1) holds a great therapeutic potential against osteoarthritis. IRAP® (Interleukin-1 Receptor Antagonist Protein) is a novel therapy, originally developed in Europe, to treat degenerative joint diseases in horses such as synovitis and osteoarthritis. IRAP prevents the binding of IL-1 on its receptors on tissues with the joint, thereby, blocking the function of IL-1 (Hraha, Doremus, Mcilwraith, & Frisbie, 2011).

Research shows that horses treated with IRAP therapy show a reduction in lameness, improved joint lining, and cartilage preservation (Clarke, Reardon, & Russell, 2015).
Recent clinical evidence suggests that the use of autologous protein serum (APS) was very beneficial. It had significantly improved the values of lameness grade, vertical peak force, and range of joint motion by 14 days when compared to control values. There were no adverse effects observed. The concentration of the interleukin-1 receptor antagonist (IL-1ra) was 5.8 times more in APS than in blood (Bertone et al., 2014).

IRAP therapy is different from other therapies in a way that helps to treat the cause of the joint disease. It aims at restoring the joint lining and function of the cartilage. It is also a long-term treatment for diseases like osteoarthritis, which usually treated with drugs or other therapies that have a short-term effect on the diseased condition.

IRAP therapy is best for those cases that show mild to moderate radiographic signs of the degenerative joint diseases and the lameness is contained to a specific joint/s. It is not recommended to use IRAP therapy to treat tendon sheaths/bursae, in joints with fractures, bone fragments, ligamentous or meniscal injuries before arthroscopic treatment. IRAP is also useful after the removal of chip fragments, arthroscopically. In such cases, proteins and anti-inflammatory cytokines reduce inflammation of the joints and promote regeneration of the damaged cartilage.

ProStride® is a combination of platelet rich plasma (PRP) and interleukin-1 receptor antagonist protein. For simplicity sake, some people have called this product IRAP due it similarity to IRAP®. However it is not exactly the same. In Prostride®, there is a combination of Platelets with autologous conditioned serum creating a dual antinflamatory and regenerative effect.
It is an exclusive dual device system, the output of which produces a concentrated solution of growth factors, cells, platelets, and anti-inflammatory proteins such as IL-1receptor antagonist and other proteins (House & Morton, 2008).

Traditional therapies to treat degenerative joint diseases include the use of nonsteroidal anti-inflammatory drugs (NSAIDs) e.g. Banamine® and Bute. These therapies are being replaced by Regenerative Therapies. PRP therapy and the use of ACS (IRAP) has shown significant clinical success against the treatment of affected tissues and other joint diseases e.g. synovitis (Frisbie, Ghivizzani, Robbins, Evans, & McIlwraith, 2002).

How It Works

To perform the Prostride procedure, 52 mLs of horse blood are collected in a specialized syringe. This is centrifuged and Platelet Rich Plasma is obtained. Then this PRP is placed in another specialized syringe. This syringe stimulates the production of the IL1 antagonist protein. After centrifugation, the collected blood will contained PRP and ACS from the blood cells. This is now injected in the affected tissues. The frequency of the treatment could also be customized based on the situation of the disease as recommended by the veterinarian (D.M. et al., 2016).

Clinical Applications of ProStride

This therapy can be used for the treatment of osteoarthritis, tendon and ligament injuries, tenosynovitis and some early osteochondritis lesions.
Osteochondritis dissecans (OCD) is a skeletal maturation complication that affects the joint cartilage and the subchondral bone (the bone beneath the surface of the cartilage). OCD can be caused by multiple factors, these include nutritional factors, genetic factors and new evidence suggest that traumatic factors play a bigger part than we thought.

There are three main courses of actions when there are OCD lesions in your horse. The first course of action could be to do nothing and monitor for the lesion to either resolve itself, get worst or to not change. The second course of action would be to performed surgery and clean the affected area. The third and newest technique would be to inject the affected joint with regenerative products and allow it to heal. The advantage of doing regenerative therapies first, is that if the lesion does not disappear, then surgery can always be performed at a later time if needed.

The stifle joint is among the primary joints affected by OCD. It is possible to diagnose stifle OCD in almost every breed. We usually find this disease in young horses because it develops while the bones are forming. However, sometimes it does not bother them until they are older and competing, and other times never causes lameness. It depends in several factors such as the location within the joint and the size. Because we do not know with complete certainty whether the OCD will cause lameness or not, it becomes a conundrum for the team in charge of the horse wether to treat or not.

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In this case presented in figure 15, the stifle OCD was treated with Prostride, it showed amazing improvement in joint lining after 90 days followed by near to complete recovery after 150 days from the diseased condition. This is quite encouraging for the clinicians and the horse owners. The back up plan for this patient was removal of the fragment via arthroscopic surgery.

Equine Amniotic Membrane Therapy (AMT)

Introduction

An embryo, when first formed, is closely covered by a membrane known as amnion or amniotic membrane. It is an immune-privileged membrane that contains collagen, several growth factors, extracellular matrix, and some other beneficial proteins known to have anti-inflammatory, anti-fibrotic, anti-bacterial, and re-epithelialization properties. Its structure is quite similar to that of skin. It is filled with a fluid, amniotic fluid, that contains nutrients and growth factors that facilitate fetal growth, provides mechanical cushioning, and serves to aid in the expansion of amnion to become a sac (amniotic sac). This sac protects the developing embryo (Baradaran-Rafii, Aghayan, Arjmand, & Javadi, 2007).

