PRP and stem cell therapy in animals: evidence review
PRP and stem cell therapy in animals: what does the evidence say about efficacy and safety in dogs and horses?
Short & honest
Moderate evidence (grade B) for PRP in equine joint disease; in dogs and for tendon/ligament injuries in horses, evidence is promising but not yet consistent enough for definitive conclusions.
Safety assessment: Safe when used correctly
Veterinary review not yet completed
This page is awaiting review by a registered veterinary surgeon. Until then, treat the text as education based on the sources listed — not as a verified veterinary judgement.
What is it?
Platelet-rich plasma (PRP) is prepared by centrifuging the animal's own blood, resulting in a concentrate of growth factors. Mesenchymal stem cells (MSCs) are undifferentiated cells harvested from tissue such as bone marrow or adipose tissue, subsequently multiplied in the laboratory before being returned to the animal. Both treatments fall under the umbrella of regenerative medicine and are aimed at stimulating tissue repair and dampening inflammation.
Used for what?
In horses, PRP and stem cells are mainly used for:
- Joint disorders (osteoarthritis, synovitis)
- Tendon and ligament injuries
In dogs, the most researched applications are:
- Osteoarthritis and joint pain
- Orthopaedic surgery and bone healing
What does the evidence say?
PRP in horses — joint disease
A meta-analysis of five RCTs found statistically significant clinical improvement with intra-articular PRP injection compared with control treatments [1]. The effect sizes were large (OR 15.32 for overall clinical effect; OR 36.64 for clinical performance), but the authors emphasised that methodological variability and the small number of RCTs warranted caution. This is the strongest available evidence within this field.
PRP in dogs — orthopaedic surgery
A systematic review evaluated PRP applications in 555 dogs and concluded that both liquid and gel formulations are safe with minimal adverse effects [2]. Gel formulations show potential for improved bone healing, but proven functional added value in the long term is currently lacking.
Stem cell therapy in dogs — osteoarthritis
Several studies report improvement in gait, pain scores and range of motion after MSC therapy in dogs with osteoarthritis [3]. The mechanism of action is presumed to occur via immunomodulation and trophic effects, rather than direct tissue replacement. However, small study sizes and inconsistent study designs preclude definitive conclusions.
PRP and stem cells in horses — tendon and ligament injuries
A separate systematic review and meta-analysis identified only five RCTs, six retrospective studies and several prospective studies with divergent outcomes [4]. There is currently no scientific consensus on effectiveness for tendon and ligament injuries.
Quality and standardisation
A recognised bottleneck across the entire field is the strong variation in preparation quality. The concentration of growth factors in PRP and the viability of MSC preparations are influenced by the preparation technique, the age and the health status of the animal. Without standardised protocols, it is difficult to compare studies and generalise results.
Regulation
In the EU, cell-based regenerative medicinal products (ATMP — Advanced Therapy Medicinal Products) fall under a strict regulatory framework. Use of allogeneic cell products (from a donor, not the animal's own) outside registered protocols requires special veterinary authorisation. Autologous applications (own cells/blood) generally have less stringent requirements, but veterinary regulations also apply here.
Summary
| Application | Evidence | Remark |
|---|---|---|
| PRP — horse, joint | Moderate (B) | Meta-analysis of RCTs, but small numbers |
| PRP — dog, surgery | Limited | Safe; long-term added value not demonstrated |
| MSC — dog, osteoarthritis | Limited | Promising; small studies |
| MSC/PRP — horse, tendon/ligament | Insufficient | No consensus |
Why this verdict?
The grade B evidence judgement is based on multiple RCTs and systematic reviews for PRP in horses and stem cell therapy in dogs, but small study sizes, methodological variability and lack of standardised preparation methods limit the reliability of the conclusions.
Interactions with medication
- Concurrent use of NSAIDs or corticosteroids may theoretically affect the efficacy of PRP or stem cell therapy; discuss timing with the treating veterinary surgeon
Legal status (Netherlands)
In the EU, allogeneic stem cell products fall under the ATMP regulation and may only be used outside registered protocols with special veterinary authorisation. Autologous PRP and stem cell preparations are subject to less stringent requirements in most EU countries but remain reserved for qualified veterinary surgeons.
Sources
- [1] A systematic review and meta-analysis of the efficacy of platelet-rich plasma products for treatment of equine joint disease. Equine Veterinary Journal, 2024. Meta-analysis doi:10.1111/evj.14042
- [2] Platelet-Rich Plasma in Veterinary Orthopedic Surgery: A Systematic Review and Quality Evaluation on Liquid- and Gel-Based Therapies in Dogs. Gels (MDPI), 2025. Narrative review doi:10.3390/gels11120994
- [3] Mesenchymal Stem Cell Therapy in Canine Osteoarthritis Research: Experientia Docet (Experience Will Teach Us). Frontiers in Veterinary Science, 2021. Narrative review doi:10.3389/fvets.2021.668881
- [4] Stem cells and platelet-rich plasma for the treatment of naturally occurring equine tendon and ligament injuries: a systematic review and meta-analysis. Journal of the American Veterinary Medical Association, 2024. Meta-analysis doi:10.2460/javma.23.12.0723