Regenerative medicine and stem cell therapy

The BSAVA recognises that biological therapies, also termed regenerative medicine including stem cell and conditioned serum therapies, have the potential to provide new treatment strategies for a wide range of diseases and conditions for which there are currently no or limited therapeutic options. Although these treatments have the potential to improve the health and welfare of animals, it is important that the benefits and risks are fully evaluated before being made commercially available. The BSAVA is aware that some products have now been licensed and are commercially available.

The BSAVA supports and encourages scientific research into the development of regenerative therapies including animal stem cell use. The BSAVA recognises the need for well-designed, ethically approved, clinical trials in order to establish a knowledge base on the safety and efficacy of stem cell therapies and determine their role in clinical management. Individuals wishing to conduct a clinical trial in the UK should refer to regulatory guidance published by the Veterinary Medicines Directorate on Animal Test Certificates.

The BSAVA recommends that veterinary surgeons considering the use of stem cell therapies should ensure their therapeutic approach is compliant with the prescribing cascade and that prescribing decision-making is evidence-based. Furthermore, informed consent should be obtained from animal owners before initiating treatments consistent with the RCVS Code of Professional Conduct for Veterinary Surgeons.

Veterinary medicines containing stem cells have been authorised in the UK for use in several animal species and indications. However, it may be appropriate under certain circumstances to use alternative treatments which may include cell therapies (e.g. use of an autologous stem cell product from a non-food animal stem cell centre) or conventional non-biological veterinary medicines (e.g. non-steroidal anti-inflammatory drugs). When the veterinary surgeon elects to use an autologous stem cell product, they should consider the available evidence to support the planned technique, the optimum tissue source from which to isolate the stem cells for production of the treatment, and any ethical issues associated with the approach in the particular case. The veterinary surgeon should make clear to the owner the nature of the procedure, the evidence that is and is not available regarding each of the treatment options and ensure that the owner understands how it complies with ‘routine veterinary practice’ where the procedure is “novel”, as part of the process of obtaining informed consent. The RCVS supporting guidance on ′routine veterinary practice′ and ′clinical veterinary research′ are available to help veterinary surgeons navigate this area of regulation.

It is incumbent on any responsible veterinary surgeon to consider all the available therapeutic options in a particular clinical case, which may include the use of a stem cell therapy under specific circumstances. Medicine prescribing activities should be undertaken in compliance with the UK guidance on the use of veterinary medicines and the Veterinary Medicines Regulations 2013, as amended. This guidance includes VMD guidance on the use of the prescribing cascade and the RCVS guidance on Veterinary Medicines within the Code of Professional Conduct for Veterinary Surgeons. Before the clinical use of a stem cell therapy, considerations should include its UK authorisation status, the terms of the marketing authorisation (for an authorised veterinary medicine), the type of stem cell and its source, and whether fully informed owner consent has been obtained following a proper consideration of the evidence base available to support the medicines use in the specific case.

The BSAVA recommends that consideration is given to appropriate regulation of these therapies in order to protect animal welfare.

Date

June 2025

Regenerative medicine is the term used to refer to methods that aim to replace or regenerate cells, tissues or organs in order to restore or establish normal function. This can include a range of techniques including cell therapies, tissue engineering and gene therapy.

Stem cells are undifferentiated cells that have the ability to divide to maintain an undifferentiated population, called self-renewal, and the ability to change into specialised cells in a process called differentiation.

Differentiation is the process by which an unspecialised cell acquires the features of a specialised cell such as a heart, liver, or muscle cell. This process is controlled by the interaction of a cell’s genes with the physical and chemical conditions outside the cell, usually through signalling pathways involving proteins embedded in the cell surface.

There are several different types of stem cells which are characterised by their origin and potential to differentiate.

Pluripotent stem cells are cells that are capable of differentiating into all tissues in the body.

• Embryonic stem cells (ESCs) are undifferentiated cells derived from a pre-implantation embryo which have the potential to differentiate into many different types of cells, i.e. they are pluripotent.
• Induced pluripotent stem cells (iPSCs) are cells that have been reprogrammed back to the stem cell state from differentiated cells through artificial activation of specific genes.

Tissue stem cells (sometimes referred to as adult or somatic stem cells) can give rise to at least one specialised (differentiated) cell-type.

• Unipotent stem cells can only make one type of specialised tissue.
• Multipotent stem cells have the ability to develop into a limited number of specialised cell types (e.g. haematopoietic stem cell, mesenchymal stem cell).

A stem cell therapy is a treatment that uses stem cells, or cells that come from stem cells, to replace or to repair a patient’s cells or tissues that are damaged.

Currently most clinical interest is in the use of mesenchymal stem cells, which can be derived from many cell types including bone marrow and adipose tissue.

The stem cells might be put into the blood, or transplanted into the damaged tissue directly, or even recruited from the patient’s own tissues for self-repair. Current evidence suggests that mesenchymal stem cells have immunomodulatory effects and stimulate tissue repair beyond direct integration/differentiation of the stem cell into that tissue, and that this is their most important therapeutic property.

Autologous stem cells are collected from the same animal in which they are used as treatment.

Allogeneic stem cells are those where the donor and recipient are different individuals from the same species.

Xenogenic stem cells are those where the donor and recipient are individuals from different species. The BSAVA is aware of licensed products being available on the market, such as those from equine umbilical cord blood stem cells, for the treatment of canine osteoarthritis via intra-articular injection and that these are showing promising results and ensure adequate patient safety.

There is currently a great deal of research taking place into stem cell therapies in both human and veterinary medicine. However, currently the most established medical use of stem cells in humans in the United Kingdom is bone marrow transplantation with haematopoietic stem cells.  Other stem cell treatments being used in human medicine, include emergency skin grafts using skin (epidermal) stem cells and repairing the cornea of the eye using limbal stem cells.

Autologous, allogenic and xenogeneic mesenchymal stem cell therapies show promise for treatment of a variety of canine and feline conditions. Although supportive data is available for canine osteoarthritis, the BSAVA would still encourage further well-designed clinical trials to fully establish the role of these cell types in clinical management of this condition. Stem cell therapies should not be routinely used in dogs for conditions other than canine osteoarthritis outside clinical trials unless the treatment is used in accordance with a UK marketing authorisation, issued in accordance with the Veterinary Medicines Regulations 2013, as amended, or there is sufficient supporting evidence to justify the clinical use in the specific case. Where the use of a medicine is considered to be a novel treatment based on BSAVA criteria, appropriate regulation is required (see also BSAVA’s novel procedures position statement). Depending on the level of evidence already available to support the use of a novel treatment and, for the clinical trial of an existing animal stem cell therapy its authorisation status in the UK; the clinical trial of such a treatment may need to be regulated under the Animals (Scientific Procedures) Act 1986 by the Home Office or, where the evidence is more mature, an Animal Test Certificate issued by the Veterinary Medicines Directorate may be required.

Novel procedures

Complementary and alternative therapies

The House of Lords Science and Technology Committee – First Report on Regenerative medicine

EuroStemCell (European consortium for stem cell research)

Voga M, Adamic N, Vengust M, Majdic G. Stem Cells in Veterinary Medicine-Current State and Treatment Options. Front Vet Sci. 2020 May 29;7:278. doi: 10.3389/fvets.2020.00278.

BSAVA Scientific Committee October 2016

BSAVA Council November 2016

Updated June 2025

Reviewed by members of BSAVA Scientific Committee (Rachel Casey, Gillian Diesel, Ben Garland, Macauly Gatenby, Melanie Hezzell, Michael Rampersad, James Warland) 2025