Modified Platelet Rich Plasma (PRP) for cruciate ligament injuries in dogs

PRP stimulates the repair of soft tissues and joints without the use of foreign chemicals, and utilizes the body’s own programming for self-healing.

Platelet Rich Plasma therapy has been applied to many different medical fields, such as cosmetics, dentistry, sports medicine, pain management — and now veterinary medicine. PRP is blood that has been processed, usually by centrifuge, to contain a higher concentration of platelets than whole blood (McCally, 2015). An interesting feature of the physiologic function of platelets is their role as vehicles for the local delivery of growth factors in wound healing. At sites of vascular injury, platelets adhere, aggregate, and also generate thrombrin, which triggers tendon and ligament growth and repair (Sánchez, 2007). In veterinary medicine, PRP is most often use for tendon/ligament injuries and osteoarthritis. Along with a higher concentration of platelets, PRP contains more than 1,500 bioactive proteins, which include many growth factors and substances normally found in plasma. These additional growth factors play a key role in reducing the expression of inflammatory cytokines, and encourage proliferation and differentiation of resident cells (McCally, 2015). This enhanced blood encourages the body’s natural healing process by directly targeting the site of injury.

Cruciate ligament injuries

Among the common injuries found in dogs today are ruptured cruciate ligaments. Caused by chronic inflammation and the highly active lifestyles of many dogs, these hind leg tears hinder daily mobility while also creating stress on the rest of the compensating body. Specifically, within the knee joint, the two cruciate ligaments that cross the joint – the cranial cruciate and the caudal cruciate — compare to the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in humans. It is important to note that CCL injuries are less likely to occur in dogs that have not yet been sterilized, supporting recommendations for the delay of sterilization procedures until dogs are two years of age and fully developed (Haghighat, 2014). This allows for proper formation of collagen and musculoskeletal structure, and avoids hormone imbalances that could harm development. With a conservative approach comprised of a good home-prepared diet, exercise program, and specific bioregulatory medicine, including PRP, patients can strengthen and prevent further damage to the knee.

What is bioregulatory medicine?

The body is full of complex biological processes that need consistent attendance in order to stay in a healthy and homeostatic state. The main idea behind bioregulatory medicine is using therapeutics and natural healing processes to regulate these biological processes during imbalances, without having to use conventional pharmaceutical medicines.

The difference between conventional and bioregulatory medicine is that the conventional route to dealing with illness aims to reduce symptoms and minimize inflammation through anti-inflammatories. This becomes problematic when viewing inflammation as a key critical response of the immune system when it is trying to fix and treat the illness at hand. In contrast, bioregulatory medicine helps the body heal itself through re-establishing normal feedback systems and stimulating healing processes (Demers, 2014). As integrative veterinary medicine becomes better known, it is important to understand that patients can live a long and full life with quick recoveries by promoting immune responses such as fever and inflammation rather than reducing such symptoms (Demers, 2014). It is important when treating dogs with PRP that they are not on any anti-inflammatory medications; these suppress the effects of PRP and the activation of that immune system response on the injury site.

The first step in treating a patient with PRP is to draw a small quantity of his own blood into a vacutainer. That blood then is placed in a centrifuge. The centrifuge spins the blood, separating it into three different layers: the platelet-poor layer, the buffy coat (which contains the platelets and white blood cells) and the red blood cells (Lehman, 2011). The buffy coat is then obtained with the use of a syringe and injected into the injury site. The high concentration of platelets becomes activated upon contact with the collagen and other substances at the injection sites and where there is a release of growth factors (McCally, 2015).

Benefits of PRP

Through the support of many talented researchers, PRP has proven very successful in many different aspects of rehabilitation. Hyunchul, et al, conducted a study using PRP for arthroscopic repair of large to massive rotator cuff tears, and found that the re-tear rate of the PRP group versus the conventional method group was 35.6% lower (20% in the PRP group versus 55.6% in the conventional group). It was found to significantly improve structural outcomes for patients with large to massive rotator cuff tears.

Many positive effects have been observed when using PRP as a treatment for tendon and ligament healing. After conducting a study on PRP versus Autologous Whole Blood for the treatment of chronic lateral elbow epicondylitis, Thanasas, et al, demonstrated that through the action of PRP it may be possible to initially inhibit excess inflammation while stimulating proliferation and maturation. This is especially important in preventing the fibrous scar tissue healing that occurs with macrophage-mediated tendon-to-bone healing (Thanasas, et al, 2011). PRP has also been found to successfully reduce pain in patellar tendon donors. In a randomized controlled trial, De Almeida, et al, concluded that the use of PRP in the patellar tendon harvest site reduced donor site morbidity after ACL reconstruction. More importantly, results showed that the patellar tendon harvest site non-regenerated area (gap area) in the PRP group patients was 4.9mm, versus 9.4mm in the control group patients, which is a significant difference; it indicates that PRP enhanced tendon healing (De Almeida, et al, 2012).

PRP is an all-natural process that stimulates the repair of soft tissues and joints without the use of foreign chemicals. This technique uses solely the patient’s own blood, eliminating the risk of rejection or negative side effects. PRP is one step closer to stem cell therapy and uses the body’s own programming for self-healing on an amplified scale. It is another example of an effective, non-invasive procedure presented and successfully implemented by veterinary integrative medicine to support health and longevity in our animal patients.


Demers, J. “Bioregulatory Medicine and Homotoxicology”, Integrative Veterinary Care, 2014.

Haghighat, S. “Cranial Cruciate Injury in Dogs — A Second Option”, Vitality, 2014.

Jo, C. Hyunchul, Shin, J. S., Lee, Y. G., Shin, W. H., Kim, H., Lee, S. Y., & Shin, S. “Platelet-rich plasma for arthroscopic repair of large to massive rotator cuff tears: a randomized, single-blind, parallel-group trial”, The American Journal of Sports Medicine, 2013.

Lehman, R. “The 5-Steps Behind Platelet-Rich Plasma Injections”, U.S. Center For Sports Medicine, 2011.

McCally, R. E. “Platelet Rich Plasma (PRP) in Canine Orthopedics”, Veterinary Health Center, 2015.

Sánchez, M., Anitua, E., Azofra, J., Andía, I., Padilla, S., & Mujika, I. “Comparison of surgically repaired Achilles tendon tears using platelet-rich fibrin matrices”, The American Journal of Sports Medicine, 2007.

Thanasas, C., Papadimitriou, G., Charalambidis, C., Paraskevopoulos, I., & Papanikolaou, A. “Platelet-rich plasma versus autologous whole blood for the treatment of chronic lateral elbow epicondylitis: a randomized controlled clinical trial”, The American Journal of Sports Medicine, 2011.

This article has been peer reviewed.


Meghan Reinders is a strong believer in integrative medicine, and an advocate in encouraging the spread of wide range holistic healthcare approaches to the veterinary world. As a recent Honors Science graduate from Western University, she is currently aspiring to attend veterinary school and to continue educating others on the positive, preventative, and minimally invasive techniques that come with an integration approach.