ทางเลือกการใช้พลาสมาเกล็ดเลือดเข้มข้น (Platelet rich plasma: PRP) ในการรักษาสัตว์เลี้ยงAlternative Use of Platelet-Rich Plasma (PRP) in Veterinary Treatment

Alternative Use of Platelet-Rich Plasma (PRP) in Veterinary Treatment
Asst. Prof. Dr. Somphote Weerakul and the Phoenix Lab Team

Autologous plasma therapy has been established for a significant period, supported by research even in veterinary medicine. It is a biological treatment that aligns with natural mechanisms, accelerating the body’s self-healing process by concentrating platelets. This concentration enhances platelet efficiency in restoring health. Platelet-Rich Plasma (PRP) is injected into injured areas or lesions to expedite healing. It is utilized to treat damaged tendons, ligaments, muscles, bones, joints, and chronic wounds.

Platelets release numerous growth factors essential for stimulating new cell formation and increasing cell proliferation for tissue repair. These factors also stimulate white blood cells and various other cells, impacting wound healing and tissue regeneration—such as stimulating fibroblasts to produce collagen and endothelial cells to repair vascular linings. This results in faster recovery. PRP reduces the expression of pro-inflammatory cytokines like IL-1 and TNF-α while promoting anti-inflammatory cytokines like IL-4 and IL-10, thereby reducing inflammation and maintaining a balanced healing process. Furthermore, it influences chemokine signaling to white blood cells and helps alleviate pain and injury, which can reduce the reliance on medications such as anti-inflammatories and analgesics. Plasma is also a well-known reservoir of electrolytes, plasma proteins, hormones, and aids in forming fibrin meshes for wound healing through fibrinogen and fibronectin.

Examples of growth factors found in platelets include:

TGF-β (Transforming Growth Factor-beta): Stimulates collagen production and angiogenesis (blood vessel formation).
PDGF (Platelet-Derived Growth Factor): Promotes collagen and vessel formation. These first two are often the most critical in the repair process and help reduce inflammation by inhibiting cytokine activity at the site of injury.
FGF (Fibroblast Growth Factors): Stimulates fibroblasts in conjunction with TNF.
EGF (Epidermal Growth Factor): Stimulates fibroblasts.
VEGF (Vascular Endothelial Growth Factor): Promotes blood vessel formation.
HGF (Hepatocyte Growth Factor) and IGF (Insulin-like Growth Factor): Stimulate new cell generation.
There are also various other chemokines and cytokines (Everts et al., 2020) that play vital biological roles in natural healing, facilitating stem cell activation and tissue regeneration. Consequently, medical professionals utilize PRP in surgical recovery, orthopedics, aesthetics, skincare, and hair loss prevention.

Veterinary Applications
In veterinary medicine, various studies have explored its use:

Ophthalmology: PRP is used in several forms—drops, injections, and clots—primarily for corneal ulcers. Eye drops have shown positive results in dogs with mild cases (Grade II) (Mishra et al., 2021), while both drops and clot forms have proven effective in both dogs and cats (Farghali et al., 2021). It is also effective in reducing inflammation (Farghali et al., 2021; Vatnikov et al., 2020).
Dermatology and Wound Healing: Studies prove its efficacy, aligning with human research that led to aesthetic innovations. In animals, it is mostly used for wound healing (Kim et al., 2009), applicable in gel or drop forms (Chung et al., 2015; Crovetti et al., 2004).
Reproductive System: PRP is used to enhance ovarian function, treat endometritis, improve follicular development, oocyte quality, and the uterine environment for embryo implantation. It is also used to restore testicular function and treat mastitis. In veterinary practice, it is used in livestock and for treating prostate issues in dogs (Bigliardi et al., 2018; Borş et al., 2022; Perego et al., 2022).
Orthopedics and Sports Medicine: PRP is frequently reported for tendon injuries and osteoarthritis. Most studies have been conducted on horses due to sports-related injuries. While research in other animals is increasing, further study is needed for precise data.

Early studies in 8 dogs with experimental patellar tendon lesions showed no significant improvement with PRP.
However, a study of 12 dogs with experimental Achilles tendon tears showed reduced lameness and improved histologic scores.
Research also supports its benefit in musculoskeletal issues; in dogs with fractures (including non-union fractures), PRP accelerates bone healing, promotes angiogenesis, and complements other orthopedic treatments (Andersen et al., 2021; López et al., 2019; Shafieian et al., 2017).
Clinical research in dogs with osteoarthritis compared PRP to intra-articular injections of corticosteroids and hyaluronic acid (HA), showing comparable positive results. Notably, using HA in combination with PRP yielded better outcomes than HA alone (Lee et al., 2019).
Summary of Clinical Uses: Veterinary applications primarily include corneal ulcers, corneal erosion, alkali burns, keratoconjunctivitis sicca (dry eye), burn wounds, chronic wounds, cutaneous ulcers, acute traumatic bone fractures, tendinopathies, cartilage pathologies, and osteoarthritis (Sharun et al., 2021).

Dosage and Concentration
While the exact optimal concentration of platelets and white blood cells (WBCs) for treatment remains undefined and may depend on the species and chronicity of the injury, PRP remains a collaborative treatment choice between veterinarians and pet owners. It offers benefits in reducing the need for other medications and painkillers.

In humans, concentrations up to 17 times the baseline are sometimes used. However, some research in dogs suggests that extremely high platelet concentrations (over 3 times that of whole blood) may not be as beneficial as moderate concentrations (2-3 times whole blood), depending on the injured organ. Additionally, high levels of WBCs in PRP can influence systemic inflammation; therefore, reducing WBC levels is as important as increasing platelet counts. This article provides a general overview; further study is required for specific dosages and administration methods for individual diseases.