It is biologically relevant in equine regenerative therapies as many therapeutic products are derived from amniotic tissue and fluid. Amniotic tissues when applied to wounds show a significant reduction in scarring and prevents fibrosis during the healing process. Due to their intrinsic biological properties, products derived from amniotic tissues show better results i.e. faster re-epithelialization and reduced healing time as compared to synthetic or biosynthetic products. The biological composition of amniotic tissue may help in the recruitment of patient’s own stem cells to the wound site that greatly enhances the regenerative ability of the body (Dua, Gomes, King, & Maharajan, 2004).

The amniotic membrane, over the last several years, has been used as a dressing to treat equine wounds. This membrane is collected as soon as a foal is born. It seems a bit unusual to employ amnion, yet it is being used in human and equine medicine to treat several diseases including a variety of ulcers, eye complications, burns, and pressure sores. Amniotic membrane, when employed, provides a protective barrier to wounds, prevents loss of protein and fluids, and reduces pain and inflammation at the wound site (Plummer, 2009).

A variety of biological products have been designed using amniotic membrane and fluid to treat several equine complications including soft tissue injuries, laminitis, dermal injuries, topical lacerations, and joint injuries. These products include surgical and resorbable membrane allografts as well as amniotic membrane suspension products. These products can be manufactured and stored at a suitable temperature for later use. Amniotic membrane and fluid is collected from healthy donors during live births without harm to the mare of foal..

How It Works

Amniotic tissue is obtained from healthy donors during live births. After collection, the amniotic tissue is processed following stringent protocols designed to preserve tissue integrity and prevent potential cross-contamination. A variety of amniotic tissue products have been developed in recent years. Differences in tissue preparation allow for products to be stored at room temperature in sheet forms or lyophilized in particulate forms. In addition, there are available products that are not lyophilized but rather frozen in a liquid form at -80°C to preserve beneficial proteins that may not survive the lyophilization process.

Clinical Applications of AMT

The use of amniotic tissue products has gain acceptance in the past decade as possible adjunctive treatment for a myriad of equine conditions. Amniotic membrane and amniotic fluid products have been utilized in horses with skin disorders such as burns, ulcers, and wounds. They have also been used for a variety of ophthalmologic conditions such as corneal surface lesions.

Corneal ulceration is one of the common equine complications. The cornea is the outermost part of the eyeball and its superficial loss of tissue is known as corneal ulceration. It may be caused by some bacteria, viruses, fungi, or even by some environmental factors e.g. pieces of hay. This ulceration could be so extreme that it can cause permanent loss of sight if it goes untreated.

Clinical studies have shown that the employment of amniotic membrane therapy to treat corneal ulceration is quite beneficial.

A case study (Figure 2) is presented here about a 4-year-old Llama that was affected by corneal ulceration. He was diagnosed with several complications including blepharospasm, epiphora, and deep neo-vascularization followed by treatment with single-layered amniotic membrane therapy. AMT therapy has helped the llama to recover completely in almost a period of less than 1 month.

This therapy is one of the most useful equine regenerative therapies and can also be employed to treat several other equine complications such as lameness caused by arthritis, laminitis, and tendon and ligament issues. It has a huge impact on the treatment because of its fast healing ability.

References

Baradaran-Rafii, A., Aghayan, H. R., Arjmand, B., & Javadi, M. A. (2007). Amniotic membrane transplantation. Journal of Ophthalmic and Vision Research. https://doi.org/10.5005/jp/books/12541_21

Bazzano, M., Piccione, G., Giannetto, C., Tosto, F., Di Pietro, S., & Giudice, E. (2013). Platelet rich plasma intralesional injection as bedside therapy for tendinitis in athletic horse. Acta Scientiae Veterinariae.

Bertone, A. L., Ishihara, A., Zekas, L. J., Wellman, M. L., Lewis, K. B., Schwarze, R. A., … Genovese, R. L. (2014). Evaluation of a single intra-articular injection of autologous protein solution for treatment of osteoarthritis in horses. American Journal of Veterinary Research. https://doi.org/10.2460/ajvr.75.2.141

Bhatt, J., Bhat, A. R., … Amarpal, A. (2016). An overview of ozone therapy in equine- an emerging healthcare solution. Journal of Experimental Biology and Agricultural Sciences. https://doi.org/10.18006/2016.4(spl-4-ehidz).s203.s210

Biehl, J. K., & Russell, B. (2009). Introduction to Stem Cell Therapy. Journal of Cardiovascular Nursing. https://doi.org/10.1097/JCN.0b013e318197a6a5

Brossi, P. M., Moreira, J. J., Machado, T. S. L., & Baccarin, R. Y. A. (2015). Platelet-rich plasma in orthopedic therapy: A comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions. BMC Veterinary Research. https://doi.org/10.1186/s12917-015-0403-z

Burk, J., Badylak, S. F., Kelly, J., & Brehm, W. (2013). Equine cellular therapy-from stall to bench to bedside? Cytometry Part A. https://doi.org/10.1002/cyto.a.22216

Clarke, K. L., Reardon, R., & Russell, T. (2015). Treatment of Osteochondrosis Dissecans in the Stifle and Tarsus of Juvenile Thoroughbred Horses. Veterinary Surgery. https://doi.org/10.1111/j.1532-950X.2014.12277.x

Dua, H. S., Gomes, J. A. P., King, A. J., & Maharajan, V. S. (2004). The amniotic membrane in ophthalmology. Survey of Ophthalmology. https://doi.org/10.1016/j.survophthal.2003.10.004

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